The Ohio Produce Growers and Marketing Association is holding their annual fruit and vegetable conference, dubbed the Grower’s Produce Network on January 17-18 at the airport Mariott in Columbus. A selection of in-state and out-of-state speakers has been assembled to cover a range of topics on vegetable and fruit production, pest management and marketing. Details on registering for the event plus the education sessions can be found on OPGMA’s website, http://www.opgma.org.

Hope to see you there!

Dear vegetable producer,

You are being asked to participate in a study, “Insect Pest Management in Vegetable Crops Survey” (Purdue IRB protocol no. 2021-979) by researchers at Purdue University and The College of Wooster. The purpose of this study is to get more information on insect pest management practices and strategies used by vegetable producers in the Great Lakes and Mid-Atlantic regions. The information provided here will help direct pest management research and extension programs in specialty crop production.

You must be at least 18 years of age to participate. The survey will take approximately 20-25 minutes to complete. The survey is anonymous. The researchers have pledged to keep your data confidential and will only report aggregated results in any published scientific study.

In appreciation of your choice to participate in the survey, you can choose to enter into a raffle for a hardcopy of one of two complimentary spray guides: the Midwest Vegetable Production Guide for Commercial Growers ($21 value), or the Mid-Atlantic Commercial Vegetable Production Guide ($25 value). Instructions for entering the raffle can be found at the end of the survey.

To begin the online survey, click this link.

Participation in this study is voluntary and you may withdraw from participation at any time. If you have any questions, you may contact the researchers:

Dr. Carlo Moreno (First point of contact)
The College of Wooster
931 College Mall, Wooster, OH, 44691
Phone: 330-287-1982
Email: cmoreno@wooster.edu

Dr. Elizabeth Long
Purdue University
901 W. State Street, Lafayette, IN 47907
Phone: 765-496-1918
Email: long132@purdue.edu

Two Bt sweet corn trials were conducted in South Charleston and Wooster in 2021 to determine the efficacy of various Bt gene traits against common lepidoptera (moth) pests such as corn earworm, European corn borer and fall armyworm. Both trials were planted in late June and harvested for evaluation in early September to maximize caterpillar damage. No insecticide treatments were applied to any of the treatments.

Corn earworm filled trap near sweet corn trial.

The South Charleston trial contained two non-Bt hybrids (Providence & Obsession I) and two Bt hybrids (BC0805 & Remedy). There was a fifth hybrid in the trial (Bt traited Obsession II) but it was destroyed by a misapplication of herbicide. In Wooster only Providence (Non-Bt) and Remedy (Bt) were planted.

The primary pest of concern for late planted sweet corn is the corn earworm. There were heavy flights around silking in South Charleston but lighter flights around silking in Wooster. In South Charleston, 98% of Obsession I ears (non-Bt) were damaged, 100% of Providence ears (non-Bt) were damaged, 91% of BC0805 ears (Bt) were damaged but only 0.7% of Remedy ears (Bt) were damaged. In Wooster, 86% of Providence ears (non-Bt) were damaged and 1% of Remedy ears (Bt) were damaged.

Corn earworm caterpillar in ear tip.

It is reasonable to assume that corn earworm would readily damage non-Bt sweet corn ears that were not protected by any insecticide, but why weren’t both Bt sweet corn hybrids (BC0805 and Remedy) protected from damage? The answer lies in the actual Bt traits each hybrid contains; BC0805 is an Attribute I series containing only Cry1Ab genes while Remedy is an Attribute II series hybrid containing Vip3A + Cry1Ab Bt genes. There is general consensus that Cry1Ab Bt genes alone are not protective in sweet corn against lepidoptera pests.

Sweet corn hybrid evaluation underway.

This was the first time any damage had been recorded on Remedy sweet corn in OSU trials. This is important to note because it is a signal that resistance against Vip may be evolving in the CEW population. ECB was not detected in the South Charleston trial and only found in one ear in the Wooster trial. No FAW was found in either trial. Regardless of location within the state, for late planted sweet corn, all hybrids not containing the Vip Bt protein (Remedy/Attribute II) will need to be protected with insecticide sprays to yield relatively worm free ears. Even Vip Bt hybrids may gain some protection from other pests such as stink bugs by adding insecticide sprays.

Much was accomplished in the 2021 growing season that relates to pumpkin and squash. In case you missed it while it was happening, here is a quick review of topics for you to peruse on some rainy and cold day when you don’t want to go outside and work around the farm. You can also find additional posts on the VegNet Blog located here: https://u.osu.edu/vegnetnews/

Videos

Over the past several years there has been a push to create video content to illustrate key monitoring, scouting, identification and management videos for key pests that affect pumpkin and squash. This content is posted to the OSU IPM YouTube channel (go.osu.edu/osuipm) and curated under a “Pumpkin” playlist at the top of the page. Recent additions include:

-2021 Pumpkin and Squash Hybrid Trial Review

-Tracking Big Foot Through the Pumpkin Patch

-2021 Herbicide Weed Screen for Pumpkins

-Managing Squash Vine Borer in Cucurbits

-Early Season Management of Cucumber Beetles and Bacterial Wilt

Screen shot of current pumpkin related videos on OSU IPM YouTube channel.

Powdery Mildew Trial Report

In 2021 we also conducted another powdery mildew fungicide evaluation trial at the Western Ag Research Station in South Charleston. Included in the trial were two novel fungicides, Cevya and Gatten, both which looked pretty good. The complete report can be accessed here toward the bottom of the page: https://u.osu.edu/jasinski.4/pumpkins/

Pumpkin and Squash Hybrid Trial Report

For those of you who want more details than those provided in the video review mentioned above, there is a detailed report posted on the VegNet Blog here that lists the hybrids, estimated number of fruits and yield, and other details related to the trial.

https://u.osu.edu/vegnetnews/2021/10/20/2021-pumpkin-and-squash-hybrid-trial-data/

A hybrid pumpkin and squash hybrid trial was planted in the Western Ag Research Station in South Charleston, OH. There were 29 hybrids evaluated in the trial ranging from traditional jack-o-lantern fruit to more colorful or textured fruit from a variety of companies as seen in this group photo (Figure 1). The trial focuses on demonstrating foliage tolerance to powdery mildew as well as observing general plant health and growth patterns. A second function of the trial is to evaluate hybrid fruit size, shape, color, etc. and to obtain some estimates of yield and fruit numbers per acre based on our production methods. As these methods are likely to change from grower to grower, so will expected yields and fruit numbers. This report is only to provide an estimate of yield and fruit potential.

Figure 1. Group shot of pumpkin and squash fruit in 2021 trial.

Each plot in the trial was 50’ long and planted on 15’ row centers. There was no replication of the plots, so all data was collected from one plot. The trial was direct seeded on June 1 but nine hybrids were transplanted on May 27 due generally to later maturities so that all fruit would be mature by the pumpkin field day on August 26, which was successfully accomplished. In-row plant spacing was set at 3.5’ for all hybrids.

Harvest and fruit number data were collected on September 2 as all plots showed 95+% mature fruit. Three to five representative fruit were clipped and weighed from each plot, with all other remaining mature and immature fruit in each plot counted. Estimations of yield and fruit numbers for each hybrid are based off of 50’ row plots (0.017A) extrapolated out to a full acre.

For weed control, Strategy (4pt) plus Dual (1.3pt) plus glyphosate (32oz) per acre was applied pre-emergent followed by Sandea (1oz/A) between the rows prior to the vines running. Based on soil sampling no P or K was applied but ca. 75 lb N was sidedressed on using 28-0-0 on June 15.

For powdery and downy mildew control we began applying fungicides July 22 on a 7-14 day schedule following proper rotation guidelines, with the last application being made on August 30. Spray applications were made at 36 GPA at a pressure of 65 PSI using hollow cone nozzles.

Below are listed the basic information and some general notes about each hybrid in the trial listed alphabetically (Table 1). All yield and fruit number data are in Table 2, listed alphabetically by hybrid name.

Table 1. Basic information about hybrid entries including seasonal notes.

Table 2. Estimated yield and fruit count data for 2021 trial.

If you have any questions about the trial, please feel free to contact Jim Jasinski, Jasinski.4@osu.edu.

Sunburned pumpkins by handle. Note even handle is burned on one side.

This title should seem familiar as a slight twist on the famous John Denver tune from 1971. With temperatures in the low to mid 90’s for at least three days last week across most of the state, fruit that were not properly covered in the canopy were placed at a higher risk for getting sunburned.

Downy mildew infested field with no leaf canopy.

Based on observations over several years, fruit that are cut off the vine tend to burn more readily than those that remain on the vine, likely a function of being able to evapotranpirate enough moisture to stave off burning. As clade 2 downy mildew was reported on August 13 (active on pumpkin/squash), fields that were not protected suffered almost 100% defoliation with 10-14 days. Amazingly this photo with near total canopy loss had nearly no detectable sun burned fruit despite several fruit actually being desiccated to the point where they were shriveling in the sun! If these fruit were cut off the vine, I would have expected significant rind burning to occur.

While there are a few “white washing” products on the market to spray on fruit in the field to prevent burning, they have not been investigated at OSU. The best prevention is a good canopy through harvest. The next best strategies though more labor intensive would be to cut and move fruit to a shaded location to cure naturally. If fruit are in a u-pick patch, moving them to distinct piles and covering with shade cloth may also be a possible solution.

Another pest that we are actively monitoring using clear sticky traps and pheromone lures is the Brown Marmorated Stink Bug. This stink bug is known to feed on vegetables, grain crops, small fruit and tree fruit.

BMSB adults on sticky trap

While we are actively monitoring for this pest in eight counties, Adams, Athens, Greene, Seneca and Wayne counties are seeing trap catch increases, mostly related to adults. Late stage nymphs and adults pose the biggest threat to tree crops like apples, with their damage resembling several other types of injury such as hail injury or bitter pit (stink bug surface injury (L), internal injury (R); Celeste Welty).

Stink bug injury on apple, courtesy of Celeste Welty

Soon these adults will migrate from the fields to structures to seek refuge from the cold temperatures as they attempt to over-winter. If you have lived in Ohio for the past few years, you are no doubt familiar with these large brown stink bugs that invade your home or office in the fall.

While we only have established thresholds for this pest in apples, these were established in the mid-Atlantic and have not been vetted in Ohio yet. We would expect these thresholds to work well in Ohio but research has not been conducted to confirm the results. Monitoring strategies for vegetables, grapes and small fruit can be found here: https://www.stopbmsb.org/managing-bmsb/management-by-crop/

The monitoring system in apples requires two traps, one placed at the edge of an apple block and one placed in the interior. When the cumulative weekly total of both trap catches exceeds 10 stink bugs, an alternate row middle spray for BMSB may be justified. The details are outlined in this article: https://www.stopbmsb.org/stopBMSB/assets/File/BMSB-in-Orchard-Crops-English.pdf

Although we are moving toward the end of the season for most small fruit producers, keep in mind that spotted-wing Drosophila populations remain high across the state where traps have been placed on farms. Because of their short life cycle and abundance of ripe fruit, expect these populations to increase up until the first significant frost/freeze event.

SWD larvae in fruit

For growers who have abandoned their small fruit plantings for this year, SWD adults can easily be seen buzzing around ripe fruit as they oviposit eggs beneath the soft skin. Evidence of infestation can be readily seen as soft juicy fruit are filled with white SWD larvae. Even for growers who have maintained a regular spray schedule to control this insect, SWD adults can still be detected flying around bramble and blueberry patches albeit in lower numbers.

Since the threshold for this pest is only one adult per trap, it is necessary to maintain a spray schedule as long as the farm intends to harvest fruit. Once the decision has been made to end harvest, the sprays can be halted.

Call for Ohio growers to participate in research.

Emily Justus is a PhD student at Purdue University working on documenting the use of insect resistant hybrids or varieties as part of an overall IPM strategy. If you have a few minutes to share your practices with her that would be very useful for her research program.

Calling all vegetable growers! Please help us learn about how you manage insect pests. I am an entomology graduate student at Purdue University and was awarded a grant from North Central Region – Sustainable Agriculture Research and Education program to investigate vegetable grower pest management strategies. My goal is to understand how vegetable growers in Ohio manage their insect pests and use of integrated pest management strategies such as resistant varieties. Responses from carrot, celery, parsley, celeriac and dill growers would be helpful but all are encouraged to respond. I hope that this work will help extension educators serve you better!

The survey (link below) should take less than 10 minutes to complete and you can enter to win a hard copy of the Midwest Vegetable production guide! Thanks so much for your help!

https://purdue.ca1.qualtrics.com/jfe/form/SV_a3RjIX30FMikubj