Avoiding Problems Associated with Too Much of a Good Thing

Just like folks who wish for rain or look for irrigation during dry times, growers experiencing more than optimal rainfall look for ways to handle soggy conditions.

Rain is obviously good but too much of it can be a huge headache or worse. While rainfall in some areas has been just about right in recent weeks, rainfall in other pockets of Ohio vegetable production has become troublesome lately.

Open field growers can prepare only so much for excess rain, especially when it falls in large amounts over short periods of time. However, predictions indicate that doing what is possible to prepare for deluges will be useful. Five steps familiar to most experienced growers because they always support positive production outcomes – not just during wet periods or seasons — can help.

1. Use a set of varieties ranging in maturity and seed/transplant multiple times (stagger plantings). This helps manage workloads, blanket market opportunities, and distribute risk since individual plantings will be at different stages in development when dry, wet, or other unwelcome conditions occur and, therefore, possibly be less affected by them.
2. Select naturally well-draining fields whenever possible. Fields that tend to hold moisture may be a blessing during dry periods but a problem during wetter ones. Assuming irrigation is available, naturally well-draining fields are likely to be more reliable across seasons.
3. Improve and maintain the site’s drainage, i.e., its capacity to withstand and “process” excess rain. Grade, tile, and employ rotations and soil management and production practices proven to limit the site’s potential to flood and for saturated conditions to persist.
4. Use appropriate crop-specific tactics to manage beds or hills from the start of each production cycle. Potato, Cucurbit, and other crops are often in direct contact with the soil. So, they can benefit from hills and beds being set and managed as if flooding is a real possibility.
5. Prepare for harvest in advance. Advanced preparation can help ensure it will be possible to harvest sooner than expected, if possible and needed.

Mid-Late Season Check of Fertilizer Programs: Are They Right?

Four Rs are the cornerstones of successful fertilizer application: the Right Material, applied at the Right Time, in the Right Amount, and to the Right Place. In the last several weeks, troubleshooting with growers and others about under-performing squash, sweet corn, tomato, and watermelon crops led us to conclude that incorrect fertilizer application rates were probably to blame. The information available suggested that too little fertilizer had been applied to the squash and sweet corn while too much had been applied to the tomato and watermelon plantings.

Ohio growers produce many different vegetable crops, each with a farm-specific fertilizer program that is best or most “right” for them. Very important, those fertilizer needs are set by the biology of each crop and its growing conditions and market. Crops, growing conditions, and markets are diverse, and that calls for setting and monitoring fertilizer applications very carefully; material, timing, rate, and placement must be optimal to have the best chance of success.

Errors at each step in the application process from selecting the rate to applying the material can lead to under- or over-applying fertilizer. For example, target rates can be miscalculated. Hoppers and injection tanks can be under- or overloaded. Gears, valves, and other equipment can be poorly calibrated or malfunctioning. Applicators/spreaders can be driven over too much or too little ground. Irrigation and/or injection valves can be closed when they were supposed to be open or vice versa.

Overall, some appear to worry less about applying too much instead of too little fertilizer. Their desire to maximize yield and quality is understandable. That said, the consequences of significantly over-applying fertilizer should also be considered since they may be wider ranging and last longer. Applying too much fertilizer in one season can create the problems of under-application in that season (lost yield, quality, and income) while also complicating fertilizer programs in the following season(s), supporting unwanted changes in soil chemistry, and contributing to other issues. Benefit the most from investments in properly selected fertilizers by applying them at the right rates and times and to the right place.

Crop Vigor and Weed Pressure

The middle of the main season can be a pivotal stage in crop-weed relations. Weed growth may begin to overcome steps taken earlier to control it, including herbicide application and cultivation. Also, pre-harvest intervals or plant-back restrictions, concerns over potential crop damage, and other factors may limit the use of additional chemical or mechanical tactics like applied before crops emerged and closed rows. Further, weed seed produced mid-late season can increase weed control challenges in following years. Under these circumstances, vigorous crops able to slow weed growth for even a short time can be beneficial. Creating shade and utilizing water and nutrients are two ways vigorous crops can tip the crop-weed competition in the grower’s favor. The vigor and “out-grow/out-compete the weeds” factor may be most important for crops for which cultivation and herbicide options are relatively limited. The two pictures below partially illustrate the crop vigor-developing weed pressure relationship as it stands in a potato planting before the potato vines fall, the canopy opens, and vines eventually decline or senesce. A large, vigorous crop canopy as a product of the variety and good growing conditions and supportive management is its own type of weed suppression.

“Can I …?”, “What about …?”: Farmers Improving Their and Other Farms through Research

The season for field days, crop walks, twilight tours, tailgate chats, blog posts, phone calls from the field, and other ways to share and receive input is underway, and the goal is always the same – learn, and improve farm operations in some way. On-farm research contributes much to that learning and improvement process. That message has been driven home to my team and me many times through our years of working closely with vegetable growers in designing, completing, and summarizing and sharing findings from on-farm research they and we completed. The same message was also highlighted in a recent conversation among farmers, researchers, and educators (view/listen at https://www.youtube.com/@OSU-organic).

For background, the OSU Organic Food and Farming and Education and Research Program (https://offer.osu.edu/home) hosts monthly online discussions focused on recent, on-going, or future research pertinent to Ohio organic production. Participants include farmers, researchers, and educators and many comments also inform and are informed by experiences with conventional production. Recordings of the meetings are available at the YouTube channel URL above.

The conversation on July 7 featured a presentation by Stefan Gailans from Practical Farmers of Iowa (PFI). Stefan leads PFI’s Cooperators’ Program (https://practicalfarmers.org/programs/farmer-led-research/cooperators-program/), where he helps farmers turn their research ideas into relevant and shareable knowledge. Information from Stefan’s presentation is below but taking in the entire presentation and follow-up discussion is encouraged (see https://www.youtube.com/watch?v=DpVAdWGG0w0).

1. PFI (https://practicalfarmers.org/), OEFFA (https://grow.oeffa.org/), and OPGMA (https://www.opgma.org/) have similar goals.

2. The PFI Cooperators’ Program helps farmers learn from each other through farmer-led on-farm investigation and information sharing.

3. The PFI Cooperators’ Program is a community of curious, creative farmers including scientific methods in how they improve their farms. Their investigations (e.g., paired trials) inform their decisions. The process involves putting ideas and farm practices to the test using simple but effective scientific methods. Intentional observation focused on what the farmer is keen to learn about and important to them is the foundation of the process.

4. Many questions are often straightforward “A versus B” or “yes versus no” types. Investigating them often leads to a-ha moments and other more complicated questions. A-ha moments can also reveal that some (new) practices reduce other costs, providing indirect but real benefits.

5. Asking “Can I …?” or “What about …?” and completing an investigation relies on curiosity, creativity, and commitment because extra work is required. Farmers receive a small stipend through program sponsors.

6. Farmer participants can discover that on-farm research helps them “train their eye” and look for or pay attention to other things then ask questions about them. They also become better able to evaluate other peoples’ research and its findings, allowing them to select and use information from industry, university, and other sources more effectively.

Comment from a PFI Cooperators’ Program participant.

7. The program is not all about only the investigations. Much effort is also put in to ensuring that lessons and findings reach other farmers through programs, publications, and YouTube videos offered on an ongoing basis.

8. About the 2022 research program –

(a) seventy-five trials were led by forty-five farmers.

(b) Most farmers had at least eleven years of farming experience and most of them took part primarily to improve their production.

(c) 88% of trials spurred new ideas or other observations. Seventy-six percent of participants reported a moderate to very large change in knowledge after completing a trial. Fifty-four percent of participants reported they will make a change on their farm following their trial but 22% said they would not make a change. Both outcomes are productive because they represent learning and increased confidence in decision-making.

It is never too late or early to start investigating a question important to you using on-farm research. If needed, consider connecting with another farmer, member of industry, or research-extension person familiar with the process.

Optimize Potato Seeding Depth and Hill Management for Your Varieties, Soils, and Markets

As a potato grower, the number, size, shape, and color of the tubers you dig at harvest affect your income. These four characteristics are influenced by how deep seed tubers or pieces were placed at planting and the width and height of the hill created and maintained from planting to crop maturity. This article provides examples of how seed depth and hill size and shape affect tuber yield and quality. Given these examples and other information, growers may wish to evaluate their variety-specific seed placement and hilling operations, particularly because stolon or tuber initiation is underway in many area potato plantings.

1. The plant genetics factor. Tubers form at the tips of stolons which arise from the stem(s) developing from the seed piece or tuber. Most stolons extend from points on stems above the seed piece/tuber, although stolon tips may reach below it. Similarly, the number of stolons most likely to develop on a plant and, therefore, its tuber yield potential, tends to differ among varieties. Once initiated, stolon length can vary with growing conditions, leading hills to hold few to many generally tightly or loosely bunched tubers. Carefully hand-digging young plants to examine their stolons and newly initiated tubers and completing test digs at various stages of tuber development is very informative. The combination of stolon number and length and growing conditions shapes tuber characteristics. Optimal planting depths and hill conditions maximize tuber yield and quality. Proper hilling increases the volume of soil available for light-free tuber development and can assist with weed control.

2. The soils factor. Regardless of seed depth, stems and young plants must develop before stolons and tubers can, so promoting rapid, high, and uniform emergence is key. Warm, loose/friable soil with the optimal level of moisture promotes grower-friendly stand establishment, a foundation for large, high-quality crops. Of course, what is required to maintain those soil conditions planting through stand establishment and tuber initiation and development differs by soil type (especially texture), at minimum. Indeed, research and experience have shown that optimizing seeding depths and hilling operations requires adjusting them for coarse-to-fine textured soils and varieties used in specific fresh and processing markets. Reviewing reliable resources and completing on-farm tests will help determine the seeding depths and timing, intensity (e.g., amount of foliage buried), and number of hilling operations that are optimal for your operation, given the major soil-variety/market combinations you work with.

3. The market factor. Individual fresh (tablestock) and processing (e.g., potato chip) markets require tubers with many specific characteristics. Tuber number, color (greening), shape, size distribution, and specific gravity are among the market traits that can be influenced by seed depth and hilling operations — i.e., seed depth and hilling as they interact with and are influenced by soil and other conditions. Taken together, plant genetic, soil, and market factors explain why planting depths and hilling regimes should be tailored to the operation and adjusted within and across seasons as varieties, as soils and markets require. Currently, potato seed in Ohio and the region is often placed 4-8 inches deep in single-row hills which are reshaped once or twice after emergence while vines remain mostly upright. Approximately 20-30 percent of the visible foliage or rosette is buried at each hilling. Burying a large percentage of foliage at any time or hilling after vines “flop” and begin to close rows can be damaging. Similarly, hilling under conditions that may promote compaction or interfere with further vine or tuber development is also counterproductive.

Electrical Weed Control in Vegetables and Field Crops

This article is provided by Chris Galbraith, MSU/OSU Extension & Jenna Falor, MSU Extension.

Late-season weed management is essential to consider when developing a weed control plan for your operation. Despite one’s best efforts, weeds can often escape early-season control. This can be a result of poor timing, missing the plants with cultivation, spray applications or flaming, or due to herbicide resistance. If allowed to reach reproductive maturity, escaped weeds can cause management problems in future years due to replenishment of the weed seedbank. These larger weeds can also harbor crop pests and diseases, interfere with harvest by obstructing equipment, or degrade final crop quality through contamination from weed residues.

Management practices for escaped weeds are notoriously limited due to the difficulty of controlling weeds when they have reached a significant size. Weed wipers use an applicator made of an absorbent material, such as sponge or a rope wick, that is saturated with herbicide and used to contact weeds growing above the crop canopy, killing the weeds but leaving the crop unaffected. The downsides of this method include a lack of herbicide options effective on larger weeds, limited efficacy on herbicide-resistant populations (depending on what product is being applied), and its unsuitability for use in organic systems. Another option is sending in hand weeding crews to manually weed the fields, which is particularly common for managing escaped weeds in vegetable production. While this method does tend to be effective, the labor is expensive, time-consuming, and hard monotonous work for employees.

The major manufacturer and supplier of electrical weeding equipment in the United States is The Weed Zapper, a Missouri-based company that began production in 2017. Electrical weed control technology has also been developed by the Brazilian company Zasso and the European companies AgXtend, Rootwave, and Crop.Zone. While electrical weeders from foreign companies are as of yet rare in the U.S., familiarizing oneself with the technology that has been developed overseas shows the versatility of this technology in different cropping systems and gives a clue as to the future of the equipment in modern agriculture.

Pro-environmental attributes of the equipment are that it does not disturb the soil and does not require the use of any chemical herbicides. Electrical weeding provides systemic control of even larger plants, making it an effective option for controlling weed seed bank inputs by terminating weeds at or prior to reproductive maturity. Similar to mechanical weeding and certain herbicides, it is non-selective and therefore caution must be taken to prevent crop injury. This typically restricts in-season use to crops with low-canopy growth habits that don’t come into the path of the electrode. While this limits the application of electrical weeding, there still remains many crops where growers might benefit from integrating this equipment into their weed control plan.

Read the full article “Electrical Weed Control in Vegetables and Field Crops”.

View the factsheet “Basics of Electrical Weed Control”.

Impacts of Drought on Vegetable Production and Potential Solutions

Much-needed rain on Sunday has given agricultural producers some reprieve from the “flash-drought” that has been building across Ohio over the past few weeks. Ohio has seen abnormally-dry to moderate-drought conditions across much of the state, according to the U.S. Drought Monitor. The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) has activated its Rapid Response Team to address the dry weather and provide extension resources for agricultural communities, including commercial vegetable producers. More information can be found at the OSU Early Drought Response webpage.

Periods of drought have plagued humanity since agriculture began. In modern vegetable production systems, dry conditions can lead to issues at multiple levels. This article will unpack the impacts of drought on vegetable production and discuss possible solutions.


Crop moisture stress

Crops vary widely in their water use efficiency (WUE), i.e. the amount of carbon produced per unit of water taken up by the plant. Many grain crops have been specifically bred for high WUE to maintain productivity in dryland systems. Vegetable crops, on the other hand, have comparatively low WUE and are typically irrigated via drip tape or center-pivot. Due to their higher water needs in “normal” seasons, many vegetable growers are already set up for irrigation and so may not be witnessing as severe crop moisture stress as field crop growers who rely on the rain.

Heat stress

In addition to the lack of rain, temperatures in northwest Ohio climbed into the high 80s near the end of May. High temps can threaten young plants in other ways apart from increased water demand. When crops are transplanted into black plastic mulch they can be stressed by heat radiating off the mulch surface. Young plants can also be burnt if any plant tissue is contacting the black plastic, which may be common if soil moisture levels are below wilting point. Transplanting into wet soil, overhead irrigation, or applying kaolin clay to plastic mulch surfaces to temporarily increase sunlight reflection can help keep temperatures around the plant cool and conducive to crop health.

Dry weather pests

Hot, dry weather in the spring can lead to earlier and increased activity in plant pests like thrips, aphids, and spider mites. These insects thrive in warm and dry conditions, which is why infestations in greenhouse environments are common. Insect feeding can reduce crop yield and quality and the pests can also vector viruses that affect vegetable plants.

Outbreaks of thrips, aphids, and spider mites can be managed in part by supporting natural enemies of the pests. These include ladybeetles (adult and larvae), lacewing larvae, and minute pirate bugs. Aphids are also preyed upon by damsel bugs, assassin bugs, aphid predatory midges and several predatory wasps. Species of predatory thrips and mites can also help keep pest thrip and spider mite populations in check. Find information on identifying natural enemies in this guide from OSU Extension and this educational video from Dr. Mary Gardiner at OSU.

Insecticide/miticide recommendations can be found in the 2023 Midwest Vegetable Production Guide. Avoid broad-spectrum products to conserve natural enemy and pollinator populations in the field. Read more on the topic in this article from Zsofia Szendrei at Michigan State University.


















Pests that prefer hot, dry conditions: aphids (top), thrips (middle), and spider mites (bottom). Photos by University of Illinois Extension (top), Ontario Ministry of Agriculture, Food and Rural Affairs (middle) and Mississippi State University Extension (bottom).

Weed control

Drought conditions also have implications for early-season weed control. With low moisture in the topsoil, weed emergence may be delayed and prolonged. Applying layby residual herbicides is important to keep weeds under control until canopy closure. Weeds that are heat/drought stressed also do not respond to postemergent spray applications as well as vigorous weeds. Plant leaves develop a thicker, waxier cuticle to minimize water loss which can also reduce herbicide absorption. Adjuvant usage may be needed to improve conditions for herbicide uptake. Weed growth and metabolism is also slowed, which reduces movement of systemic herbicides around the plant. Spraying in the morning can be advantageous for weed control, not only because of calm winds, but also because targeting plants at a time of day when they are the least heat stressed can improve performance of systemic herbicides. Read more on this topic in this recent article from Erin Burns and Christy Sprague at Michigan State University.

Wildlife damage

 Wildlife damage to crops can be worsened in hot, dry weather. Rodents and other vertebrates may increase feeding in vegetable fields when food and water is scarce elsewhere. Irrigation equipment may be damaged by wildlife (coyotes, mice, etc.) looking for a drink. Options for keeping away wildlife include netting, fencing, repellants, trapping, and other lethal/non-lethal deterrents. Resources include the Ohio DNR Nuisance Animal Control Manual and Wildlife Management Factsheets from the USDA/Michigan State University Extension.

Farm safety

Last but not least, the safety and well-being of agricultural workers is important to keep front of mind. Working in hot and dry conditions poses a risk of heat-related illnesses. Continuous hydration and proper attire can go a long way towards ensuring worker safety. Find more information on the major heat-related illnesses and their mitigation in this article from Penn State.

Dealing with drought-stressed crops and dusty fields can also take a toll on growers’ mental health. Ohio State University Extension offers resources to help handle farm stress. Farm worker/manager performance is dependent on good mental health, so be sure to take this aspect of your vegetable operation seriously.

To sum it up, hot and dry conditions impact multiple aspects of vegetable production. While the material here mainly addresses the consequences of a dry spring, drought can cause different issues depending on when in the growing season it occurs. OSU Extension is a resource to help vegetable growers through periods of drought by providing information and support. Please reach out to your county educator or a vegetable extension specialist to explore ways OSU Extension can help you make your vegetable operation more resilient to drought conditions.

Thank you to Ben Werling and Ben Phillips from Michigan State University Extension for observations and ideas that contributed to the writing of this article.

Chris Galbraith

Vegetable Extension Educator

Northwest Ohio
Ohio State University Extension
Office: 734-240-3178

Six Factors to Consider Given the Dry Season So Far

Although some areas of Ohio have received small but timely amounts of rainfall, the general lack of it across the state to this point in the season has become a concern, especially where dryland, non-irrigated crops are stake. As one example, according to one weather station at the OSU campus in Wooster, rainfall for the period May 15, 2023 – June 10, 2023 was the lowest on record for the same period since 1999 and roughly half the amount received during the same period in the previous driest year. Not surprisingly, stand establishment in a non-irrigated potato planting made on May 15 at the research station in Wooster has been much lower and slower than normal.

On the other hand, overall conditions for many irrigated crops have been acceptable, minus the damaging early season frosts and windstorms. Temperatures have been moderate for the most part, so damage due to the lack of rain has not been significantly compounded by problems associated with high temperatures. Also, a lack of rain can maximize the amount of time available to complete other work — although many would gladly trade some time for rain.

Indeed, dry conditions to date have interfered with crop establishment and development and other aspects of production, particularly where irrigation is not being applied. So, we welcome forecasts including a high probability of meaningful rainfall.

This article references six items to consider if rainfall begins to “even out” in terms of timing and amount.

1. Continued crop thirst. Irrigation tends to be beneficial in all but the wettest years. Even short periods of low water stress can damage crops. Therefore, those who have been irrigating or begin to irrigate may need to continue the practice until harvest, in accordance with rainfall amounts and other factors, per usual.

2. Nutrient availability. Dry fertilizers applied before, at, and/or soon after planting may begin to solubilize more completely, boosting nutrient availability. In-season applications may need to be adjusted to account for this increased availability, although later than planned. Consider in-season soil, tissue, and/or sap testing to assist in the process.

3. Weed control, particularly as affected by herbicide activity. Dr. Lynn Sosnoskie of Cornell University summarized this issue well in the June 7 edition of the Cornell Cooperative Extension VegEdge Newsletter. Contact Dr. Sosnoskie (lms438@cornell.edu), the Cornell Vegetable Program (cce-cvp@cornell.edu), or me (Matt Kleinhenz; kleinhenz.1@osu.edu) for a copy of the article, which summarizes factors to consider for weed control during extended dry periods and should rains resume.

4. Crop protection, especially disease. Soil moisture, nutrient availability, and weed growth may increase if rains begin and so may disease pressure. Crop protectants, application schedules, and other tactics may need to be adjusted to account for increases in leaf wetness periods, relative humidity, and, perhaps, disease inoculum levels.

5. Soil erosion. Ideally, this dry period will be broken by grower-friendly light rains capable of providing the most benefit with the least trouble. However, soil erosion is possible if rains are brief and heavy and fall on uncovered, unprotected soils. If possible, use the dry period to check, improve, and explore drainage systems and soil management tactics.

6. Crop growth and harvest readiness. The best-laid plans set before the season call for seeding and transplanting to occur on farm-specific schedules, partly to meet harvest timing and market goals. Following through on those plans is difficult under dry conditions since they slow growth and alter maturation schedules. For example, for fruiting vegetable crops, a rule of thumb has been that drought before flowering speeds maturation while drought after flowering can slow it. Regardless, early-season dry conditions followed by more normal rainfall patterns can complicate maturation timelines across plantings (early, mid, late) and variety maturities. So, monitoring and flexibility remain important.

Growers, Grafters, Researchers, and Extension Partner in Identifying Best Management Practices for Grafted Vegetable Plants – Watermelon in Ohio in 2023

Many growers know that grafting gives them access to much needed disease resistance – stronger resistance to some diseases than available in hybrids and more resistances than often found in them, too. Indeed, a quick scan of rootstock characteristics at http://www.vegetablegrafting.org/resources/rootstock-tables/ reveals that few commercial hybrid varieties of tomato or watermelon include some resistances found in rootstocks. However, the greater cost of grafted plants has many people asking how growers’ profits can be maximized when using them. Lowering costs and boosting yield and quality are key parts of the answer.

Best Management Practices (BMPs) are “how-to” guides used in commercial crop production. BMPs are developed over years of collaboration involving many people since they involve optimizing every aspect of individual production systems from site and variety selection through post-harvest handling, packaging, and delivery. Current vegetable BMPs are based on the use of nongrafted plants. However, grafted plants tend to be more vigorous than and different from nongrafted ones in other ways. More important, perhaps because of these differences, grower and researcher experience with grafted vegetable plants indicates that farm BMPs must be updated to lower the costs and maximize the grower profits associated with using grafted plants. Optimizing plant density (number of plants per acre based on in- and between-row spacing), and irrigation, fertility, and harvest management for many scion-rootstock combinations has become the focus of much on-farm and on-station research.

Four Ohio farms, The OSU North Central Agricultural Research Station (https://oardc.osu.edu/facility/north-central-agricultural-research-station), and OSUE will evaluate the effects of plant density using four scion-rootstock combinations in 2023. Drawing on previous work (e.g., https://u.osu.edu/vegnetnews/2021/08/21/grafted-watermelon-plants-under-what-conditions-and-practices-does-using-them-offer-the-best-return-on-investment/), plants provided by Tri-Hishtil of Mills River, NC (https://www.trihishtil.com/) will be set at a range of in- and between-row spacings affecting potential grower costs and, possibly, fruit maturation, yield, and/or quality. Within and across sites, the total plant population is expected to equal roughly 450 – 1,450 plants per acre in individual plots. The team is intrigued by the possibility that yield and quality will remain high in some treatments/plots although many fewer plants, rows, and various inputs will have been used.

We would like to hear from you if you have questions about making and/or using grafted vegetable plants or information on the topic. Please contact Matt Kleinhenz (kleinhenz.1@osu.edu; 330.263.3810).

Successful Production Begins with the Best Varieties: An Example from Potato Breeding

If you grow potatoes for profit, chances are you rely on varieties developed by a university-USDA-industry team dedicated to improving your success by improving the varieties available to you. This article outlines aspects of that process and The OSU’s participation in it in 2023, as in more than fifty previous years.

The overwhelming majority of potato varieties used in Ohio and the U.S. are developed by university- and USDA-based programs and teams. These teams are led by breeders-geneticists and include plant pathologists, entomologists, food scientists, horticulturalists, and others working closely with growers, grower organizations, processors, retailers, seed certification programs, and members of industry and government. The small number of teams in the U.S. are based in major production regions, e.g., Northwest North-central, and East, allowing them to develop varieties best suited to these regions. The OSU has cooperated with the Eastern team with breeding programs in Maine, New York, and North Carolina and partners in other states for more than fifty years (see https://neproject.medius.re/ and potato reports at https://u.osu.edu/vegprolab/technical-reports/). The OSU also collaborated with the North-central team with breeding programs in Michigan, Wisconsin, Minnesota, and North Dakota for more than forty years. Regardless of team, working from industry and consumer input, our goal has been to improve marketable yield regardless of production constraints (e.g., disease, nematode, abiotic stress), tuber quality (including sensory properties and nutritional value), crop use of natural resources (e.g., water, fertilizer) and other characteristics. Efforts completed here continue to benefit growers, processors, retailers, chefs, consumers, and others in Ohio and throughout the Eastern U.S.

Potatoes are clonally propagated – i.e., tubers are clones of their mother plant. This means that increasing the availability of seed for a new superior variety can be more straightforward than in crops requiring true botanical seed. However, in its early stages, potato breeding requires creating and evaluating experimental lines resulting from ‘hybridizing’ crosses, e.g., as in tomato variety development. Many crosses are unproductive while others result in experimental lines worthy of additional evaluation under a wide range of conditions. That is when a network of collaborating evaluators operating in various environments where the experimental line/new variety could be grown commercially becomes essential.

In 2023, The OSU will evaluate 126 experimental selections against 12 standard varieties. As before, selections from the University of Maine, Cornell University, USDA-ARS in Maine, and North Carolina State University will be featured and our evaluation process will focus on the interests of growers, processors, retailers, chefs, and consumers. Plots are located at the OSU-Wooster/OARDC and can be viewed anytime. If possible, please contact Matt Kleinhenz ahead of time so he can welcome you properly and help you benefit fully from the tour (kleinhenz.1@osu.edu, 330.263.3810). Also, seed is available to growers who wish to evaluate experimental selections on their farms.

A subset of the information that will be collected for each experimental line through November-2023 is listed below.

Before Harvest
1. Percent stand (# seed pieces planted versus number of plants established)
2. Plant maturity
3. Tuber bulking period
After Harvest
4. Total yield
5. Percent tubers greater and less than 2 inch in diameter
6. Percent of tubers that are misshapen or have a similar market defect
7. Basic tuber characteristics (9 options for each of the following six characteristics – 531,441 possible combinations!): a) skin color, b) skin texture, c) shape, d) flesh color, e) eye depth, and f) uniformity
8. Tuber internal quality (incidence of defects)
9. Specific gravity
10. Chip quality (color, blister), including as chipped directly after harvest or storage (with or without reconditioning). Chip-stock production in Ohio is mainly for situations in which crops are chipped directly after harvest with no storage period.

Regardless of market, on all but a small set of operations, potato vines are removed before harvest either mechanically (quickly) or chemically (slowly). How vines are removed is important to growers and all members of the potato value chain. They all want tubers well suited to a specific end use; however, some varieties may respond less desirably to quick, mechanical vine killing, especially if vines have not died naturally or are not actively senescing. Applying a desiccant that kills the vines slowly and promotes tuber skin set and stolon detachment is most common. However, some growers may choose or be required to harvest crops “green,” when vines have not died or have been chopped very recently, a typical approach to mechanical vine killing. Importantly, vine killing methodology can affect the condition of the tubers at harvest and after, during processing, storage, shipment, and preparation. Killing vines quickly and harvesting soon after can influence various tuber properties including: a) stolon attachment, b) skin integrity/scuffing, c) physical damage, d) relative abundance of starch versus reducing sugars, e) incidence of bruises, and f) storability. Buyer and grower tolerances for these issues can be low so identifying lines capable of being harvested “green” and used effectively can be important. Of course, some consumers prefer small “new” tubers with very thin skins so these crops must be handled carefully. Similarly, growers and processors are also keen to discover the optimal storage conditions for experimental lines and new varieties and the extent to which their tubers must be “reconditioned” before use as referenced in https://www.potatogrower.com/2019/03/top-5-factors-to-successful. Through the years, once popular processing varieties were displaced by new ones with less stringent storage-reconditioning requirements, a discovery made during collaborative testing by variety development teams and industry.

As always, the 126 experimental lines will also be evaluated for their resistances to multiple diseases, nematodes, and insect pests by other team members in Maine, New York, Pennsylvania, Virginia, North Carolina, and Florida. Cooking and consumer evaluation tests will be completed.

Information that will be collected before and after harvest is key because plant and tuber characteristics and yield strongly help determine the main end use and market for which a variety is best suited: a) general fresh market, b) specialty fresh market, c) processing (e.g., chip), or d) fresh-processing dual purpose. Of course, this also means the same variety profile also determines which farms and farmers will benefit most from using a new variety. Production for chip and direct-retail markets has increased in Ohio in recent years.

As shown earlier (see https://u.osu.edu/vegnetnews/2023/03/11/how-will-your-yield-and-efficiency-increase-this-season/), U.S. potato yields have climbed steadily for more than a century. This increase is due to better varieties and crop management. Regardless of your market, if potatoes are part of your business, it can be essential to watch for and test new varieties since they provide the greatest reward for your high-level skill as a grower. As much as possible, take advantage of that skill by using superior varieties instead of relying on it to overcome weaknesses of inferior ones. Future related articles will provide information specific to obtaining seed for new or “alternative” varieties that may benefit your business.