vegetables

OSU Extension Bi-Weekly Fruit & Vegetable Report – September 15th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates below:

Farm Science Review 2023

The Farm Science Review (FSR) is one of the nation’s premier farm shows and one of OSU Extension’s largest, most far-reaching educational programs. The event will be held at the Molly Caren Agricultural Center near London, Ohio on September 19th – 21st. The OSU Extension Fruit & Vegetable Team will be hosting a tent all 3 days that will feature presentations from academic and industry speakers on a variety of topics, including nutrient management, entomophagy, integrated pest management, variety trial results, farm marketing, and more. The OSU Extension Fruits & Vegetables exhibit will be located near the gazebo near the Utzinger Garden (booth 385). We hope to see you there!

Check out the 2023 Farm Science Review Program for further information.

Speaker schedule for OSU Extension Fruits & Vegetables exhibit at FSR 2023. Note: There will also be a presentation by Dr. Marne Titchnell, Extension Wildlife Program Director for OSU,  on wildlife management in fruits & vegetables on Wednesday, September 20th from 1:30 – 2:00 PM.

Purple carrot-seed moth detection

The OSU Plant & Pest Diagnostic Clinic (PPDC) recently received an insect sample that was identified to be purple carrot-seed moth (Depressaria depressana), a known pest of crops in the Apiaceae family. This was the first report of purple carrot-seed moth found in Ohio, though it has been found in neighboring states. The insect feeds on the flower heads of crops like carrot, parsnip, dill, celery, parsley, and more, but it is yet unknown if it will be an economically important pest of these crops in Ohio. Check out the article from PPDC for more information.

Please report any suspected larvae/adults with pictures to entomology@osu.edu or ppdc@osu.edu.

Purple carrot seed moth larvae (top) and adult (bottom). Photo by Iowa State University Extension (top) and University of Wisconsin-Madison Department of Entomology (bottom). 

Crop updates

Vegetables

Cucurbits

Downy mildew continues to wreak havoc in cucurbit plantings this time of year. As a refresher, here is a factsheet from Michigan State University on downy mildew mitigation. Powdery mildew pressure is reported to be increasing in southern Ohio. Striped cucumber beetles populations are declining in central/northeast Ohio and transitioning more towards higher numbers of corn rootworm beetles. Western corn rootworm, a look-alike of striped cucumber beetle, also feeds on cucurbits and can impact yield if heavy populations are present. Check out this article from Iowa State University for information on identifying different rootworm beetle pests. 

Virus symptoms are being observed in some melon plantings. There are various aphid-vectored potyviruses that affect cucurbits and they can be hard to differentiate from one another, though control practices are similar for all of them. The big 4 for cucurbit crops are cucumber mosaic virus, papaya ring spot virus, watermelon mosaic virus, and zucchini yellow mosaic virus. Like many crop diseases, management practices are preventative and include using resistant varieties or planting earlier to ensure harvest before viral symptoms appear towards the end of the season. Getting aphids under control may also minimize virus infection to some degree.

Cucumber mosaic virus – symptoms include yellowish-green “mosaic” mottling on foliage or fruit and crinkled leaves. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.

Papaya ringspot virus – symptoms include wrinkled leaves and discolored, bumpy fruit. Photo by Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org.

 

Watermelon mosaic virus – symptoms include wrinkled leaves and geometric patterns on fruit.  Photo by Dorina Pitorac, European Plant Protection Organization.

Zucchini yellow mosaic virus – symptoms include blistered, wrinkled leaves and fruit with discolored bumps. Photo by University of Massachusetts Extension.

Fruiting Vegetables

Late-season aphid feeding is being observed in some solanaceous crops. Honeydew is a sugary liquid secreted by aphids and other sap-sucking insects (whiteflies, spotted lanternfly, etc.). Honeydew accumulation on crop foliage or fruit can lead to growth of sooty mold, which is a term for various genera of fungi that colonize the sticky exudate. Sooty mold does not render vegetables inedible, however, and can be readily washed off. 

Honeydew from aphids (and other sap-suckers) on plant leaves is sticky to the touch and can be colonized by sooty mold. Photos by Kansas State University Entomology (top) and Joe Boggs, the Ohio State University Extension (bottom). 

Regular bouts of rainfall as we head into the fall are leading to increased incidence of Phytophthora infection in peppers (and cucurbits). While excess water is a problem for some vegetable growers in Ohio, some parts of western Ohio still remain abnormally dry, according to the U.S. Drought Monitor. Mites have been a problem in some areas, while thrips have taken a downturn. Keeping mites under control towards the end of the season can reduce the chance of heavy pressure next season by reducing the egg load/number of overwintering adults that will become next year’s mite infestations.

Fruit

Tree fruits

Early varieties of apples are being harvested across the state. Brown marmorated stinkbug pressure is increasing. Bitter rot is starting to be observed in some orchards. Marssonina leaf blotch is also being seen in some organic orchards, where management can be difficult without the use of fungicides. Removal/destruction of leaves on the orchard floor in the fall can reduce overwintering sites for the pathogen. Black knot is being seen on some ornamental plum trees, so commercial plum and cherry growers should keep an eye out for black knot galls on their trees and promptly remove them if they see them.

Gall of black knot (Apiosporina morbosa), a fungal pathogen of plum, cherry, and other types of fruit trees. Photo by Joseph O Brien, USDA Forest Service, Bugwood.org.

Small Fruits

Preparing Brambles for Winter – Sanitation Practices for Disease Prevention
Melanie Ivey, State Fruit Pathologist and Fresh Produce Safety Specialist, The Ohio State University

Disease management of perennial fruit crops is a year-round endeavor. Many fungal pathogens survive the winter months in the soil or plant debris, infected canes or buds, or dead canes. As part of an integrated disease management program fall sanitation practices to reduce inoculum in the planting should be done.  Best sanitation practices include removing floricanes after harvest, removing diseased and dead canes, removing dead or systemically infected plants, and raking or chopping fallen leaves. Pruning debris should be destroyed by burning or placing in the trash or discarding it away from the planting. Diseased plant material should not be composted.  Pruning cuts should be sharp and clean to avoid unnecessary mechanical wounds.

The fall is also a good time to scout for and remove wild bramble populations that are near the production field. In addition to fall sanitation practices, some diseases require a dormant or delayed dormant fungicide application. For dormant or delayed dormant fungicide recommendations consult the Midwest Fruit Pest Management Guide (OSU Extension Bulletin 506).

The table below summarizes where the fungi for several common diseases of brambles in Ohio overwinter, the recommended fall sanitation practices for each disease, and whether a dormant or delayed dormant fungicide application is recommended.

Upcoming Events: 

September 19 – 21, Farm Science Review

September 27, Wooster, OH, Midwest Mechanical Weed Control Field Day

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

December 5th – 7th, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference

OSU Extension Bi-Weekly Fruit & Vegetable Report – July 7th 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state.

Air Quality

With the recent poor air quality caused by wildfire smoke, questions were filtering into county offices regarding potential effects on crops. One of the major potential concerns is ozone damage to plant tissue if there are significant concentrations in wildfire smoke. Check out this article from University of Minnesota Extension for more information.

A question came in from the community asking if the smoke from the Canadian wildfires would affect the ability to eat lettuce from their garden. Information from Jennifer Little, Family and Consumer Sciences Extension Educator in Hancock County, cited that according to the Environmental Protection Agency (EPA) and the United States Department of Agriculture (USDA) that there should not be any issue with consuming the lettuce. Folks can follow normal harvesting/cleaning processes prior to consuming vegetables. Any harm to humans would be from breathing the smoke-filled air, which could cause respiratory issues. Therefore, the concern is not in consuming the lettuce but in spending time outdoors. It is wise to take precaution with the amount of time you are spending outside when air quality is poor, especially if you have underlying respiratory issues. More information on air quality can be found on the Ohio Department of Health’s website.

Crop updates

Vegetables

Beans/Peas

A number of insect pests are being found in bean plantings, including Japanese beetles, Mexican bean leaf beetles, and potato leafhopper. Aphids have also been found in beans, as they have been found in many other crops this year. With the extremely elevated number of aphids, there has been ample opportunity for natural enemies such as predatory and beneficial insects to also build their populations. Species such as lady beetles, predatory stink bugs, and parasitic wasps are being found in abundant numbers. Signs of natural enemy activity include “aphid mummies”, which are the remains of aphids resulting from parasitic wasps laying their eggs in the insect. When the eggs hatch, the wasp larvae consume the host from the inside, leaving behind only the dried outer shell of the aphid.

Aphid mummy present in an alfalfa field. Photo by Frank Becker, OSU Extension.

Brassicas

  Cross-striped cabbage worm is being detected in eastern Ohio. Check out this article from Kansas State for a quick primer on this insect pest. 

Cucurbits 

  Striped cucumber beetle pressure is sporadic across Ohio, with some farms showing high populations and levels of damage while others show very little. Even plantings where the Farmore FI400 (thiamethoxam) seed treatment was used are showing outsized amounts of feeding. For information on integrated cultural management practices to use, check out this article on non-chemical striped cucumber beetle control.

Squash vine borer (SVB) egg laying is underway. Check out this article from Michigan State University Extension on SVB biology and control to learn more about the pest’s life cycle. Squash vine borer is one of the many insect pests that OSU Extension’s IPM program traps throughout the growing season to monitor population spread and density. For more information on how to use trapping to monitor this pest, check out this instructional video from the OSU IPM program. 

  Mice and vole feeding on young cucurbit seedlings this year has been severe and exacerbated by the dry weather. Wildlife damage in fruits and vegetables persists as a problem for which there are no surefire solutions. Tactics for preventing wildlife damage include employing 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.

Root crops 

High thrips populations are currently being observed in maturing onion crops.

Both homeowners and commercial garlic growers alike have been impacted by garlic bloat nematodes this growing season. This pest will damage other plants in the allium family as well, including onions, chives, and leeks. Some of the symptoms we see resulting from damage caused by garlic bloat nematodes are stunted leaf growth, distortion, yellowing, wilting, and premature dieback of the leaves, as well as bulbs that can look rotten since the damage opens up the plant tissue to be infected by other bacteria and fungi. As shown in the pictures (below), the roots can be partially or completely missing.

Garlic bulbs showing damage caused by garlic bloat nematode. Photos by Thomas Becker, OSU Extension

The best thing that garlic growers can do to prevent future crops from being infested is to rotate out of alliums and to use fresh seed every year. Mature, reproductive nematodes can live in the bulbs both during the growing season and while in storage. Growers that use saved seed from the previous year’s crop are risking re-infestation. Crop rotation is encouraged for many vegetable crop species to help break pest and disease cycles.    

Colorado potato beetles are being sighted, primarily in organic and volunteer potatoes. Refer to the Midwest Vegetable Production Guide for chemical options for Colorado potato beetle control. 

Tuber quality in potatoes can be impacted by a number of variables over the course of a growing season. Specifically, tuber formation can be impacted by management factors like planting depth and hilling intensity- learn more in this recent article from Matt Kleinhenz of OSU Extension.

Potato flowering signals the start of tuber bulking period. Photo credit, Chris Galbraith, OSU Extension. 

Sweet corn

First plantings of sweet corn around both Huron and Seneca Counties were wiped out by Spring frosts, with later plantings expected to have low yields from both frost damage and heat/drought. Corn earworm is being caught in traps near sweet corn plantings, while European corn borer catches are low. 

Fruits

Tree fruits

  Despite the dry spring, the pome and stone fruit crop is looking good for the season. Sporadic hail storms near the end of June have caused some damage in apple orchards, as well as to other crops. 

Small fruits

Blueberry u-picks in southern Ohio have opened up to the public. Late frosts in north-central Ohio killed most strawberry blossoms in both matted-row and plasticulture systems, leading to a drastically reduced crop.

Gary Gao, OSU professor and small fruit specialist, received a few messages about the collapsing of blackberry floricanes before fruits reach full maturity. Miki and John Pringle sent him a few pictures of the dying canes. They said that the affected canes turned white and died. The problem was not widespread on their farm. The Pringles grow their blackberry bushes on a rotatable cross arm trellis (RCA). The plants had winter protection with row covers when most parts of Ohio experienced the low temperatures in December 2022. However, it was still possible that some spots of the blackberry patch were not protected well due to holes in the row cover and weaker bushes. 

Gary attributed this problem to blackberry cane blight triggered by cold injuries. Cane blight is a fungal disease. Growers who grow blackberries on RCA are encouraged to put on a dormant spray like Sulforix before they cover the blackberry plants with row covers in December. This is probably the reason that Pringles only saw this problem on some bushes. Growers who grow blackberry bushes in a traditional hedge row without winter protection are not as lucky. Cold injuries induced cane blight are showing up around late June and early July. The affected canes will completely collapse before fruits ripen. It is very disheartening to see since growers invested a lot of time and money on managing the canes. This is why the use of Rotatable Cross Arm trellis with 3 oz. row covers is recommended if growers desire consistent production year after year. 

Collapsing blackberry floricanes from cold injuries and possibly cane blight. Photo by John and Miki Pringle, Pringles Orchard, Goshen, Ohio.

A good way to assess the damage from cold temperatures is to cut the bark to see if the cambium tissue is healthy. Healthy cambium looks light green while dead cambium is dark brown. The ideal time for doing this is April. By then, growers can determine if it is worth all the time and expenses to manage the bushes. If the cambium tissue of the floricanes is damaged and the damage is widespread, growers may elect to cut out all of the damaged canes in April and call it a total loss. 

Floricanes with light green healthy cambium tissue. Photo by Gary Gao, The Ohio State University. 

Blackberry floricanes with dead cambium tissue. Note the dark brown area between outer epidermis or the bark and the xylem or the woody tissue in the middle of the cane. Photo by Gary Gao, The Ohio State University.

Blueberry and Raspberry Harvest Update: Blueberry and raspberry harvest is in full swing in early July. Most blueberry and raspberry growers do pick your own. The crops look quite good despite all of the weather challenges with cold temperatures in December 2022, warm winter, and a drought in spring. It is nice to see rain across Ohio. If you did not see much rain in your area, it is very important to irrigate the bushes to keep plants health and make the fruits grow. 

Ripe Bluetta Blueberry ready for harvest. Photo by Gary Gao, The Ohio State University.

 

For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.

 

Upcoming Events: 

July 12, 10:00 am – 2 pm, Ontario AgRobotics Field Tour, Part 2

July 20, 9:00 am – 1:30 pm, In-Field and Edge-of-Field Conservation Practice Field Day

July 20, 8:30 am – 3:30 pm, “Climate Smart: Farming with Weather Extremes” conference

August 23, 8:00 am – 4:00 pm, Agriculture Technology Field Day

August 24, 5:30 – 8:00 pm, Western Ag Research Station Pumpkin Field Day

September 19 – 21,  Farm Science Review

September 27,  Midwest Mechanical Weed Control Field Day

December 5th – 7th,  Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 4th – 5th, Ohio Organic Grain Conference