Vegetable Recommendations

First Cucurbit Downy Mildew Observation in OH in 2024

Sporulation evident on the underside of the cucumber leaf, F. Becker.

Cucurbit Downy Mildew has been confirmed today (July 2nd, 2024) in Ohio, specifically in Medina County. The observation was made by area growers and the Wayne County IPM Program, and was confirmed by the C. Wayne Ellett Plant and Pest Diagnostic Clinic at the OSU CFAES Wooster Campus. This is almost an entire month earlier than when it was first found in 2023. Western New York had several confirmed cases during the last week of June and southern Michigan has a confirmed observation that was reported today, July 2nd, 2024. The 2 farms outside of Homerville, OH, where samples were taken from ranged in severity and incidence, with one farm having a severe, mature infestation, and the other in the very early stages of disease development and progression.

Heavy sporulation on the underside of a cucumber leaf, F. Becker.

Growers who have cucumbers and cantaloupe in their fields should take quick action to protect their crop. Cucurbit Downy Mildew is best managed with preventative applications before infection takes place. Once visual symptoms appear, control becomes increasingly difficult and yield reductions may occur. In conditions favorable for disease development, and without effective and timely management, Cucurbit Downy Mildew can cause rapid decline of the plant, severe defoliation and ultimately plant death in just the matter of days. Disease development is favored by rainy, humid conditions (relative humidity greater than 85%) and cooler temperatures ( 60°F to 70°F)

Visual foliar symptoms on the upper surface of cucumber leaves, F. Becker.

According to research trials completed in Ohio, Michigan, and other states and provinces around the Great Lakes region, the best fungicide options are as follows: Orondis Opti (FRAC 49+M05), Ranman (FRAC 21), Omega (FRAC 29), Previcur Flex (FRAC 28), and Elumin (FRAC 22). These should be tank mixed with chlorothalanil (Bravo, Equus, etc.) or mancozeb (Dithane, Manzate, etc.). Orondis Opti is a premix already containing chlorothalanil, but at a reduced rate.  Fungicides have restrictions on how much product can be applied and how often, so follow the label, the label is the law. The more effective fungicides should be rotated to avoid resistance development in the pathogen.

Growers in Ohio should also intensify scouting of cucumbers and melons. Look for yellow or tan angular lesions delimited by veins on the top surface of leaves, and fuzzy grey/brown growth on the undersides of the lesions. With a good hand lens or a smartphone camera with high magnification you may be able to see small dark brown/purple spots within the fuzzy growth. These are the spores of the downy mildew pathogen. You can also utilize the Cucurbit Downy Mildew IPM Pipeline website, where you can sign up for alerts notifying you of nearby confirmed Cucurbit Downy Mildew observations.

Microscope view of Cucurbit Downy Mildew, where the individual, lemon-shaped, sporangia can be observed, F. Rotondo.

If you suspect downy mildew in cucumber or melon please submit samples to the C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWE-PPDC) for confirmation. Instructions for sample submission are here. Please contact Dr. Francesca Rotondo at 330-263-3721 or rotondo.11@osu.edu with any questions. You can also work with your county extension educator to get samples submitted to the lab. A major ‘thank you’ to Dr. Rotondo and her staff in the Plant and Pest Diagnostic Clinic for their critically important work! Also, thanks to financial support from the Ohio Produce Growers and Marketers Association’s Ohio Vegetable and Small Fruit Research and Development Program, there is no fee for this service for Ohio vegetable growers. Please find additional information on Cucurbit Downy Mildew here from OSU and Michigan State.

Wayne County IPM Notes from the Week of June 1- June 4

Agronomic Crops

Emerging soybeans in a no-till field.

Corn and soybeans are emerging and beginning to progress through early vegetative stages. Within the next week or so we will begin doing stand counts and encourage you to do the same. We will also keep an eye out for early season insect and pest problems such as slug damage and bean leaf beetle feeding in soybeans as well as slug feeding, cut worm damage and flea beetle activity in field corn.

In alfalfa most of the fields we are scouting are now in regrowth after first cutting. These second cutting fields have very limited pressure from weevil larvae and overall are relatively problem free. In the coming weeks, we need to be alert with regard to the potato leaf hopper. According to the most recent C.O.R.N. newsletter, potato leaf hoppers are now being found in Ohio alfalfa fields. We plan on starting with sweep net counts this week to determine current populations of PLH in our area fields.

Vegetable Crops

Cucumber beetle feeding on the foliage of a summer squash plant.

Insects continue to be the main headline in the vegetable crops in our area. Of greatest concern is the cucumber beetle. The populations continue to increase in number and the efficacy of seed treatments or in-furrow applied insecticide starts to decline 4-6 weeks after the seed germinates or after the insecticide is applied. This means that more of the beetles are feeding without being affected by the insecticide. Be sure to scout cucurbit crops frequently and carefully to get accurate counts of the beetles. The thresholds for cucumber beetles are as follows: Cotyledon stage – .5 beetles per plant, 2-4 leaf stage – 1 beetle per plant, greater than 4 leaves – 3 beetles per plant. Limiting the amount of feeding that cucumber beetles do will also limit the amount of bacterial wilt occurring in these plantings. Do be cognizant of the plants that are in bloom and limit your spraying to a time when it will be least impactful on the pollinators.

 

Colorado potato beetle larva feeding on a potato plant. Tommy Becker photo.

Other insects that were spotted this week include Colorado Potato Beetle larvae and imported cabbage worms. Both of these pests can cause significant damage in their respective crops when left unchecked. Flea beetles also continue to feed on plantings of cole crops, preferring young transplants versus older, more established plantings, although both should be inspected for beetles.

Sweet corn plantings are growing quickly and some plantings that were done into plastic mulch and covered this spring already have a few tassels poking out. Overall, there has been no major concerns in the sweet corn plantings so far, however, do your best to keep up on weed control. Weeds such as bindweed, thistle, and ragweed can not only compete for resources, but can also make harvest difficult and may serve as refuge locations for insect pests to retreat to.

Small Fruit and Orchards

We are beginning to enter a critical period for managing diseases in grapes. This period, which extends from immediate pre-bloom through four to five weeks post bloom, is a critical time to control fruit infections by the pathogens which cause black rot, powdery mildew, and downy mildew. According to the 2021-2022 Midwest Fruit Pest Management Guide, the fruit of the most commonly planted varieties becomes resistant to infection by these diseases by four to five weeks after bloom.

In strawberry plantings we are seeing a lot of green fruit and in some locations, harvest is beginning to ramp up. Overall, there have been very few concerns in the

Blueberries starting to enter the “fruit coloring” stage.

strawberries to this point, with just a few slugs here and there and a spotting of powdery mildew on a few plants. Powdery mildew is managed by spraying either pre-bloom or during the early bloom through bloom stage.

Other small fruit like blueberries and brambles look to have a heavy fruit set this year. Blueberries are beginning to get some color to them, and the blackberry and raspberries are either in bloom or in fruit development.

In apple and peach orchards, the fruit are noticeably starting to increase in size. We are finding some aphids in apple trees, feeding on the leaves and new shoots. In peaches, we did find a few instances of powdery mildew affecting the fruit. Trap counts for OFM and CM were under threshold in all of our traps this week. The counts are down after last week with several orchards above threshold for CM and OFM counts.

Wayne County IPM Notes from the Week of May 17th – May 21st, 2021

Agronomic Crops

Cut alfalfa field in Wayne County.

The weather was very cooperative this week and a lot of forages were cut, and field conditions were right to either get fields ready to plant or start to get seeds in the ground.

In the interest of alfalfa growers, we have been paying close attention to the alfalfa weevil larvae and their development. The weevil larvae are forming cocoons and pupating.  Typically, we only experience a single generation of alfalfa weevil per season, however, given the early development and continuation of above average temperature, there is the chance of seeing a fairly substantial 2nd generation. This is problematic for a few reasons. First off, if we continue to see hot and dry conditions, that in itself will stunt regrowth on cut alfalfa. Additional feeding by young 2nd gen weevil larvae on stressed alfalfa regrowth can either severely delay 2nd cutting or if the infestation is significant enough, total loss of 2nd cutting.  Typically, by this point in the year, we begin to move on from alfalfa weevil scouting and turn our attention to the Potato Leaf Hopper, however, this year we may be dealing with both at the same time.

We are not yet scouting any corn or soybeans; however, we expect that we will begin to see more of those acres planted and have relatively rapid germination due to increasing soil temperatures. A few timely rains can help to push these crops germination as well. Soil temperature and GDD Accumulation

Vegetable Crops

             As we move into warmer temperatures, it would be best to remove row covers from field planted crops in the interest of pollination and reducing heat stress. In crops that do not need pollinated such as cole crops, the row cover can serve as an insect barrier and prevent early infestation from the Imported Cabbageworm. Crops such as summer squash, cucumbers and tomatoes

Flea beetles feeding on a recently transplanted brassica plant.

all need to be uncovered sooner than later to avoid poor pollination and subsequently, poor fruit set.

Hot weather can also be problematic when transplanting into black plastic. The black plastic can become very hot and planting a young, tender transplant into the plastic on a hot, sunny day can cause a significant amount of stress, burns on the leaves and stems and in some cases, death of the transplant. Try to plant in the evenings, as temperatures cool down or on cloudy, cooler days.

Colorado Potato Beetle adults on a potato plant.

In the last week we have seen an explosion of flea beetle in cole crops, and the Colorado potato beetles have begun to make their way into potato plantings. Frequent scouting and monitoring of these insect pests is extremely important. Large populations on young plants can stunt their growth and reduce yields. Conditions have been ideal for rapid population increases, hence the need for frequent scouting. An interesting insect problem we observed was a planting of cole crops where the roots of some plants were being destroyed by ants. In most cases, as you turn on your irrigation lines under plastic, it will drive the ants elsewhere.

Generally speaking, disease pressure has been very low in vegetable crops to this point. We have observed some early blight in a tomato high tunnel, as well as blossom end rot in high tunnel tomatoes.

Small Fruit and Orchards

            Apples and peaches are both reaching fruit development. There was significant growth and change in the size of the fruit over the past week. Out of all of

Strawberry blooms with black centers, damaged by freezing temperatures, alongside healthy blooms.

the orchard traps that we have out, we caught 1 OFM and 1 CM. We began to find aphids in apple orchards. The feeding was evident by curling leaves and shoots.

Blueberries are in petal fall and are setting fruit. Raspberries are getting ready to bloom and overall seem to be coming along just fine.

 

Grape bud that had been damaged due to freezing temperatures now showing secondary growth. Tommy Becker photo.

Strawberry varieties that were early to bloom, and left uncovered, likely suffered heavy bloom loss due to the freezing temperatures that we experienced. Some early blooming varieties had very few, if any, healthy looking blooms. Many plants have put on new blooms, which are very easy to distinguish from the frosted blooms. Early varieties of plasticulutre strawberries that were covered and protected from the cold are setting fruit and beginning to ripen and may even be in harvest. We are not finding any thrips at this time. Unfortunately, we are finding a lot of slugs in strawberry plants and on the berries.

Currently, grapes are now past the bud burst stage, as most are at the 4-8” shoot stage.  We are beginning to see where grape buds that had been damaged due to freezing temperatures are putting out secondary buds and shoot growth, which is very promising.

Wayne County IPM Notes, May 3-7, 2021

Agronomic Crops

Mycelial growth on the crown of an alfalfa plant due to infection by Sclerotinia Crown Rot.

Generally speaking, the crop that we are most interested in at this point of the year is alfalfa. The corn and soybeans may have been planted, and in some areas, may be starting to emerge. The main concern in alfalfa in terms of insect pests is the alfalfa weevil. This year, it is especially problematic due to increased GDD accumulation. The early warm temperatures pushed us to about two weeks ahead of where we were last year in terms of our accumulated heat units. This is reflected in the progression of the alfalfa weevil, not only in size, but in number. Most fields were not over threshold, but certainly showed weevil damage and the weevils that were feeding ranged from 1st to 3rd instar.

While scouting alfalfa fields, its important to inspect the entire plant. The prolonged cool and wet weather that we have been experiencing has been perfect for development of Sclerotinia crown and stem rot in alfalfa and clover fields. It can be easy to confuse this disease as winter kill, but further inspection of the plant, especially near the crown can reveal white, mycelial, cotton like growth. You may also find sclerotia in or on the stems and crown. Once the weather warms up and fields dry out, this disease will likely stop progressing, and some infected stands may recover and produce sufficient yields in subsequent years. Keep in mind that those sclerotia will remain in the soil for many years waiting for perfect conditions to start the disease cycle again.

Vegetable Crops

            With the cold temperatures extending into our early growing season many growers with high tunnels are using heat sources such as wood burners and gas stoves to keep their high tunnels warm. If you are doing this, please make sure your vents are clear and that all of the exhaust, fumes and smoke are making their way out of the tunnel. Double check to make sure chimney pipes are snug and the joints are not loose. Plants, especially tomatoes, are very sensitive to ethylene gas, a by-product of burning and when the smoke or fumes from the stoves are making it back into the tunnel, the plants are exposed to the ethylene for prolonged periods of time. Plants exposed to ethylene will show signs of epinasty, or a downward spiral of shoots and curling leaves, as well as blossom abortion.

Epinasty in tomato due to ethylene exposure.

Other than vegetables in high tunnels, some cole crops and lettuce are planted. Onions and fall planted garlic are also handling this cool wet weather with relative ease. As a word of caution, wet soils and cold temperatures do not equate to great growing conditions for both transplants and direct seeded crops. Some crops handle it much better than others. For crops like summer squash, peppers, and tomatoes, it would be wise to hold off for a bit longer be fore attempting to get them in the ground.

Small Fruit and Orchards

            Apples are at petal fall. Peaches are at petal fall and, in some cases, shuck split. No CM or OFM concerns at this point in the orchards. We did observe some frost or freeze damage on some apple blossoms, but there are more than enough healthy blossoms to cover any loss from the freeze that occurred.

Blueberries are in full bloom and have no concerns at this time.

 

Strawberry bloom with a dark center. The dark center is the dead part of the bloom that would grow into the berry.

Strawberry varieties that were early to bloom, and left uncovered, likely suffered heavy bloom loss due to the freezing temperatures that we experienced. Some early blooming varieties had very few, if any, healthy looking blooms. They will still put on new blooms, but do not expect large yields from early season strawberries.

Grapes also experienced some damage due to the cold temperatures. Currently, grapes are around the bud burst stage. Some buds that were exposed to the cold have died; others look damaged. In another week or so, we will be better able to tell the extent of the damage that occurred to the grapes.

Storage of Fall Fruit and Vegetable Crops After Harvest

As the growing season comes to a close and crops are harvested this fall, many growers may look at storing some crops to sell throughout the winter and early spring. Some commonly stored vegetables include potatoes, onions, and garlic. Most of the stored fruit crops, in terms of long-term storage, is focused on apples and pears. Proper care and storage of these products can provide additional income throughout the winter months when other crops are unable to be locally grown and sold. These storage practices may be useful for those just simply looking to store crops for home use as well.

Delving into the practice of storing vegetable crops, to start out, you want to make sure that you are only attempting to store what would be considered “firsts” or products of the highest quality grade. Products that have blemishes or defects are not suitable for long term storage. Attempting to work some of the “seconds” into your stored products can be risky and may result in a higher loss of product during the storage process. Some other pointers before putting away crops over winter include finding varieties that are better suited for winter storage, planting the crops so that at the end of the season you are harvesting the crops in their prime (which is when they will store best), and having an area where you can provide suitable conditions for storage of the desired crops. Another important step in the process is called curing. Curing is a process that allows the skin to become more durable which helps to extend shelf life. Potatoes cured at 60-70 degrees F for 4-5 days can be kept for 4-5 months. Onions need cured for approximately 2 weeks, where they need to be spread out and dried until the outer skin becomes papery and dry. Garlic is cured in a very similar manner as onions. Winter Squash and sweet potatoes that are cured for 10-14 days at 75-80 degrees F can be stored for several months.

Appropriate storage conditions are another major factor of being able to keep vegetables long term. Potatoes are best kept at between 40-50 degrees F with higher humidity and no light. Large temperature fluctuations or too much light can induce sprouting. Sweet potatoes also store best in higher humidity, and with temperatures between 45 and 60. Pumpkins and squash store better in low humidity environments. Garlic is stored best at temperatures near 35-40 degrees F and with low humidity and no light. Onions storage temperatures are recommended at around 35 degrees F with moderate humidity. These areas also need to be well ventilated to prevent excess moisture from building up and to provide the area with “clean”, fresh air. Storage areas should not only be set up to allow for good airflow, but they should also be set up in a way to allow you to inspect the crops at various times throughout the winter. It is important to watch the stored crops closely and remove any decaying products as soon as possible. The longer a decaying fruit or vegetable is allowed to be there, the higher the risk of others being affected.

Apple and pear storage is not too different from vegetable storage. They too need to be harvested at the correct time to prevent them from becoming over ripe in storage. Too, they need to be in a cool and well-ventilated space with no light. The ventilation also prevents the buildup of ethylene, which helps to slow down the ripening process. Ethylene increases the speed at which the fruit ripens.  It is important to note that these storage spaces should not drop below freezing. Freezing temperatures followed by above freezing temperatures will damage fruit and vegetables and make long term storage nearly impossible. Apples and pears also need checked to make sure that there is no fruit going bad. The saying goes “one rotten apple spoils the whole barrel” and that is true for both fruits and vegetables. When fruits and vegetables are harvested at the correct time and given good storage conditions, they can be enjoyed many months after the growing season has wrapped up.

Soil Management in Specialty Crops

Specialty crops, such as fruits and vegetables, require special considerations in terms of soil management and fertility. As the growing season winds down and more crops are harvested, you may feel as though you have nothing left to do except wait to start it all over again in the spring. Soil that is continuously cropped with fruit and vegetable crops can become depleted of key nutrients rather quickly and, now is the best time to work on addressing issues that you may have with your soil. Additionally, addressing issues with your soil may even resolve other issues such as disease and weed pressure.

An important aspect of determining whether you have areas that need addressed or even how to address them is to take soil samples. Soil sampling is the most direct way to understand what is going on in your soil. Most soil test will give you the results for the macro nutrients phosphorus and potash, which are used in the highest amounts by the plants. They will also usually include the secondary nutrients calcium and magnesium, that are used to a lesser degree. Soil test results may also show you your soil pH, organic matter percentage and the cation exchange capacity. All of these factors are important in making a decision on your soil fertility and soil management strategies.

Before diving into any of the topics surrounding soil management and soil fertility after a growing season, it is first important to understand the basics of nutrient uptake by the plant. The roots are the main pathway in which nutrients are transported into the plant. In order for this to occur, the nutrients must be in a form in which they are mobile. The nutrients are mobile in the soil when they are broken down or dissolved into the soil solution, at which point, the roots are able to take them in and move them throughout the plant.

The process of a nutrient breaking down or being dissolved in the soil solution takes time. That is one of the major reasons to address soil fertility concerns in the fall. Being able to apply certain nutrients, such as potassium, in the fall and allowing them all winter to break down and become available to the plant is optimal. Certain nutrients like nitrogen, you can apply right before planting, as nitrogen is available to the plant for uptake rather quickly after application. Regardless of whether you are addressing soil fertility issues in the fall or the spring, it is important that you do so with careful consideration for nutrient loss. Nitrogen is a very mobile nutrient and can be lost through several pathways fairly easily. It is also of your best interest to make soil amendments based on a recent soil test report. How else would you know what to apply or how much? Knowing what your soils already have and how to make them better will not only prevent over application that could lead to nutrient runoff, it will also save you money. Over buying and over applying nutrients is doing nothing but pouring money down the drain.

Another important factor of your soil management decisions should be based on your soil pH. Each crop type will have a more specific optimal pH, however, in general a pH between 6.0 and 7.0 is recommended for most crops. Being able to maintain an appropriate pH level will also help to influence plant growth due to optimal nutrient uptake. At a pH of approximately 6.2-7.3, nutrient availability is at its highest. With a pH any lower or higher than this range, nutrient availability sharply declines. So even if you were applying the correct amount of nutrients or over applying because the plants weren’t responding to the fertilization, having a pH outside of the optimal range is likely preventing the nutrients from becoming available for plant uptake.

Soil fertility is one of the biggest factors that influence crop yield. Foliar feeding has its place with specialty crops; however, it should not be relied on to address issues with crops that are due to poor soil nutrient management. Excessive foliar feeding, especially with nutrients that are not mobile in the plant, is costing you money that you are not getting a return on. If you are having issues year after year that you are associating with soil fertility issues, address the issues in the soil. Remember that the roots are specifically there to take up water and nutrients. Not only will improved soil fertility help with crop yields, it will also improve overall plant health. A healthy plant is a strong plant, and a strong plant stands up better to disease and insect pressure.

Take the time this fall to take soil samples. Work with your local co-op or soil lab and address the nutrient concerns in your soil. Your soil is worth your time and investment. You should put in the effort to take care of the soil and consider even improving it and leaving it in a better condition for future generations. I heard it said once that despite all of our accomplishments, we owe our existence to a six-inch layer of topsoil and the fact that it rains. Take care of your soil and it will take care of you.

Wayne County IPM Notes from September 20-26

Wayne County IPM Notes

(From the Week of September 20 – September 26)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

Aphids feeding on pumpkin leaves. F. Becker photo.

Cucurbit growers need to check their crops for infestations of aphids. Large populations of aphids can be found feeding on the underside of leaves. While the feeding on the foliage is not of major concern at this point in the growing season, the exudate from the aphids is. Aphids secrete a sticky substance known as honeydew and when large amounts of the honeydew are being formed, it can drip down onto the pumpkins and result in black sooty mold growing on the fruit.

Continue to keep watch over late season cole crops as there are still a lot of imported cabbageworm adult butterflies in and around crops such as broccoli, cabbage, brussels sprouts, and cauliflower. Additionally, other fall insect pests such as the cabbage looper and aphids can become problematic. Aphids can have rampant infestations during cooler and dry weather.  Therefore, routine scouting, especially at this time of year, is important to effective pest detection and management.

Imported cabbageworm larva feeding on cole crop leaves. F. Becker photo.

Fruit and Vegetable Diseases

Residue management of fruit and vegetable crops is an important component of integrated disease management. Typically, at the end of the season, plants are commonly being affected by a range of diseases. As management of these diseases dwindles towards the end of the season, there is an increased level of inoculum that may be able to over winter. Many of the pathogens affecting the plants now are able to over winter and result in disease challenges again next year. It is important to know what diseases you have in your fields. This knowledge can help you make crop management decisions such as how long to rotate out of a certain crop. Additionally, the residue that is left at the end of the season should either be composted or tilled into the soil as soon as possible. Composting or incorporating the crop residue allows for the plant to be broken down by soil microorganisms and prevents the spread of the pathogen to other plants that may be alternative hosts that could overwinter the pathogen. Doing this in association with crop rotation will help give time for the pathogens to die off. Typical crop rotations allow for 3-

A field that has been cleared of plant debris, run through with a disc and then planted with cover crops. F. Becker photo.

4 years between planting a crop in the same family.

Fruit Pests

Stink bugs are still active and can be found along wood-lines and field edges. Although, numbers do seem to be dropping as the summer comes to an end. I am still finding the occasional fruit that has been damaged by a stink bug. The damage is typically occurring in trees along the edges of orchard blocks, especially near wooded areas.

Wayne County IPM Notes from September 13 – September 19

Wayne County IPM Notes

(From the Week of September 13 – September 19)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

Large masses of cucumber beetles on pumpkin plants late in the season. F. Becker photo.

Cucumber beetles continue to have high populations in pumpkin fields. The spotted cucumber beetle, which is also the southern corn rootworm adult, are migrating in masses out of corn fields as corn silks dry down and finding their way into pumpkin fields. So long as the beetles are not chewing on the skin of the pumpkin, they are not anything to be concerned about, however, once they start damaging the skin of the fall vine crops, an insecticide application may be warranted.

Scouting your latest plantings of cole crops is recommended to make sure that cabbageworms do not get out of hand. It can be easy to let your guard down as the season winds down, but if you want to have a marketable crop, you need to keep an eye out for the imported cabbageworms doing damage.

Vegetable Diseases

Peppers, at this point in the season should be winding down, however, disease pressure can force a premature end

Anthracnose lesions on a bell pepper. F. Becker photo.

to the season quite rapidly. One disease that can cause a rapid decline in peppers is anthracnose. At this point in the season, it is not worth the investment in any fungicide applications. For future planning, practice a three-year crop rotation with crops that are not in the Solanaceae family and consider doing seed disinfestation before planting. This disease can be managed with fungicides; however, it is important to address the issue of the origin of the diseases, rather than trying to fix the issue by applying a rescue fungicide every year.

At this point in the season, it is of your best interest to consider the cost of any fungicide application in respect to how much more you expect to get out of a crop. With pumpkins, for example, as the plants are beginning to die off at this point in the season, it is not likely that any fungicide application will be effective or result in any increase of yield or crop value. For a crop like cole crops that are just a few weeks in the ground, then you may have opportunity to apply fungicides, should the need arise. As always, follow the label and pay close attention to the pre-harvest interval when applying a fungicide.

Fruit Pests

Stink bugs are still active and can be found along wood-lines and field edges. I am still finding the occasional fruit that has been damaged by a stink bug. The damage is typically occurring in trees along the edges of orchard blocks, especially near wooded areas.

Fruit Diseases

Apples are now ripening and being harvested in orchards around Wayne County. F. Becker photo.

As fruit continues to ripen and be harvested, we continue to move forward through the growing season without many disease issues in our area. If you are doing any final treatments for fruit diseases, pay close attention to the PHI on the product label. The pre-harvest interval determines how long after you applied that product that you may harvest the crop. This is especially important to pay attention to as many varieties of orchard crops as well as grapes are maturing and nearing harvest.

Wayne County IPM Notes from September 6 – 12

Wayne County IPM Notes

(From the Week of September 6 – September 12)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

After seeing the adult butterflies flying amongst cabbage, kale, and broccoli plantings for the past week or so, I am now finding imported cabbageworms feeding on these plants. Scouting your latest plantings of cole crops is recommended to make sure that these worms do not get out of hand. It can be easy to let your guard down as the season winds down, but if you want to have a marketable crop, you need to keep an eye out for the imported cabbageworms doing damage.

Corn earworm numbers continue to increase in our traps in Wayne County, as well as across the state. Since late planted sweet corn has green silks and is an attractive crop for the moths to lay their eggs on, we typically see an increase in moths this time of year in, or near, sweet corn plantings. This time of year, field corn may be responsible for the large increase in moths, as the lack of green silks leads them to find alternative sites to lay their eggs.

Vegetable Diseases

            At this point in the season, it is of your best interest to consider the cost of any fungicide application in respect to how much more you expect to get out of a crop. With pumpkins, for example, as the plants are beginning to die off at this point in the season, it is not likely that any fungicide application will be effective or result in any increase of yield or crop value. For a crop like cole crops that are just a few weeks in the ground, then you may have opportunity to apply fungicides, should the need arise. As always, follow the label and pay close attention to the pre-harvest interval when applying a fungicide.

Fruit Pests

All of the traps out for codling moth and oriental fruit moth continue to decline, and in some cases are dropping to no moths being found in the traps.

Stink bugs are still active and can be found along wood-lines and field edges. I am still finding the occasional fruit that has been damaged by a stink bug. The damage is typically occurring in trees along the edges of orchard blocks, especially near wooded areas.

Fruit Diseases

            As fruit continues to ripen and be harvested, we continue to move forward through the growing season without many disease issues in our area. If you are doing any final treatments for fruit diseases, pay close attention to the PHI on the product label. The pre-harvest interval determines how long after you applied that product that you may harvest the crop. This is especially important to pay attention to as many varieties of orchard crops as well as grapes are maturing and nearing harvest.

Wayne County IPM Notes for August 30 – September 5

Wayne County IPM Notes

(From the Week of August 30 – September 5)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

Various sizes of stink bug nymphs in the leaf litter of fall vine crops. F. Becker photo.

With daytime high temperatures becoming cooler, we are starting to see more and more activity from the squash bugs. If you are actively harvesting your fall vine crops, the squash bugs may not be of concern to you. However, if you are not yet harvesting or choosing to leave your fall vine crops out in the field, the squash bugs can and will do damage to the skin of the pumpkins and gourds. The best time to scout your fields to look for squash bugs is early in the morning or into the evening when they are not in direct sunlight. More on squash bug management.

Cucumber beetles have made a late season come back, much to the dismay of many fall vine crop growers. The cucumber beetles, this late in the season, tend to do very little damage to the foliage of the plants. What they do go for is the fruit instead. Beetles will damage the skins of pumpkins and gourds. This leaves the pumpkins and gourds as less desirable crops and also opens them up to infection and secondary insect pests that would otherwise not affect the fruit.

Late season damage being done by cucumber beetles. F. Becker photo.

Stink bugs are out and doing damage to crops such as tomatoes. The stink bugs activity and feeding starts to increase most noticeably from late July through August and they remain active through the end of the growing season. Their damage on green tomatoes may appear as small, whiteish areas. On ripe tomatoes, the damage shows up as a golden yellow “starburst” pattern. While this damage is typically only cosmetic, higher amounts of feeding can result in infection and result in the fruit being unmarketable.

Vegetable Diseases

Plectosporium blight on pumpkin can cause significant crop losses. The disease typically presents itself as diamond shaped lesions on the stems and can also affect the veins on the leaves, although it can infect all parts of the plant. The lesions start out small but can quickly cover the entire stem. This disease has started to show up within the last few weeks in Ohio due to the favorable conditions of rain, and cooler temperatures.

Plectosporium blight lesions on a pumpkin stem. F. Becker photo.

A common thing to see in pumpkin fields as plants are maturing is yellowing leaves and the leaves starting to die back. Although there may be diseases such as powdery mildew present in the field, this rapid deterioration is not likely solely the result of the disease pressure and rather the natural senescence of the plant. As the plant matures and the pumpkins and gourds begin to cure, the plant has essentially reached the end of its life cycle. The leaves begin to change from dark green to a pale green/yellowish color and will eventually begin to die back. So long as this is happening at the end of the season and the pumpkins and gourds are mature, there should be no concern.

Fruit Pests

Spotted wing drosophila have been active in small fruits for some time, but with peaches now being harvested, the SWD can and will target the peaches as well. I have found peaches that have SWD larva feeding just under the skin. SWD can also do damage to grapes. I have started to find berries in grape clusters that were soft or looked poorly. Just under the skin of these grapes I found SWD larva feeding and moving around. Many grapes are ripening and getting close to harvest so anyone with grapes should consider treating for SWD.

Stink bugs can also do a lot of damage to fruit crops this time of year. I have set out traps and they are already showing very active stink bug populations. I am also finding damage from stink bugs in orchard crops. Most of the damage I am finding has been occurring in apples. This damage appears as a discolored depression in the skin with corking of the flesh all the way up to the skin. This damage can occur anywhere on the apple, although it can be frequently found on the “shoulder” of the fruit.

Fruit Diseases

Overall, disease pressure has been fairly limited this year. Hot and dry conditions have prevented favorable conditions needed for disease development. As fruit continues to ripen and be harvested, we continue to move forward through the growing season without many disease issues in our area. If you are doing any final treatments for fruit diseases, pay close attention to the PHI on the product label. The pre-harvest interval determines how long after you applied that product that you may harvest the crop. This is especially important to pay attention to as many varieties of orchard crops as well as grapes are maturing and nearing harvest.

Apple that has cracked and split after a heavy rain following drought conditions. F. Becker photo.

After this recent round of heavy rain and subsequent heat and high humidity, apple growers should be aware that some apples may crack or split while still on the tree. We are fortunate that we were beginning to have some more frequent rains that were starting to alleviate drought conditions, and this prevented rapid uptake from the trees. Typically, when a heavy rain occurs after prolonged dry spells or during drought conditions, there is large amounts of moisture taken up through the roots as well as absorbed through the skin of the fruit. This results in rapid cell expansion and thus cracking, and splitting occurs.