forages

Wayne County IPM Notes from the Week of August 9 – 13

Agronomic Crops

There was a significant reduction in potato leaf hopper counts this week. This drop is likely due to timely cutting in the fields we scout, along with frequent heavy rains. When wetter weather, or with days that have heavier morning dews occur, potato leafhoppers can diminish quickly due to the entomopathogenic fungi that can cause the population to collapse. When these conditions occur, and populations of potato leafhoppers drop, there is no need to treat.

Field corn is pushing R3-R4, as the silk is now drying down all the way to the kernel and the kernel is filling out and the ears start into maturity. In soybean, pods are developing all of the way up the plant, and pods are starting to fill. As pod fill begins to occur, it is a critical time to be watching for insects like stink bugs that would be damaging the pods and developing seeds.

Vegetable Crops

Squash vine borer damaged plants.

This week brought about many sightings of squash vine borer larva. The adult squash vine borer moths were actively flying and lay eggs about a month ago. We are now seeing plants that are declining in health and when inspected further, are oozing frass and have stems that look shredded. When we split the stem of these plants, in nearly every instance, we found at least one, if not several squash vine borer larvae. Unfortunately, there is nothing that can be done to reverse such severe damage.

A large squash vine borer found feeding in a pumpkin plant.

Flea beetles are feeding on young cabbage and broccoli, and the cabbage worm butterflies are finding their way into these plantings as well. We are starting to see some damage in peppers from the European corn borer and expect the ECB and CEW numbers in the traps to increase in the next week or so.

Small Fruit and Orchards

As apples and peaches are harvested, do not let your guard down on the late season generations of codling moth and oriental fruit moth. This past week was another week of rising codling moth numbers, and consistent oriental fruit moth catches, although the oriental fruit moth numbers have not gone back over threshold.

Grapes damaged by grape berry moth larvae.

Grapes are starting to ripen, and as the season progresses, we are still finding consistent trap catches of grape berry moth. Although it may be too late for some varieties, you may still be able to protect later maturing varieties with a treatment for grape berry moth.

Wayne County IPM Notes from the Week of July 19 – 23

Agronomic Crops

Rapid crop growth and development is a common sight around the area in corn and soybean fields. The majority of corn fields have tasseled

Alfalfa field in bloom.

and are beginning to silk. Soybeans are flowering and pod development is starting to occur.

We are beginning to find some foliar diseases affecting corn fields, as well as the continuation of insect damage from flea beetles, grasshoppers, armyworm, and several other pests. Soybeans are still being fed on by a wide variety of foliar pests. Our focus will start to shift to pod feeding pest, such as stink bugs and bean leaf beetles. Read more on Corn and Soybean management decisions.

Potato leaf hoppers are remaining consistent in population in alfalfa fields. We are seeing populations either at or below threshold. Some fields have cases of leaf spot; however, we are not seeing any fields with any severe infections at this time.

Vegetable Crops

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

The Vegetable Pathology Lab at OARDC has confirmed several more cases of downy mildew, on both cucumbers and cantaloupe. It is important to take steps to either protect your crop or stop the spread of any ongoing infections. Powdery mildew is also spreading rapidly through the area. Although some heavy rains may have slowed its spread, favorable conditions have led to some fields rapidly becoming infected.

Flea beetles feeding on young green cabbage plants.

Bacterial diseases continue to spread in pepper and tomato plantings. Pay close attention to these crops in particular, and make sure that you are taking the necessary precautions so as to not spread bacterial diseases. Bacteria can be spread from plant to plant via clothing, equipment, or animals. More from APS

Flea beetles are feeding heavily on recently planted cole crops, which left uncontrolled can cause stunted and underperforming plants. Another insect we have seen quite a few of is the squash vine borer. Although these are not typically going to harm large numbers of plants, they can still be a nuisance, especially in smaller plantings.

Small Fruit and Orchards

 This week we found our first incidence of scab in apples. While this was only an isolated find on a few leaves, it is a good reminder to take some time to scout your apple trees and look for any signs of scab. Oriental fruit moth numbers were significantly above threshold again this week. Japanese beetles were also

Severe damage from Japanese beetles feeding on the foliage of apple trees.

still feeding heavily in many of the fruit crops we scout. Spotted wing drosophila are still being found in all of our traps, and for anyone with small fruit in the area, it is recommended that you treat for SWD.

Wayne County IPM Notes From the Week of June 14-18

Agronomic Crops

Bindweed wrapping up a corn plant.

The corn planted in our area is really starting to outgrow any early concerns that may have been had regarding insect pressure. The corn is also out growing many of the competing weeds, however, it is still recommended to do what you can to reduce the weed pressure on the corn plants. Soybeans also have seemed to escape most of the insect pressure; however, we are now seeing large areas of heavy feeding from deer and groundhogs.

We noted in our scouting this week on the large amount of 2nd cutting alfalfa coming off. 2nd cutting came and went without many concerns, and very limited pressure from insects. We will continue to scout for potato leaf hoppers, especially on the regrowth after 2nd cutting.

Vegetable Crops

            This growing season, so far, has been all about the bugs. We have not had a huge amount of disease pressure

Squash bug eggs on summer squash.

on the vegetable crops in our area. We have, however, continued to find more insects impacting local crops.

Newly spotted insect pests this week included Japanese Beetles, thrips, and squash bugs. The Japanese Beetles were found in silking sweet corn, the thrips are being found in onions and the squash bugs are being found laying eggs in summer squash plantings.

 

Japanese Beetle found in a sweet corn stand.

In green beans we are still seeing a light population of potato leaf hoppers and a few bean leaf beetles feeding here and there. Cucurbits still have some cucumber beetles feeding, as well as some aphids. Aphids are not picky about which crops they are in, as we continue to find them in a variety of crops, including peppers and tomatoes. Both eggplant and potatoes are dealing with flea beetle and Colorado potato beetle. The Colorado potato beetle larva are becoming very prolific in some areas and causing significant defoliation. Cole crops, while also dealing with pressure from flea beetle, are now seeing an increase in activity from the imported cabbage worm caterpillar.

Small Fruit and Orchards

Aphids and mites are being found in fruit trees, primarily apple trees. This week, we began to find European red mites, green apple aphids and wooly apple aphids. Trap counts for CM in apples and OFM in peaches were all below threshold, with many traps reporting zeros.

The biggest update in our pest outlook in small fruit was not an insect, instead it involved birds. There was bird damage being found in strawberries, as well as in blueberry areas where the berries are starting to color. Some growers are using netting to exclude the birds from blueberry plantings. This is a lot of work but saves a lot of berries from being damaged.

Wayne County IPM Notes From the Week of June 7-11

Agronomic Crops

            Corn and soybeans are both being impacted by slug feeding. In most cases, corn will be able to outgrow the pressure from the slug feeding. Soybeans, however, are much more susceptible to being severely damaged by slug feeding, even to the point of significant crop loss. Slugs are best managed by avoidance and habitat reduction. Slugs thrive in heavy residue fields with minimal tillage disturbance. Later planting dates, when soils start to dry out, along with some tillage or residue management can help to prevent major impacts from slug feeding.

Black cutworm, Matthew Nussbaum photo.

Some corn fields are also being impacted by black cutworms. These caterpillars can do significant damage in young corn stands. We are reaching the end of their feeding activity in our area, but we will continue to monitor for other larva pests. Weed management is also important this time of year in agronomic crops. Being able to knock the weeds back until we start to get some canopy closure can help prevent the weeds from competing with corn or soybean plants for water, nutrients, and sunlight.

Alfalfa fields are showing good regrowth with minimal pressure from diseases or insect pests. There are some concerns with increasing aphid populations, along with the arrival of the potato leaf hoppers.

Vegetable Crops

            The insect pressure on the area vegetable crops has continued without much fluctuation.  In summary, the Colorado potato beetle larvae, along with flea beetles, continue to feed on potatoes, tomatoes and eggplant, we began to find tortoise-shell beetle feeding on the leaves of sweet potatoes, thrips are starting to feed in onions, aphids are continuing to feed in many crops, including peppers and tomatoes, slugs are feeding on sweetcorn, as are cutworms, cucumber beetles are all over cucurbit crops, and potato

Golden Tortoise Beetle on Sweet Potato.

leaf hoppers and bean leaf beetles have started to build population in green beans.

The warm and wet weather has led to some disease concerns, especially in lettuce. We have started to find heads of lettuce being affected by white mold. It is best to remove these heads of lettuce from the field to prevent further infection and soil infestation.

Small Fruit and Orchards

Our trap counts for CM and OFM were either 0, or low this week, with none of our trapping locations being near threshold. Most of the small fruit in our area is in fruit development, or fruit maturity. Strawberry harvest is fully underway at this time. We are seeing some slug feeding on strawberries, but very few other concerns at this time. Grapes are beginning to bloom, and depending on the variety, may already be in full bloom. Don’t forget to spray for black rot during this period.

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

Agronomic Crops

Cut alfalfa field in Wayne County.

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

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

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

Vegetable Crops

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

Flea beetles feeding on a recently transplanted brassica plant.

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

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

Colorado Potato Beetle adults on a potato plant.

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

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

Small Fruit and Orchards

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

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

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

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

 

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

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

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

Wayne County IPM Notes for the week of May 10 – May 14

Agronomic Crops

            This week again, we saw sustained activity and feeding from the alfalfa weevil. At this point, we have started to observe some of the weevil reaching later stages of development and beginning to pupate. In cases where there is a poor alfalfa stand, the weevil damage is more severe as compared to feeding in a full, healthy stand.

Alfalfa weevil cocoon. Tommy Becker photo.

            As the alfalfa continues to grow taller, we also noticed some lodging where after heavy rains, the alfalfa began to lay over. This is not a major concern, but just something to be aware of.

            While driving around the county, we did observe some corn fields that were planted, and the corn plants are beginning to emerge. In our travels we did not see any soybean fields, although, we have heard reports of some soybeans emerging as well.

Vegetable Crops

            Remember to keep your high tunnels ventilated and not too wet as not doing so can lead to conditions that can create the perfect environment for diseases. As such, we began to observe high tunnel tomatoes with early blight. Low humidity, consistent air movement and proper plant spacing can all help to avoid experiencing certain foliar and root diseases.

Early flea beetle feeding on young cole crops.

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

We did note some frost damage to potatoes that were emerging. We also spotted some flea beetles on cole crops this week.

Sweet corn that was planted early is somewhere around the V2 mark, standing about 3-4” tall. Given some warm temperatures and sunshine, the corn will really take off.

Small Fruit and Orchards

            Apples are at fruit development. Peaches are at shuck split. No CM or OFM concerns at this point in the orchards.

Blueberries are in petal fall and are setting fruit. We are starting to see Phomopsis blight in some blueberry bushes.

Ripening “plasticulture” strawberries. Tommy Becker photo.

Raspberries are getting ready to bloom and overall seem to be coming along just fine.

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

Grapes also experienced some damage due to the cold temperatures. Currently, grapes are around the bud burst stage, and some are at the 4-8” shoot stage. Some buds that were exposed to the cold have died; others look damaged. We are still waiting to see the full extent of the frost damage in many of our small fruit and orchard crops.

Wayne County IPM Notes, May 3-7, 2021

Agronomic Crops

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

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

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

Vegetable Crops

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

Epinasty in tomato due to ethylene exposure.

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

Small Fruit and Orchards

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

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

 

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

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

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

Winter Injury to Forages, Wheat and Rye

Ohio is no stranger to a wide range of fluctuating winter conditions. After the recent spell of cold and snow in Ohio, we are now looking ahead to rain and warmer temperatures. While this relief from the winter elements may be appreciated by many, this flip of conditions can result in some challenges with our over wintering grain and forage crops.

Dennis Pennington, a wheat system specialist from Michigan State University shares some of the details on why crops such as wheat need the cold weather and why the break in cold temperatures can cause problems.

Pennington, on wheat states, “Winter wheat goes through a vernalization period where the plant hardens and adjusts to the colder winter temperatures. The hardening off period begins in the fall once temperatures at the crown (growing point, generally placed about 1-2 inches below ground surface level) drop below 48 F and continues as the temperature decreases. The hardening process causes a reduction in moisture content in the cells of the crown which slows growth processes and the accumulation of soluble carbohydrates, all of which help the plant to resist frost damage.”

Dennis goes on to discuss the hardening process, as he states, “The hardening process takes place over four to eight weeks and the level of hardiness is directly related to the soil temperature at the crown depth. Daylength also impacts hardiness, as shortening days in the fall induce wheat winter hardiness. Conversely, longer days in spring bring wheat out of hardiness. Cold tolerance is dynamic and can be lost if soil temperatures rise above the previous temperature that the plant hardened to. According to a study by D.B. Fowler from the University of Saskatchewan in 1982, if the crowns of the plants are exposed to warmer temperatures for as little as 50 hours, the cold hardiness can be decreased substantially. The loss of cold tolerance has several major implications.”

Winter wheat greening up in the spring. Some tip die-back is visible in this photo.

The two major implications that Pennington describes in his article are the following: First, if soil temperature decreases below the current level of winter hardiness, injury will occur. Secondly, once a crop loses winter hardiness, it will never reach the original level of hardiness and it will de-harden more quickly each time the soil temperature rises above the minimum survival temperature.

As pointed out by Pennington in his article, what you want to see is a steady line in the temperature, without large spikes in either direction. Whenever the temperature spikes up followed by a spike down below the original temperature, injury can occur.

Generally speaking, when looking at the crops that are over-wintering in the fields, snow melt can be a concern. Obviously, warm weather causes the snow to melt. Snow, however, serves as an insulator and can protect the crowns of plants against major swings in air temperature. Snow melting can also result in ponding in the fields. In cases where drainage is adequate, there should be little to no concerns, but where water persists, evident by ponding or high levels of field saturation, waterlogging may occur. Additionally, if the water persists, the crowns may absorb more water, which could be problematic should conditions become cold again as it would result in cell rupture when the water in the plant freezes and expands. Ice damage can also occur in areas where standing water freezes over dormant plants for an extended period of time, essentially suffocating them. There is really a wide range of problems that can occur when we have a significant amount of snow the melts off before we are safely out of reach of winters grasp.

An example of how far an alfalfa plant can be heaved out of the ground via several rounds of freeze/thaw cycles.

Another concern, especially in forages, is heaving. Now that the ground is exposed, should we get back into a freeze/thaw pattern, heaving could occur. Heaving occurrence can increase significantly in areas of fields where there is a lot of moisture, and with the recent snow melt, there are a lot of fields with excess moisture.

Getting closer to spring, these issues may not be anything to worry about, but certainly something to be aware of. Worrying about temperatures will do nothing to change them, and this area of crop production is unfortunately out of our hands but being aware of these concerns can help you assess damages should any occur. Getting out to scout alfalfa, wheat and rye fields in the spring is recommended, not only this year, but every year. Evaluating your fields as early as you can in the spring can help you make efficient and impactful management decisions and consequently, take action if warranted.