Posts Tagged ‘16:20’

Volume 16, Issue 20 – August 1, 2008

Thursday, July 31st, 2008

PDF Version of WCU 16:20 – August 1, 2008

In this issue:

Vegetables
Vegetable Crop Insects
Potato Disease Advisory #22 – July 31, 2008
Downy Mildew on Cucumbers

Agronomic Crops
Agronomic Crop Insects
Downy Mildew on Soybeans
Soybean Rust Update
Preliminary Results from Small Grain Trials
Key Rulings Have Positive Price Impacts on Commodity Markets

General
Reducing Weed Seed Production in Pastures and Non-Cropped Areas

Fruit
Late Summer Matted Row Strawberry Maintenance
Fumigation Alternatives in Plasticulture Strawberries

Announcements
UD Watermelon Twilight Meeting – August 13
Niche Market Opportunities – August 14
Small Flock Poultry Seminar – August 16
Recent Topics on Gordon’s Blog

Weather

Small Flock Poultry Seminar

Thursday, July 31st, 2008

Saturday, August 16, 2008     9:00 a.m. – noon
University of Delaware Webb Livestock Farm
South Chapel Street, Newark, DE

Want to learn more about starting up a small poultry flock or get information on health and maintenance of your current small flock?  Then come to our Small Flock Poultry Seminar.  We’ll have experts from the University of Delaware, Delaware State University and University of Maryland Cooperative Extension on hand to provide information and answers to your questions, plus local feed and supply stores to provide information on product availability. 

This meeting is free and everyone interested in attending is welcome.  To register, request more information or if you require special needs assistance for this meeting, please call our office in advance at (302) 831-2506.

Please register by August 12, by calling
(302) 831-2506.

See you there!

Anna Stoops, New Castle County

Fumigation Alternatives in Plasticulture Strawberries

Thursday, July 31st, 2008

Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu

Each year there is more acreage of annual plasticulture system strawberries planted in Delaware. New plantings will go in again this September. One critical practice is fumigation. I recently came across a very good article on fumigation alternatives in strawberries with the loss of methyl bromide looming. The information is from the North Carolina Pest News:

Choosing Alternatives to Methyl Bromide for Strawberries

From: Rob Welker, Department of Plant Pathology, Katie Jennings, Department of Horticultural Science, and Frank Louws, Department of Plant Pathology in the June 27, 2008 edition of the North Carolina Pest News http://ipm.ncsu.edu/current_ipm/08PestNews/08News12/pestnews.html#title3.

After many years of discussing the end of methyl bromide, we are nearing the actual end of methyl bromide for use in crops. Shortages will occur, and cost is going to be a factor as demand for the limited supply drives up the price. If you have not tried alternative fumigants on your farm, this is the time to seriously think about why you fumigate and switch a portion of your production to an alternative. The opportunity to test an alternative on a portion of your crop on your farm before being forced to use something is running out.

If you use a good crop rotation, or are moving onto new production land, then the need to fumigate is minimal. It might not even be needed at all. For many growers, though, rotations are not practical, and the same crop has been on the same fields for years, making fumigation the answer to reduce pathogens and weeds.

How can you make a good decision about what to use? Think about why you fumigate on your farm. What are the soil issues that make fumigation desirable? If you are unsure of your problems and have been fumigating simply because it is part of the plasticulture system, then try leaving some of your production unfumigated and see what the results are. You might be surprised. For most cases, however, we have seen approximately 20 percent reduction in yield when strawberries have not been fumigated. So what should you use? Rate your production field for the four problems in the chart below using a 0 to 5 scale, where 0 is not a problem at all, and 5 is a problem that will cause significant yield loss if not controlled. If you marked 3 or higher for a problem, then it should be treated with fumigation; 2 or lower can be managed in a different manner.

  No Problem to Huge Problem
Fungal Disease 1

0

1

2

3

4

5

Nematodes

0

1

2

3

4

5

Annual and Biennial Weeds

0

1

2

3

4

5

Perennial Nutsedge (yellow and purple)

0

1

2

3

4

5

1 e.g., Black Root Rot Complex; Phytophthora crown rot

What is currently labeled for use that might be used for your pest problems? Use the chart below to find a product or combination of products that treats the problems rated at 3 or higher.

Fumigants

Fungal Disease

Nematodes

Annual/biennial weeds1

Perennial Nutsedge

Chloropicrin

E

N

N

N

Metam Sodium2 (MS)

F to G

P to F

G to E

F

Chloropicrin + MS

E

P to F

G to E

G to E or
F-G5

Telone C-35

E

E

P to F

P

Telone C-35 + VIF3

E

E

G to E

P to F

PicClor 60

E

E

P to F

P

PicClor 60 + VIF

E

E

G to E

P to F

MIDAS + VIF

E

E

G to E

G to E

Paladin4 + VIF

E

E

G to E

G to E

Herbicides6

 

 

 

 

Goal herbicide (under plastic)

 

 

G to E

N

Stinger herbicide (very specific weed spectrum)

 

 

G to E

N

Chateau herbicide (under plastic)

 

 

G to E

N

1 Limited data is available on control of annual and biennial weeds by these fumigants.
2 Vapam, Sectagon or other registered formulations.
3 VIF refers to Virtually Impenetrable Film which allows lower fumigant application rates but at the same time has improved efficacy of fumigants.
4 Paladin is a new fumigant currently being used under an experimental use permit in North Carolina, Georgia and Florida and could potentially be available soon on the open market.
5 When applied in the spring control is Good to Excellent, however when applied in the fall control is reduced because the fumigant gasses off due to the warm soils.
6 See respective labels to determine the specific weeds each herbicide controls.

Key:
E = excellent control, 90% or better
G = good control, 80% to 90%
F = fair control, 50% to 80%
P = poor control, 25% to 50%
N = no control, less than 25%

Late Summer Matted Row Strawberry Maintenance

Thursday, July 31st, 2008

Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu

There are many small commercial plantings of matted-row strawberries in Delaware such as Earliglow and Allstar. Daughter plants that root from runners coming from mother plants will produce the bulk of the berries in matted row systems in both new and renovated plantings. It is therefore critical to encourage the development of new daughter plants of sufficient size to produce high yields for harvest next spring. A critical period for matted row strawberries is between August and October. It is in this period when the flower buds for next year’s berries are initiated. Any stress that limits the initiation of flower buds will lead to fewer berries next year. Irrigation during hot and dry periods this summer and fall is the key to next year’s production. Keep strawberries growing and healthy by providing at least 1.5 inches of water through combined rainfall and irrigation each week (2 inches may be required when temperatures are in the nineties). Another critical cultural practice is controlling weed escapes by hand hoeing/pulling in the rows to limit competition. It is also important to keep runners out of row middles with cultivation. Matted row strawberries are edge bearers. That means that most of the berries will be produced on the edge of rows so it is important to keep rows narrow (about 12″ is ideal) using cultivators, disc coulters, rotary tillers, or other mechanical devices.

Reducing Weed Seed Production in Pastures and Non-Cropped Areas

Thursday, July 31st, 2008

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Many annual and some perennial weeds are beginning to flower now, particularly those that emerged early in the summer. Removing the flowering portions of the plant or seed heads now will prevent most of these plants from producing mature seed. If these plants are mowed off, they are likely to regrow and eventually produce seed, but the quantity of seed produced will be dramatically reduced. Many of these fields will need at least one additional mowing to prevent seed production. However, delaying a mowing for a few weeks will allow a greater proportion of the developing seeds to mature and contribute to the seedbank.

Key Rulings Have Positive Price Impacts on Commodity Markets

Thursday, July 31st, 2008

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

Two political issues impacting grain and oilseed markets received rulings this week. First, USDA reached a decision not to allow farmers early release from Conservation Reserve Program contracts. This decision was weighted heavily by a recent federal judge’s ruling in Seattle issuing a permanent injunction against USDA’s critical-feed use program releasing acreage from CRP for haying and grazing. Second, the U.S. House of Representatives defeated a bill yesterday that was designed to prevent excessive speculation in commodity futures trading. Both rulings can be viewed as bullish.

The U.S. needs to bring into production an additional 5 to 7 million acres in the ’09/’10 marketing year. A key component of whether the CRP ruling is good or not will is whether the August 12th supply/demand report projects adequate supply to forge ahead into the 2009 crop year. If not, the CRP ruling is likely to be contested, eventually, requiring an act of Congress.

The defeat of the anti-speculation act comes at a time when more needs to be known in order to make a definitive ruling. What is the driving force behind high oil, corn, soybean, and wheat prices? To what extent, if any, are the high prices to be attributed to speculation within the various commodity markets? Commodity trading is a complex business. Increases in speculative trading create opportunities to sell at higher prices than they otherwise would have been. Most ‘free market’ commodity traders and analysts argue that the markets do not need government intervention. Nevertheless, the issue of commodity speculation is likely to come up again.

Perhaps the best way to solve high oil and other commodity prices (other than high prices cure high prices) is for Congress to act upon a viable energy policy aimed at increasing U.S. energy production and supply. During a recent phone conversation an informed individual stated, “In France, where 70% of their energy needs are generated by nuclear power, the spent rods are processed thereby eliminating the waste.” One has to wonder why that point of information is not a known fact in this country. Or stated another way – to what degree is that point of information known in this country? If we can solve the nuclear waste problem then will that be enough to squelch concerns about building additional nuclear power plants?

Market Strategy
USDA will release the next supply/demand report for U.S./World Grains & Oilseeds on August 12th. Of interest will be projected stock situations for corn, soybeans, and wheat that will shed light on how many acres the U.S. will need to plant in the 2009 crop year? Currently, Dec ’08 corn futures are trading at $6.13 per bushel; Nov ’08 soybean futures at $14.05 per bushel; and Dec ’08 SRW wheat futures are at $8.12 per bushel. For technical assistance on making grain marketing decisions contact Carl L. German, Extension Crops Marketing Specialist.

Preliminary Results from Small Grain Trials

Thursday, July 31st, 2008

Bob Uniatowski, Associate Scientist; bobuni@udel.edu

Preliminary results from the 2008 Delaware Small Grain Trials are available online at http://www.udel.edu/varietytrials/small_grains/index.html. Trials were conducted in Georgetown, Selbyville and Middletown.

Soybean Rust Update

Thursday, July 31st, 2008

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

On July 28, soybean rust was confirmed in soybean production fields in Cameron County, Texas. On July 25, soybean rust was detected on leaves collected from a soybean sentinel plot in Baldwin County, Alabama. This is the first report of rust on soybeans in Alabama this year. The disease was observed on kudzu in Mobile County earlier this year.

Rust is developing more slowly this year than last which is good news for soybean growers. The risk of rust reaching us is low at this time, but the situation could change. Disease development in the South has been slow so far. This delay may mean that if soybean rust does eventually make it north it will be too late to affect yields as we have seen in the past. Our six sentinel plots are being checked weekly now since all but one plot have reached at least R1 (flowering).

Downy Mildew on Soybeans

Thursday, July 31st, 2008

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

Downy mildew is showing up in Delaware soybean fields with the increased humidity and shower activity. Downy mildew is a common disease of soybean that occurs wherever soybean is grown. Fortunately, however, it rarely affects soybean productivity in Delaware. The downy mildew fungus, Peronospora manshurica, is biotrophic, which means it can only grow in association with the soybean plant. Because of this very close relationship with the soybean plant, it is capable of rapid genetic change in response to genetic changes in soybean. Thirty-three races are described for P. manshurica and the number of described races will likely increase as research continues.

Downy mildew appears on the upper surface of young leaves as pale green to light yellow spots which enlarge into pale to bright yellow spots. The spots look slightly gray and fuzzy when viewed from below, especially during periods of high relative humidity. (See the following photos) Younger leaves are more susceptible to downy mildew than older leaves. Occasionally when conditions are very favorable for disease and the variety is susceptible seed infection can occur which produces a dull white crusty coating of spores on the seed. Fungicide control is rarely needed.

 

Downy mildew on soybean (upper surface)

 

Downy mildew (lower surface)

Agronomic Crop Insects

Thursday, July 31st, 2008

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

Forage Grass
Baythroid XL recently received an expanded label for forage grass. The following is the link to the new label (http://www.cdms.net/LDat/ld7JO034.pdf).

Soybeans
We continue to see high levels of bean leaf beetles, especially on the western half of the state from Greenwood through Middletown. Remember, at this time you will need to consider a treatment for defoliation as well as consider their ability to feed on the pods. At the pod fill stage, the defoliation threshold drops to 10-15% defoliation. This insect can also feed on pods. Bean leaf beetles can clip pods or plant diseases may enter the pod through their feeding sites. This can result in seeds that appear shrunken, discolored, and moldy resulting in a reduction in seed quality. Although we have not established thresholds for pod feeding in our area, the following link provides information that is used in the Midwest (http://www.ipm.iastate.edu/ipm/icm/2000/8-21-2000/lblroof.html). They have also included some new information in a recent newsletter that may better address the pod feeding aspect. It should be noted that we may be ahead of them in emergence of second generation since we have been seeing newly emerged soft gray beetles (http://www.extension.iastate.edu/CropNews/2008/Issues/20080728.htm). Also, we do not have any data on bean leaf beetle control in our area. When possible, a material with residual control should be used. However, the presence of other pests, especially mites, will impact your selection of a control material.

You should also scout for stinkbugs and pods worms as we enter the pod set and pod fill stages. In VA, Ames Herbert reported last week that they are expecting the major corn earworm moth flight to begin a little earlier than normal based on what they are seeing in their corn survey, which is still in progress. We continue to have high corn earworm trap catches in some locations; however, only time will tell if this will translate into a major podworm outbreak in soybeans. Although we are finding low levels of corn earworm in full season soybeans, this is not unusual for this time of year and only scouting on a routine basis will tell you if you have an economic problem. As trap catches increase, open canopy blooming fields will be attractive to egg laying moths. A treatment should be considered if you find 3 podworms per 25 sweeps in narrow fields and 5 podworms per 25 sweeps in wide row fields (20 inches or greater).