Volume 9, Issue 18 July 27, 2001
Volume 9, Issue 18 July 27, 2001
Vegetables
Vegetable Insects
- Derby Walker,
Sussex County Extension Agent, derby@udel.edu
Rindworms and cucumber beetle damage has been seen on
watermelons. There are many effective materials to choose from, but consider
days to harvest and re-entry restrictions before applying control options to
avoid harvest delays and residue issues. Ambush and Pounce have 0 days to
harvest with a 24 hour re-entry time, Thiodan is 2 days to harvest and 48 hour
re-entry, and Pounce and Capture have a 3 day restriction with a 24 hour
re-entry.
Vegetable Diseases
- - Bob Mulrooney,
Extension Plant Pathologist; bobmul@udel.edu
Lima beans.
Surveys of infected lima beans with downy mildew in 1999 and
2000 by graduate students Carley Davidson and Jen Dominiak, working with Tom
Evans, Bob Carroll and myself from the Plant and Soil Science Dept., have shown
that the predominant race of the downy mildew causing fungus, Phytophthora phaseoli, is race E. Race D
was only found in two fields and represented only 2.3% of the isolates of the
fungus that have been identified so far. The disturbing fact is that race F was
discovered to which there is no resistance available at the present time. Only
three fields were identified with race F in 2000 on the varieties, C-Elite
select, 184-85, and the new Cypress. This occurrence is very low, but we have
no idea how fast the race situation can change. Growers with the new Cypress
and 184-85 both resistant to race E should have a low probability of seeing
downy mildew. The most vulnerable varieties are those with no resistance to
race E including M-15, Eastland, 8-78, and 328. The speckled lima bean, Jackson
Wonder, has no resistance to any race.
Field Samples of Downy Mildew on Lima Beans.
Carley Davidson, a graduate student at the University of Delaware is working on downy mildew of lima beans. As part of her research, she needs to collect field samples of infected pods. Any help you can give her in the collection of these samples would be greatly appreciated. You can contact Carley at 302-831-2548 or carleyd@udel.edu . If you are able to collect a sample of the infected pods, please place them in a paper bag (not plastic) and refrigerate the sample. Marking the bag with the date, lima bean variety name and field location will also be very helpful. Please call Carley at the above number or contact your county extension agent so we can get the samples to Newark. Thank you for your help.
Late Blight Update
|
Date |
Total DSV |
Spray Recommendation |
|
5/16 |
0 |
|
|
5/17 |
11 |
|
|
5/20 |
29 |
|
|
5/30 |
51 |
5-day, low rate |
|
6/3 |
57 |
5-day, low rate |
|
6/5 |
57 |
5-day, low rate |
|
6/7 |
57 |
7-day, low rate |
|
6/11 |
59 |
10-day, mid rate |
|
6/13 |
60 |
10-day, mid rate |
|
6/17 |
76 |
7-day mid rate |
|
6/20 |
76 |
7-day high rate |
|
6/24 |
88 |
7-day high rate |
|
6/27 |
88 |
7-day high rate |
|
7/1 |
89 |
10-day, high rate |
|
7/4 |
90 |
10-day, high rate |
|
7/8 |
92 |
10-day, high rate |
|
7/11 |
94 |
10-day, high rate |
|
7/15 |
94 |
10-day, high rate |
|
7/18 |
99 |
7-day, high rate |
|
7/22 |
102 |
7-day, high rate |
|
7/25 |
106 |
10-day, high rate |
Vegetable Diseases - Kate Everts, Extension Vegetable Pathologist, University of Delaware and University of Maryland; everts@udel.edu
EFI Values (Environmental Favorability Index)
Do
not use MELCAST if there is a disease outbreak in your field, it is a preventative program. Any questions,
please call David Armentrout at (410) 742-8788 or e-mail: da88@umail.umd.edu
|
Location |
7/18 |
7/19 |
7/20 |
7/21 |
7/22 |
7/23 |
7/24 |
7/25 |
|
Bridgeville, DE |
4 |
7 |
1 |
1 |
1 |
3 |
1 |
0 |
|
Laurel, DE (Collins Farms) |
1 |
5 |
1 |
1 |
1 |
5 |
3 |
0 |
|
Galestown, MD |
3 |
7 |
1 |