VegNet Vol. 14,
No. 24.
Ohio
State University Extension Vegetable Crops
On the WEB at: http://vegnet.osu.edu
In This Issue
1. Vegetable pest observations
2. Crop Reports
3. Pumpkin Field Day
4. Vegetable Field Days, This Week:
Vegetable
pest observations
Western corn
rootworm beetles are present at unusually high levels in many fields of sweet
corn and pumpkins. Some whorl-stage corn is having leaves shredded and killed
by extensive feeding damage, and pollination is poor in some fields where silks
were clipped by beetles during the early silk stage. We do not have a threshold
for rootworm beetles on whorl-stage corn but if whole leaves are being killed,
then an insecticide spray is probably warranted. The beetles are very
susceptible to carbaryl (Sevin)
and pyrethroids. There are reports of beetles
re-infesting a field after a spray due to continued emergence of new beetles
from the soil. The large populations are likely due to the dry weather during
June, which allowed excellent survival of the beetles during their final larval
feeding period and during pupal development in the
soil.
In pumpkins, the
western corn rootworm beetle feeds on pollen and does not cause damage to fruit
as long as many flowers are present in the crop, but beetles will move to fruit
and feed on the rind once flowering tapers off in late summer. As always,
precautions must be made to avoid harming bees if an insecticide spray is
needed; spraying in the evening is advised.
Sweet corn that is
starting to silk is at risk of worm infestation this week, after an increase in
all three key pests during the past week.
Corn earworm moths
have been absent for nearly absent from Ohio locations during July, but low to moderate
levels of earworm moths were detected in pheromone traps last week in Meigs County, Clark County, and Franklin County. This pest
is migratory and arrives at different times each year in
European corn borer
has been following a typical pattern so far this summer. Moths from the overwintering generation were active from late May to late
June, then few were seen in July. In the last week of
July, moths of the new generation began to emerge as detected in pheromone
traps and blacklight traps. Peppers will be infested
by this pest if preventive insecticide sprays are not made during August. Silking sweet corn is also at risk but can be protected by
a 5-day spray schedule.
Fall armyworm moths
were first detected in Celeryville in late June and
in
While the striped
cucumber beetle was unusually scarce in early summer in
On cabbage and cole crops, high levels of imported cabbageworm are
reported, but diamondback moth is also active. In
Crop Reports by Ron Becker and Brad Bergefurd
As a result of the heavy rains (up to 5 inches in some areas) that
were received on July 27th-28th, growers are seeing plants collapse in the
lower area of their pepper, tomato and melon fields. Pythium
and phytophthora were the diseases suspected in some
cases with others just being under water for too long a period. The rains did
seem to reduce the numbers of two spotted spider mites that were starting to be
found in area melon fields. Downy mildew is being found in cucumbers on
more farms throughout the area and powdery mildew is being found in almost all
fields of pumpkins and squash. Sweet corn fields are on a 5-7 day spray
schedule for corn borer as we are finding corn borer egg masses in the fields
but have not yet caught earworm in our traps. Many cole
crop fields are having to be sprayed because of large
numbers of imported cabbage worm, diamond back moth larvae and cabbage loopers starting to hatch out. Growers reported that large
numbers of the white butterflies (imported cabbage worm adult) were seen in the
fields immediately after the heavy rains.
Hot and Dry this past week with most of the week in the mid to
high 90's. Plasticulture strawberry growers began
sticking runner tips last week to begin growing out their plug plants that will go to the field the first part of September.
Canadian strawberry runner tips I have observed on farms have been of very high
quality and seem to be disease free. Under proper mist propagation systems,
where misting intervals have ben shortened over past
years due to the high temperatures, rooting is taking place within 48 hours of
sticking. Growers continue to cultivate and multivate
matted row strawberry beds to set runners.
Irrigation systems are once again being run around the clock due to the dry
conditions and high heat, with no real measurable rainfall received for the
growing region since July 19. Harvest of all summer produce is in full swing.
The market price and demand for cantaloupe remains high in the wholesale
market. Tomatoes had a drop in wholesale price and demand early in the week but
price and demand quickly rebounded by weeks end at the Bainbridge wholesale
produce auction. Growers are getting ready to harvest Ornamental corn in about
2 weeks and are preparing drying and sorting racks. Heavy morning dews and high
humidity have helped spread Powdery and Downy Mildew disease pressure in vine
crops where unprotected fields are showing serious injury from these diseases.
Fungicide schedules for vine crops have been narrowed to 7 day schedules where
allowed due to the heavy disease pressure.
Growers transplanted cauliflower, broccoli, cabbage and fall high tunnel tomato
crops this past week. Growers directed seeded to the fields green beans, half
runner beans, snap peas, radishes, turnips, cucumbers, pickles, zucchini and
yellow summer squash crops this past week as well.
Pumpkin
Field Day, August 23rd, - Jim Jasinski
The 8th annual pumpkin field day will be held
Growers will be taken around the 420 acre station to various
research and demonstration plots on wagons pulled by tractors. The
tour stops will include a 5 treatment transplant media study and a large scale
fungicide demonstration trial using 11 products. There are 15 commercial
entries in this year's pumpkin variety trial, and a 19 entry Microdochium/Plectosporium resistance screening trial with
plant materials from four other countries. At each stop, growers will be
encouraged to wander around the plots and ask questions of the specialists
before boarding the wagons and heading to the next stop. At one of these stops,
highlights of general insect management including seed treatment will also
be given. A no-till zone tiller used to prepare several of the
research trials will also be on display for growers to look at.
Refreshments, water and pop, will be placed on each wagon, but no food will be
served.
The Western Ag Research Station is located on SR 41, between I-70
and the town of
No CCA or PAT credits will be offered this year. Admission
is $3 per person, no pre-registration is required. Contact Jim Jasinski for more information, 937-484-1526 or jasinski.4@osu.edu.
Hope to see you out there!
Vegetable Field Days, This Week:
Walking
the Fields Tour: All are
again reminded of the August 8, OSU
Extension and the North Central Ag Research Station sponsored “Walking the
Field Tour”. The tour will originate
for the North Central Research Station at 1165 CR. 43 in
Horticulture Field Night Thursday
August 9th to be held at the OSU South Centers at Piketon on
Thursday August 9th from 5 till
Research trials to be highlighted include high tunnel tomato, pumpkin, seedless
watermelon, fresh-market tomato, fresh-market bell pepper, summer squash, primocane-bearing brambles and strawberry plug plant
production.
Other information to be discussed includes edible landscaping, ornamental corn,
annual bedding plant and ornamental grass evaluations. Contact Information:
Brad Bergefurd, 740-289-2071 ext. 136 , 1-800-297-2072
ext. 136 (in