In 2024, agents were again asked to investigate new and known pumpkin varieties within
two different Cucurbita species: Cucurbita pepo and Cucurbita maxima to assess potential
varietal resistance to melonworms and powdery mildew (Table 1).
In 2023, the state-wide county agent horticulture demonstration focused on 3 pumpkin
varieties within Cucurbita pepo that featured three different colored rinds. 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 and proven varieties to enhance
grower profitability. This Google Maps image in Figure 1 shows the location of many, but not all , 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 at pumpkins again for this year’s agent demonstration.
The table below highlights some of the attributes of the four pumpkin varieties we
demonstrated in 2024.
Table 1. A table showing the four varieties of pumpkins in the demonstration, their different
characteristics, and advertised size from seed companies.
Preparation
This year we decided to use seeds instead of transplants (Figure 2 ) and shipped them out to county agents in early June for a targeted planting of around
June 20 - July 4th . Most agents received 5 seeds per variety, but some agents received as many as 10
seeds per variety if they had a larger planting space available with collaborators.
Agents were given enough seed of each variety to plant “2 seeds per hill” and then
thin to “one seed per hill” if desired or to start all seeds as transplants. We felt
like this gave agents and collaborators the freedom to plant the demo to match their
schedules. The vines were to be spaced 3 feet apart in-row with at least 10-feet row
spacing if necessary (Figure 3 ). Grower standard practices for irrigation and fertility were suggested. Data collection
and growing information was given out to agents in April’s What’s Up Wednesday webinar
by Aaron Cato.
Figure 2. Seeds were sorted into smaller coin envelopes based upon how many seeds were requested
by county ag agents. These seeds were sent to agents via the county dispatch service.
Photo by Ryan Keiffer.
Figure 3. Pumpkin demo in White County with Sherri Sanders showing row and plant spacing. This grower got a new irrigation
system set up this year in preparation for the demo. You can see the post on X, formerly
Twitter, was made on July 8th , 2024, and reached 304 views.
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.
Many agents sent email and text updates to staff weekly or monthly. For the harvest
metrics, we asked agents to record the yield (weight and count), the number of pumpkins
per plant, and percent marketable fruit in terms of what percentage of pumpkins they
thought they could sell. Secondly, in terms of pests and diseases, the agents scouted
for melonworm and powdery mildew. At demo completion, we also asked agents to report
any barriers to demo success, such as weed control issues, deer, heat or irrigation
issues, and squash bugs.
Melonworm (Figure 4 top and bottom) is a tropical moth species that infests cucurbit fields as early as August here in
Arkansas and can cause serious damage to pumpkins by feeding on the rind and burrowing
into the handles causing them to fall off. Tropical storm systems can be a source
of early arriving melonworm moths and Arkansas faced two tropical storm systems this
summer. One of the worst outbreaks of melonworm that caused widespread loss was in
the fall of 2021 when melonworm was first found on September 7th , 2021. In 2024, Horticulture IPM staff found melonworm on August 8th , 2024, in research trials near Fort Smith and on August 15th in Southwest Arkansas near Hope. The early arrival of melonworm in 2024 caused concern
for many growers throughout the state and safe to say melonworm was widespread this
year. Pest alerts to agents and growers were communicated by Horticulture IPM staff.
Figure 4. A dult Melonworm moth, Diaphania hyalinata, on a Cucurbita pepo pumpkin from research trials near Kibler, Arkansas (Top) . Numerous melonworm larvae feeding on a pumpkin vine in Hope, Arkansas (Bottom) . Photos by Ryan Keiffer.
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 levels of resistance have been selected
in many commercially available varieties including the two Cucurbita pepo demonstration varieties. The Cucurbita maxima demonstration varieties did not have any level of resistance for Cucurbit Powdery
Mildew. Some agents posted progress of the demonstration on social media using the
hashtag #uaexHORT or on Facebook (Figures 3, 6, 7, 8) . Below are some additional examples of social media posts made by agents that really
helped to showcase this work and get the community interested (Figures 6-8).
Figure 5. Powdery Mildew was observed by many agents late in the season for 2024. Half of the
varieties in the demo have some level of Powdery Mildew tolerance incorporated but
wet conditions or skipped fungicide applications caused some outbreaks. Photo by Amy
Simpson from Clark County, Arkansas.
Figure 6. Phil Horton posted an update to X, formerly Twitter, thanking his cooperating grower
with the pumpkin demonstration. He mentioned how the plants look good in the morning
but were looking for some rain by the afternoon! He used the hashtag, #uaexHORT and
impacted 291 different views.
Figure 7. A Facebook post by Jenna Martin, Ag Agent from Cross County ¸ showed a good crop of pumpkins on all four varieties in the demonstration.
Figure 8. Shaney Hill, Ag Agent for Calhoun County , shared a local newspaper clipping that featured the pumpkin demonstration and her
updates.
Results In 2024, 37 agents signed up for this year’s demo, but overall we had 19 counties
submit usable data to analyze. Horticulture IPM staff also participated and had two
site locations, one in Crawford County and one in Hempstead County which are included
in the 19 counties with data. Many agents faced various crop failures from drought,
drift, weed pressure, vandalization, or disease. These data are still useful so we
thank those agents for letting us know why the demonstration wasn’t a success.
The table and figures below show the average of the measured pumpkin characteristics
across the 17 to 18 counties that reported yield data for the demonstration (Table 2) . Data collection by variety differed in the number of responses received due to some
agents having issues with Jarrahdale not setting fruit for them.
On average, each variety produced 1.5-2 pumpkins per vine with Cinderella having the
highest average of 2.1 pumpkins per vine. The average weight of the two Cucurbita pepo varieties were lower than advertised size descriptions, while the two Cucurbita maxima varieties were at the lower end of size descriptions from Table 1.
Overall, the percent marketability of the pumpkins was good with all four varieties
above 80 percent. Powdery mildew was especially bad in 2024 late in the season when we got some warm
rains in August and September. Cinderella was reported to have powdery mildew by 44% of counties who reported on
that category (n=16) compared to 40% for Jarrahdale (n=15). These are the two varieties
that we expected to be a little higher in their risk to Powdery Mildew. The two Cucurbita pepo varieties showed a lower risk to Powdery Mildew with Carbonado Gold at 35% (n=16)
and Gumdrop at only 24% (n=17) (Figure 1) . Many other factors might have contributed to reduced size or % marketability when
compared to advertised weight, but the most likely culprits were drought conditions
during flowering and/or water delivery issues.
Table 2. Results from the 2024 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 of Jarrahdale for some agents and ranged from 17 to 18 responses.
Figure 10. Powdery mildew observed on 4 varieties of pumpkin in two different Cucurbita species across 19 counties. Gumdrop and Carbonado Gold were reported to have an intermediate
amount of powdery mildew resistance while Cinderella and Jarrahdale lack powdery mildew
resistance.
Figure 11. The percentage of fruit impacted by melonworm on 4 varieties of pumpkin in two different
Cucurbita species across 19 counties. Jarrahdale exhibited less observations of melonworm (21%)
compared to the other 3 varieties of pumpkins which were above 30% of observations.
Figure 12. Common issues resulting in loss of data in pumpkin demonstrations.
Conclusions One of the main objectives of this demonstration was to evaluate melonworm resistance
in pumpkin varieties (Figure 11). Because melonworm larvae can quickly defoliate plants, as well as feed on the rind
and handles of pumpkins, we urge frequent scouting of pumpkins to detect this pest.
Melonworm was found in research trials at the VRS in Northwest Arkansas in early August
and about a week later in Southwest Arkansas. This early arrival indicated that the
pest might be detected in county agent demonstrations, and some melonworm damage was
observed by county agents and Horticulture IPM staff across the state. Cucurbita pepo has been observed to be much more susceptible than Cucurbita maxima in replicated trials. Data from this demonstration suggests that susceptibility would
be equal and is likely a result of over reporting melonworm in some varieties and
under reporting in others. Several other sources of variance shown also obfuscated
data. Luckily there are some good resources available to combat some of these issues,
such as FSA9111 and FSA6160.
Statewide, agents harvested 1017 pumpkins for a weight of 7123 lbs.! Figures 13-19 for additional pictures of agent demonstrations and special thanks to all the participating
agents who contributed data and their collaborators on the 2024 Horticultural Demonstration.
Further special thanks to the staff at the SWREC and VRS stations in Hope and Kibler
for their help with the demonstrations conducted by Horticulture IPM staff this year.
Figure 13. Brad McGinley worked with Sheridan Elementary and Intermediate Schools for the pumpkin
demonstration. Students from Sheridan Elementary are shown here with their wheelbarrow
full of demonstration pumpkins. Picture by Brad McGinley.
Figure 14. Jerri Dew worked with Bradley Sweetcorn and Produce in Lafayette County again this year after great success in 2023. Looks like 2024 was also a success.
Photo by Jerri Dew.
Figure 15. Freshly harvested Carbonado Gold pumpkins sit on the ground as part of Jesse Taylor’s
data collection efforts in Johnson County . Picture by Jesse Taylor.
Figure 16. Freshly harvested Gumdrop pumpkins sit on the ground as part of Katrina Boyd’s data
collection efforts in Crittenden County . Picture by Katrina Boyd.
Figure 17. Freshly harvested Jarrahdale pumpkins sit on the ground as part of Colin Massey’s
data collection efforts in Washington County . Picture by Colin Massey.
Figure 18. Freshly harvested Cinderella pumpkins (plus one mystery pumpkin) sit on the ground
as part of Colin Massey’s data collection efforts in Washington County. Picture by
Colin Massey.
Figure 19. All four varieties of demo pumpkins sit on a flatbed trailer for Scott Hayes’ data
collection efforts in Drew County . Picture by Scott Hayes.
Agents
