Pawpaw Day at the 2023 Farm Science Review

Authors: Carrie Brown

Pawpaw Day at the 2023 Farm Science Review on September 19!

On Tuesday, September 19, The Gwynne Conservation area is teaming up with the North American Pawpaw Growers Association to bring you a fun-filled day packed with pawpaw talks, walks, demos, and tastings! Events run throughout the day, 10:30am-3:00pm, and will be located at the Gwynne Conservation Area at Farm Science Review.

Are you familiar with Farm Science Review and the Gwynne Conservation Area? The Gwynne is a 67-acre conservation area where conservation demos, talks, displays, and tours are held during Farm Science Review, September 19-21, in London, Ohio. Featuring a pond, wetland, tallgrass prairie, stream, pawpaw orchard, and forage plots, the Gwynne offers a little something for everyone.

Though September 19th is dedicated to Pawpaws, talks on a variety of natural resource topics will be held throughout each of the three days of Farm Science Review. And new to the Gwynne this year, the “Ask a Master Gardener” table will be on site to answer all of your horticultural questions!

Late Appearance of Phytophthora Blight in Peppers and Cucurbits Wreaking Havoc

Bell pepper fruits with Phytophthora blight, received in late August 2023 by the OSU Plant and Pest Diagnostic Clinic. Photo by Francesca Rotondo.

Phytophthora blight on pumpkins received in October 2021 by the OSU Plant Disease Diagnostic Lab in Wooster. Photo by Francesca Rotondo.

After a hot dry early summer in many parts of Ohio this year, growers may have thought that they escaped the scourge of Phytophthora blight, and for a while this appeared to be true. However, several intensive rainfall events during the past several weeks, some bringing as much as 10 inches of rain over a weekend, resulted in flooded soil conditions perfect for spread of Phytophthora blight. Unfortunately, this late in the season, growers have invested a lot of money in these crops and may see significant reductions in yield.

The cause of Phytophthora blight is Phytophthora capsici,  a soilborne oomycete pathogen that thrives in rainy weather. It produces sporangia that release motile spores (zoospores) that are attracted to plants, then form a structure that allows them to infect, and aggressively attack any type of plant tissue. Sporangia and zoospores can be splashed onto leaves, stems and fruits during rain events and overhead irrigation. Phytophthora blight must be  managed preventatively.  This includes the use of resistant varieties (partially resistant varieties are available for pepper but not for cucurbits), cultural practices and fungicides.

We have received several reports of fruit infections of peppers and pumpkins this week. Once fruits have become infected with Phytophthora, nothing can be done to rescue them. Additionally, some lesions on pepper fruits may not be obvious initially but develop during shipping, putting healthy fruits at risk of infection. For pumpkins, if Phytophthora blight was detected in a field at any time during the season, growers are advised to harvest mature, uninfected fruits as early as possible.  These fruits need to be laid out individually (not touching, so bins are not acceptable) in a shaded area with good ventilation so that they can cure.  A barn floor would be an ideal location since they would not get rained on, but outside under a tree (to prevent sunscald) would be better than nothing.  If putting them outside, do NOT put them on a tarp or plastic that would tend to hold rainwater and spread the disease to the other fruits.  If any of these fruits start to show signs of infection (discolored areas or white, cottony growth – see photo) remove them from the area immediately and discard them in an area away from the fields or curing location.

Dr. Meg McGrath of Cornell University found that hosing pumpkins off first to remove soil (using a garden hose with a trigger spray nozzle) was the second most important step in reducing disease incidence (getting them out of the field being the most important).  Washed fruits need to be dried as quickly as possible. Dipping fruit in 10% Clorox, GreenShield or Kocide was no better than just hosing them off, and these products are not labeled for this use.

Pepper and cucurbit fruits with symptoms in the field should be removed and destroyed away from the field and surface water sources. Leaving them in the field will contribute to inoculum buildup; if Phytophthora blight was present in a field, practice rotation of at least four years away from susceptible crops including all cucurbits, peppers, tomatoes, and beans.

[Updated from previous posts. Information on fungicides to manage Phytophthora blight in peppers and pumpkins is available in previous posts.]

We thank the Ohio Produce Growers and Marketers Association’s Ohio Vegetable and Small Fruit Research and Development Program for financial support of the OSU PPDC.

Downy Mildew Reported on Pumpkins in Fulton County, OH

Partial map of 2023 cucurbit downy mildew reports as of August 7, 2023. Counties in red indicate new reports (<7 days), while counties in green have older reports.

Bill Holdsworth of Rupp Seeds confirmed a severe outbreak of downy mildew on pumpkins in his field trials in Fulton County, Ohio today. Downy mildew was extensive in this field, indicating that it had begun some time ago, perhaps a week or two. Last year, Bill reported pumpkin downy mildew in the same county on August 10. It was likely caused by Clade 1 of the downy mildew pathogen Pseudoperonospora cubensis, which has a broad host range among cucurbits, preferring pumpkins, squash and watermelons, but also infecting cucumbers and melons. Clade 2 isolates infect and cause damage to cucumbers and melons, and are seen in northern Ohio first. As in 2022, the Fulton County outbreak on pumpkins was unusual for the Great Lakes region. There are no reports of downy mildew on cucurbits other than cucumber in the Midwest, Northeast or Canada at this time – although not being reported doesn’t mean it is not there. We have not seen downy mildew on pumpkins, squash, melons or watermelons in sentinel plots in Sandusky and Franklin Counties, and Jim Jasinski, OSU Extension, has not found downy mildew in scouted pumpkin fields on OSU’s Western Agricultural Research Station in South Charleston.

Downy mildew can kill cucurbit foliage, including that of pumpkins, which will stop the fruit from maturing unless it is controlled preventatively. Pumpkin, squash, and watermelon growers should be applying at least a protectant fungicide such as chlorothalanil (Bravo, Eqqus, etc.) and amp up scouting efforts. Growers in Fulton and surrounding counties should apply downy mildew-targeted fungicides (Orondis Opti, Ranman, Omega, Previcur Flex, and Elumin) posted here and here in a spray program alternating fungicides with different modes of action/FRAC group.  Follow all label instructions.

Bacterial spot on pumpkin – can be mistaken for downy mildew.

Downy mildew symptoms on a pumpkin leaf (top)

If you suspect cucurbit downy mildew you can text or email pictures to Sally Miller (330-466-5249; of both sides of lesions, with the underside in the highest possible magnification. It is harder to confirm downy mildew in pumpkins and squash from photos because lesions are less distinctive and sporulation is less than in cucumbers.  So you may need to send a sample to the OSU C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) in Wooster for confirmation. Instructions for sample submission are here. Digital images may also be sent to the CWEPPDÇ.

Thanks to financial support from the Ohio Produce Growers and Marketers Association’s Ohio Vegetable and Small Fruit Research and Development Program, there is no fee for this service for Ohio vegetable growers.

Southern Ohio Specialty Crop Update 4.28.23

Ohio Specialty Crop Update 4.28.23: Spring arrived early March and has been a roller coaster ride with March weather in February, February weather in March, May and March weather combined in April. GDD’s have been running above average since end of February which triggered early bloom in peaches, nectarines, plums, apples with freeze controls such as row covers, smudge fires, wind machines, frost control sprays, being implemented to protect crops as recent as Tuesday 4/25 when morning lows dipped into the mid 20’s, which damaged southern Ohio pawpaw bloom. A 7.5 acre Ohio greenhouse tomato operation at I-75/U.S. 33 in Auglaize county Ohio was destroyed by a tornado on April 1. Other recent high wind events in April destroyed and damaged high tunnels, barns, and brought up to 2 inches of rain in less than an hour at some locations. Field conditions have been great for most of the area since early February and field activities include plowing, working ground, lime, gypsum, compost, manure, P & K applications, fertigation, fungicide/insecticide applications, drain tile installation, laying plastic mulch, bedding, herbicide applications, frost protection, planting of potato, sweet corn, cole crops, lettuce, peas, greens; and pruning, training, tying in vineyards, orchards, hop yards and berries. High tunnel tomatoes planted end January/early February are being harvested along with tunnel squash, lettuce, radishes, spinach, strawberries and cucumbers with strong market demand. Strawberry harvest in tunnels began on March 17 in southern Ohio. Asparagus harvest began around the first week of April and demand has been strong. No disease or insect pressures being observed or reported only remnants of freeze and cold damage from freeze/frost events going back to Christmas.

Freeze protection has been a common practice in April with Pawpaw bloom damaged on 4.25.

Plastic sweet corn was planted mid-March and bare ground was planted early April. Spring cover crop planting began in March.

Ohio State strawberry nutrition trials at Piketon began harvest on March 17 and harvest continues.

Greenhouses and high tunnels were damaged by a tornado and winds on 4.1.23

Potato planting began in the Scioto River Valley on March 8 and continues.

March and early April field conditions were ideal for activities.

Brad R. Bergefurd
Retired, Assistant Professor Emeritus


USDA Announces Signup for 2023 Assistance for On-Farm Food Safety Expenses for Specialty Crop Growers

01/20/2023 02:00 PM EST

WASHINGTON, Jan. 20, 2023— The U.S. Department of Agriculture (USDA) reminds specialty crop producers of available assistance to help cover certain costs of complying with regulatory and market-driven food safety certification requirements ….Read More

2022 Pumpkin and Squash Hybrid Trial Results

What better day to post the pumpkin and squash hybrid trial results than Halloween?

A pumpkin and squash hybrid demonstration trial was conducted at the Western Ag Research Station in South Charleston, OH. In order to have mature fruit for the late August field day, the following longer season hybrids were seeded early and transplanted on May 31: Giltedge Gold, Quigley Gold, Igor, Bannack Gold, Death Star, Tons of Fun, Sweet Baby Jane, Spartacus, Garnet Gold, Fireball, Autumn Frost and Icicle. The remaining eight hybrids were also direct seeded on May 31, bringing the total number of hybrids in the trial to 20. Hybrids in the trial included traditional orange jack-o-lantern fruit, other colorful or textured fruit, various edible ornamental squash types, and some recently released hybrids (Table 1).

The trial focuses on demonstrating host plant resistance to powdery mildew, as well as observing general plant health and vine growth. A second function of the trial is to evaluate hybrid fruit size, shape, color, etc. and to obtain some estimates of yield, average fruit weight and number of fruit per acre based on our production methods.

Each plot in the trial was 60’ long and planted on 15’ row centers (0.02A per plot). There was no replication of the plots, all data was collected from a single plot. In-row plant spacing was set at 3.5’ for all hybrids. Despite using FarMore FI400 treated seeds when possible some additional seedling losses occurred due to bacterial wilt infections. Some plants were also lost to mid-season infestations of squash vine borer. Reduced stand is noted in Table 1.

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. Hand hoeing and pulling on weekly basis prevented major weed escapes. Based on soil sampling no P or K was applied but ca. 75 lb N was sidedressed using 28-0-0 on June 24.

Table 1. Hybrids in trial and associated development notes. * = reduced stand, BW = bacterial wilt, BLS = bacterial leaf spot

Harvest data was collected on September 1 as the majority of plots showed 95+% mature fruit. From each plot, four representative fruit were clipped and weighed, with all other remaining mature and immature fruit counted and used to estimate yield data per acre. Please keep in mind this report only provides an estimate of yield and fruit potential based on our production methods which are likely quite different than traditional production farms. If harvest was delayed a few weeks later in the season, yield estimates would likely increase as immature fruit become mature.

Table 2. Hybrid trial yield data. * = reduced stand.

For powdery and downy mildew control, fungicides were initially applied July 25 but then re-applied on a 7-10 day schedule throughout the season following proper resistance management rotation guidelines. The last application was made on August 26. Spray applications were made at 36 GPA and 65 PSI using hollow cone nozzles.

 A group photo of all the fruit in the trial can be found in Figure 1, with a basketball and softball for size reference.

Figure 1. Group shot of 2022 pumpkin and squash fruit with basketball and softball as a size reference. On straw bales (L to R) Giltedge Gold, Lemonade, Eros, Fireball, Hermes, Garnet Gold, Spartacus. Large fruit in front of straw bales (L to R) Quigley Gold, Tons of Fun, Igor, Bannack Gold, Death Star, Sweet Baby Jane. Small fruit in front of straw bales (L to R) Autumn Frost, Autumn Pearl, Fort Knox, Winter Blush, Moon Stacker, Icicle, Warty Gnome.

If you have any questions about the trial, please feel free to contact Jim Jasinski,

Spotted Lanternfly and the Potential Impacts on the Maple Syrup Industry

There will be a free webinar on November 16, 2022, at 10:00 AM EST, titled Spotted Lanternfly and the Potential Impacts on the Maple Syrup Industry.

Extension Educator Brian Walsh, Penn State Extension, will discuss what is known about the spotted lanternfly and observations about maple trees that provide insight as to the impact the insect could have on the industry.

Ever since the spotted lanternfly was found in Southeast Pennsylvania, it has been causing damage to agricultural plants as well as non-agricultural plants. As the insect continues to expand its range, more is being learned about the insect’s lifecycle and its feeding habitats. Since the spotted lanternfly can feed very heavily upon certain tree species, the insect can potentially impact the maple syrup industry.

Click this link to register:

Pumpkin and Sunflower Field Day – August 25

For over 20 years the pumpkin field day has been a source of production and pest management information for both new and experienced growers. This year we will be adding some flair as we begin to tackle the production and pest management issues surrounding the popular trend of sunflower fields for photographs and cut flowers as an additional source of revenue on diversified farms. So if you want to learn about two popular fall attractions, pumpkins and sunflowers, this is a field day that can’t be missed.

Pumpkin and sunflower

The field day will be divided roughly in half, with the first hour focused on sunflower topics ranging from grower experiences in production (Matt Sullivan, grower) to impacts from the ag tourism perspective (Kate Hornyak, OSU). A nine-hybrid sunflower demo strip trial will be in various stages of bloom for attendees to walk through and examine.

The second hour will focus on pumpkins, starting off with managing pollinators in cucurbits (Ashley Leach, OSU), foliar fertilizers and plant nutrition (Bryan Reed, Sunrise) and then a review of powdery mildew fungicide management and a walk through the 24 hybrid trial (Jim Jasinski, OSU).

The field day will be held at the Western Ag Research Station, 7721 S. Charleston Pike, South Charleston Ohio. The field day will begin promptly at 5:30 PM and end at 7:30 PM. Pre-registration is required for attendance and there is a $5 charge per person for handouts and refreshments (and likely a few sunflowers). For more information contact Jim Jasinski,

Pre-register at this link:

More details are listed on the attached flyer. Hope to see you there!

Pumpkin and Sunflower 2022 Flyer

Spotted Wing Drosophila Spotted

Spotted-wing Drosophila (SWD) is one of the major pests of cane berries, blueberries, black berries, strawberries and peaches. Last week it was detected in Greene, Monroe, Geauga and Wayne counties but likely is present and active in most Ohio counties at this point in the season (

Spotted wing Drosophila male (L) and female (R).

Recall that this pest is relatively new to Ohio, first discovered in 2011, and has the distinction from other drosophila flies of being able to attack whole, healthy fruit as they begin to blush and ripen.

The best way to monitor for this pest on your farm is to use a trap with either a commercial lure or apple cider vinegar as a bait.

Spotted wing drosophila baited Scentry trap.

If you do this, it will be necessary to empty the trap weekly and look through the catch to identify the male (with the spot on its wing) or female (which has an enlarged serrated ovipositor) using a stereoscope. Remember that the threshold for this pest is 1 SWD fly, male or female. Once the threshold is exceeded, trapping can be halted. This can be a fairly intensive endeavor but has been described in detail in various videos posted to the OSU IPM YouTube channel (setting up trap, identification, salt water tests, etc.).

If you choose not to monitor for this pest and have had SWD on your farm before, it is nearly 100% certain they will return once fruit is in the blush or ripe stage, so you should prepare to manage based on their assumed presence. A fact sheet on SWD giving more detail on management and biology with an up to date list of insecticides can be found here:

Once you decide to stop harvesting in a certain block, insecticide treatment for SWD can be halted. For smaller or organic growers, some cultural methods including use of black mulch, pruning and netting have been shown to reduce and delay infestation.

Medina County grower talking about his exclusion netting project to manage SWD.

Notes from the Pumpkin Patch – June 26

The seasonal pattern of too wet to do any field work has relented to extremely dry conditions given the past week of temperatures in the 90’s. I managed to get caught up on planting the last of my trials, side dressing those trials with emerged plants and applying herbicides in anticipation of rain.

Perhaps the biggest pest to note over the past week was Squash Vine Borer becoming active in Greene and Coshocton counties ( This pest can cause some plant loss if active in fields (egg laid on stem, hatches into caterpillar which bore into the plant stem and can no longer be successfully treated) but usually not more than five percent of plants are infested. In prior years I have seen losses up to 30% in some of my research plots.

Squash vine borer adult on pumpkin leaf.

One way to determine if this pest is active near your field is to observe a large purple and orange moth flying around the field, but the best way is to use a pheromone trap. Once increases in trap catches are seen, 2-3 applications toward the base of the plant every 7-10 days is an effective control measure. Foliar insecticide options are listed in the Midwest Vegetable Production Guide ( I produced a short video on monitoring and treatment options as an overview on the OSU IPM YouTube site (

SVB pheromone trap.

Not much other pest activity to note at the research station but it was obvious to see while working around the various trials which hybrids had been treated with FarMore FI400 and which ones were not based on their Striped cucumber beetle feeding levels. I also saw my first Spotted cucumber beetle of the season this past week.

Spotted cucumber beetle.

Spotted cucumber beetle.

Keep an eye out for the third major early season pest, Squash bug, which should be making an appearance soon.

Squash bug adult.

Squash bug eggs.