We are staring to find the first corn earworm larvae in fields with pin pods. You should also continue to sample for lygus and stinkbugs. A treatment should be applied if you find one corn earworm per 6 foot of row or 15 tarnished plant bugs and/or stinkbugs per 50 sweeps. Lannate, Mustang or Capture can be used to control all 3 insects on lima beans.
Spider mite populations are still at threshold in many fields. As a general guideline, fields should be sprayed if 20-30% of the plants are infested with 1-2 mites per leaf. However, if hot spots are present in fields, the percentage of infested plants continues to increase and numerous eggs can be found, a spray should be considered before you find 1 per leaf. We are also starting to see an increase in aphids and cucumber beetles.
At the present time, all peppers should be sprayed on a 7-day schedule for corn borer, corn earworm and pepper maggot control. With the recent increase in corn earworm catches and the occurrence of beet armyworm, chemical selection will be important. Remember Orthene or Address will not provide satisfactory earworm control. A pyrethroid or Lannate will be needed for earworm control. Dimethoate should still be added to the mix for pepper maggot control if a pyrethroid or Lannate are used. Also, a continuous pyrethroid program should not be used to avoid aphid explosions. If beet armyworms are present, the pyrethroids have not provided effective control. Avaunt, Spintor, Confirm or Lannate will provide the best beet armyworm control. Depending on the pest complex present, a combination of products will be needed.
Processing snap beans in all areas of the state should be
treated at the bud and pin stages for corn borer control. Orthene
or Address should be used at the bud and/or pin stages for corn borer control.
In the Rising Sun,
Fresh market silking sweet corn
should be sprayed on a 3-day schedule in all areas of the state except in the
Bridgeville, Rising Sun and
- Kate Everts, Extension Vegetable Pathologist, University of
Latest EFI values from local weather stations
Any questions please call (410) 742-8788
EFI Values (Environmental Favorability Index)
Do not use MELCAST if there is a disease outbreak in your field, it is a preventative program.
Charles Co. 0 0 1 9 10 4 4
Collins Farms 1 1 0 5 1 1 1
Vincent Farms 4 3 2 5 2 1 1
White Marsh 0 0 0 8 10 1 4
The first fungicide spray should be applied when the watermelon vines meet within the row. Additional sprays
should be applied using MELCAST. Accumulate EFI (environmental favorability index) values beginning the
day after your first fungicide spray. Apply a fungicide spray when 30 EFI values have accumulated by the
weather station nearest your fields. Add 2 points for every overhead irrigation. After a fungicide spray, reset
your counter to 0 and start over. If a spray has not been applied in 14 days, apply a fungicide and reset the
counter to 0 and start over. The first and last day listed above can be partial days so use the larger EFI value
of this report and other reports for any specific day.
If, for some reason, a serious disease outbreak occurs in your field, return to a weekly spray schedule.
More detailed information concerning MELCAST and sample data sheets are available on the web at http://www.agnr.umd.edu/users/vegdisease/vegdisease.htm.
Field Crop Insects
Continue to watch for spider mites, leafhoppers and defoliators in soybeans. The spider mite threshold is 20 per leaflet or 10% of plants with 1/3 or more of the leaf area damaged and the leafhopper threshold is 4-8 per sweep. If defoliators are present, the treatment threshold is 30% defoliation prebloom and 15% once bloom occurs. If a combination of insects is present, reduce the threshold for each pest by one-third. Now that most locations have received rain, you should achieve better control with applications of dimethoate plus LI-700 or AD-100 for spider mite control. Although a few diseased mites have been observed this week, in general we have not had enough consistent wet, humid weather to cause spider mite populations to crash. If mites can be found on new growth and you can observe stippling on the leaves, a treatment should be applied as soon as possible to prevent additional yield loss. Application made very early in the morning or late in the evening when leaf stomates are open will help move materials into the leaves. In many cases, at least 2 applications will be needed.
You should start sampling fields as soon as blossoms and pin
pods are present for corn earworm. We have found our first corn earworm larvae
in a full season soybean field in
Grain Marketing Highlights -
Commodity Prices Rebound on Weather Developments
The end of last
week through the first of this week saw commodity prices drift lower on trader
expectations for an improvement in overall crop conditions for
Dec '02 corn futures and Nov '02 soybean futures are now expected to trade higher from current levels due to, among other things, a return to hot and dry conditions in a large portion of the corn belt, currently trading at $2.56 and $5.36 respectively. $2.70 Dec '02 corn and $5.80 Nov beans (CBT) appear to be well within reach in terms of new crop pricing objectives for advancing new crop sales.
The latest issue of Pesticide Briefs has been posted at:http://www.udel.edu/pesticide/briefs.htm
(1) NEW PESTICIDE CHEMISTRIES
(2) METHYL BROMIDE
(3) TOLERANCE REVOCATIONS FOR EIGHT PESTICIDES
(4) BENOMYL TOLERANCE REVOCATIONS ANNOUNCED
(5) METHOXYCHLOR TOLERANCES REVOKED
(6) REASSESSMENT OF MORE NON-CONTRIBUTING OP's
(7) OXADIXYL TOLERANCE REVOCATION
(8) LINURON TOLERANCE REASSESSMENT
(9) TOLERANCE REVOCATIONS FOR 23 PESTICIDES
Wicomico Farm & Home Show
RT 50 &
Week of July 26
July 26 th -0.03 inches
July 27th- 0.57 inches
Highs Ranged from 96°F on July 29 & August 1 to 73°F on July 26.
Lows Ranged from 77°F on July 29 to 61°F on July 26.
83 °F average for the week.
(Soil temperature taken at a 2 inch depth, under sod)
Web Address for the U of D
Compiled and Edited By:
Extension Associate-Vegetable Crops
Extension Education in Agriculture and Home Economics, University of Delaware, Delaware
State University and the United States Department of Agriculture cooperating,
Robin Morgan, Dean and Director. Distributed in furtherance of the Acts of Congress of May 8 and
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