In 2023, the state-wide county agent horticulture demonstration shifted away from
sweet corn and sought to investigate 3 pumpkin varieties within the Cucurbita pepo species.
We wanted to investigate new pumpkin varieties of varying colors and assess potential
varietal resistance to melonworms and powdery mildew (Table 1) . Many specialty crop growers in the state are planting pumpkins to capitalize on
the fall agritourism market and this demonstration aimed to give both growers and
agents insight on new varieties to enhance grower profitability. The Google Maps image
in Figure 1 shows the location of many of the pumpkin patches found across the state. It gives
some insight into the rapid expansion of agritourism in Arkansas and the part that
pumpkins play in getting the public out on the farm.
Figure 1 . A festive Google Maps image of some, but not all, of the pumpkin patches found in
Arkansas.
With the increasing amount of pumpkin acreage comes additional pest and disease concerns
for growers, which inspired us to look into this Agent demonstration. The table below
highlights some of the attributes of the 3 Jack O’ Lantern pumpkin varieties we demonstrated
in 2023.
Table 1. A table showing the three varieties of pumpkins in the demonstration and their different
characteristics and advertised size from seed companies.
Preparation Seeds were started in a greenhouse at the Southwest Research & Extension Center (SWREC)
on June 1st . The pumpkin starts were moved outside to a high tunnel in mid-June (Figure 2) in preparation for getting them to County Agents for a target planting of around
July 1st . Pumpkin starts were delivered to the Little Rock State Office (LRSO) for agents
to pick up on June 20th (Figure 3) . Other agents were able to pick up their plants at SWREC during the Horticulture
Field Day on June 28th or were hand delivered by Horticulture IPM staff to the Fruit Research Station (FRS)
and the Vegetable Research Station (VRS) for convenient pick-up. Most Agents received
5 plants per variety, but some Agents received as many as 15 plants per variety if
they had a larger planting space available with collaborators. The plants were to
be spaced 3 feet apart in- row with a 10-feet row spacing if necessary. Grower standard
practices for irrigation and fertility were suggested but not required.
Figure 2. Dr. Aaron Cato posted a photo update on X, formerly Twitter, showing hundreds of
pumpkins sitting in a high tunnel to be used for the agent demonstration.
Figure 3. Pumpkin Demonstration starts sitting on the courtyard bench at the Little Rock State
Office awaiting pick-up by County Agents.
Reporting We asked county agents to report their results in two ways. First, agents reported
their observations on growth and harvest characteristics of the pumpkin varieties.
For the harvest metrics, we asked agents to record the yield, the number of pumpkins
per plant, and percent marketable fruit in terms of what percentage of pumpkins they
thought they could sell. In terms of pests and diseases, the agents scouted for melonworm
and powdery mildew. Melonworm (Figure 4) is a tropical moth species that infests cucurbit fields in early September and can
cause serious damage to pumpkins by feeding on the rind and burrowing into the handles
causing them to fall off. One of the worst outbreaks of melonworm was in the fall
of 2021. Cucurbit powdery mildew (Figure 5) is caused by two different fungal pathogens and is identified by white powdery fungal
growth on leaves and stems of all cucurbits and if left unchecked, can cause defoliation,
fruit quality, and size issues. Luckily, some resistance has been included into certain
commercially available varieties including two-thirds of the demonstration varieties.
Secondly, agents posted progress of the demonstration on social media using the hashtag
#uaexHORT . Below are some examples of social media posts made by agents that really helped
to showcase this work and get the community interested (Figures 6-8).
Figure 4. Dr. Aaron Cato admires an adult Melonworm moth, Diaphania hyalinata, on a Justify pumpkin from research trials near Hope, Arkansas.
Figure 5. Powdery mildew was observed on Moonshine in additional research trials by Aaron Cato.
Moonshine does not have any powdery mildew tolerance incorporated and was expected
to have some level of disease pressure. Photo by Ryan Keiffer from Kibler, Arkansas.
Figure 6. Sherri Sanders posted an update to X, formerly Twitter, on Sept. 20th which highlighted the harvest of the pumpkin demonstration. You can see the three
different varieties in the top right corner. She used the hashtag, #uaexHORT and impacted
46 different users with her post.
Figure 7. A Facebook post by Michelle Mobley, Ag Agent from Independence County¸ showed a good
crop of pumpkins on all three varieties in the demonstration.
Figure 8. Adam Willis, Ag Agent for Newton County, shared the results from his pumpkin demonstration
on Facebook. The three pumpkin varieties are sorted by variety and sitting on a rock
wall. Left to right are Spicy Mocha, Moonshine, and Justify.
Results Overall we had 19 counties submit usable data. The table and charts below show the
average of the measured pumpkin characteristics across the 10 to 13 counties that
reported yield data for the demonstration (Table 2) . Data collection by variety differed in the number of responses received due to crop
failures such as deer, ground hogs, weed control, heat, irrigation, or squash bugs.
That information was helpful to receive as well, as it enables us to identify future
outreach efforts for specialty crop protection. On average, each variety produced 2-3 pumpkins per vine with Moonshine having the
highest average of 2.8 pumpkins per vine. The average weight of each variety was lower
than advertised size descriptions from Table 1. Spicy Mocha and Justify were similar
in all metrics, with an average of 2 pumpkins per vine with an approximate weight
of 7.5 lbs. each. Moonshine pumpkins averaged 4.1 lbs per pumpkin, but set almost
one more fruit per vine compared to Justify and Spicy Mocha. Overall, the percent
marketability of the pumpkins was good with all three varieties near 85 percent. However,
we would have expected many more pumpkins in a summer that didn’t have record heat.
One large grower in Northwest Arkansas reported that Moonshine was “a tough sell because
several never ripened properly due to powdery mildew and didn’t sell a high percentage
of because they do not hold their color well.” Moonshine was reported to have powdery mildew by 18% of counties who reported on that
category compared to 8% for Justify and Spicy Mocha (Charts 1) . Many other factors might have contributed to reduced size or % marketability when
compared to advertised weight, but the most likely culprit was drought conditions
during flowering and/or water delivery issues.
Table 2. Results from the 2023 Horticultural Agent Pumpkin Demonstration, showing average
number of pumpkins per vine, average weight per pumpkin (Lbs.), and percent marketable
fruit. Data collection by variety varied in the number of responses mainly due to
crop failure and ranged from 10 to 13 responses.
Chart 1. Powdery mildew can break through fungicide spray programs in Arkansas when conditions
are favorable. This year (2023) was an extremely hot and relatively dry summer, which
meant that we saw powdery mildew later than we would normally. Powdery mildew was
observed on Spicy Mocha and Justify even though they have an intermediate amount of
powdery mildew resistance. Moonshine lacks powdery mildew resistance and was observed
in 18% of reporting counties compared to 8% for the other two varieties.
Conclusions One of the main objectives of this demonstration was to evaluate melonworm resistance
in pumpkin varieties, however we failed to observe melonworm across much of the state.
Because melonworm larvae can quickly defoliate plants, as well as feed on the rind
and handles of pumpkins, we urged frequent scouting of pumpkins to detect this pest.
Melonworm was found in research trials at the SWREC in Southwest Arkansas in late
August. This indicated that the pest may be detected in county agent demonstrations,
but melonworm wasn’t observed anywhere else in the state until the pest was found
again in research trials at the VRS in Kibler on October 10th . Thus, we were unable to evaluate the susceptibility of the demonstration varieties
to melonworm this year; although research trials are still being conducted by state
specialists to determine cucurbit species susceptibility to melonworm. However, this demonstration showcased the importance of scouting when considering
insecticide applications, as none were warranted for melonworm this year, unlike several
previous years. Other issues presented themselves when agents reported their data, and Chart 2 shows some of the common issues that impacted demonstration success or failure. Luckily
there are some good resources available to combat some of these issues, such as FSA9111 and FSA6160.
Chart 2. Heat and irrigation issues were the number one issue impacting demonstration success.
Additionally, deer pressure and squash bug damage were the second biggest issues for
agents.
Statewide, agents harvested 397 pumpkins for a weight of 1842 lbs.! We were also thrilled
to see agents working with their growers and enriching their communities. See Figures 9-11 for additional pictures of agent demonstrations and special thanks to all the participating agents who contributed data and their collaborators on the
2023 Horticultural Demonstration. We also would like to thank the staff at SWREC for
their help in starting the pumpkins.
Figure 9. Brad McGinley worked with Sheridan Elementary and Intermediate Schools for the pumpkin
demonstration. Teachers and students are shown here collecting data on Justify pumpkins.
Figure 10. Jerri Dew worked with Bradley Sweetcorn and Produce in Lafayette County and the growers
even planted additional Justify pumpkins into their operations with good results!
Figure 11. A freshly harvested Moonshine pumpkin sits on a digital scale as part of Jennifer
Sansom’s data collection efforts. This Moonshine pumpkin weighs 2.92 lbs.
Agents:
