OSU Extension Bi-Weekly Fruit & Vegetable Report – August 17th, 2023

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

Tillage Options for Annual Vegetables

Different kinds of tillage equipment vary widely in their level of soil disturbance. Some tools work the ground to a fine tilth for planting, while others cause minimal disturbance or target only the area where the crop will be planted. Certain vegetable crops succeed better with certain tillage types than others. The following will provide a brief rundown on several common tillage systems and their respective benefits and drawbacks.

Conventional tillage consists of a primary tillage event to turn over the soil and provide a basis for further secondary tillage that is used to further chop and bury vegetation/residues and prepare the seed bed. A moldboard plow is one of the most common types of primary tillage, inverting the topsoil and fully burying surface vegetation. A chisel plow can also be used for primary (as well as secondary) tillage and involves fracturing the subsoil using shanks tipped with chisel points in a way that does not turn over the topsoil. Secondary tillage implements include a disc harrow, which uses steel discs to slice up soil clumps, weeds, and residue. Newer high-speed discs perform better at faster operating speeds compared to traditional types.

   

Tillage equipment uses a variety of tools to fracture and mix the soil as well as chop and bury residues. Top to bottom – chisel plow, vertical tillage implement, high speed disc, and strip till unit. Photos by Chris Galbraith, OSU Extension. 

 

Conservation tillage refers to tillage systems that create considerably less disturbance, leaving > 30% of the soil surface covered with residues. The advantage is reduced erosion, increased organic matter, and improved soil structure and quality. Various conservation tillage practices include:

  • No-Till is a very common production system where the soil is not disturbed at all by tillage operations and crops are planted into the previous year’s residues. The advantages of eliminating tillage are well-established – no-till maintains soil structure, conserves organic matter, retains moisture, and prevents runoff. The potential downsides are also well known and include greater difficulties in accessing the field for planting during wet springs, delayed soil warming early in the season, and greater reliance on chemical weed control. Large-seeded vegetables like sweet corn or pumpkins are more typically grown in no-till production.
  • Vertical Tillage is a shallow form of tillage designed to work the soil minimally while leaving residues on the surface for ground cover benefits. This tool helps incorporate soil amendments or chop up residues to more manageable sizes while side-stepping the more disruptive effects of conventional tillage. Vertical tillage equipment consists of fluted coulters, chopper reels, rolling baskets, and other features that open up the ground for warming and speeds decomposition by chopping/sizing residues, all in a way that has less negative repercussions than the heavier forms of tillage achieved by a plow or disc harrow.
  • Strip Tillage is the method of tilling only in strips where the crop will be planted, leaving soils undisturbed in between the strips. A typical row unit will include a coulter to slice through residue, followed by a row cleaner to clear the way for shanks, wavy discs, conditioners, and other attachments that help create a finely tilled strip. This method offers the best of both worlds by preparing a worked area that warms quicker than the inter-row zones while also retaining cover on top of most of the soil. Row units can further be set up to apply fertilizer or a fumigant to the strip during the same pass. Vegetables commonly grown in strip-tillage systems include sweet corn, squash, carrots, potatoes, and more.
  • Ridge Tillage is similar to strip tillage except that strips are formed as raised ridges to promote better drainage and aeration. Ridge tillage tends to be less common than strip tillage, particularly in vegetable production.

Crop updates

Vegetables

Cucurbits

Downy mildew continues to spread throughout Ohio, with the clade that can infect squash, pumpkins, and watermelons being reported in Fulton county. You can continue to track the spread on the Cucurbit Downy Mildew Forecasting website.

 

Cucurbit downy mildew symptoms on upper leaf surface (top image) and lower leaf surface (bottom image) of cucumber. Photo by Frank Becker, OSU Extension. 

Fruiting Vegetables

Harvest of tomatoes, peppers, eggplant, and okra are all well underway. Verticillium wiltPythium fruit rot, and Phytophthora capsici have been causing problems in some fields. Preventative practices for managing these pathogens by promoting proper drainage and preventing spread from infected to non-infected fields can help in reducing disease severity.

Pythium colonizing pepper fruit. Pythium appears as white, “cottony” fungal growth on fruit while Phytophthora spores on fruit more resemble powdered sugar. Photo by Chris Galbraith, OSU Extension.

Sweet Corn

Western bean cutworm catches in NW Ohio have decreased as of late, with high numbers still being reported in NE Ohio. Corn earworm and European corn borer catches remain low. Check out the most recent OSU C.O.R.N newsletter for most recent trap counts. Japanese beetles remain a pest on sweet corn, as well as other crops. Insecticide options include Assail (acetamiprid), Baythroid (beta-cyfluthrin), Warrior II (lambda-cyhalothrin) and other products. See this article from Iowa State University on the biology of this pest and spray thresholds.

Japanese beetles feeding on corn silks. Photo by Frank Becker, OSU Extension. 

Fruits

Elderberry Fruits “Disappearing” from the Cluster (Cymes).

Dr. Gary Gao, Professor and Small Fruit Specialist, OSU South Centers

Ed Brown, the Agricultural and Natural Resources Educator with OSU Extension in Athens County, reached out to Gary Gao for answers on a question from a grower about fruits “disappearing” from the clusters or cymes of elderberries. There are several possible reasons for this phenomenon. The most common reason is bird feeding. As elderberry fruits turn color, birds typically start eating them. These little fruits are the perfect size for a lot of birds. Netting is the most effective way to keep birds out of the planting. It is important to put the netting on before fruits turn color.

Elderberry bushes with ripening fruits under bird netting. Photo by Gary Gao, The Ohio State University.

There are other possible reasons. Japanese beetles can feed on florets causing the elderberry plants to set fewer fruits. Herbicide damage from 2,4-D or Dicamba is getting more and more common. These chemicals could cause fruits to abort. More studies need to be done to verify this hypothesis.

Mineral nutrient deficiency can be a possible cause too. Boron is one element that is important for fruit set. Tissue testing will help determine if boron levels are too low. If they are, a foliar application of boron will help increase fruit set in the future.

Ripe elderberry fruit cymes. Photo by Gary Gao, The Ohio State University.

Cross pollination can increase fruit set. Elderberries can set fruit when only one cultivar is planted. However, planting two different cultivars that bloom at the same time will significantly increase fruit set cyme size.

Follow this link https://ohioline.osu.edu/factsheet/anr-0110 for more information on elderberry production in Ohio and possibly beyond.

Net Grapes for Preventing Bird Depredation

Dr. Gary Gao, Professor and Small Fruit Specialist, OSU South Centers

Some of the cold hardy grape cultivars, such as Frontenac, Frontenac Blanc, and Frontenac Gris, have reached veraison at OSU South Centers in Piketon, Ohio. Veraison is the onset of fruit ripening and change of fruit color of grape berries. This is the time when birds started poking fruits for sugar and moisture. All of the punctures are the perfect sites for attracting bees and wasps. These wounds also cause fruits to rot and make grapes less marketable. Birds can peck the fruits off. All of these activities can cause severe yield loss. In the case of wine grapes, fruit and wine quality will also suffer.

Frontenac grapes at veraison. Photo by Gary Gao, The Ohio State University.

Veraison is the time to net the grapes to prevent bird depredation. Many grape growers use this method. There are many different nets out there. Since we grow mostly hybrid grapes on high wire cordon, we put the netting over the row. Our netting material is a black plastic netting that comes in a large roll. We bought a Netter-Getter a few years ago. This tractor mounted net applicator is typically operated by three people. One person drives the tractor and two other people follow behind to drape the net over the entire vine.

Bird netting being applied to grapes. Photo by Gary Gao, The Ohio State University.

If you grower Vinifera grapes, side netting is the preferred method. We do grow several short rows of Cabernet Franc and Regent. They are trained on the Vertical Shoot Positioning system, or VSP.

Typically, the size of the openings is typically half an inch or smaller. Netting is quite an effective method in preventing bird damage. It is by no means perfect since birds can still peck the fruits through the openings. Raccoons and other animals can manage to get the netting to eat the fruits.

Frontenac grapes with bird netting applied. Photo by Gary Gao, The Ohio State University.

Other methods of bird damage prevention are bird distress calls, noise makers like propane cannons, and scarecrows. There is not one method that is 100% effective.

It is important to get the net on the grapes as soon as they turn color. As a matter of fact, it is better to do this sooner than later. Sometimes, birds may just peck the green grapes off just for the fun of it!

 

Upcoming Events: 

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

August 24, 5:30 – 8:00 pm, OSU Extension Pumpkin Field Day

September 19 – 21, Farm Science Review

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

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

January 4th – 5th, Ohio Organic Grain Conference

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