Wayne County IPM Notes from July 11-15

Agronomic Crops

Our area alfalfa has shown very low activity from potato leaf hoppers. Remember, that the threshold for potato leaf hoppers is determined by the height of the alfalfa. So, for 12” alfalfa, you would need to average 12 potato leaf hoppers per 10 sweeps to be over threshold. Currently, we are averaging between 1-3 potato leaf hoppers per 10 sweeps. The heat dome over the center of the country has limited our number of southern storms, with many systems moving through our area coming out of the northwest.

The path of most of our recent weather systems.

Insect pests are currently the main concern in corn and soy. Soybeans are being impacted by Japanese beetles and young grasshoppers. Corn is seeing some feeding damage from the corn flea beetle and Japanese beetles. In non-Bt corn, we are finding damage from common armyworms and European corn borer. Essentially all of Wayne County remains in a moisture deficit, even after a decent shot of rain on Wednesday.

Vegetable Crops

Probably the biggest development in our area was the presence of cucurbit downy mildew on a path of cucumbers in southern Wayne County. This means there are active infections in Wayne and Medina counties, and likely the surrounding counties. Ideal conditions for continued progression and infection will exist in the coming days. It is important to take steps now to protect your cucumber and cantaloupe plants.

Powdery mildew found on a cucurbit plant in a Wayne County field.

Powdery mildew on cucurbits continued to spread rapidly, spurned on by several foggy mornings in the area.

As early plantings of summer squash and other cucurbits are harvested, it is important to practice good sanitation in the fields. Do not allow these areas to become diseased and insect infested, as they will only lead to problems in other areas on your farm. Once you are done harvesting an area, it is best to terminate the crop and either incorporate or remove the residue. 2

Other disease concerns revolved around bacterial diseases on peppers and tomatoes. We started to find some bacterial spot/speck on these crops.

Insect wise, it was an active week. Cole crops are still facing significant pressure from flea beetles and imported cabbage worm. European corn borer was identified in a few pepper plantings. Cucurbit crops have increased activity from cucumber beetles, squash bug and squash vine borer.

Small Fruit and Orchards

A few diseases like scab and blister spot have started to show up on leaves in apples orchards, otherwise, disease pressure has subsided after some recent fire blight outbreaks. Insect pressure in apples has slowed some as codling presence has remained low, however, some orchards are still facing some persistent feeding from European red mites.

Some of our oriental fruit moth traps showed a significant flight, with some traps averaging nearly 30 moths per trap. Red mites were still active in the peach blocks as well this week.

The season is wrapping up for some of our raspberry growers, and blueberries won’t be far behind. With blackberries now coming into season, it is still important to be aware of the presence of the spotted wing drosophila, which are still being found in most of our traps. Japanese beetles may also be causing some troubles for small fruit grower, especially those with grape vines. We observed significant defoliation from Japanese beetles on grapes in several areas of the county this week.

Wayne County IPM notes from the week of July 4 – July 8

Agronomic Crops

Some much needed rain made its way through our area this week. Unfortunately, the extended forecast shows a return to a dry pattern. Nonetheless, we are thankful for the moisture that gave some relief for drought stressed crops. Insect pressure has become the leading concern in corn and soy. Japanese beetles are out in force and feeding, in some cases heavily. Other insect pressure can be found via feeding from European corn borer larvae, young grasshoppers, and other various foliar feeding pests. Disease pressure at this point is relatively light at this time.

Vegetable Crops

The warm temperatures and accumulated heat units have kept our insect pests active and building in population. Cucumber beetles, squash bugs and squash vine borer were all active this week in squash plantings and fields. Additionally in squash, we noted our first sighting of powdery mildew in an area of first planting summer squash.

The warm and sunny days have also led to some challenges with sun scald. Unfortunately, the heavy winds and rains from the storms had pushed plants over, which allowed for the first set of vegetables, such as peppers or tomatoes, to be exposed to full sun and extreme heat.

Growers with cole crops may still be battling flea beetle and imported cabbage worms. Significant egg laying from the cabbage white butterflies gives us the heads up to scout our cucurbit crops very closely to watch for hatching eggs and early instar larvae.

Generally, the Japanese beetles have begun their entrance into a wide range of vegetable crops. In some cases, isolated feeding damage may severely damage the foliage and stunt young plants. Frequent scouting can help you make timely management decisions, therefore avoiding significant damage from the Japanese beetles.

Small Fruit and Orchards

European red mites were found in apples and peaches this week, and in a few cases, the populations had reached significant levels, with severe feeding damage present on the foliage. As was the case in vegetable crops, the Japanese beetles feeding on orchard trees and small fruit plants started to cause some significant defoliation.

Spotted wing drosophila were found in all of our traps. Accordingly, small fruit growers should be aware that we are now fully into SWD season.

Fire blight in apples has been our main disease concern to this point. We did note a few cases of apple scab on leaves in some orchards around the area.

Overall, fruit development in orchards and small fruit production areas is coming along nicely and should be greatly benefited by the timely rains.

Wayne County IPM Notes Week of June 20-24, 2022

Agronomic Crops

Last week we discussed in our agronomic crop report about moisture stress in crops from too much rain. This week, we have certainly flipped the script as we are dealing with a flash drought. In a recent Crop Observation and Recommendation Network (C.O.R.N.) article by Taylor Dill and Jamie Hampton, it was shared that we can actually calculate at what point we may see damage from the heat and drought stress in our crops. When temperatures exceed 86 degrees, you can calculate those periods as stress degree days. Once corn reaches 140 stress degree days, the chance of reaching above average yields begins to decrease. Dill and Hampton also point out that “Leaf rolling is a common symptom of high-temperature stress. Yield diminishes by 1% for every 12 hours of leaf rolling during vegetative growth but increases to 1% every four (4) hours during silking. When water is deficient during a heat wave the loss of yield increases after four consecutive days of 93°F or above, not including the stress from leaf rolling. So, the impact of heat stress can be two-fold.”

Japanese beetles in field corn, F. Becker, 2022.

Soybeans are in a similar situation, as shared in the article by Dill and Hampton. “Soybeans have a similar range in temperature to corn for heat stress. Temperatures above 85°F for several consecutive days can cause heat stress. This heat can accelerate maturity because soybeans are photoperiod and temperature-controlled when it comes to flowering. During vegetative stages, these high temperatures can slow or stop photosynthesis because the plant is making an effort to conserve water. Thus, inhibiting new vegetative growth, which is vital for late-planted soybeans. Temperatures above 86°F can also reduce nodulation and therefore N-fixation in the soybean which could have an effect until the reproductive stages.”

Japanese beetles were found in agronomic crops this week. Potato leaf hoppers are present in alfalfa; however, our scouting did not find any significant populations.

Vegetable Crops

Now is a critical time to be monitoring your cucurbit crops for cucumber beetles. Early populations may not seem as evident due to the presence of insecticide in treated seed, however, as the efficacy of the seed treatment diminishes, the cucumber beetle feeding will begin to increase. The threshold for beetles while the plants are in the 2-4 leaf stage is 1 beetle per plant. Once the plant is above the 4-leaf stage, the threshold increases to 3 beetles per plant. The greatest chance for impactful feeding damage and bacterial wilt infection via the cucumber beetle occurs during early season feeding.

Squash bug found in Wayne County on yellow squash. Cucumber beetles feeding in the background. F. Becker, 2022.

Also, of note in cucurbits, the excess moisture and warm conditions allowed for development of some phytophthora cases. If you suspect that you have plants infected by this pathogen, avoid spreading it in your fields by removing and destroying infected fruit and plant material. An integrated approach to managing this disease includes practices such as avoiding excess water, sufficient crop rotations and fungicide treated seed. Additional findings in cucurbits included squash bugs being found this week in an early planting of yellow squash.

An area of yellow squash plants lost due to phytophthora, F. Becker, 2022.

Continue to monitor onions for thrips populations. The recent heavy rain may have prevented populations from building, however, hot dry weather, combined with the increased size and number of leaves can provide the opportunity for thrips numbers to escalate rapidly.

In tomatoes our scouts noted some observations of early blight and Septoria.

Remember to check your crops for any signs of foliar diseases, especially with the amount of soil splashing that took place in the last few weeks. Bacterial and fungal diseases can be spread on the lower leaves of plants when heavy rains splash soil and pathogens onto the foliage. Overall, stress from high temperatures has been evident in a majority of the crops that we are scouting.

Small Fruit and Orchards

Male SWD, Thomas Becker photo, 2022

Female SWD, Thomas Becker photo, 2022.

Spotted winged drosophila have been caught in traps around Wayne County. As we move out of strawberry season into raspberries/blackberries/blueberries, the SWD populations will begin to increase leading to possible infestations in ripening brambles and blueberries.

In apples, we continued to find strikes of fire blight. Conditions have been ideal for fire blight development, although dryer conditions may hinder further development. This week we continued to find aphids in apple trees. Our IPM program identified populations of green apple aphids in several orchards as well as a case of wooly apple aphids. Both aphid species can cause significant damage at this time of year. Accordingly, diligent scouting is a crucial aspect to not allowing either of these aphid species from getting out of hand. The heavy rains likely knocked back some of these aphid populations, but it will be important to monitor aphid populations as dry conditions take hold.

We have had sustained catches (over threshold) of both Codling Moth and Oriental Fruit Moth in apple and peach orchards, respectively. Over the last week, both Codling Moth and Oriental Fruit Moth populations have been trending downward, however, numbers have still exceeded the thresholds.

Now is the time to be managing early season diseases in apples. Scab, rust and powdery mildew are the three main diseases of concern at this point in the season.

Once strawberry harvest is over, it is a good time to consider renovation of the patch. the goals in renovation are to reduce plant numbers by narrowing the rows, remove old foliage (reduces diseases), control weeds, and reduce insect pests. After renovation, regular irrigation and weed control are essential. High yields next year depend on having large, healthy, vigorous plants when fruit buds are initiated in late summer

Grapes are currently around the buckshot berry stage. It is still possible to spray for and manage black rot during this time. We have started catching grape berry moth in our traps.

Wayne County IPM Notes From the Week of June 13-17, 2022

Agronomic Crops

We certainly got our fair share of rain the in last few weeks, but we have also seen a significant increase in temperature just in the last week. Given the warmer weather, slugs may feed on young corn and soybean plants at night and early in the morning but will likely retreat to the soil or under crop residue during the day. The black cutworm was still active in corn, although as some of the corn fields we are scouting are approaching V7, the feeding has not been as severe as compared to some fields that are VE through V3. Black cutworms are much less likely to cut plants at the V4 stage and beyond. Many of the soybean fields in the area are beginning to emerge. We are typically seeing plant maturity anywhere from sprouts to VC (unrolled unifoliolate leaves). We are beginning to find some potato leaf hoppers in the alfalfa. Remember that the best way to scout and check for leaf hopper populations is to use a sweep net. The threshold for potato leaf hoppers is based on the alfalfa height in inches and the number of leaf hoppers per 10 sweeps. If you have more leafhoppers in 10 sweeps than the height of the alfalfa, then you are over threshold.

 

Vegetable Crops

The Colorado Potato Beetle larvae have hatched and are now feeding in both potato and eggplant. When approaching plants to look for them, be cautious. When the beetle is startled, they drop to the ground and may be difficult to see. They do significant damage to the foliage and can cause significant reduction in yield. The Colorado Potato Beetle also has a history of developing resistance to insecticides being used as control measures. This has limited our choices for treatment options. The best way to prevent further resistance is to avoid using the same insecticide repeatedly. At the current plant stage for potato, the threshold is approximately 1 beetle per plant. For eggplant, it is 25 beetles per 50 plants.

In summer squash/zucchini, we are seeing an increase in the number of cucumber beetles. The seed treatment on these plants is beginning to wear off. For fall vine crops that have just been planted in the last few weeks, that seed treatment should still have a few weeks of efficacy left.

In onions, we have noticed an increase in the number of thrips, in many cases approaching an action threshold. Threshold is 25-30 thrips per plant. This week we also found more incidences of slippery skin which was confirmed by the vegetable pathology lab at OARDC earlier this month. Slippery skin is caused by Pseudomonas gladioli. This bacterium is spread via soil splashing from heavy rains and enters the plant through natural openings or openings from mechanical injury. Given the heavy rains we have experienced in the past week, it would probably be a good idea to get out and check your onions.

Overall, tomatoes are continuing to grow rapidly in the greater Wayne County area, with some plantings of field tomatoes beginning to set blooms. We did have a case of timber rot identified in the West Salem area in field tomato. It is important to practice good crop rotations and rotate out of a crop family completely for at least 3-4 years. A complete crop rotation will help to break up disease and pest cycles. Similar to onions, tomatoes can contract bacterial diseases from soil splashing. If you have tomatoes, it may be worthwhile checking the lower canopy of your plants to monitor the presence of any diseases.

Our IPM pest scouts have continued to find Mexican bean leaf beetles in the green beans this week. Light foliar feeding was observed.

With the warmer weather and plants maturing rapidly, the slug threat has greatly reduced in the last week. Any new transplants should still be monitored for feeding, however there should be less of a slug presence for the rest of the growing season.

 

Small Fruit and Orchards

This week we continued to find aphids in apple trees. Our IPM program identified populations of green apple aphids in several orchards as well as a case of wooly apple aphids. Both aphid species can cause significant damage at this time of year. Accordingly, diligent scouting is a crucial aspect to not allowing either of these aphid species from getting out of hand. The heavy rains likely knocked back some of these aphid populations, but it will be important to monitor aphid populations as the weather dries out a bit.

In apples, we continued to so find a few instances of fire blight. Conditions have been ideal for fire blight development, so it is not much of a surprise to see some cases.

We have had sustained catches (over threshold) of both Codling Moth and Oriental Fruit Moth in apple and peach orchards, respectively. Over the last week, both Codling Moth and Oriental Fruit Moth populations have been trending downward, however, numbers have still exceeded the action thresholds.

With the storms over the course of the last week, it is not unlikely that we will see some yield loss from wind, heavy rains, or hail damage in many of the area’s fruit trees.

Now is the time to be managing early season diseases in apples. Scab, rust and powdery mildew are the three main diseases of concern at this point in the season.

Strawberry leaf diseases may appear unsightly right now, however, now is not the time to be managing these leaf diseases. Once harvest is done and during patch renovation it is recommended that you address these concerns, either with a fungicide or with resistant plant varieties. This is also a critical time to be watching for fruit rots such as Botrytis.

Grapes are currently around the buckshot berry stage. It is still possible to spray for and manage black rot during this time.

Cold Temperatures Forecasted to Impact Ohio

Managing Fruit Trees and Horticultural Plants During Prolonged Exposure to Subfreezing Temperatures

Having a few 80-degree days in April was a nice relief from winter like temperatures and renewed our hope for summer to arrive as quickly as it can. That kind of weather encouraged rapid progression of our landscape plants, fruit trees and other plant species, which has given us a spectacular show of spring blooms and flowers. The plants responded to the above average number of growing degree days that they accumulated and began their flowering, budding, pushing shoot growth, and beginning progress through developmental stages and reproductive processes. The flowers and buds are the most important part of the plant when we consider fruit production. They are also the most delicate and vulnerable part of the plant. Now we are faced with several nights of forecasted lows in the 20’s. This article may seem familiar, and it is because we had a very similar set up in spring of 2021.

Frost advisories in blue and hazardous weather outlooks in beige, all relating to freezing temperatures. Photo from the Cleveland National Weather Service. 

Regarding the cold temperatures: do what you can to protect your plants tonight. We are under a Frost Advisory for tonight, April 26th. Temperatures will be at or below freezing for roughly 8-9 hours for the next few nights. This is all very concerning due to the cold temperatures following multiple days of abundant heat. Wednesday night and Thursday night low temperatures look to be very concerning. The forecasted lows are 26 and 29, respectively. The clear skies on both nights will provide ample opportunity for extended periods below freezing. Being in the 20’s for 6-8 hours would result in a killing freeze. Tomorrow night is when growers should take more extreme measures to try to protect their trees and plants.
These kinds of weather events can have major implications on Ohio’s agricultural and horticultural crops.
So, what can be done to protect your plants? The challenge here is that our forecasted lows are between 26 – 29 degrees F, with almost 12 hours forecasted to be below freezing and 6-8 hours forecasted to be in the 20’s. This is not just a light frost, but rather a hard freeze. There are a few steps that you can take to try to protect the plants, and some of these steps can be better utilized on a small scale, while others are better utilized on a larger scale.
On a smaller scale, simple actions like covering the plants with a sheet or some kind of fabric can help insulate them. This helps trap some of the warmer air from the ground around the plant and keeps the plant from being directly exposed to the colder air. It may also be of interest to protect the crown of the plant. This freeze may be severe enough to damage the foliage, but you can take steps to protect the crown and the roots by mulching with straw, leaves or wood mulch around the plant to keep the warmer air from the ground around these vital parts of the plant to keep it alive. Basically, anything that you can do to insulate the plant, conserve the heat in the ground, and shield it from the cold air, will be beneficial to the plant and give it a better shot at making it through the night.
Adding a strand of Christmas lights (not LED) under the sheets covering your plants can help add a little extra heat to keep the ambient temperature a little warmer. Make sure that the lights are not touching the covering material and keep the covering material off of the plants. If the covering material is sitting directly on the foliage, that is defeating the purpose of having it there in the first place. Use stakes to keep the sheets or other covering materials just above the foliage. This will prevent the cold temperatures from being conducted onto the plants.
Watering the soil can also keep the immediate area around the plant a few degrees warmer. A wet soil is going to hold heat better than a dry soil. Even a few degrees can make a big difference. With single plants or with small enough shrubs or tree seedlings, an overturned bucket serves the save purpose as the sheets or coverings. Just remember, as soon as the sun comes up the next morning, you will want to remove whatever coverings you have to allow the plant to be exposed to the sunlight and begin to warm back up.
On a larger scale, orchard growers and those with small fruit have big challenges. They are dealing with a lot of plants and trees over a big area. Some orchards use frost fans to try and protect the crop. Frost fans work by utilizing warmer/drier air from the ‘inversion’ layer to create air movement at the fruiting/flowering height in orchards on still cold nights—preventing damage to flowers, soft tissue, and fruit. Some orchards utilize water sprinkler systems to actually create a layer of ice on the trees. The key to using water is to continually use it to form clear ice. Clear ice means that an endothermic reaction is taking place and the warmth of the plant is being trapped inside it. If the ice starts to become cloudy, the plant is losing heat and damage can occur. Spraying water must continue the entire time the freeze event is taking place, and the sprays must keep going from before there is a freeze event that would damage the fruit until the ice is completely melted from the tree after the event. If the water stops spraying on the clear ice, it goes from being endothermic to exothermic, and the heat loss and ice will damage the fruit.
In some cases, burn barrels and smudge pots are placed around an orchard to add heat in the hopes of keeping the temperatures at, or above freezing. Unfortunately, it can take roughly 30-50 heaters per acre to effectively protect the trees. In some cases, if you are working with just a few trees, a strategically placed burn barrel can do the trick. Keep in mind that if you decide to use any type of heater you need to be extremely cautious using them.
Minimizing damage and losses requires knowledge of weather conditions and how to mitigate weather extremes. Just as important is having a knowledge of plant hardiness. Some plants will do just fine with this cold weather. Others may appear to be killed off but may regrow from the roots or the crown, even though the foliage appears dead. The important thing here is to not be over-reactive. Give the plants time to recover. Plants can be remarkably resilient. If you see signs of frost damage, do not prune off the affected parts or dig up the plant immediately. Wait until the weather warms up to see whether new leaves sprout. You may see healthy new growth at the base of the plant, at which point you can prune out the damaged parts.
Hoping for the best and doing nothing will not result in any positive outcomes, so take this opportunity to at least cover the plants that you can and give them a fighting chance to make it through the cold.

Attention Specialty Crop Growers!

Get Started Now On Your Ideas for the …

OHIO SPECIALTY CROP PARTNERS VIRTUAL LISTENING SESSION

March 25, 2022

9:30 – 11:00 a.m. ESTYou have received an invitation to join this quality conversation about CFAES research and Extension support for Ohio Specialty Crops Partners. CFAES will:

  • Provide updates on our priorities, existing support for specialty crops, and actions we are taking related to research and education for specialty crops.
  • Explore emerging trends for specialty crops agriculture in the state.
  • Listen to the industry needs and how CFAES plays a role in the industry.

We’re anxious to get started in this conversation and want to give you time and opportunities to give us your thoughts. If you would like to, please go ahead and get started by answering a few questions for us at this link https://go.osu.edu/listenspecialtycrops .Please plan to attend the virtual session even if you complete this form. We want you to have as many opportunities as possible to provide feedback and have your voice heard. Please send your thoughts back to us no later than March 23.  And don’t forget to register for the virtual session no later than March 24, 2022 at register me now!

Ohio Grape Grower Survey

Attention grape growers! Please consider participating in the Ohio Grape Grower Survey! Contact Dr. Jackson-Smith at Jackson-smith.1@osu.edu or by phone at 330-202-3540 with any questions or to get involved.

The Ohio grape industry produces grapes for wine, juice, and table grape use. Over the last decade, the industry has grown rapidly in our state. Unfortunately, the USDA ceased conducting a regular Ohio grape census five years ago, making it difficult to track this growth or collect accurate information about the number of acres and production by grape variety. To fill this gap, the Ohio Grape Industries Committee has commissioned researchers at The Ohio State University to conduct an independent survey of all Ohio grape growers.

Dr. Douglas Jackson-Smith, a professor in the College of Food, Agricultural, and Environmental Sciences at Ohio State, is leading the survey effort which is designed to reach all Ohio producers who grew wine, juice, or table grapes in 2021. Beginning the third week of January, researchers will send the survey to a comprehensive list of grape growers in the state, with an opportunity to respond through the mail or online.

The survey is voluntary and all responses will be treated as confidential. To get an accurate picture of the size and scope of the current Ohio grape industry, it will be critical to hear back from all producers. Aggregated results will be shared in a report that will be available to farmers, wineries, juice processors, and others to inform their decisions.

 

Sign-Up Info for the 2022 IPM Scouting Season

The enrollment period for the 2022 Wayne County IPM scouting program is now open. Please call the Wayne County OSU Extension Office at 330-264-8722 if you are interested in signing up or for more information about the program. Enrollment forms are being sent in the mail to previous program participants.

More information about the IPM program and details on how to enroll may be found here: 2022 IPM Forms