Specialty Crop Research

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.

Grafted Watermelon Plants: Under What Conditions and Practices Does Using Them Offer the Best Return on Investment?

A lot of research is focused on answering that two-part question for watermelon and other crops (e.g., cucumber, cantaloupe, tomato, pepper). Full answers will emerge as growers and researchers share and integrate their experiences then evolve as circumstances change. Currently, most agree that using grafted plants is most beneficial when a resistant rootstock is selected to help offset the effects of a significant soilborne disease (e.g., Fusarium, Verticillium), regardless of crop. However, rootstocks with additional traits are being tested under other troublesome conditions (e.g., salinity, heat, cold, drought, flood). Growers are encouraged to listen as peers and research-extension and industry personnel share new information on the performance of grafted plants under various conditions. Information will be specific to crop, setting (field, high tunnel), system (conventional, organic), market, farm size, and other key variables.

Soil and other production conditions are not the only factors that influence the value of grafted plants to growers. Practices used to grow the plants are also important. Plant and row spacings (plant populations), irrigation and fertility programs, and planting and harvesting dates may also affect growers’ experiences with grafted plants.

Industry-research/extension partnerships can help fast-track arriving at answers to where and how grafted plants should be grown for growers to benefit most. We work with plots at OSU and on farms to understand the impacts of in-row spacing, fertility programs, and more on watermelon fruit yield and quality. Grafted and standard (ungrafted) plants are included in each experiment. Results from a multi-year study in Wooster through 2020 are summarized in a short video at https://go.osu.edu/vegeprosystemslab. Overall, fruit number and total weight have been significantly greater in grafted plots and at an in-row spacing of five versus four feet (between-row spacing of six feet in all cases). The results suggest growers can reduce plant populations but increase yield meaningfully – i.e., reduce plant costs while increasing income potential. Importantly, evidence of Fusarium in this experiment has been absent or minimal in all previous years. As explained and shown in the panels below, Fusarium is affecting the experiment significantly in 2021. Standard (ungrafted) Fascination and Sweet Dawn plants are very weak or dead while grafted versions of both (Carnivor, Pelops as rootstocks) remain healthy and vigorous. Harvest will begin soon and fruit yield data will be available by season’s end. Please contact me if you would like more information on this experiment or grafting.

Notes from the Pumpkin Patch

Pumpkin Field Day – August 26

Pumpkin field day flyer

We are less than 13 days away from the 2021 in-person pumpkin field day on August 26 at the Western Ag Research Station (7721 S. Charleston Pike, S. Charleston). We will have two hours of presentations plus time for growers to roam the plots and see what interests them, including the powdery mildew fungicide trial, pumpkin and squash hybrid trial, and weed control plots.

The field day starts promptly at 5:30 PM where we will have Dr. Aaron Wilson from OSU talking about weather impacts on pumpkin production and Tony Dobbels reviewing a weed screen plot with 10 herbicide treatment combinations of Reflex, Sandea, Dual Magnum and Strategy. For diseases, we were very fortunate to pry Dr. Dan Egel from Purdue University to speak about disease control in pumpkins. Jim Jasinski will briefly cover the pumpkin and squash trial and powdery mildew fungicide trial. After the presentations the participants will be allowed to move around the plots. The field day will end at 7:30 PM.

Pre-registration is a must for this event so please use this link.
https://osu.az1.qualtrics.com/jfe/form/SV_7WnQLmG3bcyQWc6

Cut-off for pre-registration will be Aug. 24. No walk in registration will be possible. Social distancing and mask wearing might be required for the outdoor event so come prepared. No beverages will be provided so bring your own.

Weed Control Video on IPM YouTube

Tony Dobbels talks about weed control in pumpkins and squash

For growers who are unsatisfied with their early and mid-season weed control in pumpkin and squash,  take 15 minutes and check out this new pre-emergent herbicide video narrated by Tony Dobbels, Department of Horticulture and Crop Science. In the video, Tony reviews 10 herbicide treatments and combinations of  Sandea, Dual Magnum, Strategy and Reflex (currently under a 24c label) and gives his thoughts on their level of control and fit for overall pumpkin and squash production. Watch the video here: https://youtu.be/NmSX4FqK7T4

Powdery Mildew Beginning to Roll
After what seemed like a slower than average start to the powdery mildew season (at least at the research station), leaves in the untreated checks have been climbing to between 50-75% coverage. Be sure to treat on a 7-10 days schedule and use proper FRAC number rotation to reduce the incidence of fungicide insensitivity. Sally Miller’s article on July 10 (https://u.osu.edu/vegnetnews/2021/07/10/addendum-more-powdery-mildew-fungicides-for-cucurbits/) is a great resource to what has been working lately in Ohio and is a must read as we approach the mid point of the disease management season.

Pumpkin Insects Report
For the most part squash vine borer has died down for the season. I saw some extensive damage in the Hardin County crop walk a few weeks back in zucchini but haven’t seen it in any of my pumpkin or squash plantings at the station, although I have been actively catching adults until about two weeks ago.

Cucumber beetles are still hanging out in the flowers but as we approach 100% orange in some of our trials, fewer and fewer flowers are being produced so I expect a switch soon to possible rind feeding. If you are in a similar situation, keep an eye on flower production and where the beetles are actively feeding to avoid rind damage which could lower market quality.

Mating squash bugs.

So that leaves squash bugs as the only insect I see at the station beginning to increase fairly steadily, with many egg masses being detected on leaves, followed by gray nymphs typically aggregated together and eventually larger brown adults. These pests have sucking mouth parts and can feed extensively on the petioles, vines and fruit, sometimes causing collapse. If there are over one egg mass per planting, treatment of the emerged nymphs is easier than waiting for them to become adults. Only treat if necessary to avoid aphid explosions with their accompanying honey dew and black sooty mold on leaves and fruit.

2020 Pumpkin and Squash Trial Results

There are literally hundreds of commercially available pumpkin and squash hybrids on the market today. For the past 20 years we have tried show a small sample of what is available for growers to take a look at during our annual pumpkin field day. The primarily purpose of the trial is to evaluate disease resistance to powdery mildew but also for fruit size, shape, color and yield.  Although the field day was held virtually this year, here are some details about the trial including a group photo (Figure 1) plus individual statistics about each squash and pumpkin hybrid.

2020 Pumpkin and Squash Fruit Group Photo.

The trial was direct seeded on June 1 into plots 50’ long with a row spacing of 15’. The final seed spacing in each row was 3’ – 4’ allowing for 12 or 13 plants per plot. Strategy (4.5 pt/A) and Dual Magnum (1.3 pt/A) were applied for weed control pre-emerge on June 2. Later emerging weeds were removed from the plots throughout the season. Soil testing for P and K were sufficient in that field so only nitrogen was applied side-dressed at 65 lb N / A using liquid 28-0-0 on June 26. The plots were managed for powdery mildew upon first detection on July 27, with the first fungicide spray applied on July 29. Future sprays were alternated on a 7-10 day schedule with the last application on September 4. An early harvest occurred on Aug. 12 and 18 to accommodate the filming of the virtual pumpkin field day. It is important to underscore that because the harvest was conducted prior to all immature fruit sizing and maturing, the number of marketable fruit and therefore the estimated yield values are all below their full yield potential. For the fruit that were mature at harvest, the average weight should be fairly accurate under our trial conditions. Realize also that these hybrids planted in your spacing regime may have different results than this trial. Overall, the trial received 6.8 inches of rain from June 1 – September 1.

The hybrids are listed by their seed company, powdery mildew rating (none, PM tolerant, PM resistant) and days to maturity (Table 1). The same list is also shown with the range of fruit weight, average weight, number of marketable fruit, and estimated fruit and tonnage per acre (Table 2).

Table 1. Data related to hybrids in trial.

 

Table 2. Physical data associated with trial harvest.

* seed received and planted ca. 1 month later than other hybrids leading to immature fruit at harvest.
** calculated using 50ft row length with 15ft row centers.
*** missing plants in plot leading to fewer fruit and reduced yield.

For a more detailed review of the fruit and foliage, view the Virtual Pumpkin Field Day Video from 52:84-68:43.  You can also take a look at the hybrids using the 3D Field Scale Model. Click the play button and then anywhere on the model or use the shortcuts in the left hand pane.

Missed the Virtual Pumpkin Field Day?

A total of 61 people signed up for the 2020 Virtual Pumpkin Field Day which premiered last week on August 27. If you weren’t able to participate in the field day last week, you can still watch the whole program which is posted here: https://u.osu.edu/jasinski.4/pumpkins/.

Since this is our first time doing a video based field day, take 3 minutes and tell us what you learned, liked or didn’t like. https://www.surveymonkey.com/r/vpumpkin20impact.

Also on the main pumpkin page you will find additional pumpkin related resources including past reports on powdery mildew management, hybrid trial results and other information.

The pumpkin field day video has been viewed 74 times and is hosted on the OSU IPM YouTube channel https://go.osu.edu/osuipm.

OSU pumpkin page with lots of resources.

Pumpkin & Squash Growers Wanted for On-Farm Mustard Biofumigation Trial

Plectosporium blight on fruit and handle.

Plectosporium blight on petioles and leaf veins.

In 2019, research was conducted into the use of mustard cover crops as a biofumigant to reduce a specific soil borne disease in pumpkins, Plectosporium blight, also known as white speck or Microdochium. The signs of this disease start out as spindle shaped lesions on the petioles, vines and back of leaf veins potentially killing the plant. If the disease progress, it can infect the handles and turn immature and mature fruit white.

Although our trial in 2019 was planted in a Plectosporium infested field, very little disease developed due to the near drought like conditions at the research station in South Charleston. In wetter locations around Ohio this disease was seen last year and we still think there is potential for this cultural technique to reduce disease in pumpkin and squash fields. To accomplish this on a wider scale in 2020, we plan to replicate and expand our mustard cover crop (MCC) biofumigation study to include on-farm trials with growers.

We are looking to recruit 4-6 growers preferably in the central or southern part of the state to put out a mustard cover crop biofumigation trial to reduce soil borne disease pressure with the following guidelines and conditions.

Growers requirements and general protocol:
-Growers must plant in field known to have a Plectosporium blight infestation. Growers with fields infested with Fusarium or Phytophthora will also be considered.

Equipment needed to successfully manage a mustard cover crop.

-Growers need to have equipment to seed the cover crop, chop (bush hog or flail), incorporate (rototill), pack the soil (culti-mulcher) and possibly seal the soil using a sprayer or irrigation system. These steps will be done in rapid succession so 3-4 tractors are ideally needed, each hooked to an implement.

-Growers will put out 4 strips of MCC and 4 strips without a MCC.

-Strip sizes will be up to 0.1A for a maximum of 0.8A needed for the entire on-farm study.

-Growers will plant Caliente Rojo, currently the highest yielding glucosinolate mustard cover crop available.

OSU will provide:
-The MCC seed, the fertilizer (urea + granular ammonium sulfate) and 1K seeds of the pumpkin hybrid Solid Gold (Rupp).

-Also evaluate each grower site for disease incidence on foliage three times during the season, plus a harvest where mature fruit are weighed and graded for disease.

Study Timeline:
-The MCC strip plots fertilizer will be disked into the soil prior to seeding to ensure high biomass production.

-The MCC planting date will be between March 30 and April 30 based on soil conditions and weather forecasts.

Mustard cover crop at full bloom.

-Approximately 50-60 days later, the MCC will be at peak flowering and will be chopped, rototill incorporated into the soil and then packed using culti-mulcher. If irrigation is available, water will be applied to help seal the soil and create a better environment for biofumigation.

-Within 10-14 days of incorporation, Solid Gold pumpkins will be transplanted into those strips at roughly 4ft spacing between plants. Note that transplants are preferred at each site instead of direct seeding, but if this is not possible, we can discuss options. Transplants will lead to an earlier harvest.

Plot Care:
Each farm will follow their own standard weed, insect and disease control and fertility practices on the 8 strips. The fungicides used on the crop will need to be discussed ahead of time so we can limit the use of fungicides that might help control Plectosporium blight. These fungicides are Flint, Cabrio, Quadris, Inspire Super and Merivon.

Disease ratings of incidence on vines, foliage and fruit will be taken at 14-21 day intervals from vining until fruit maturity. Sections of all strips will be harvested and fruit will be weighed and graded for disease.

The Big Picture:
By expanding the number of sites for this research through on-farm trials, we expect to see the potential MCC may have to reduce the soil borne disease complex affecting cucurbits. By recruiting growers into this process at a small scale, we hope to gain their valuable feedback as to the feasibility and challenges of using MCC on their farm. If successful, growers will spread the news to other growers who might be willing to try MCC on their farm. In addition to the potential biofumigation benefit, growers will be enhancing their soil organic matter levels and provide premium although brief pollinator habitat during flowering.

If growers want to see a video detailing the steps and processes involved with planting MCC as a biofumigant, check out the work we did in 2019 at https://youtu.be/Taz-PhDphhA.

Sign up:
If interested in participating in this project or have questions, please contact me at 937-484-1526 or jasinski.4@osu.edu by March 14.

This project is being funded by the Ohio Vegetable and Small Fruit Research and Development Program and the IPM Program.

Pumpkin Hybrid Review – 2017

In an effort to help growers select and grow the best pumpkins for their operation, the Integrated Pest Management Program planted a demonstration trial at the Western Ag Research Station in South Charleston to highlight foliage, handle, fruit size, and fruit quality. There were 20 entries from four companies in the trial, with emphasis placed on hybrids that offered some type of disease resistance, primarily to powdery mildew. The intent of the trial was primarily for growers who attended the pumpkin field day to observe differences in plant and fruit quality in person, in order to generate a visceral opinion and appreciation for the hybrid.

The trial was originally direct seeded June 1st, but due to mice damage and flooding rains, was replanted with transplants June 16th. Approximately 75 pounds of nitrogen was side dressed as liquid 28-0-0 on June 9th, with no P or K applied per soil test recommendations. Strategy and Dual were used pre-emerge to control weeds, with shielded applications of glyphosate followed by hoeing and hand weeding throughout the season. Once powdery mildew was detected in these plots on July 24th, they were sprayed on a 7-10 day schedule with a standard fungicide program that alternated several modes of action, per OSU recommendations.

While specific trial data was collected, because it was not replicated or randomized, all calculations for yield and fruit size should be seen as estimates taken from one site, under a specific set of weather conditions. When making decisions about hybrid selection for 2018, this information should be combined with other trial data from around the state or region. This trial was not irrigated, and received above average rain fall for this location based on historical records.

Group shot of pumpkin hybrid trial, large fruit in top row, medium sized fruit in middle row, and small fruit in bottom row.

To obtain average fruit weight, 3-5 fruit of each hybrid per plot representing the largest, smallest, and average sized fruit were chosen and weighed. All other marketable fruit in plot were counted and used in yield calculation, which was based on a 15’ row spacing, 35’ length of row, with plant spacing 3-4’ apart.

If you have additional questions about the trial, contact me directly at jasinski.4@osu.edu.

Yield data from pumpkin hybrid trial, see above for yield estimates. *indicates reduced stand in trial.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Seed companies and other pumpkin hybrid attributes from 2017 trial. PMR = powdery mildew resistant, PMT = powdery mildew tolerant.