Wayne County IPM Notes from July 26 – August 1

Wayne County IPM Notes

(From the Week of July 26 – August 1)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

 

Heavy foliar feeding by flea beetles on a young cole crop transplant. F. Becker photo.

Flea beetles continue to be a problem in both young, recently transplanted crucifer crops, as well as cabbage and kale either in harvest or near harvest. Feeding damage from flea beetles on the younger crops can cause stunting and reduced yield. This damage can be especially impactful on heat stressed transplants. The foliar feeding being done on maturing crops can affect the visual appearance of the crop and may result in a less desirable product.

In sweetcorn, the European corn borer trap counts have shown some moth activity. A trap in Wayne County had a catch of 22 ECB moths this week. Corn earworm traps have shown little moth activity over the last few weeks. Regarding damage being done to the plants, I have started to notice increasing damage being done by armyworms. The damage I am finding is typically being done in the whorls on the young tender leaves. Another sign of armyworm feeding is large areas along the leaf edges that have a ragged appearance.

Squash bug eggs are starting to hatch, and I am starting to find various stages of larva out in pumpkin fields and squash plantings. Currently most feeding is being done on the leaves; however, the focus of the feeding can shift to the fruit and cause scarring to the skin resulting in decreased marketability. The squash bug has also been found to be the vector of a bacterium that causes the disease Yellow Vine Decline.

Vegetable Diseases

            Downy Mildew is in Wayne and Medina counties and likely in surrounding counties as well. Cucumber growers need to be spraying for downy mildew.

The aborted pumpkin on this plant resting on top of the first pumpkin set shows that environmental stress is limiting the amount of pumpkins the plant is capable of sustaining. F. Becker photo.

Powdery mildew can be just as destructive on squash as downy mildew is on cucumbers. I have been finding powdery mildew consistently in younger squash plantings. Unfortunately, the earlier the plant is infected with powdery mildew, the shorter the life span of the plant. With an infected plant having a short life span, the yield for the plant can also be expected to decrease.

Although not a disease by definition, “fruit drop” is something that I am seeing in a lot of crops. Non-irrigated open field crops seem to be the most affected right now. Specifically looking at pumpkins, the first fruit set seems okay. The newer fruit sets are what is being impacted the most. The young fruit are being aborted by the plant, as well as the blossoms that have come on after the most recent fruit set. High temperatures and drought conditions have brought about the poor fruit set on pumpkin plants. With high temperatures affecting the viability of the pollen and the flower combined with low nutrient uptake due to limited soil moisture, the plant simply can’t sustain a heavy fruit set, at least not until we get some more consistent rain.

Fruit Pests

Japanese beetles are still feeding in nearly every crop that I am scouting. They are doing damage to apple leaves, peach leaves, grape leaves, blueberry leaves and blueberry fruit. It is important to watch the populations of Japanese beetles because they can transition from only feeding on the leaves to doing significant damage to the fruit.

After a few weeks of high numbers in both oriental fruit moth and codling moth traps, the trap counts have started to back down a bit.

Woolly apple aphid clusters on apple trees. F. Becker photo.

On apple trees, I am starting to find some woolly apple aphids. Mature trees do not often face major damage from these infestations; however, young trees typically suffer from the damage that the woolly apple aphids cause to the roots. Continued feeding can damage or kill roots, resulting in reduced yield, growth, and tree vigor, and even death of some trees.

Fruit Diseases

            Overall, disease pressure has been fairly limited this year. Hot and dry conditions have prevented favorable conditions needed for disease development. As fruit continues to ripen and be harvested, we continue to move forward through the growing season without many disease issues in our area.

Grape clusters beginning to ripen. F. Becker photo.

Grapes should be starting to get some color to them as the clusters are starting to increase in size. At this point, most varieties of grapes should be resistant to black rot. Although symptoms of black rot may be showing up on untreated grapes, it is too late to do anything.

Growers with varieties of grapes that are not resistant to downy mildew should consider a spray program. Grape growers should also keep an eye out for powdery mildew, as this is the time of year when powdery mildew is typically found on grapes.

Apple and peach growers should continue their spray programs to manage fruit rots and diseases such as flyspeck and sooty blotch in apples and brown rot in peaches. Alternaria leaf blotch can be found on some apple trees right now. This can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur.

Wayne County IPM Notes for July 19 – July 25

Wayne County IPM Notes

(From the Week of July 19 – July 25)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

            Hot and dry conditions are often ideal for spider mites to thrive, and this year is no different. Spider mites proliferate during these conditions and are currently doing so in melon plantings. They feed on the undersides of the leaves and their feeding damage over time can cause chlorosis and stippling, and eventually the leaf will shrivel and die. More on spider mite management

Cucumber Beetles are feeding again, primarily on young, recently transplanted squash. However, the adults are not the only ones causing damage. The larvae of the cucumber beetles have also been doing damage. I have seen damage to the skin of melons where the melon is sitting on the soil. This contact area between the ground and the melon provides the perfect place for cucumber beetle larva to feed.

 

Tomato hornworm that was feeding on tomato plants. F. Becker photo.

I have started to see a decent amount of damage from tomato hornworms. Be sure to keep an eye on your tomato plants for large areas of defoliation near the top of the plant, as well as damage to the fruit. Tomato hornworms may also feed on Solanaceous plants such as peppers, eggplant and potato, although not to the extent of which they feed on tomato plants.

Japanese beetles are out in large numbers on a wide range of crops. Sweet corn growers should be especially wary of Japanese Beetles feeding since one of their target areas on sweet corn is the silk. The beetles can clip the silk which limits the silk’s receptivity to pollen.

Vegetable Diseases

            Downy Mildew has now been detected and confirmed in Wayne County. Cucumber growers should have started a spray program for cucurbit downy mildew.

Powdery mildew is starting to show up on cucurbit crops around the area. If older plantings of summer squash are heavily infested and you are no longer harvesting from those areas, it would be of your best interest to terminate that crop so that you are not allowing the powdery mildew to have a place to thrive. This is especially important if you have younger, successive plantings of summer squash nearby.

This week, the lab at OARDC confirmed bacterial leaf spot on pepper. Bacterial infections have been limited this year due to the heat and dry weather, however, they should still be managed appropriately. This is one of the most destructive diseases for peppers and will result in a yield reduction due to loss of foliage and infection on the fruit.

Bacterial wilt is starting to show up in older squash plants, unfortunately at this point there is nothing that can be done. The cucumber beetles feeding on the plant while it was young vectored the bacteria responsible for bacterial wilt and the plant is finally being impacted by the infection.

Fruit Pests

Grape berry moth larvae are starting to feed and cause damage in grape clusters. Scouting grapes and carefully assessing the grape clusters can help you determine management needs. Infestations of grape berry moths are typically higher along the borders, and near woods or hedge lines as compared to the interior of the vineyard.

Spotted Wing Drosophila numbers are remaining high. Other than spraying insecticides such as malathion, it is beneficial to limit the

Grapes damaged by grape berry moth. F. Becker photo.

amount of overripe/cull fruit that is on the ground around the plants. The fruit on the ground only attracts more flies and in encouraging good sanitation in the patch it can help reduce the number of flies being drawn in.

Codling Moth traps have started to show increasing numbers, with some inconsistency, but nonetheless, the counts have trended up. Oriental fruit moth traps spiked this week, going from essentially 0 per trap to averaging between 7 and 8 per trap.

Japanese beetles are feeding across the spectrum of fruit crops that I am scouting. I have noticed heavy damage primarily occurring on ripe blueberries and on grape leaves. Left uncontrolled, the Japanese beetles can cause significant damage to blueberries and severe defoliation in grapes.

Fruit Diseases

            Apple and peach growers should continue their spray programs to manage fruit rots and diseases such as flyspeck and sooty blotch in apples and brown rot in peaches. Alternaria leaf blotch can be found on some apple trees right now. This can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur.

Grapes should be starting to get some color to them as the clusters are starting to increase in size. At this point, most varieties of grapes should be resistant to black rot. Although symptoms of black rot may be showing up on untreated grapes, it is too late to do anything.  Growers with varieties of grapes that are not resistant to downy mildew should consider a spray program. Grape growers should also keep an eye out for powdery mildew, as this is the time of year when powdery mildew is typically found on grapes.

Wayne County IPM Notes from July 12-July 18

Wayne County IPM Notes

(From the Week of July 12 – July 18)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

            Squash Bugs are starting to lay large numbers of egg masses on summer squash, gourds, and pumpkins. Large numbers of squash bugs feeding can cause leaves to yellow and eventually die which can significantly reduce yield.

Japanese beetles on summer squash. F. Becker photo.

Cucumber Beetles are feeding again, primarily on young, recently transplanted squash. This is a important time to work on control of cucumber beetle as with young plants, the cucumber beetles can cause severe damage, stunt the growth of the plant and may lead to plants going down later with bacterial wilt.

Potato Leaf Hoppers (PLH) still have very high populations in several crops this year. PLH cause “hopper burn” on the leaves on which they are feeding. I have seen this damage to potatoes and green beans.

Japanese beetles are feeding in basically every crop that I scout. Sweet corn growers should be especially wary of the Japanese Beetles feeding since one of their target areas on sweet corn is the silk. The beetles can clip the silks and affect the success of the pollination. More on Japanese beetles and other sweet corn pests.

Vegetable Diseases

            Downy Mildew has been confirmed, again, in Medina County. Cucumber growers should have started a spray program for the cucurbit downy mildew.

Powdery mildew is starting to show up on cucurbit crops around the area. If older plantings of summer squash are heavily infested and you are no longer harvesting from those areas, it would be of your best interest to terminate that crop so that you are not allowing the powdery mildew to have a place to thrive. This is especially important if you have younger, successive plantings of summer squash nearby.

Powdery mildew starting to show on summer squash. F. Becker photo.

Some field tomatoes are showing symptoms of early blight. Early blight is a common tomato disease and happens when soil is splashed up onto the older, lower leaves. If not treated, early blight can cause significant defoliation of a plant.

In melon patches, specifically in cantaloupe, there is some Alternaria leaf blight showing up. This disease primarily affects the foliage but if the infection is severe enough, it may also infect the fruit.

Although not technically a disease, blossom end rot is still affecting a lot of crops. This is technically a deficiency of calcium in the plant but not necessarily in the soil. The best way to attempt to prevent further issues is to have consistent moisture to the plant and provide an environment conducive to adequate nutrient uptake.

Fruit Pests

Grape berry moth larva feeding inside a grape. F. Becker photo.

I have started to see grape berry moth larvae feeding in grape clusters. Scouting grapes and carefully assessing the grape clusters can help you determine management needs. Infestations of grape berry moths are typically higher along the borders, and near woods or hedge lines as compared to the interior of the vineyard.

Spotted Wing Drosophila numbers are still increasing. The trap counts were up again this week, with all the traps being in blueberry patches.

Codling Moth and Oriental Fruit Moth trap counts were low again this week and showed very little activity.

I am still seeing red mites in apple orchards throughout the county. Feeding by large populations of red mites can cause leaves to “bronze” and when left uncontrolled, this heavy feeding could result in leaf drop and a reduced size and quality of the crop. This hot and dry weather has been ideal for the red mite populations to get established in orchards.

Japanese beetles are feeding across the spectrum of fruit crops that I am scouting. I have noticed heavy damage primarily occurring on ripe blueberries and on grape leaves. Left uncontrolled, the Japanese beetles can cause severe defoliation in grapes.

Fruit Diseases

            Alternaria leaf blotch can be found on some apple trees right now. This can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur.

Apple and peach growers should continue their spray programs to manage fruit rots and diseases such as flyspeck and sooty blotch.

Grapes should be starting to get some color to them as the clusters are starting to increase in size. At this point, most varieties of grapes should be resistant to black rot. Growers with varieties of grapes that are not resistant to downy mildew should consider a spray program. Find more here on grape diseases.

Wayne County IPM Notes From July 5 – July 11

Wayne County IPM Notes

(From the Week of July 5 – July 11)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

            In sweet corn, the European corn borer (ECB) larvae are still doing damage. This week I started seeing some corn earworm (CEW) damage as well. The ECB trap counts dropped and showed little activity but the CEW traps started to increase in numbers. Even if the ECB activity seems to be slowing down, you need to be scouting your sweet corn for the CEW as well.

Squash bug egg mass on a zucchini leaf. F. Becker photo.

Squash Bugs have started to make their presence known. I have started seeing squash bug adults, primarily in summer squash plantings. I have also started to find squash bug egg masses. Large numbers of squash bugs feeding can cause leaves to yellow and eventually die which can significantly reduce yield.

Flea beetles are still very active and on a wide range of plants. Damage can be seen primarily on cole crops and potatoes.

Potato Leaf Hoppers (PLH) have high populations in several crops this year. PLH cause “hopper burn” on the leaves on which they are feeding. I have seen this damage to potatoes and green beans. Some of the PLH populations within green bean plantings have been incredibly high, in some cases, over 40 PLH per single leaf.

Potato leaf hoppers feeding on a green bean leaf. F. Becker photo.

Hopper burn from potato leaf hopper feeding on green beans. F. Becker photo

Vegetable Diseases

            Downy Mildew has been confirmed in Medina County. Cucumber growers should have started a spray program for the cucurbit downy mildew.

Powdery mildew is starting to show up on cucurbit crops around the state. I have not yet had any cases in Wayne County, but this disease should be watched for closely.

Cucurbit downy mildew on cucumber leaves. F. Becker photo.

Some field tomatoes are showing symptoms of early blight. Early blight is a common tomato disease which gets its start typically on the older, lower leaves. If not treated, early blight can cause significant defoliation of a plant.

In some melon patches, specifically in cantaloupe, there is some Alternaria leaf blight showing up. This disease primarily affects the foliage but if the infection is severe enough, it may also infect the fruit.

Fruit Pests

Spotted Wing Drosophila numbers are still increasing. The trap counts were up again this week, with all the traps being in blueberry patches.

Codling Moth and Oriental Fruit Moth trap counts were low again this week and showed very little activity.

I started to find red mites in apple orchards throughout the county. Feeding by large populations of red mites can cause leaves to “bronze” and when left uncontrolled, this heavy feeding could result in leaf drop and a reduced size and quality of the crop. This hot and dry weather has been ideal for the red mite populations to get established in orchards. Read more on Red Mite Management.

Mites feeding on an apple leaf. F. Becker photo.

Fruit Diseases

            Alternaria leaf blotch can be found on some apple trees right now. This can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur.

Apple and peach growers should continue their spray programs to manage fruit rots and diseases such as flyspeck and sooty blotch. Managing Apple and Peach Summer Diseases

Grapes should be starting to get some color to them. At this point, most varieties of grapes should be resistant to black rot. Growers with varieties of grapes that are not resistant to downy mildew should consider a spray program.

Wayne County IPM Notes from June 28 – July 4

Wayne County IPM Notes

(From the Week of June 28 – July 4)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

 

ECB damage to sweet corn tassel. F. Becker photo.

European Corn Borer has been doing damage in tasseling corn. The small ECB larva feed in the tassels as well as the young developing ears. It is important to thoroughly inspect the plants as you are scouting, especially with early season corn as their damage will not always be detected in the tassel like in later planted sweet corn. The ECB moth traps were high again this week, which is consistent with the amount of damage being done in early planted sweet corn.

Japanese Beetles are also starting to increase in number. They are a pest on most any crop. They can be especially damaging to sweet corn. The beetles can defoliate the leaves, but they can also clip the silks which can prevent proper pollination from occurring.

Worm feeding on cole crops has really started to pick up. I am finding a lot of imported cabbageworms doing damage on all ages of cole crops such as cabbage and kale. The adult butterflies can be seen in large numbers in cole crop plantings laying eggs on the plants. Read more here on pests of crucifers. I saw an uptick in the population of the flea beetle as well. Keep in mind that especially on younger plants, the flea beetles can cause a lot of damage and may stunt the plant.

Imported Cabbageworm larva on cabbage. F. Becker photo.

This hot and dry weather has been perfect weather for onion thrips. The thrips population has been high already in some areas, so this weather is favorable for large populations of thrips to develop. The thrips feeding can open the plant up to diseases such as purple blotch, so early detection and management are crucial to maintaining the health of the plant.

Vegetable Diseases

            Downy Mildew has been confirmed, again, in southern Michigan. Considering the proximity to Ohio, it has been recommended that cucumber growers begin a downy mildew fungicide program immediately. “Managing Downy Mildew in Cucurbits”

Powdery mildew is starting to show up on cucurbit crops around the state. I have not yet had any cases in Wayne County, but this disease should be watched for closely.

Some of the field peppers I am scouting showed signs of damping off. Damping off is caused by soil borne fungi such as Rhizoctonia, Pythium, Fusarium and Phytophthora.

Angular leaf spot has started to show up on some cucurbit crops, however, the hot and dry weather has helped slow it down or stop its progression altogether. Angular leaf spot is a bacterial disease, meaning that fungicides are not effective for management of this disease.

Fruit Pests

SWD female with a serrated ovipositor. F. Becker photo.

Spotted Wing Drosophila are here. All the traps out in Wayne County were positive for SWD. These traps are out in blueberry and strawberry patches. Strawberries are winding down, but the blueberries and raspberries getting ripe should be managed accordingly.

Codling Moth and Oriental Fruit Moth trap counts were down this week. Another week with our traps not over threshold.

Keep an eye out for aphids and mites in orchard crops. We are getting into the time of year where aphid and mite populations begin to increase and can do so rapidly. Leafhoppers are also a pest to be on the look out for, especially in grapes. More on Spider Mites

Fruit Diseases

            It is the right time to consider looking at managing summer diseases such as flyspeck, sooty blotch, and fruit rots. This can go for peaches as well with diseases such as brown rot and scab.

Peach “mummy” still present in a tree this spring. F Becker photo.

Necrotic leaf blotch and Alternaria leaf blotch can be found on some apple trees right now. Alternaria leaf blotch can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur. More on foliar apple diseases: Leaf Spots

Another note on apples, although not a disease, the effect of freeze/cold damage can appear unsightly and may be confused for a disease. This scabby looking ring or spots on the fruit are known as “frost rings”. This is a result of the tissues being damaged in cold or freezing temperatures.

Grapes are now around the “shatter” stage where the unfertilized berries fall off the clusters. It is important to be considering proactive treatments for grape downy mildew especially if you have a variety of grapes that are susceptible to downy mildew.

Scouting Notes From June 21-June 27

Wayne County IPM Notes

(From the Week of June 21 – June 27)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

            Potato Leaf Hoppers are feeding on potato and green beans. They will also cause damage to eggplant and other crops as well. Their feeding causes what is known as “hopper burn” around the leaf edges and if left untreated, the feeding will eventually cause the leaves to turn brown and begin to die back.

Cucumber Beetles are high in numbers right now. Cucumber Beetles vector the Bacterial Wilt disease so early season control of the beetles is vital to the long-term health of the plant. Also note that as your plants are blooming, the beetles may be in the blossoms. In small enough numbers, this is okay, but they can also damage the fruit from feeding on the blossom. Consider the pollinators when planning out treatment options for cucumber beetle.

European Corn Borer is now doing damage in tasseling corn. The small ECB larva feed in the tassels as well as the ears. It is important to thoroughly inspect the plants as you are scouting, especially with early season corn as their damage will not always be detected in the tassel like in later planted sweet corn. An ECB trap in Wayne County had 9 moths in the trap this week.

Onion thrips populations have really trended upwards. Damage from thrips occurs primarily in the center of the plant where the new growth is emerging. Heavy feeding can lead to reduced bulb size or even plant death. The thrips damage can also open the plant up to purple blotch which is able to infect the plant via the wounds created by the thrips feeding. Click here to see photos of thrips and the damage they cause.

Colorado Potato Beetle are still feeding on eggplant and potatoes. Although their numbers are not as high where there has been several treatments, their populations can quickly get out of hand.

Vegetable Diseases

            Downy Mildew has been confirmed in south west Michigan. Considering the proximity to Ohio, it has been recommended that cucumber growers begin a downy mildew fungicide program immediately. Read more from Sally Miller’s lab.

Some of the field peppers I am scouting showed signs of damping off. Damping off is caused by soil borne fungi such as Rhizoctonia, Pythium, Fusarium and Phytophthora.

Powdery mildew is starting to show up on cucurbit crops around the state. I have not yet had any cases in Wayne County, but this disease should be watched for closely.

Fruit Pests

Spotted Wing Drosophila are starting to be found in Wayne County and surrounding areas. As more small fruits come into season, expect the number of SWD to increase rapidly. “Monitoring and Managing Spotted Wing Drosophila in Fruit Crops” 

Codling Moth and Oriental Fruit Moth traps had an increase in numbers but nothing above threshold levels.

Keep an eye out for aphids in orchard crops. We are getting into the time of year where aphid populations begin to increase and can do so rapidly. Leafhoppers are another pest to be on the look out for.

Fruit Diseases

            It is the right time to consider looking at managing summer diseases such as flyspeck, sooty blotch, and fruit rots. This note can go for peaches as well with diseases such as brown rot and scab.

Another note on apples, although not a disease, the effect of freeze/cold damage can appear unsightly and may be confused for a disease. This scabby looking ring or spots on the fruit are known as “frost rings”. This is a result of the tissues being damaged in cold or freezing temperatures. Rich Marini from Penn State notes “Sometimes frost during bloom may not kill a flower or small fruit, but may injure the skin tissues and cause a ring of russet around the fruit and these are referred to as frost rings.” Read more here about apple skin disorders.

Grapes are now around the “shatter” stage where the unfertilized berries fall off the clusters. It is important to be considering proactive treatments for grape downy mildew especially if you have a variety of grapes that are susceptible to downy mildew.