Foliar Feeding of Vegetable Crops: An Overview of Why, Why Not, and What to Consider

The number of vegetable growers who are either curious about foliar feeding or using the practice routinely has risen in recent years. Foliar feeding has become a major component of the crop management plans of some vegetable growers while other people are concerned that too many growers rely too heavily on the practice. Let’s review some basic information specific to the process to improve decision-making about it.

1. It is true that plants can absorb nutrients through their leaves. However, it is also true that absorption differs with leaf age and condition, among individual nutrients, and based on other factors. Overall, young leaves tend to take-in nutrients more readily than older ones but are also more easily damaged by caustic solutions. Also, while micronutrients are absorbed at higher rates than macronutrients, micronutrients are present at sufficient levels in most complete soil-applied fertilizers or can be added to them effectively. Similarly, nutrients must reach specific locations in the plant regardless of where they enter it and may be less likely to do so at needed levels after entering through leaves instead of roots. Finally, nutrients entering through leaves and moving within the plant does not guarantee that the application will affect it in ways increasing profit. So, consider the following when asking what role, if any, foliar feeding will have in your comprehensive nutrient management plan: a) relative need for various nutrients, and b) nutrient absorption/uptake rates, mobility, effects once in the plant based on where they enter, and availability in different fertilizers.

2. Proponents of foliar feeding mention that it can: a) be highly tailored, b) bypass soil-based issues, c) lessen the potential for leaching or other losses, and d) create quick responses that may boost crop quality and/or reduce or help plants recover from stress. However, it is also important to consider major concerns with foliar feeding as a primary, routine practice, including how it: a) can damage leaves and fruits, create nutrient imbalances, facilitate the onset and/or progression of foliar disease, and contribute to runoff, b) usually has only short-term effects (requiring repeated use), c) should be done during specific environmental conditions which may not occur during large portions of the season, and d) requires great care to balance risks/rewards and costs.

Therefore, on balance, it is best to:
1. Consider “foliar feeding” as a supplement to, NOT a replacement for a comprehensive nutrient management program in which nearly all fertilizer is applied to the root zone. Strengthening root zone-based delivery programs will address the clear majority of nutrient management questions and challenges. Focus on specific and unique situations in which foliar applications MAY be useful instead of utilizing them as a rule or standard practice.

2. Be clear about the challenges associated with foliar feeding as a routine practice and experiment with it carefully. Select the key crop and crop stage and use the right material, at the right rate, and at the right time (under the required conditions), being sure to check solution chemistry and monitor crop condition.

For Additional Reading:

https://ipm.missouri.edu/mpg/2019/4/foliarFeeding/

https://s3.wp.wsu.edu/uploads/sites/403/2015/03/foliar-feeding.pdf

https://crops.extension.iastate.edu/blog/aaron-saeugling/foliar-feed-or-not

Blotchy Ripening of Tomato Fruit: Description, Contributing Factors, and Prevention

Marketable yield is more important than total yield. Physiological disorders like ‘blotchy ripening’ typically do not affect total yield but do reduce marketable yield, which reduces income and profit potential.

Description
Blotchy ripening refers to one or more conditions specific to the external and/or internal color of tomato fruit. Ideally, the skin and flesh color of mature tomato fruit are uniform throughout, with red being most common. Fruit exhibiting blotchy ripening have discolored sections. For example, defected fruits are mostly red on the outside but contain areas that are green, yellow, gray, or paler red than the remainder of the fruit, such as shown in the picture. Blemished areas may be more common on the half of the fruit nearest the stem. The flesh, especially vasculature, of fruit exhibiting blotchy ripening may be brown or broken down.

Symptoms associated with blotchy ripening have underlying physiological, or disease or insect feeding causes. Symptoms can be mild and in only a small number of fruit or severe and/or in many fruit. Regardless, it is important to note that fruit are said to exhibit blotchy ripening only when they are also in the mid-late stages of ripening as determined by changes in firmness and other variables and when insect (e.g., whitefly) and disease (e.g., TMV) are ruled out as causal agents. These two criteria separate truly ‘blotchy’ ripened fruit from firm, immature fruit in the early stages of ripening (which can be mottled in color inside and out) and fruit damaged by the action of pathogens and/or insects. Blotchy ripening is a physiological disorder.

Blotchy ripening has been discussed as a potentially significant marketable yield issue in research and extension publications for nearly ninety years. Seaton and Gray of the Michigan Agricultural Research Station reported on their analysis of the anatomy of blotchy-ripened fruit in 1936. Also, after touring commercial and research farms throughout the U.S., Minges and Sadik of Cornell University published a protocol for evaluating blotchy ripening in 1964 (https://journals.flvc.org/fshs/article/view/100632/96587). These landmark works provided much needed insight on blotchy ripening, and they were followed by other steps that helped identify factors that contribute to the disorder.

Contributing Factors and Prevention

1. Genetics
Immature tomato fruit are green and photosynthetic. Later however, the set of pigments found in fruit of most hybrids shifts and red becomes the dominant color.

This shift is pre-programmed but influenced by conditions surrounding the fruit and within the plant and soil. The first and one of the most reliable steps in minimizing blotchy ripening is selecting varieties known to display it very infrequently – i.e., among few crops year to year and among few fruit within a season.

Hybrid tomato varieties are the culmination of huge, coordinated efforts requiring in-depth knowledge of tomato genes. Nearly 100 years ago, these genes were found to include a natural mutation that led individual fruit to ripen uniformly red, today’s most common standard. Decades of development of varieties whose fruit turn red over their entire surface and throughout their flesh at precisely the right time relative to other variables related to market-readiness have followed. However, the natural condition of NON-uniform reddening remains in the tomato genome and it shows itself most readily in certain varieties. As a category, heirloom varieties may display the blotchy ripening disorder most consistently. As an early step in avoiding blotchy ripening, consult reliable reports on variety performance in your area and select varieties that exhibit the problem rarely, if at all.

2. Environmental Conditions, including Air Temperature, Soil Status, and Nutrient Levels

A variety’s genes may predispose it to physiological disorders like blotchy ripening but this weakness can be minimized or masked with luck and proper management. Factors contributing to the development of physiological disorders like blotchy ripening can be difficult or take a long time to determine because they are difficult to induce experimentally. That said, research and experience have shown that blotchy ripening is most prevalent when air temperatures during mid-late stages of fruit ripening are extreme (e.g., below 60 deg F and/or above 90 deg F) or highly variable, when humidity levels remain high, and/or when these conditions are common and light levels are low. Low soil quality and high salinity are also associated with the occurrence of blotchy ripening.

Most also agree that severe cases of blotchy ripening are most often associated with factors that limit the supply of potassium (especially) and to a lesser extent, magnesium, to maturing fruit. These factors include: waterlogged and/or compacted soils, below-optimal potassium or magnesium application rates, above-optimal nitrogen application rates, excessive application of potassium and magnesium competitors, excessively large or dense canopies, and the environmental conditions mentioned previously.

Potassium supplies may be restricted for different reasons. So, do not over-compensate when evaluating and adjusting irrigation and nutrient management practices. Articles written by Gordon Johnson (University of Delaware), Jerry Brust (University of Maryland), and others are excellent overviews of blotchy ripening and its management. All point to limiting blotchy ripening and similar disorders through careful nutrient and water management, considering soil, plant, and fruit factors in the process.

Limiting the Occurrence and Severity of Blotchy Ripening in Tomato
A. Select resistant varieties.

B. Minimize large temperature swings and extreme high temperatures during fruit development and ripening.

C. Ensure adequate and balanced nutrient levels, paying special attention to potassium and magnesium and their competitors or factors that limit their availability.

D. Maintain consistent and appropriate soil moisture levels.

E. Maintain or improve biological, chemical, and physical characteristics of soils allowing them to support maximum root and plant health.

First Report of Cucurbit Downy Mildew in Ohio 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.

Prune Fresh Market Tomatoes (field, high tunnel): Yes or No?

Growers and others continue to discuss and ask questions about the pros and cons of pruning fresh market tomato plants in field and high tunnel plantings. Some growers expect to prune and plan for the process while others decide long before planting that they will not prune. For others, the decision is less clear. Regardless, genetic, market, and other factors affect the decision.

Major Factors Affecting the Decision to Prune
1. Variety type (determinate, semi-determinate, indeterminate). Overall, determinate varieties require the least amount of pruning and indeterminate varieties the greatest amount with semi-determinate varieties potentially benefitting from a moderate amount. Whether grafted plants are used, and the effects of the rootstock can also influence if the grower may benefit from pruning them.
2. Variety-specific characteristics. Varieties within each major type differ in how they respond to pruning. Consult reliable sources and use experience to determine if and how much each variety being grown should be pruned.
3. Market price and expectations. Typical market prices and expectations of fruit quality may steer growers to prune or to not prune individual varieties and/or plantings.
4. Pruning process requirements (e.g., time, cost, expertise, materials). Pruning is recommended for some varieties and in some situations. However, if pruning is done incorrectly (wrong time, wrong method), it can result in undesirable outcomes.

Potential benefits and drawbacks associated with pruning field- or high tunnel-grown fresh market tomato plants.

Potential Benefits
• Can enhance earliness
• Can increase fruit quality (e.g., size, shape)
• Can reduce some disease pressure
• Can enhance coverage of protective sprays
Potential Drawbacks
• Adds cost (time, labor) and requires care
• Can spread disease
• Can reduce fruit quality
• Timing is key (crop stage and when foliage is dry)

Fresh market tomato plantings in Ohio differ significantly in size, market, growing environment (field, high tunnel), production system (e.g., organic, not organic), varieties used, and other characteristics. A small-scale test comparing pruned and unpruned plots will help reveal if your current approach is ideal.

For More Information

1. http://www.hort.cornell.edu/expo/proceedings/2015/high-tunnels/BMPs%20Proper%20pruning%20and%20training.pdf
2. http://www.hort.cornell.edu/expo/proceedings/2017/HighTunnel.cherrytomatopruning.ivy.17.pdf
3. https://extension.uga.edu/publications/detail.html?number=B1312&title=commercial-tomato-production-handbook
4. https://extension.okstate.edu/fact-sheets/print-publications/hla/commercial-production-of-fresh-market-tomatoes-hla-6019.pdf
5. https://mwveguide.org/uploads/pdfs/2024-MW-Veg-Guide-full-draft-20231219.pdf
6. https://www.vegetables.bayer.com/au/en-au/resources/growing-tips/agronomic-spotlights/fresh-market-tomato-pruning.html

High Tunnel Crop and Market Period Diversity

High tunnel use is very popular and has been increasing in Ohio and many other states for decades. Growers are now asking new questions partly because high tunnel production is so popular and increasing and has been practiced for so long on some farms, creating new challenges and opportunities.

“How can I utilize my high tunnel(s) more effectively year-round or fall through spring?” is one very frequently asked question. Many agree that spring-fall tomato harvests can offer the greatest revenue or profit potential. However, others have shown or are learning that harvesting other crops from their high tunnel(s) during summer and/or fall through spring can also be lucrative and beneficial in other ways. Many examples of this have been shared in recent Extension and other programs in Ohio and neighboring states. Working with multiple crops across more of or the entire year requires being familiar with conditions affecting their growth, quality, and potential costs of production and market (profit) potential. Labor and other input costs and how one figures costs of production are obvious factors. For example, one grower-speaker at a recent conference recently described high tunnel space on their farm as “rented,” meaning that their costs of production include how much time is required for a crop to be market-ready. This approach (calculation) directs them and, possibly, others: a) to include lower-cost, quicker-cycling, high value crops in their systems, and b) to be selective when devoting space to high value crops demanding more space, time, and labor. For some, producing multiple crops, managing their investments in crops prone to boom-bust supply-price cycles, and accessing markets through most of or the entire is key to their business. They describe how the approach can limit risk and increase opportunity.

As described in our Feb-3 VegNet article, we seeded Mokum carrot, Red Russian kale, Oriole Swiss chard, Red Pac pac choi, and Music garlic in early Oct-2023 and have given them “minimal” care since that time. Our goal was to discover/demonstrate the potential yield and quality of these crops when grown and overwintered in this way, although the kale, Swiss chard, and pac choi were appropriate for some markets in December-January. This approach may interest growers unfamiliar with and/or currently lacking the ability to make large investments in fall through spring production-harvesting. Recent samples taken from the carrot seedings demonstrate that growth is accelerating and roots are likely to be market-ready soon. A large number of other edible and non-edible crops can be overwintered and/or harvested successfully fall-through spring in Ohio.

Please contact Matt Kleinhenz (330.263.3810; kleinhenz.1@osu.edu) for more information.

 

A Minimalist Approach to Ensuring Fall through Spring Vegetable Harvests

Interest in marketing locally-grown, freshly-harvested vegetables fall through spring is strong and increasing among high tunnel growers in the Midwest, Great Lakes, Mid-Atlantic, Mid-South, and Northeast. Scanning the agendas of industry meetings and listening to growers and others in these areas makes clear that fall through spring harvest and marketing of high tunnel-grown crops is an established and increasingly common practice. Importantly, some growers have transitioned to cash cropping their high tunnels only fall through spring and leaving summer to grow cover crops and focus on other priorities, including field-based production. Conversations with and public presentations by these growers and other experts make clear that fall through spring income from high tunnel production can be significant if the correct crops and varieties are chosen and suitable practices are used.

We have long wondered which crops, varieties, and practices may be ideal for Ohio high tunnel growers looking to harvest fall through spring. Much of our previous research focused on a relatively small number of crops and the use of various tools and practices (e.g., films, fabrics, and/or soil heating). Our goal was to describe potential production outcomes when high tunnel growers invested in the process to various levels. Results from those experiments suggest that yields are likely to be greatest when investments are also highest, for example, when soil heating, plastic films, and row covers and the effort to maximize their utility are used. Those studies were summarized previously in this blog.

We are asking a different question in Winter 2023-2024. As the three panels below describe, seven crops were seeded in two high tunnels in October-2023 and grown without any supplemental heating, films, or row covers. This “minimalist” approach explores the worst-case scenario, the minimum that can be expected from these crops under the conditions they have experienced since seeding. This approach may appeal to growers unfamiliar with fall through spring production and/or those who are unwilling or unable to invest much time, money, or effort in it, at least at this time. The test outlined below is one example of what can be expected but many others exist. Of course, different outcomes may be possible when other varieties, planting dates, and growing practices are used. Upcoming evaluations will push the “minimalist” approach further as all crops capable of being grown and harvested fall through spring do not require a high tunnel. Please contact me (Matt Kleinhenz, 330.263.3810, kleinhenz.1@osu.edu) if you would like more information.

 

Maximize Success with Summertime High Tunnel Crops by Enhancing Soil Conditions Fall to Spring

The April 29, 2023 addition of the OSU Fruit, Vegetable, and Specialty Crop News included a short video summarizing challenges associated with maintaining the productivity of soils in high tunnels (see https://u.osu.edu/vegnetnews/2023/04/29/maintaining-soil-productivity-health-in-high-tunnels-whats-the-problem/). This article focuses on specific examples of those challenges and steps that can be taken to address them from fall to spring.

So, tomato harvest and other chores are complete, and the high tunnel may be taken out of production until next spring. What can be done fall to spring to help maintain or improve high tunnel soil productivity before the next cash crop is established?

First, consider how productivity and profit potential may be lost if nothing is done. Many high tunnels contain tomatoes soon before they are taken out of production in the fall and, chances are, the same high tunnels contained tomatoes for at least one season, if not multiple seasons, before that. Importantly:
a) most core stand establishment, fertilizer/input application, irrigation, and other cultural management practices occur in the same places in the high tunnel each season;
b) fertilizer use can be high;
c) spaces between rows may be covered or uncovered and receive variable amounts of foot and equipment traffic;
d) crops remove major and minor nutrients selectively, in different amounts and ratios; and
e) water lost to evapotranspiration differs by location and depth in the high tunnel.

Combined, these factors can lead to significant variation in soil physical, chemical, and biological characteristics depending on position on the floor (crop row or between) and depth. Crop access to soils with optimal characteristics may be limited. Fertilizer may be present in excess where it does not mineralize. Salt levels may rise where evapotranspiration rates are greatest relative to water supply. Compaction may develop. And, beneficial soil microbial activity may decline or cease due to these conditions and/or a lack of water.

Second, take one or more steps to help correct or limit the development of these and other unwanted soil conditions. For example:

1. Mix soil comprising the footprint of the high tunnel. Move soil past crop row-furrow, if possible, and to below rooting depth. Add organic matter (e.g., green manure, compost) and other key materials (e.g., lime) before or during the process.

2. Consider deep tillage. Past research completed at Penn State Univ suggests that occasional deep tillage in a high tunnel can be beneficial, especially when plow-pans, salt layers, or other symptoms of sub-optimal soil status develop.

3. Regardless of approach, test soil before and after mixing and other interventions, keeping samples separate when submitting them for analysis (e.g., see https://u.osu.edu/vegnetnews/2021/02/20/soil-sampling-and-analysis-for-high-tunnel-production/). Soil test reports from samples taken from the same locations (in and between crop rows) before and after mixing and other steps can be informative.

4. Establish and incorporate a suitable green manure and/or subsoiling cover crop(s) that can perform some of the same functions as machinery and provide many other benefits. Resources for selecting cover crops for high tunnels include: a) https://projects.sare.org/wp-content/uploads/CoverCropsHT-fact-sheet.pdf, b) https://www.sare.org/resources/managing-cover-crops-profitably-3rd-edition/, c) https://www.midwestcovercrops.org/getting-started-correct/, and d) https://mdc.itap.purdue.edu/item.asp?Item_Number=ID-433.

5. Flood the high tunnel slowly. Move water through the profile carefully to dissolve and disperse salts and help mineralize and increase the future availability of remaining fertilizer without contributing to runoff or unwanted leaching. Moist soils may also remain more biologically active, and mix and open pores by freeze-thaw action, providing other benefits. Some of the same benefits of purposeful fallow period irrigation can be achieved by removing the high tunnel cover to allow precipitation and natural freeze-thaw cycles to work for you.

Please contact Matt Kleinhenz (kleinhenz.1@osu.edu; 330.263.3810) with questions or for more information.

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