OSU Extension Fruit & Vegetable Report – August 17th, 2024

This edition of the OSU Extension Fruit & Vegetable Report was written using field observations and expertise from the following OSU Extension staff: Frank Becker, Thomas Becker, Chris Galbraith, Matt Kleinhenz, Ashley Leach, Carri Jagger, James Jasinski, Logan Minter, & Francesca Rotondo. 

Vegetables

Much needed rain has fallen across parts of Ohio to alleviate the dry weather – too much in some areas, which has caused standing water in fields that has harmed some plantings. This provides a good opportunity to discuss how to treat produce that may come into contact with floodwaters. 

One thing that might be good to clarify up front is the difference between floodwaters and pooling. Pooling occurs when there is a depression in the topography of the land where irrigation or rain water may collect. Standing water from pooling is not considered to be high-risk with regard to produce safety. Flood water comes from water that is flowing or overflowing from heavy rain events that may pick up contaminants and other things as it moves across the landscape. These contaminants include, but are not limited to bacteria, molds, human and animal waste, fungi, and other pathogens. Not only could these contaminants lead to rot issues in produce, there is also a significant food safety concern with produce that comes into contact with floodwaters. Any produce that comes into contact with floodwaters should not enter the food chain. If there are any questions or uncertainty, you can do a risk assessment of your flooded field. More information on flood risks and conducting a risk assessment can be found in this fact sheet on Ohioline: https://ohioline.osu.edu/factsheet/anr-27 

Necrosis beginning along leaf edges is one symptom of bacterial canker in tomato. Photo source: Dan Egel, Purdue University.

Bacterial diseases are still being reported, including bacterial canker in peppers and tomatoes. Reports of severe feeding from cucumber beetles and squash bugs is ongoing – some squash varieties such as Taybelle seem to be particularly attractive to these insect pests. Populations of spider mites and brown marmorated stink bug have seen an uptick. According the the recent OSU C.O.R.N newsletter, trap counts for the sweet corn caterpillar pests corn earworm and western bean cutworm are fairly low across the state at this time.

Late blight has been confirmed in tomatoes in Western New York and Western Pennsylvania. Now is a critical time to be scouting for late blight in potatoes and tomatoes. You can utilize the University of Wisconsin late blight disease risk model for the upper Midwest to help determine if conditions have been favorable for disease to occur. This model can also be used for several other disease and pest issues in our area. 

Example of a late blight lesion on potato foliage. Photo Source: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org

 

Fruit

Educators are trapping for spotted wing drosophila (SWD) in blackberries and other small fruits. Populations were high and have only dropped off just recently. During periods of high SWD trap catches, it can be beneficial to do a salt test to get a sense of the level of infestation. You can conduct a salt test by placing a number of fruit in a small container with some water and salt. It can help to mash the berries a bit to help coax out any SWD larvae. Any larvae that were in the berries should be drawn out and will float to the surface of the water. A salt test can help growers determine how effective their pest management program is compared to just going off of trap counts. With SWD, we will likely see decent numbers in traps once they are present throughout the season. High trap counts can be alarming, but aren’t always what we want to base the success of our spray programs on. The salt test can help us see if we are managing populations enough to prevent berries from becoming infested with larvae. If we don’t see any larvae after conducting a salt test, this could be a good indicator that our pest management program is effective.  

Anthracnose crown rot has been confirmed on the crown and runners of strawberries. Anthracnose is a fungal disease caused by several species of Colletotrichum. Crown rot of strawberries is typically the result of infection by Colletotrichum fragariae. Mild winters have allowed for continued northward expansion of this disease. Accordingly, we have continued to see an increased impact on strawberry plants, with losses due to anthracnose crown rot. In an OSU Fact Sheet written by Mike Ellis and Omer Erincik (PLPATH-FRU-16), several strategies are recommended for prevention and management. First, it is important to start off with disease-free plants. It is also important to irrigate correctly, reducing overhead irrigation if possible, but also providing moisture to plants after harvest to prevent stress on the plant from excessively dry conditions. Mulching can also help reduce disease incidence by reducing soil splash. If you have infected plants, remove them from the planting, including berries and as much of the plant as possible. Weed control can also be impactful in reducing disease inoculum as several weed species can serve as alternative hosts for this disease. Overall, sanitation is highly important for successful prevention and management of anthracnose in strawberries. 

Excess fertility and heat caused fruit abortion in strawberries and other small fruit. It is recommended across all crop types that fertilization is not done during times when plants are under heat and drought stress. Not only can this burn and stress plants, but without adequate soil moisture, the nutrients applied will not be available for uptake via the root system. There needs to be moisture available to allow for the nutrients to enter the soil solution and move into the roots through mass flow.  

Dr. Ashley Leach, Assistant Professor of Specialty Crop Entomology with OSU, has provided the comprehensive fruit insect pest update below, including figures and tables:

Stink bugs are here. Some sites with large influxes (>20/bugs per trap). BUT, most sites have only a few bugs (0-3 bugs/trap). Codling moth counts are lower, but not at zero. Oriental fruit moth is hitting its third generation throughout the state – treat if you catch >8 moths/trap. Mite and aphid populations are pretty low this week. We noticed a HUGE natural enemy population with lots of “good” guys (ladybugs, lacewings and minute pirate bugs).

For those of you near the Northeast side of the state or receiving bins from the Mid-Atlantic, watch out for Spotted Lanternfly. This new invasive insect has a limited impact on tree fruit, but will harm grape.

**These updates include NEWA weather modeling which estimates insect development based on growing degree days. If you’re interested in how that works, you can follow this link: https://newa.cornell.edu/crop-and-pest-management. **

As mentioned, stink bugs (Brown marmorated stink bug and green stink bugs) are present in orchards. If you see an influx, consider one of the products in the table below, but apply sparingly since certain products will make mites and aphids worse (below).

Mites seem to be held in check recently. If needed, consult the miticide chart below. Make sure to take the product efficacy into account (****=best control,***= good control, **=fair control, *=poor control).

Oriental Fruit Moth is in its 3rd generation in the south – applications may be needed in higher pressure areas. Options for applications are in the chart below. Make sure to take the product efficacy into account (****=best control,***= good control, **=fair control, *=poor control).

Codling Moth  If treating the second generation, rotate insecticides to feature a different active (IRAC code) than what you sprayed in May. If facing high pressure, >5 moths/trap, make additional insecticide applications. Some options are also included in the chart below.

As a reminder, be sure to always consult your pesticide label and regional pest management guides.

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

OSU Extension Fruit & Vegetable Report – August 5th, 2024

This edition of the OSU Extension Fruit & Vegetable Report was written using field observations and expertise from the following OSU Extension staff: Frank Becker, Thomas Becker, Chris Galbraith, Gary Gao, Melanie Ivey, Carri Jagger, Dan Lima, Diane Miller, Francesca Rotondo, Ryan Slaughter

Vegetables

Tobacco hornworm. Photo by Ryan Slaughter, OSU Extension.

Hot, humid conditions have brought upon bacterial diseases in fruiting vegetables. Management of bacterial diseases can be challenging and frustrating. Foliar bacterial diseases are best managed with an integrated approach of sanitation, selection for disease resistance, and application of effective bactericides. There are 2 main groups of bacteria that cause diseases in plants, and they are Pseudomonas and Xanthomonas. Pseudomonas has a favorable temperature range of 60-75 degrees fahrenheit. Xanthomonas has a favorable temperature range of 77-86 degrees fahrenheit. Once present on the plant, the bacterial infection may appear to be inactive during periods of unfavorable conditions, however, the infections become active again when conducive environmental conditions return. 

Symptoms of bacterial disease present on leaves and fruit of tomato. Photos by Frank Becker, OSU Extension.

Bacteria can be easily spread via splashing rain, plant to plant contact, human activity, insect activity and on equipment. It is critically important to properly diagnose foliar lesions observed in your crops to allow you to take proper care and precaution, especially if the disease is found to be bacterial. Aside from using clean seed and following proper sanitation practices and other cultural crop management recommendations, utilizing chemical control products such as copper, mancozeb, certain botanical oils and Bacillus species can help to combat bacterial infections. Always read the label to ensure that the product that you are considering using has activity against bacterial pathogens. 

Pith necrosis, also a bacterial disease, has been observed in tomatoes. The only strategy for managing pith necrosis is prevention by avoiding favorable conditions, in particular excessive nitrogen. Copper fungicides are not able to provide control because this soil-borne bacterial pathogen is inside the plant.

Fungal diseases are also being reported, including Septoria leaf spot in tomatoes and Alternaria in melons. Downy mildew (clade 2 that affects cucumber and cantaloupe) has been found in at least five Ohio counties to date. Samples with yellow vine decline and bacterial wilt have been coming into the diagnostic lab. A reminder that when sending samples into the lab, make sure to include the full plant with roots if possible.

The 2nd generation of flea beetles continues to cause trouble in young cole crops. Spider mites are also seeing an uptick with the recent scorching weather. Corn leaf aphids are being observed around the Great Lakes region, affecting mostly sweet corn.

Corn leaf aphids on sweet corn tassel. Photo by Chris Galbraith, OSU Extension.

It’s getting to be that time of the year where we might have some of our early crops reaching the end of their productivity. Whether it’s cucurbits or cole crops or anything that we got planted early, we are now left with trying to figure out what to do with this now unproductive space in our field or garden. You have a couple of options:

Succession Planting: You may decide that you really don’t want to be done with growing something just yet. You could consider succession planting. Succession planting is a way for you to grow a crop throughout more of the growing season, instead of, for example, just growing a cool-season crop in the spring and being done for the rest of the season or waiting until you can plant warm-season crops and only having the one crop for the season. In the right circumstances, you could have an early cool-season crop, followed by a warm-season crop, followed by another cool-season crop depending on the amount of time it takes each crop to reach maturity. For example, you might plant something like lettuce or radishes early in the spring, then after you have harvested that crop, you might come in and plant something like beans, tomatoes, peppers, etc.

Done for the season: Maybe you are done planting new crops for the season, and that’s just fine! There are some best management practices though we can implement to make sure we are keeping our other crops protected and healthy. If you have a crop that is done producing, and perhaps starting to senesce, it is best to remove that plant material from the garden or field. Even though you might be done with the plants, pests and diseases certainly are not. If left in the garden or the field, this plant material can serve as a harborage for pests and diseases that could still impact our crops that are still growing. Removing this plant material gets rid of a favorable environment for things that would otherwise pose a threat to the rest of our garden or field. You can either physically remove the plant material and burn it or compost it, or you could work it into the garden or field to bury the plant material. 

So, whether you are done with an area in your garden or field or if you plan to keep planting, don’t just leave all that plant material behind. End of season best management practices can set us up for success for the rest of this season and for the next growing season! 

Fruit

Hot and dry weather has continued to promote population development of European red mites and two-spotted spider mites. This problem can be made worse with applications of certain insecticides that wipe out beneficial insects and natural enemies that would otherwise be keeping the mite population in check. Codling moth and oriental fruit moth seem to be slowing down in eastern Ohio.

Strange spots were observed on apple across the Great Lakes region. Some cases from other states have been confirmed as blister spot (Pseudomonas). Blister spot tends to occur more frequently in cool, wet weather which has not been characteristic of the season in much of Ohio. The apple variety Mutsu is particularly susceptible to blister spot. Ohio cases were not found to be bacterial in nature – final diagnosis concluded the symptoms were likely due to spray injury that occurred during recent high temperatures. 

Blister spot in apple. Photo source: John Hartman, University of Kentucky, Bugwood.org.

Some apple trees this year were observed to have “mummy” fruit that didn’t size up and develop properly but still remained on the tree. MaxCel, a plant growth regulator used for thinning, seems to cause this issue in some years with different varieties. Going back through to hand-thin is too labor intensive and so growers often resort to having workers  just harvest around the undeveloped fruit.

The hot weather has also resulted in sunscald concerns in small fruit and orchards. Once sunscald occurs, the fruit can become susceptible to other pathogens and secondary pests. 

Strawberry foliar and crown rot diseases seem to be widespread this year. Much of the management for this is preventative, such as practicing sanitary propagation methods. Blueberry season is wrapping up in many areas. High tunnel blackberries are being harvested and field blackberries are close to ripening in northern Ohio. Blackberry yields have been high in central and southern Ohio. Newer blackberry varieties such as Ponca that been planted more and more in recent years have lower acidity and are sweeter, improving sales and customer satisfaction.

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

 

Managing Post-Harvest Rots in Vegetables

Author: Chris Galbraith, Ohio State University Extension/Michigan State University Extension

This article was originally posted on Michigan State University Extension News.

Photo courtesy of MSU Plant and Pest Diagnostics.

Post-harvest rots occurring in vegetable crops can deal a brutal blow both financially and in terms of morale. All the investment and hard work of growing produce is lost if the crop spoils before it can be sold. Fortunately, many of the factors influencing prevalence of post-harvest rots are well-known and there are actions growers can take during the growing season, at-harvest, and post-harvest to reduce losses from premature decay.

What causes a rot?

Once vegetable crops are harvested, they are cut off from their source of nutrients and water. However, the produce continues to respire, using up its energy reserves and releasing water during metabolism. Cellular breakdown occurs as the produce spends its energy/moisture savings without any means of replenishment. As the produce degrades in quality, it becomes more susceptible to colonization by rot-causing pathogens.

There are many different microbes that bring about premature decay if they are able to infect vegetable crops during the different stages of growth and storage. These organisms may be latent pathogens, which can remain quiescent upon entering the crop and begin colonization of host plant tissue during storage (eg. Colletotrichum). Pathogens may also begin colonization immediately after infection, in which case spoilage occurs rapidly. Many rot-causing microbes are considered weak pathogens (eg. different bacterial soft rots), which cannot penetrate healthy plant tissue but instead require wound sites (nicks, scrapes, bruises) to enter and begin colonization. Table 1 lists common post-harvest pathogens for various vegetable crops. Many of these pathogens not only occur in storage but can also cause disease during the growing season.

Table 1. Common Post-Harvest Pathogens of Vegetable Storage Crops
Vegetable Post-Harvest Pathogens Symptoms
Pumpkins/Hard Squash Fusarium Rot (Fusarium spp.) · Tan, corky lesions

· White mold

Sclerotium Rot (Sclerotinia sclerotiorum) · White, fluffy mold

· Hard, black pellets (sclerotia)

Cottony Leak (Pythium spp.) · Brownish water-soaked lesions

· White, cottony mold

Anthracnose (Colletotrichum spp.) · Round, tan, black lesions

· Water-soaked tissue around lesions

Black Rot (Didymella bryoniae) · Water-soaked lesions

· Small black spots

Carrots Gray Mold (Botrytis cinerea) · Gray velvety mold
Watery Rot (Sclerotinia minor) · White fluffy mold

· Hard, black pellets (sclerotia)

Bacterial Soft Rot (various spp.) · Sunken, water-soaked spots

· Seepage from affected area

Potatoes Bacterial Soft Rot (various spp.) · Sunken, water-soaked spots

· Seepage from affected area

Dry Rot (Fusarium spp.) · Sunken, brown/black areas of decay

· White mold may be present

Pink Rot (Phytophthora erythroseptica) · Brown, dry sunken lesions

· Brown internal rot

Pythium Leak (Pythium spp.) · Brownish water-soaked lesions

· White, cottony mold

Onions Bacterial Soft Rot (various spp.) · Sunken, water-soaked spots

· Seepage from affected area

Black Mold (Aspergillus niger) · Dark mold growth

· Shriveling of bulb

Blue Mold (Penicillium spp.) · Soft, watery lesions

· Bluish-green mold growth

Basal Rot (Fusarium spp.) · Red-brown rot at basal end
Neck Rot (Botrytis spp.) · Grey, velvety mold
Cabbage Bacterial Soft Rots (various spp.) · Sunken, water-soaked spots

· Seepage from affected area

Watery Soft Rot (Sclerotinia spp.) · White fluffy mold

· Hard, black pellets (sclerotia)

Gray Mold (Botrytis cinerea) · Grey, velvety mold
Alternaria Leaf Spot (Alternaria brassicola) · Small, brown lesions that turn black

· Lesions are circular and spongy

The disease triangle is a useful framework. Spoilage occurs if the pathogen encounters a susceptible host in conditions that are favorable for infection. Post-harvest spoilage occurs more frequently in warm, wet and humid conditions. High temperatures encourage pathogen activity and increase the rates of produce respiration/ripening. Excess moisture on produce encourages pathogen activity and entry into plant tissue. Similarly, high relative humidity supports free moisture accumulation on vegetable crops in storage. Controlling these factors mitigates risk of premature spoilage and increases the shelf life of vegetable crops.

The disease triangle is a useful framework – spoilage occurs if the pathogen encounters a susceptible host in conditions that are favorable for infection.

Best management practices

Steps can be taken throughout production and storage to minimize losses from post-harvest rots. During the growing season, preventing fruit from coming into contact with the ground using plastic or organic mulch keeps produce cleaner and reduces opportunities for infection. Mulch also helps to reduce soil splash during irrigation or rainfall events, further limiting pathogens from being moved onto susceptible tissue.

Minimizing damage to produce throughout the season reduces wound sites and therefore pathogen entry points. This means gentle handling of vegetable crops at harvest and reducing the number of times produce is touched to minimize accidental skin breaks or bruises. Protecting vegetables from insects, wildlife, and environmental damage (hail, sunscald, wind) also reduces wound sites. Culling produce that is already damaged can reduce spread of spoilage in storage bins. Harvesting at proper maturity also helps optimize shelf-life.

Keeping vegetables cool can go a long way toward preventing premature spoilage. Harvesting during the coolest part of the day and removing the field heat from vegetables immediately after harvest is key. There are different pre-cooling methods available to rapidly bring down the temperature of produce prior to storage, including room-cooling, forced-air cooling, hydrocooling, package icing and vacuum cooling procedures.

Storage temperature and humidity recommendations vary by vegetable crop and following the right guidelines is important for maximizing shelf life. Specific storage recommendations and information on pre-cooling methods can be found in the Guide to Vegetable Production in Ontario (OMAFRA Publication 839). Maintaining proper temperature is also important to prevent chilling or freezing injury, which presents as sunken, water-soaked spots on susceptible produce.

For certain storage crops, curing is a crucial step for optimizing shelf life. Curing allows skins to dry out and harden, increasing protection against infections that cause rot. The area used for curing should always be a well-ventilated space with adequate air circulation. Recommended curing guidelines for several storage vegetable crops are listed in Table 2.

Table 2. Curing Guidelines for Storage Vegetable Crops
Vegetable Time Temperature Relative Humidity Source(s)
Hard Squash (Hubbard, Buttercup, Kabocha, Butternut) 5-10 days 80-85°F 80-85% Pumpkin and Winter Squash Harvest and Storage, University of Massachusetts Extension

Winter Squash Curing & Storage Chart, Johnnys Selected Seeds

Onions 2-4 weeks 75-80°F 70-80% 2024 Midwest Vegetable Production Guide

Growing onions in home gardens, University of Minnesota Extension

Garlic Up to 2 weeks 75-90°F 60-75% Organic Garlic Production, Michigan State University Extension
Potatoes 10-14 days 50-60°F 95% Potato Harvest and Storage, University of Massachusetts Extension
Sweet Potatoes 3-5 days 85°F 85-90% Guide to Vegetable Production in Ontario (OMAFRA Publication 839)

In conclusion, there are various factors that contribute to the occurrence of post-harvest rots. By taking the right action during the growing season, at-harvest, and post-harvest, losses from premature decay can be minimized and crop quality preserved.

OSU Extension Fruit & Vegetable Report – July 19th, 2024

This edition of the OSU Extension Fruit & Vegetable Report was written using field observations and expertise from the following OSU Extension staff: Frank Becker, Thomas Becker, Ed Brown, Chris Galbraith, Gary Gao, Kate Hornyak, Carri Jagger, Jim Jasinski, Matt Kleinhenz, Ashley Leach, Dan Lima, Diane Miller, Logan Minter, Francesca Rotondo, Ryan Slaughter

Vegetables

Spider mite flares ups have started to cause damage in watermelon fields. The observed infestations are severe and resulting in rapidly declining plants. Spider mite flare ups are not uncommon during hot and dry conditions, which are currently being experienced by some areas of the state. Frequent or heavy rains typically wash spider mites off of the plants. There are also several natural enemies that can help hold spider mite populations in check such as lacewing larvae, predatory mites, predatory thrips, and minute pirate bugs. Spider mites are typically found in the underside of the leaves. The visual symptoms of their feeding are often observed on the top side of the leaves as the mite feeding damages the cells in the leaves and results in yellowing, stippling and eventually necrotic areas and foliar dieback. When utilizing insecticides for insect control, there is a potential to wipe out beneficial insect populations, allowing for mite flare ups to occur. Also, if you do need to make an application to control mites, make sure you are using a miticide that is labeled for use against the mite species that you are finding and that it has activity on all life stages of the mites. It is common to have all stages of the mites life cycle present at one time, especially as populations increase and generations advance rapidly.  

Spider mite webbing and damage on melon leaves. Photo by Frank Becker, OSU Extension. 

Severe groundhog damage is being reported in various vegetable crops, including those grown at OSU research facilities. Fencing can be used, but the fence must be semi-buried to prevent the varmints from just burrowing underneath it. Trapping is the other most common option. For more information, check out the two articles below: 

Animal Damage Management: Groundhogs – Purdue Extension

Ecology and Management of the Groundhog – Rutgers

There has been a resurgence of flea beetles as the second generation descends on the newer planting of cole crops. Squash bugs, squash vine borer, powdery mildew, and downy mildew are all damaging cucurbits. A flare up of cucumber beetles and bacterial wilt is also occurring. Corn smut is affecting some sweet corn plantings. Oftentimes, desirable and productive varieties may have poor disease resistance to pathogens like corn smut. Cultural practices for reducing incidence of corn smut in your field includes minimizing mechanical damage to plants that provides entry points for pathogens, as well as other standard practices like crop rotation, timely destruction of crop residues, and keeping nutrient levels balanced.

Bacterial diseases are also being reported in peppers. Anthracnose was diagnosed on cucumbers. Fusarium and verticillium are occurring in tomatoes, and Fusarium is also being reported in melons. Bacterial spot is popping up on tomatoes due to the recent heavy rains. 

Early anthracnose infection on cucumber leaves. Photo source: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org

Fruit

It has been a good year for peaches and plums in Ohio. It has also been an early season – Dr. Diane Miller remarked that the variety sequence will be slotted earlier than normal this year. Fire blight risk has decreased considerably. White apple leafhopper has been observed causing moderate feeding damage in several orchards. White apple leafhoppers have piercing-sucking mouthparts that cause yellow-whitish stippling on the leaves. Both adults and nymphs can be found currently when scouting apple trees.  At this point in the season, try to target insecticide applications when you get 3 leafhopper nymphs per 25 leaves/tree. Neonicotinoids are effective against this pest (e.g., Belay (Clothianidin), Actara (Thiamethoxam), Assail (acetamiprid)). Be mindful of the pre-harvest interval since applications of these products at higher rates will increase the interval.  

White apple leafhoppers. Photo by Frank Becker, OSU Extension. 

High mite pressure has been reported in high tunnel raspberries. Are beneficial mites sufficient for mite control in high tunnels or greenhouse settings? It depends on environmental conditions – overly high temperatures can be detrimental for predatory mite survival which causes diminished levels of control. Phytophthora root rot has been reported in raspberries.

Photo by Thomas Becker, OSU Extension. 

With blueberry season in full swing and blackberry season about to get underway in much of the state, Spotted Wing Drosophila is a pest that small fruit growers need to have on their radar. Drosophila suzuki or spotted wing drosophila (SWD) is a fruit fly pest of small, soft-bodied fruits. To be able to identify the adults, many extension educators and specialists have to use a stereo microscope. It would take a hand lens at the very least, and even that may not be enough, as the key identifying features are quite small. Interestingly enough, only the male SWD has the characteristic spotted wing. The wings of the males are mostly clear, with one lone spot near the tip of each wing. Another ID tip for the males that is a bit more difficult to see is the presence of 2 black bands on their front legs. These bands are actually patches of hairs called sex combs. The main identifying feature on the females is their unique ovipositor. The ovipositor is the structure that female insects use to lay/deposit their eggs. For SWD, their ovipositor is lined with two rows of dark colored serrations or teeth. These serrations allow the female SWD to cut into ripening or just ripe fruits. This is different from many of the other fruit fly species we are used to, that infest over ripe or rotten fruit. 

Photo by Thomas Becker, OSU Extension. 

The fruits of primary concern are raspberries, blackberries, grapes, cherries, and strawberries. In Ohio, it seems that strawberries are pretty well done by the time that we start to detect SWD. Generally, first detection occurs when blueberries and raspberries are coming into season. Extension Educators and specialists around the state have SWD traps out to monitor pest populations. First detection is a critical aspect of managing this economically significant pest. The tolerance for damaged or wormy fruit is extremely low. The threshold for management to be implemented is one adult SWD in the trap. According to trapping data collected this year, first detection in the state occurred mid to late June. 

Once SWD is present in the environment, there are a couple of ways to try and manage it. You can start with cultural management by harvesting as thoroughly as you can and disposing of cull fruits. While it might be time consuming and require some extra labor, managing those culls could be worth the time and effort if it means you are removing a host site for the SWD. In addition, the more quickly you can get the fresh fruit off the plants, the less chance the flies have to lay their eggs in them. There are also some recommendations out there for physical exclusion. Berries under plastic, like a high tunnel for example, or under a fine mesh can reduce the number of adults gaining access to the fruit. However, there are some micro-climate considerations to keep in mind. Of note are air movement and access for pollinators (if needed). A fact sheet from Penn State University discusses the potential for biological control. There is apparently work being done to introduce a parasitoid wasp that targets SWD, but this work is still in its early stages. There are also multiple chemical options as well. You can find up-to-date chemical recommendations by checking in the Midwest Fruit Pest Management Guide or contacting your county Extension Educator. Penn State also has a 4-part fact sheet series on SWD with lots of good information. 

Resources: https://extension.umn.edu/yard-and-garden-insects/spotted-wing-drosophila#using-insecticides-2403912 

https://extension.psu.edu/spotted-wing-drosophila-part-1-overview-and-identification 

Orange Rust is a frequent problem on blackberries in Ohio. It is no exception this year. Dr. Gary Gao got a grant from Ohio Vegetable & Small Fruit Research & Development Program this year to evaluate the orange rust disease resistance of two new blackberry varieties from University of Arkansas. The varieties are Caddo and Ponca. A few plants were planted between the orange rusted blackberry plants. In addition, Ryan Slaughter and Dr. Pengfei Wen, a visiting scholar from Shanxi Agricultural University, helped inoculate the new plants with orange rust infected plant leaves. So far, Caddo and Ponca have not shown any symptoms of orange rust. This is a pretty crude field trial. Gary also asked growers about their experiences with Caddo and Ponca.

Photo by Dr. Gary Gao.

Ouachita, a leading blackberry cultivar for Rotatable Cross Arm training system, is reported to have shown good tolerance for orange rust. Growers look for orange rust resistant varieties to extend the harvest season. Caddo started its initial harvest a few says before Ouachita and a few days after Natchez. Caddo’s peak harvest season is also earlier than Ouachita. However, Caddo yield is quite lower than that of Ouachita based on observations in Ohio. 

Sweet-Ark™ Ponca is an early ripening blackberry cultivar with extremely sweet flavor. It ripens at about same time as Natchez. Some of the growers in Ohio have planted Sweet-Ark™ Ponca Blackberries. It is hard to know if this variety will be a good fit for your blackberry operation. However, a blackberry variety with super sweetness may be worth consideration on a small scale. Sweet-Ark™ Ponca blackberry may now be as productive as Ouachita, but early fruit, sub acid and super sweetness may warrant a small planting. Sweet-Ark™ Ponca blackberry is reported to be resistant to orange rust. Hopefully, we will get a better idea about its orange rust resistance after we wrap up our trial.

In addition to planting orange rust resistant blackberry cultivars, a fungicide spray needs to be implemented. Here is an informative article from University of Maryland:  https://extension.umd.edu/resource/orange-rust-bigger-problem-usual-year-brambles/.   Growers can also follow the following link for detailed a spray schedule for blackberries: https://ag.purdue.edu/department/hla/extension/_docs/id-465.pdf 

OSU Extension Fruit & Vegetable Report – July 6th, 2024

 This edition of the OSU Extension Fruit & Vegetable Report was written using field observations and expertise from the following OSU Extension staff: Mark Badertscher, Thomas Becker, Chris Galbraith, Melanie Ivey, Carri Jagger, Matt Kleinhenz, Ashley Leach, Gigi Neal, Francesca Rotondo, Sabrina Schirtzinger, Ryan Slaughter

Vegetables

With periods of hot, intense weather so far this season, there have been reports of heat stress in transplants and in hoophouse crops. It is during times like these that managing temperatures in high tunnels becomes of great importance. It can pay to be proactive and utilize strategies for cooling your hoophouse before symptoms appear in your crop. Consider the specific crop, its growth stage, whether it is fruiting vs. non-fruiting, its temperature tolerances, and other factors when determining whether to apply shade cloth, vent the tunnel, or take other measures. Dr. Matt Kleinhenz of the OSU Vegetable Production Systems lab recently gave a lecture on the topic of high tunnel temperature management – check it out at the following link:https://www.youtube.com/watch?v=9dZyPo7Itv4

Squash bugs and squash vine borer are out and feeding. Squash bugs do not seem to be much of an issue yet in some areas. Striped cucumber beetle populations are high and reaching threshold in watermelons and other crops. Some organic growers have been using kaolin clay to prevent cucumber beetle feeding. Kaolin clay can also be applied to black plastic mulch during hot spells in order to cool down the microclimate and reduce heat stress in transplants. Cucumber downy mildew has been found in Ohio. Flea beetle defoliation is being seen in cole crops.  Diamondback moth larvae,  imported cabbageworm, and other caterpillars are out and feeding. Heat blistering on tomato stem tissue was reported during the recent period of extreme heat. There is very high thrips pressure in some pepper plantings. Japanese beetle, slug, and vertebrate wildlife damage is also being reported in various vegetable crops.

Flea beetles can be voracious pests of cole crops, leaving shot hole patterns in leaves. Photo by Chris Galbraith, OSU Extension. 

Fruit

Many abiotic disorders related to the unusual weather have been coming into the diagnostic lab this season. Wooly apple aphids have begun moving out on tender new growth. Diazinon, one of the chief crop protection products for this pest, is no longer being manufactured so control is more of a struggle. Oriental fruit moth populations are peaking. Bacterial leaf spot is being reported in peach. Powdery mildew is also being observed in apples, grapes, and peach.

Bacterial leaf spot can be a severe disease of stone fruits. Photo by U. Mazzucchi, Università di Bologna, Bugwood.org.

Blueberries have been hitting their peak in harvest, around two weeks ahead of normal this year. The strawberry season was reported to be poor this year – berries did not size up well and plants were not as vigorous this season on some farms. 

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

OSU Extension Fruit & Vegetable Report – June 17th, 2024

This edition of the OSU Extension Fruit & Vegetable Report was created using field observations and expertise from the following OSU Extension staff: Mark Badertscher, Frank Becker, Thomas Becker, Ed Brown, Chris Galbraith, Melanie Ivey, Matt Kleinhenz, Ashley Leach, Logan Minter, Gigi Neal, Sabrina Schirtzinger, Ryan Slaughter

Vegetables

A common trend this spring is the delayed planting in many parts of the state due to consistent rainfall that held up field work. Transplants that have been held onto for too long may become rootbound and stressed, exacerbating transplant shock and generally delaying growth and development. With that said, conditions have been dry in other parts of the state such as SE Ohio and could benefit from more rain at this point.

Cucumber beetles are out feeding and bacterial wilt was reported in southern Ohio. Cucumber beetles thresholds are lower for younger plants because of the outsized risk of lethal infection. Seed treatments have been the go-to solution and they seem to be handling pressure well so far this season where they were used. Squash bugs have also emerged and are active. 

Bacterial wilt of cucurbits. Photo by Jim Jasinski, OSU Extension, Bugwood.org

 Flea beetles are feeding in cole crops. Imported cabbageworm and cabbage maggot feeding is severe in some brassica plantings. Heavy imported cabbageworm pressure has been observed in western Ohio.

Severely stunted growth can be an above-ground symptom of cabbage maggot root feeding. Photo by Chris Galbraith, OSU Extension. 

Severe Colorado potato beetle defoliation is being seen in eggplant and potatoes. Some growers have found extended protection using imidacloprid when planting seed pieces. Spinosad is another option in the arsenal, with the added benefit of being organic compliant.

Foliar diseases are being detected in high tunnel tomatoes. Many of these pathogens present on lower foliage first. At the time of fruit set, the lower ⅓ of leaves on tomato plants are generally not particularly productive from a photosynthesis standpoint, and therefore can be pruned to improve airflow between plants. Whitefly and aphid presence has been noted in peppers. Thrip pressure is heavy in onions in some areas.

As is the case every year, spray drift is being observed in vegetables. In some instances, symptoms resembling drift damage may occur on your vegetable crops when there is no obvious source of pesticides nearby. Drift particles may be moved surprisingly far by temperature inversions or other weather conditions. Other times, it may be an issue with herbicide residual activity in the soil.

One question from a community member: Is produce still safe to eat in cases where there is crop damage from pesticide drift? As is the case with most food safety questions – when in doubt, it’s best not to take the risk. There is uncertainty around how long it takes before residue levels are at or below the tolerance levels for situations in which a chemical is not registered for a specific crop. It is better to be on the side of caution when it comes to pesticides and produce safety.

Fruit

Fire blight incidence is high in some apple orchards. Apple scab is also being observed this year, with most infection occurring on fruit rather than foliage. Powdery mildew is being reported. Codling moth flights have been strong this season which is leaving growers with weekly sprays. Dogwood borer flights are particularly strong, and we do not have clear peaks this season. Some rosy and green apple aphids, as well as white apple leafhoppers, are being observed in orchards. 

Bacterial leaf spot is being reported on peaches. Peach leaf curl incidence is also high so far this season. Peach X-disease was recently confirmed by the OSU diagnostic lab. There is oriental fruit moth activity in some peach orchards but seems to be well controlled in most cases.

Foliar symptoms of peach leaf curl. Photo source: Nancy Gregory, University of Delaware, Bugwood.org

There have been calls about thrips and sap beetles in strawberries. 

Similar to vegetables, herbicide drift damage is popping up in vineyards and other fruit. For commercial growers who have experienced significant losses, reach out to ODA to report drift damage. For those wishing to pursue legal action – as soon as damage is observed, store damaged tissue in the freezer for preservation so that it can be tested at a later date.

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

 

OSU Extension Fruit & Vegetable Report – May 28th, 2024

The OSU Extension Fruit & Vegetable Report is written and published collectively by OSU Extension staff across the state.

Vegetables

Onion plants are off to a quick start this spring. As the plants quickly add leaves, this provides ample opportunity for onion thrips to get started. Scouting for onion thrips is incredibly important early in the season as they become increasingly more difficult to manage as the season progresses and the onion plants become larger and more heavily foliated. Scouting for thrips involves carefully pulling apart onion leaves near the neck and examining down into the crotch of the leaves. On a sunny day, thrips will react to the sudden exposure of sunlight by moving downward, deeper into the leaf collar. As you evaluate management decisions, also be aware that heavy rains may provide assistance in management of onion thrips as the rain washes the thrips out of the leaves or drowns the insect.

Photo by Frank Becker, OSU Extension.

Colorado potato beetles are emerging and becoming active in potato plantings. The adults are very difficult to control with pesticide applications. Control is more effective when applied to newly hatched larvae. Please reference the Midwest Vegetable Production Guide to find effective products for management of the Colorado Potato Beetle. 

Colorado potato beetle larva feeding on potato foliage. Photo by Chris Galbraith, OSU Extension. 

Squash and cucumber continue to be seeded. Striped cucumber beetles are out. As an important reminder, early season control of cucumber beetle is critically important in preventing bacterial wilt in your cucurbit plantings. The threshold for beetles while plants are in the cotyledon stage is 0.5 beetles per plant. The threshold for beetles at the 3-4 leaf stage is 1-2 beetles per plant, and for plants with 4 or more leaves, 3-5 beetles per plant. Scouting during the morning or evening will give you the best results, as beetles are often difficult to find during the heat of the day. Recent chewing and feeding damage can also be indicative of beetle activity. This can be differentiated from “old” feeding damage as the older damage will look scabbed over, but the recent feeding will appear as a “wet” wound.

Cabbage maggot, caterpillar, and swede midge damage is being observed in cole crops. Reports of some early season flea beetle activity have led to some growers already making applications to limit damage to young cole crops. Flea beetle feeding can be scouted for by looking for “shot hole” style feeding patterns on the foliage of the plants. Early season feeding, especially on young transplants can significantly stunt the plants, and in some cases when feeding is severe enough, seedling death can occur. 

High tunnel tomatoes are fruiting and field tomatoes are being planted where growers can get into the fields. 2-4,D drift damage has been observed in some high tunnels. Powdery mildew and thrips are the main pest of concern in greenhouse tomatoes at this point in the season. 

Early blight and powdery mildew have both been found in high tunnel tomatoes. Powdery mildew, as the name describes looks like powdered sugar on the upper leaf surface. These symptoms can develop at any level of the plant.  Early blight, or Alternaria, has an alternating ring/bullseye like pattern, often with a yellow halo around the lesion. Early blight is most often first found on the older foliage near the bottom of the plant.  Please scout your high tunnel tomatoes frequently and thoroughly, especially early season to catch early season disease presence and hopefully prevent major impacts throughout the season. Please read fungicide labels carefully to make sure that the crop and disease are both listed on the label. Remember, the label is the law. 

Recently planted sweet corn is beginning to emerge. Slug damage is being observed, although not severe at this point. Now is also an important time to be checking sweet corn for black cutworm. Cutworms damage the pants by cutting the plant off at or slightly below the soil line, significantly stunting the plant or causing plant death. If infestation levels are high enough, stand loss can occur to the point of necessitating a replant. 

Fruit

With the mild winter, fruit, vegetable, and agronomic crops alike are getting a quick start in Ohio this year! It seems the pathogens got the memo as well as educators and specialists around the state are reporting an early onset of several diseases on fruit. One disease that we are seeing in orchards this spring is apple powdery mildew.

Powdery mildews are among one of the more recognizable diseases in our specialty crops and can have a significant impact. Some folks are probably familiar with the cucurbit powdery mildew that we find on the cucumbers, zucchini, and other cucurbit crops in our fields in gardens. Powdery mildews are host specific, so the powdery that we observe on apple trees will not lead to powdery mildew infections in our cucurbit crops. They are different species. Usually, we see cucurbit powdery mildew as we get further into summer, around July. That particular pathogen does not overwinter in Ohio and has to be blown in by the wind from areas where it can overwinter.

Apple powdery mildew is quite different, caused by the species Podosphaera leucotricha. Apple powdery mildew can overwinter in fruit buds that were infected in the previous season. Another interesting thing about powdery mildew is that while it does need a higher relative humidity, it does not require free water for development. Many of our other diseases do have that requirement. So, even in drier years, powdery mildew can still pose a challenge.

Powdery mildew is one of those diseases where when we scout, we can observe both the signs and symptoms of the disease. In other words, we can see both the physical evidence of the powdery (Sign: the white fungal growth) as well as the plants response to the infection (Symptom: stunted, crinkled leaves). The first thing you will likely see in spring is the white fuzzy or waxy appearance to the leaves. As the disease persists, leaves will become stunted, crinkled, and brittle. As the season goes on, the disease can spread to the twigs, stunting their growth, and potentially leading to dieback issues. In severe cases, symptoms can show up on fruit resulting in russetted apples.

Photos by Thomas Becker, OSU Extension.

Apple powdery mildew can be managed with some cultural integrated pest management tactics. One tactic is to plant varieties that are less susceptible or potentially resistant to powdery mildew. Another tactic is to plant and manage your trees to allow for good air movement and light penetration. This can lower the relative humidity around the trees and make it more difficult for the pathogen to get established. Chemical controls are also an option. If powdery is a persistent problem in your orchard, it may require the development of a good fungicide program to get adequate control. Contact your county extension educator, one of our state specialists, or reference the Midwest Fruit Pest Management Guide for current fungicide recommendations.

References:

Apples have progressed quickly in their development. Codling moth trap catches are high across the state. Insecticides to control first generation codling moth should be on to slow the second generation. Wooly Apple Aphids are on the move in the trees, as they move from the roots to the limbs. San Jose Scale is present as well and male flight has been observed in southern Ohio. Plum curculio damage present (petal fall applications are best to control infestations). Pear psylla adults active. 

Lacewing eggs hanging from branch. Lacewings are beneficial insects that feeds on aphids and other fruit & vegetable pests. Photo by Frank Becker, OSU Extension. 

Strawberries are ripening and some varieties are in harvest. Main pests at this point are slugs, spittlebugs and birds. Phytophthora leather rot and sun scald being observed in fruit. Brambles are blooming, blueberries setting fruit. 

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

OSU Extension Bi-Weekly Fruit & Vegetable Report – October 17th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

Biological Soil Health

When it comes to supporting healthy soils, the physical and chemical aspects of soil quality are often highlighted. However, the importance of biological activity and diversity, and how it influences soil structure and chemical properties (pH, electrical conductivity, etc.), is becoming increasingly appreciated in modern farming. As we discover more about the different microbe-microbe and microbe-plant interactions unfolding in the soil habitat, we can create better farming practices that optimize crop health and soil quality.

Three areas of soil health: physical, chemical, and biological. Image courtesy of University of Massachusetts. 

The source of and final destination of all soil life is soil organic matter (SOM). SOM consists of biological material in the soil, derived from plants, fungi, animals, and other organisms, that are in various stages of decomposition. Certain forms of SOM break down quickly and provide nutrients for crop use, others are more stable (i.e. inaccessible to microbial decay) and contribute to aggregate stability and tilth. A SOM content of 5% in mineral soils is considered high; in muck soils, SOM can be as high as 80%. Conservation ag practices like reduced tillage and cover cropping are used to support high levels of SOM for improved nutrient cycling, soil structure, and cation exchange capacity. 

The food webs that produce SOM are characterized by an astonishing diversity of soil life made up of bacteria, fungi, archaea, nematodes, protozoa, and other microfauna, as well as the larger organisms like springtails and earthworms higher up the food chain. These organisms not only drive nutrient cycling through consuming and contributing to SOM, but can influence crop health through more specialized relationships. Plant-growth promoting rhizobacteria that interact with plant roots can boost crop productivity by producing hormones, fixing atmospheric N, solubilizing P for increased availability, and inducing plant resistance to pathogens. The growing biologicals industry (biopesticides, biofertilizers, and biostimulants) is based on the premise that certain organisms benefit crop health through either direct interactions or interactions with other soil life. 

Keeping in mind how soil biodiversity and activity affect soil health through the lens of SOM and interactions between organisms can help us make decisions that support crops by maintaining a thriving, balanced soil habitat.

Examples of soil organisms at different scales – Microfauna: Azospirillium soil bacteria (top), Mesofauna: tardigrade (middle), Macrofauna: earthworm (bottom). Photos courtesy of Science Source (top), National Geographic (middle), Dan Brekke – Flickr (bottom).

Crop Updates

Vegetables

Cucurbits

Plectosporium leaf blight is being detected. Continue to watch for aphids, cucumber beetles and squash bugs. Significant damage was detected within the last week in harvested pumpkins due to large populations of cucumber beetles. Aphids can still be found in green foliage, and may be spotted via large accumulations of honey dew beneath healthy foliage.

Cucumber beetles feeding on harvested pumpkins. Photo by Frank Becker, OSU Extension.

Cole Crops

Alternaria leaf spot is being observed in brassicas. This pathogen is supported by warm, wet conditions. Cultural practices for reducing alternaria pressure include increasing crop spacing for improved airflow, crop rotation, tilling under crop residue after harvest and controlling brassica weeds (shepherd’s purse, wild mustard, wild radish, yellow rocket, etc.)  to decrease disease inoculum. Treating seed with hot water prior to planting may also help  to decrease prevalence of this seed-borne pathogen. Consult the Midwest Vegetable Guide for fungicide options in Brassicas.

Tomatoes/Peppers

Hoop house tomatoes are nearing the end. Powdery mildew, bacterial diseases, aphids, and other pests are all being observed under plastic. Late blight and early blight are prevalent in remaining field tomatoes. 

Anthracnose is continuing to be an issue on peppers and tomatoes. Infested fruits rapidly decline in quality and are unmarketable. Lesions are typically observed as sunken, round lesions on the fruit. At times you may also be able to see the salmon colored spores within the lesion on the fruit. 

Anthracnose on peppers. Photo by Frank Becker, OSU Extension. 

Fruit

Many orchards are nearing completion of harvest and pest monitoring traps are being taken down for the season. As tree fruits are harvested and leaves begin to fall, it may be a good opportunity to take a closer look at your trees and scout the trunk and branches for presence or evidence of insect pests such as scale and borers. Scouting for these pests now can help you make adjustments to your integrated pest management program.

October Small Fruit Updates

Dr. Gary Gao, Professor and Small Fruit Specialist, CFAES South Centers. The Ohio State University

Update on Long Cane Raspberry Project:

We are only getting a few straggling raspberries from our long cane raspberry trial at OSU South Centers in Piketon during the week of October 6, 2023. There were only enough for Gary to snack on. Pictured in the first photo is Kweli®. As you can tell from the picture, fruit color is still looking quite nice. Kweli® is an everbearing variety that is capable of producing two crops inside a high tunnel and out in the open field. Follow this link for more information on the variety: https://www.abbreeding.nl/varieties/kweli/?lang=en

We are still fine-tuning the method of growing long cane Kweli®. We just wrapped up our 2021-2023 Specialty Crop Block Grant (SCBG) funded by Ohio Department of Agriculture (ODA). There is a lot more to learn about this highly innovative production method. Fortunately, we received another SCBG from ODA to do just that!

Kweli® fruits. Photo by Dr. Gary Gao, The Ohio State University.

Gary was able to find several Tulameen raspberries from our long cane raspberry trial plot. This is definitely too late for the Tulameen harvest since it is a summer-bearing variety which does not produce fruits on primocanes. It was still neat to check them out. Earlier in the season, we harvested a lot of beautiful Tulameen fruits. Some of our grower cooperators were able to sell them for $9 per pint in a Columbus farmer’s market. Raspberry bushes in a long cane production system can produce 22,000 lbs. per acre! Tulameen is well suited for long cane raspberry production and is well known for its large fruit size and excellent taste! Follow this link – https://www.researchgate.net/publication/292928034_’Tulameen’_red_raspberry – for more information on Tulameen variety.

Tulameen fruits picked in October from our long cane raspberry trial. Photo by Dr. Gary Gao, The Ohio State University.

Late Leaf Rust on Raspberries:

Gary noticed that some of the raspberry bushes in their raspberry trial had late leaf rust. Late leaf rust on raspberry is a fungal disease. Follow link – https://ohioline.osu.edu/factsheet/plpath-fru-17#:~:text=Late%20leaf%20rust%20is%20caused,rust%20fungus%20is%20not%20systemic. -for more information on symptoms and management of this disease. Do not confuse this disease with orange rust of brambles. Fortunately, red raspberries are resistant to orange rust.

Late leaf rust on raspberries. Photo by Dr. Gary Gao, The Ohio State University.

Fall is for Figs in Ohio!

Even though fall is typically for apples, mums, and pumpkins, it is also for figs – well hardy figs for that matter. Gary has been picking hardy figs from their fig planting at OSU South Centers in Piketon from early September to now. The figs will keep ripening until frost. A high tunnel will extend the harvest season.  Our figs were from another Ohio Specialty Crop Block Grant funded by ODA a few years ago. The varieties in our trial are Brown Turkey, Hardy Chicago, and Olympian. Brown Turkey and Chicago Hardy performed the best in our trial. Follow this link https://ohioline.osu.edu/factsheet/hyg-1439 for more information.

OSU hardy fig trial. Photo by Dr. Gary Gao, The Ohio State University.

Brown Turkey figs from the hardy fig trial at OSU South Centers in Piketon. Photo by Dr. Gary Gao, The Ohio State University.

Berry Production Workshops Presented by OSU Extension in Medina County

I will be going to Medina County on Friday, October 27 to give two talks, one on blueberries and one on raspberries. Ms. Ashley Kulhanek, the Ag. and Natural Resource Educator, is organizing the program. I will show gardeners and growers how to grow blueberries and raspberries. Please call OSU Extension in Medina County at 330-725-4911 for more information and to RSVP!

This is our last bi-weekly report for the 2023 season. Thank you for reading and please feel free to direct any feedback on the report series to Chris Galbraith at galbraith.108@osu.edu.

Upcoming Events

December 5 – 7, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference

 

OSU Extension Bi-Weekly Fruit & Vegetable Report – September 28th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates below:

Strip Tillage

Strip tillage is a form of conservation tillage that attempts to combine the benefits of no-till and conventional tillage by working only the area where the crop will be planted. Leaving residue cover over the majority of the field protects the soil against erosion and helps to build organic matter, improve aggregate stability, and boost other indicators of soil health. Working the soil in the strip zone warms the soil faster and prepares a better seedbed to support plant growth. 

Components of a strip till unit – A) lead coulter for slicing through residue, B) row cleaners for parting residue, C) shank for fracturing and lifting soil, D) berm-building coulters to shape tilled soil into strip, & E) rolling basket for creating level seedbed. Photo courtesy of Orthsman/Unverferth Manufacturing. 

 

Strip-till in sweet corn stubble. Photo by Chris Galbraith, OSU Extension.

While strip till targets the benefits that come with integrating the two systems, there are downsides to consider as well. These mostly involve issues with cover crop and/or residue interference with growing the crop. Vigorous cover crops need to be terminated in a timely fashion and crop development can still be delayed in strip-till if the season begins cold and wet. Pests like slugs and voles can also build-up with the increased residue cover. The cost of the equipment can also be a substantial investment which creates a barrier to entry for many growers.

Many vegetables can be grown in strip tillage systems, including cucurbits, sweet corn, snap beans, potatoes, cole crops, carrots, and more. Recent studies at Michigan State University have found a slight yield increase from strip till in vegetable crops, but many of the issues mentioned can impact this (climate, residue management, pest pressure). It is important to consider the factors that go into making strip till a successful venture in order to make the most of the equipment and the practice.

For additional info on strip till in vegetables, check out this website on strip tillage from the Cornell Small Farms Program. 

Wildlife Control in Fruits & Vegetables

This season has been severe in terms of wildlife damage in specialty crops. Animals like deer, groundhogs, voles, raccoons, and birds have caused major losses on some farms. Dr. Marne Titchnell, wildlife program director for OSU Extension, recently gave an in-depth presentation at Farm Science Review on different wildlife mitigation strategies for growers. The information and slides can be found on her blog through the link below:

Managing and Preventing Damage from Wildlife in Fruits & Vegetables

OSU Extension Center for Cooperatives

Opportunities abound for farms when it comes to teaming up to save money and improve effectiveness through joint purchasing, collaborative marketing, and other similar practices. These types of partnerships between farm businesses is captured by the cooperative or “co-op” model where growers access resources and savings by acting together and making decisions as a group in certain scenarios. The Center for Cooperatives at OSU specializes in these sorts of opportunities and can offer guidance to growers who are interested in leveraging the benefits of organizing for collaborative business purposes.

Find more information at the center’s website. Read more about the topic of collaborative marketing in this recent article on the Center of Cooperatives blog.

Crop updates

Vegetables

Cole Crops

Heavy cross striped cabbageworm and imported cabbageworm feeding is still being observed in some brassica plantings. Aphids have made a late season push in brussel sprouts, cabbage, cauliflower and broccoli plantings. Cabbage aphids are typically a grayish color, and are often found amongst a waxy, white secretion which covers their body. Reproduction rates of these aphids are highest in temperatures between 50-68F. Scout for these pests on the underside of younger leaves, between leaf layers and on flower buds or seed stalks. It is recommended to treat cabbage when you see 1-2% of plants infested with aphids. There are a number of products that can be used to treat aphids in cabbage including Movento, Sivanto, Assail, Exirel and Beleaf. Prioritize products that have reduced toxicity (e.g., Beleaf) which will conserve natural enemy communities. Refer to the Midwest Vegetable production guide for other options. 

Cabbage aphid infestation. Photo by Frank Becker, OSU Extension. 

Cucurbits

Cucurbits are seeing upticks in a variety of beetles in flowers and fruit. These include corn rootworm species. Spotted cucumber beetles are active. Aphids are also beginning to be found with some more frequency in the fall vine crops. Squash bugs are also active within the crop. Most cucurbits do not have blooms in fields, so pyrethroid and carbamate applications may be applied (e.g., Sevin, Pounce, Capture). Refer to the Midwest Vegetable production guide for other options.

The pumpkin crop has been strong in Ohio this season. Many growers in northwest Ohio were able to manage downy mildew with fungicides. Plectosporium blight has been causing some problems for growers where fungicide spray coverage may not have been as thorough as desired. Most fungicide spray programs being used are adequate to limit impacts from plectosporium blight. Spray penetration into the canopy and coverage across the field is as important as selecting the right product.

Plectosporium blight on pumpkin, identified by light colored lesions on fruit, handles, and vines.  Photos by Frank Becker, OSU Extension.

Fruiting Vegetables 

Late blight has been confirmed in several tomato fields in and around Wayne County. Bacterial diseases have also begun to start, and with cool mornings and heavy dews, it will become increasingly more difficult to manage. 

Several high tunnel producers have reported dealing with broad mites/cyclamen mites in their high tunnel peppers. The mites feed on the fruit while it is still developing and their feeding damage causes the peppers to become russested and misshapen. The leaves may also appear distorted, almost as if they were drifted with herbicides. Keep in mind that these mites are in a different group than two-spotted spider mites. Therefore, it’s important to select control options that are appropriate and effective on this species. Sanitation and crop rotation are also important cultural control measures that need to be taken when dealing with mites in high tunnels.  

Onions 

Although the growing season is behind us for onions, curing is still ongoing, and some growers have reported some challenges with curing. Make sure that you are providing the proper conditions for curing onions. Less than ideal conditions will result in frustrations and losses of product. Ideal conditions are warm, dry, well ventilated areas. Ideal temperature range is between 75-90F. The other factor that contributes to losses while curing is not curing the best graded onions. Curing is not an attempt to bring quality back, only preserve it. Grading hard for only the best onions to be cured will help reduce the chance that rots begin to develop. Take note of any disease or insect issues that you have observed this year and use these notes to help you next year. Onions that may have had heavy thrips loads, or untreated disease infection during the season are not going to hold up as well as desired during the curing process. 

Green onions are seeing thrips populations slow down. Typically, thrips populations will decrease as we enter into Autumn and see these species move onto weedy hosts. 

Fruit

Sanitation is an important component of an integrated disease management program. In small fruit and tree fruit alike, there are diseases that can over winter on infested fruit, foliage and branches. As the season winds down, it is still important to scout for diseases that may be present, identify the disease and have a plan of action to manage the disease. Finding and removing mummy fruit, which are dried and shriveled fruit that are typically full of fungal structures, will help to significantly reduce disease inoculum from the production area. Too, mowing and mulching or raking away the leaves from around the trees and bushes reduces the amount of viable inoculum that may be overwintering in foliage. Much progress can be made towards disease management with efforts made in the fall. Taking these steps, and committing to them long term, helps to break disease cycles and reduce the overall pathogen load over time. 

Fruit rots are being observed in apples, including white rot and bitter rot. Bitter rot is common in apples during warm, wet conditions. For more information, take a look at this OSU article on bitter rot in apple. Marsoninna blotch is also found on apples. 

The pawpaw crop in Ohio this season has been later and smaller than past years. Pawpaw is a niche crop that is gaining popularity with Ohio consumers and can be used as an ingredient in specialty craft beers, ice cream, and other value-added items. For more information on pawpaw production, check out this factsheet from Cornell University. Learn more about the pawpaw industry in Ohio by visiting the Ohio PawPaw Growers Association website.

Pawpaw fruit cluster. Photo by Clemson University. 

 

Upcoming Events

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

December 5 – 7, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference

 

OSU Extension Bi-Weekly Fruit & Vegetable Report – September 15th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates below:

Farm Science Review 2023

The Farm Science Review (FSR) is one of the nation’s premier farm shows and one of OSU Extension’s largest, most far-reaching educational programs. The event will be held at the Molly Caren Agricultural Center near London, Ohio on September 19th – 21st. The OSU Extension Fruit & Vegetable Team will be hosting a tent all 3 days that will feature presentations from academic and industry speakers on a variety of topics, including nutrient management, entomophagy, integrated pest management, variety trial results, farm marketing, and more. The OSU Extension Fruits & Vegetables exhibit will be located near the gazebo near the Utzinger Garden (booth 385). We hope to see you there!

Check out the 2023 Farm Science Review Program for further information.

Speaker schedule for OSU Extension Fruits & Vegetables exhibit at FSR 2023. Note: There will also be a presentation by Dr. Marne Titchnell, Extension Wildlife Program Director for OSU,  on wildlife management in fruits & vegetables on Wednesday, September 20th from 1:30 – 2:00 PM.

Purple carrot-seed moth detection

The OSU Plant & Pest Diagnostic Clinic (PPDC) recently received an insect sample that was identified to be purple carrot-seed moth (Depressaria depressana), a known pest of crops in the Apiaceae family. This was the first report of purple carrot-seed moth found in Ohio, though it has been found in neighboring states. The insect feeds on the flower heads of crops like carrot, parsnip, dill, celery, parsley, and more, but it is yet unknown if it will be an economically important pest of these crops in Ohio. Check out the article from PPDC for more information.

Please report any suspected larvae/adults with pictures to entomology@osu.edu or ppdc@osu.edu.

Purple carrot seed moth larvae (top) and adult (bottom). Photo by Iowa State University Extension (top) and University of Wisconsin-Madison Department of Entomology (bottom). 

Crop updates

Vegetables

Cucurbits

Downy mildew continues to wreak havoc in cucurbit plantings this time of year. As a refresher, here is a factsheet from Michigan State University on downy mildew mitigation. Powdery mildew pressure is reported to be increasing in southern Ohio. Striped cucumber beetles populations are declining in central/northeast Ohio and transitioning more towards higher numbers of corn rootworm beetles. Western corn rootworm, a look-alike of striped cucumber beetle, also feeds on cucurbits and can impact yield if heavy populations are present. Check out this article from Iowa State University for information on identifying different rootworm beetle pests. 

Virus symptoms are being observed in some melon plantings. There are various aphid-vectored potyviruses that affect cucurbits and they can be hard to differentiate from one another, though control practices are similar for all of them. The big 4 for cucurbit crops are cucumber mosaic virus, papaya ring spot virus, watermelon mosaic virus, and zucchini yellow mosaic virus. Like many crop diseases, management practices are preventative and include using resistant varieties or planting earlier to ensure harvest before viral symptoms appear towards the end of the season. Getting aphids under control may also minimize virus infection to some degree.

Cucumber mosaic virus – symptoms include yellowish-green “mosaic” mottling on foliage or fruit and crinkled leaves. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.

Papaya ringspot virus – symptoms include wrinkled leaves and discolored, bumpy fruit. Photo by Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org.

 

Watermelon mosaic virus – symptoms include wrinkled leaves and geometric patterns on fruit.  Photo by Dorina Pitorac, European Plant Protection Organization.

Zucchini yellow mosaic virus – symptoms include blistered, wrinkled leaves and fruit with discolored bumps. Photo by University of Massachusetts Extension.

Fruiting Vegetables

Late-season aphid feeding is being observed in some solanaceous crops. Honeydew is a sugary liquid secreted by aphids and other sap-sucking insects (whiteflies, spotted lanternfly, etc.). Honeydew accumulation on crop foliage or fruit can lead to growth of sooty mold, which is a term for various genera of fungi that colonize the sticky exudate. Sooty mold does not render vegetables inedible, however, and can be readily washed off. 

Honeydew from aphids (and other sap-suckers) on plant leaves is sticky to the touch and can be colonized by sooty mold. Photos by Kansas State University Entomology (top) and Joe Boggs, the Ohio State University Extension (bottom). 

Regular bouts of rainfall as we head into the fall are leading to increased incidence of Phytophthora infection in peppers (and cucurbits). While excess water is a problem for some vegetable growers in Ohio, some parts of western Ohio still remain abnormally dry, according to the U.S. Drought Monitor. Mites have been a problem in some areas, while thrips have taken a downturn. Keeping mites under control towards the end of the season can reduce the chance of heavy pressure next season by reducing the egg load/number of overwintering adults that will become next year’s mite infestations.

Fruit

Tree fruits

Early varieties of apples are being harvested across the state. Brown marmorated stinkbug pressure is increasing. Bitter rot is starting to be observed in some orchards. Marssonina leaf blotch is also being seen in some organic orchards, where management can be difficult without the use of fungicides. Removal/destruction of leaves on the orchard floor in the fall can reduce overwintering sites for the pathogen. Black knot is being seen on some ornamental plum trees, so commercial plum and cherry growers should keep an eye out for black knot galls on their trees and promptly remove them if they see them.

Gall of black knot (Apiosporina morbosa), a fungal pathogen of plum, cherry, and other types of fruit trees. Photo by Joseph O Brien, USDA Forest Service, Bugwood.org.

Small Fruits

Preparing Brambles for Winter – Sanitation Practices for Disease Prevention
Melanie Ivey, State Fruit Pathologist and Fresh Produce Safety Specialist, The Ohio State University

Disease management of perennial fruit crops is a year-round endeavor. Many fungal pathogens survive the winter months in the soil or plant debris, infected canes or buds, or dead canes. As part of an integrated disease management program fall sanitation practices to reduce inoculum in the planting should be done.  Best sanitation practices include removing floricanes after harvest, removing diseased and dead canes, removing dead or systemically infected plants, and raking or chopping fallen leaves. Pruning debris should be destroyed by burning or placing in the trash or discarding it away from the planting. Diseased plant material should not be composted.  Pruning cuts should be sharp and clean to avoid unnecessary mechanical wounds.

The fall is also a good time to scout for and remove wild bramble populations that are near the production field. In addition to fall sanitation practices, some diseases require a dormant or delayed dormant fungicide application. For dormant or delayed dormant fungicide recommendations consult the Midwest Fruit Pest Management Guide (OSU Extension Bulletin 506).

The table below summarizes where the fungi for several common diseases of brambles in Ohio overwinter, the recommended fall sanitation practices for each disease, and whether a dormant or delayed dormant fungicide application is recommended.

Upcoming Events: 

September 19 – 21, Farm Science Review

September 27, Wooster, OH, Midwest Mechanical Weed Control Field Day

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

December 5th – 7th, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference