Volume 9, Issue16                                                                             July 13, 2001

 

Vegetables

 

Vegetable Insects -  Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

 

Lima Beans.

Continue to scout fields for lygus bugs, stinkbugs and green cloverworms. As soon as pin pods are present, you should begin sampling for corn earworm larvae. The treatment threshold is one per 6 foot of row.

 

Snap Beans.

Leafhoppers and thrips remain active in seedling stage snap beans. A treatment is needed if you find 5-6 thrips per leaflet or 5 leafhoppers per sweep. If both insects are present, the threshold of each should be reduced by ½ the level for each insect. Asana, Capture, dimethoate, Lannate or Orthene will provide control of both insects. We continue to find defoliators feeding on the pin pods. Even though corn borer counts remain low, a treatment should be applied if defoliators are feeding on pin pods.  Lannate, Asana or Capture will provide the best control of defoliators.

 

Sweet Corn.

Fresh market silking sweet corn should be sprayed on a 5 to 6-day schedule in most areas of the state. We are also seeing an increase in sap beetle populations, especially on diversified vegetable farms. In general, Penncap, diazinon and Warrior have provided the best sap beetle control. However, Penncap should not be used if bees are foraging in the area. The first fall armyworm (FAW) larvae have been found in whorl stage corn.  A treatment will be needed if you find 15% of the whorls infested. Remember that insecticides must be washed into the whorls and 2 treatments are generally needed for FAW control. Avaunt, Lannate, Spintor or Warrior will provide the best control in whorl stage sweet corn.

 

 


 

Vegetable Diseases - - Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

 

Potatoes.

Late Blight Update

Disease Severity Value (DSV) Accumulations as of July 11, 2001, are as follows:

Location: Joe Jackewicz Farm, Magnolia, DE

Remember that 18 DSV’s is the threshold to begin a spray program

 

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

 

 

Growers should be applying a fungicide for foliar diseases. There have been no reports of late blight on potatoes from our region.

 

Early blight is now evident on the oldest leaves in many plantings. As vines run out of nitrogen and senesce, look for more early blight to occur.

 

For late varieties or early blight susceptible varieties control is necessary.

 

 


Vegetable Diseases -  Kate Everts, Extension Vegetable Pathologist, University of Delaware and University of Maryland;  everts@udel.edu

 

MELCAST for Watermelons

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

7/3

7/4

7/5

7/6

7/7

7/8

7/9

7/10

7/11

Bridgeville, DE

0

0

2

3

1

1

4

3

2

Laurel, DE

(Collins Farms)

0

1

3

3

1

2

4

4

3

Galestown, MD

0

0

4

3

1

1

3

3

3

Georgetown, DE

0

1

0

3

1

0

0

4

1

Hebron, MD

0

1

3

3

1

1

4

3

4

Salisbury, MD

1

2

1

2

1

1

4

4

3

Laurel, DE

(Vincent Farms)

0

0

3

3

0

1

3

3

2

Watermelon Fields should be sprayed with a fungicide when 30 EFI values have been 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 zero.  The first and last day above can be partial days so use the larger EFI value of this report and other reports for any specific day

 

More detailed information concerning MELCAST and sample data sheets are available on the web at http://www.agnr.umd.edu/users/vegdisease/vegdisease.htm. .     v

 

 


Field Crops

 

Field Crop Insects - Joanne Whalen, Extension  IPM Specialist;   jwhalen@udel.edu

 

Alfalfa

If economic levels of leafhoppers were present before cutting, be sure to sample re-growth within 7 days of cutting. The threshold is 20 leafhoppers per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 in 4-6 inch alfalfa, and 100 per 100 sweeps in 7 - 11 inch alfalfa. There are also a number of defoliators present in alfalfa including green cloverworms, salt marsh and alfalfa caterpillars. If you have reached 1/2 the leafhopper threshold and you are approaching 50% tip damage from defoliators, a treatment should be considered. Baythroid, Lorsban  or Warrior would provide control of the insect complex present at this time.

 

Field Corn.

We can now find Japanese beetles and corn rootworm adult beetles feeding on silking corn. The decision to treat should be based on the number of beetles per ear as well as how far you are in the pollination period. Although we rarely treat for Japanese beetles, populations seem to be higher and staying around longer than in past years. In comparison, economic levels of rootworm beetles feeding on silks before 50% pollination have resulted in significant yield losses, especially along field edges. As a general rule, a treatment is recommended on silking corn if you can find 4-5 Japanese and/or corn rootworm beetles per plant and they are clipping silks to less than ½ inch long before 50% pollination.

 

Soybeans.

Continue to watch for spider mites, leafhoppers and defoliators in soybeans. We have seen a significant increase in leafhopper populations in soybeans; however, a treatment is not recommended unless you find at least 4 per sweep in drought stressed beans or 8 leafhoppers per sweep in actively growing soybeans. Japanese beetle adults and feeding damage has increased in full season soybeans. No controls will be needed prebloom unless you find 7 beetles per foot of row and 30% defoliation. If plants are blooming, the threshold decreases to 15 % defoliation. If a combination of insects is present, the threshold for each pest should be reduced by 1/3.

 

 


Grain Marketing Highlights - Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu

 

July's Supply and Demand Report Fuels Market Gains
Several positive factors are rallying commodity prices at this time. First, the demand for U.S. soybeans in the export market has been explosive, keeping beans moving at a record pace. Second, sporadic crop development across the U.S. is resulting in a 'wide window' of opportunity for something positive to happen to commodity prices. We still have approximately 20 to 25 days before we see the majority of the U.S. corn crop in the pollination stage, and about 40 days to get to the 80 percentile range for soybean bloom and pod development. This factor alone is bidding a weather premium into the market, which is not likely to evaporate until we see nearly 85% of the U.S. corn crop pollinated. A third factor fueling commodity prices at this point in time is strong fund buying. Commodity speculators have entered the markets heavily this past week and are likely to be around for a while due to weather concerns. The most recent weekly crop condition report for U.S. grains and soybeans was relatively unchanged from the week before. One has to wonder whether we could possibly see any progress in the next report due to the heat index that has been hovering over a fair portion of the U.S. cornbelt. Nevertheless, these factors coupled with information contained in the July crop report all have corn, soybean, and to a lesser extent wheat prices presently trending higher.

The most significant news stemming from the July 11th USDA Supply and Demand report was the reduction in ending stocks for U.S. corn and soybeans, from last month's estimate. U.S. corn stocks are now projected at 1.828 billion bushels, 65 million bushels less than last month. Ending stocks for U.S. soybeans were reduced 95 million bushels from the June report, now estimated at 345 million bushels for the 2001/02 marketing year. U. S. wheat stocks were increased 25 million bushels from the June estimate, now projected at 610 million bushels.

General Comments
Dec. new crop corn futures are now trading at $2.36, Nov. beans at $5.10, and July wheat at $2.65 per bushel. Considering that the markets are trending higher the best strategy appears to be to ride the up-trend before advancing new crop sales. The weather market, although slow in coming, is likely to be with us for another month or so. New crop corn and soybean pricing objectives, those prices necessary to consider before advancing new crop sales, are now estimated to be $2.40 or better for corn and $5.50 or better per bushel for new crop beans (CBT prices).

 

 


UPCOMING MEETINGS:

 

AGRONOMIC CROPS FIELD DAY JULY 17 AT UD DEMO PLOTS

 

New Castle County Cooperative Extension and the Delaware Soybean Board invite you to join your fellow farmers and other members of the agricultural community on Tuesday, July 17, 2001, 10:00 am - 1:30 pm, as our Extension Specialists lead discussions of this year’s field trials and other in-season issues related to corn, soybeans, and small grains. Other topics will include grain marketing and nutrient management. We expect to have the 2000-2001 wheat and barley variety trial results for distribution and discussion.  There will be time to discuss your current cropping issues.  Credit toward Delaware pesticide license recertification (Ag Plant category) and CCA (Certified Crop Advisor) CEUs will be awarded.

 

The Demo Plots are on Marl Pit Road (Rd. 429, approximately ½ mile east of the intersection with Del. Rt. 71/U.S. Rt. 301 (Armstrong’s Corner).  Look for the University of Delaware signs on the left.  The traditional Extension Staff lunch will be provided.

 

The meeting is free and everyone interested in attending is welcome.  For more information or for special consideration in accessing this meeting, please contact Carl Davis, NCC Agriculture Agent at 302-831-2506 or email: cpdavis@udel.edu.

 

 

University of Delaware Farm & Home Field Day

August 8, 2001

U of D Research & Education Center, Georgetown, DE

 


                     Weather Summary

Week of July 5 to July 11, 2001

Rainfall:

July 5: 0.72 inches

July 6: 0.01 inches

July 8: 0.05 inches

July 10: 0.02 inches

Readings taken for the previous 24 hours at 8 a.m.

Air Temperature:

Highs Ranged from 91°F on July 10 to 77°F on July 6.

Lows Ranged from 69°F on July 9 to 58°F on July 7.

Soil Temperature:

78°F average for the week.

(Soil temperature taken at a 2 inch depth, under sod)

 

Web Address for the U of D Research & Education Center:

http://www.rec.udel.edu


Compiled and Edited By:

Tracy Wootten

Extension Associate - Vegetable Crops


Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating, John C. Nye, Dean and Director.  Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.  It is the policy of the Delaware Cooperative Extension System that no person shall be subjected to discrimination on the grounds of race, sex, disability, age or national origin.