Posts Tagged ‘16:2’

MELCAST for Cantaloupes and TOMCAST for Tomatoes

Friday, June 6th, 2008

Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland;

In addition to MELCAST for Watermelon, we have two models that are designed to help you make spray-timing decisions on diseases of cantaloupe and tomato. MELCAST for Cantaloupes is a fungicide application program for Alternaria leaf blight. It can be used by anyone growing a powdery mildew resistant variety, such as Athena. To use MELCAST for Cantaloupe, apply the first fungicide spray when the cantaloupe 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 20 EFI values have accumulated by the weather station nearest your fields. Add 2 points for each 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.

TOMCAST is a spray forecaster for leaf blights and fruit diseases of processing tomato. However, it does not work for bacterial diseases or for late blight. In fields that were not rotated away from tomatoes and in late-planted fields begin sprays shortly after transplanting. In all other areas begin sprays when crown fruit are a third their final size. Additional sprays can be scheduled using TOMCAST. Sprays should be applied after accumulating 18 DSVs (disease severity values) since the last fungicide application. Scout fields for bacterial diseases and late blight. If bacterial speck or spot or late blight occurs additional sprays are warranted (see Delaware Extension Bulletin 137 or Maryland Extension Bulletin 236: Commercial Vegetable Production Recommendations).

These disease models are available at In addition you can receive the models by e-mail or fax. Everyone who received the models last year is automatically signed up. To change the way you receive the information or to sign up, please call Jeri Cook at (410) 742-8788.

Volume 16, Issue 2 – March 28, 2008

Friday, March 28th, 2008

PDF Version of WCU 16:2 – March 28, 2008

In this issue:

Winter Temperature Index for Predicting Stewart’s Wilt in Delaware Sweet Corn, 1998-2008
Seed Vigor in Sweet Corn
Lima Bean Fungicide Update
Understanding FRAC Codes is Important for Managing Fungicide Resistance Development

Agronomic Crops
Scout Alfalfa for Alfalfa Weevil and Pea Aphids
Field Corn Soil Insect Management
Scout Small Grains for Aphids, Winter Grain Mites and Cereal Leaf Beetle
Soybean Rust Update for 2008
Several Pest Management Issues to Think About if You are Saving Cover Crop Wheat or Barley for Grain Production
Grain Marketing Highlights

General Info
New Insecticides/New Uses for Vegetables and Field Crops

E-Commerce in Agriculture Study Participants Sought
Recent Topics on Gordon’s Blog


Weather Summary

Friday, March 28th, 2008


Weather Summary

Carvel Research and Education Center Georgetown, DE

Week of March 20 to March 26, 2008

Readings Taken from Midnight to Midnight

0.09 inch: March 20
Air Temperature:
Highs Ranged from 69°F on March 20 to 49°F on March 23.
Lows Ranged from 44°F on March 26 to 25°F on March 24.
Soil Temperature:
48°F average.
(Soil temperature taken at a 2″ depth, under sod)

Additional Delaware weather data is available at

Recent Topics on Gordon’s Blog

Friday, March 28th, 2008


For Current Agricultural Information from the UD Kent Co. Extension Office Visit

Recent Topics:

  • Managing Wheat in a Year of High Prices – More on Early Fungicide Applications
  • Small Grains – Another Outbreak of Winter Grain Mites
  • Corn – Starter and Popup Fertilizers
  • Corn – What Population Should You Plant
  • Inoculating Soybeans
  • Grain Markets Rebound, Limits Change for Corn and Soybeans
  • Managing Wheat in a Year of High Prices – Early Fungicide Applications
  • Forage Sampling
  • Poultry – Attic Inlets
  • Don’t Forget Soybean Cyst Nematode
  • Fruit and Vegetable Crops – Planning For Pest Control
  • Fungicide Treatments for Soybean Seed

E-Commerce in Agriculture Study Participants Sought

Friday, March 28th, 2008, in conjunction with the Mid-Atlantic Direct Marketing Conference (MADMC) and WebIXI Inc., is sponsoring an “E-Commerce in Agriculture” study.E-commerce sites will be designed, developed and hosted for 10 study participants. The objective of the study is to allow participants to enter the e-commerce world at a reduced rate, while creating real-world case studies for evaluation and analysis of e-commerce strategies in agriculture businesses.

Site development for the project participants will begin May 1, 2008 with a projected “go live” date of July 1, 2008. Analysis will be conducted over the first year that the sites are live to measure site traffic, search engine performance and e-commerce system performance.

As only 10 participants will be accepted into the study, agricultural businesses interested in participating should contact Carl German ( or Pat Chambers ( by April 21, 2008.

Participant selections will be made on Wednesday, April 23, 2008; chosen participants will be notified prior to April 25, 2008.

Details of the study are attached, or can be viewed online at:

Examples of WebIXI’s work can be viewed online at:

New Insecticides/New Uses for Vegetables and Field Crops

Friday, March 28th, 2008

Joanne Whalen, Extension IPM Specialist;

We have received a number of new insecticide registrations for the 2008 season including both new active ingredients and new uses of currently registered products. Be sure to check the label for labeled crops, use rates and restrictions.

Endigo ZC® – A mixture of thiamethoxam (Actara) and lambda-cyhalothrin(Warrior) now labeled on potatoes.

Leverage® – A mixture of imidacloprid (Provado) and cyfluthrin (Baythroid) now labeled on soybeans.

RadiantTMSC (spinetoram) – Labeled on a number of vegetable crops as well as small grains, corn and soybeans. Note – It is only used as a foliar spray. It is incorrectly listed under at-planting materials in the potato section of the Vegetable Production Recommendations.

Regent 4SC (fipronil) – Now labeled on potatoes for wireworm control. Note – The rate is incorrectly listed as 0.184- 0.22 oz/acre in the 2008 Vegetable Recommendation Book. The correct rate is 0.184-0.22 oz/1000 row ft.

Warrior (lambda-cyhalothrin) – Additional vegetable crops as well as barley, the grass forage, fodder and hay group, grasses grown for seed, pastures and rangeland were added to the label in the fall of 2007.

Zeal® Miticide1 (etoxazole) – Now labeled on melons for spider mite control

Grain Marketing Highlights

Friday, March 28th, 2008

Carl German, Extension Crops Marketing Specialist;

March Madness Hits Commodities Market
Nearby crude closed at $105.90 per barrel in yesterday’s trading, within a few dollars of the recent high. The U.S. dollar index closed at 71.95, within .75 of the recent low. Nearby corn closed at $5.52, soybeans at $13.52, and nearby soft red winter wheat at $10.33 per bushel in yesterday’s trading. Speculative funds may be pulling back on some of their commodity trading as the credit crunch and bargain stock prices dictate. Volatility in commodity prices remains at extremely high levels, with limit up and down price swings common of late. Corn and soybean futures contracts will join the ranks of wheat in tomorrow’s trading (March 28th) with increases in the daily trading limits taking effect coupled with expanded limits of plus 50% in the event that the market closes at the limit on a given day. With the new daily trading limits for corn (30 cents per bushel); soybeans (70 cents per bushel); and wheat (already at 60 cents per bushel), the expanded limits then become 45 cents/bushel for corn; $1.05 per bushel for soybeans; and 90 cents per bushel for wheat. The new expanded limits amounts to a daily limit of $2,250 for a 5,000 bushel corn contract; $5,250 for a soybean contract; and $4,500 for a 5,000 bushel wheat contract.

The cost of using commodity futures for price risk management strategies down on the farm has become unacceptable and cost prohibitive to farmers and the agricultural industry (merchandisers). Hearings to that effect will soon be held on Capitol Hill to address the concerns that agriculture has with unlimited trading activity and the effect this is having on traditional price discovery mechanisms. More information will follow on the hearing date, scheduled for the later part of April.

In the meantime, expect these markets to remain quite volatile. The March 31st Planting Intentions report to be issued on Monday may or may not portend to price expectations for the near future. In other words, will commodity traders, other than farmers and the commercial traders even care about the numbers in the report? For that matter, will the planting intentions report line up with what actually gets planted this year? The Southern Hemisphere is currently in the process of harvesting what promises to be their largest crop on record while ’07/’08 U.S. soybean ending stocks are projected at 140 million bushels.

A late spring to early summer Options on Agricultural Futures webinar is being planned. Details to follow concerning the airing date. For technical assistance on making grain marketing decisions contact: Carl L. German, Extension Crops Marketing Specialist.

Several Pest Management Issues to Think About if You are Saving Cover Crop Wheat or Barley for Grain Production

Friday, March 28th, 2008

Bob Mulrooney, Extension Plant Pathologist; and Joanne Whalen, Extension IPM Specialist;

With the high prices of wheat and barley some cover crops may be kept for grain instead of plowing them under. As long as the stand is sufficient for economical yield the fields can be managed for grain production. There are several pest management issues that could be a problem if you have decided to do this. Loose smut is a systemic fungus disease that is transmitted in infected seed. Infected seed looks healthy and germinates as if it were not infected. When the seed germinates the fungus is activated and systemically grows within the young seedlings. The fungus remains in the plant over the winter and when growth resumes the fungus grows with the plants and eventually to the head where the fungus spores replace the wheat or barley kernel and other flower parts. The only window to control this disease, if the seed is contaminated, is with a seed treatment for loose smut at planting. If the cover crop seed was certified and/or treated with Baytan, Raxil, Vitavax, or Dividend at rates for loose smut control, the crop is protected. Currently there is no labeled foliar fungicide for wheat or barley that will control loose smut if the plants are infected. There is no way to tell if the crop is infected until heading, so if you planted untreated, saved seed or untreated seed from an unknown source there is a risk of loose smut at heading.

Since cover crops are often planted before production fields, Hessian fly could be a potential problem. Fields planted well before the “fly free” dates (New Castle County -Oct 3; Kent County – Oct 8 and Sussex County- Oct 10) could have been exposed for a longer time to egg laying by Hessian fly adults. Any eggs laid in the cover crop wheat hatched into maggots which fed on that wheat and then changed into pupae (called flax seeds) to survive the winter. When the Hessian fly adults emerge from the flaxseed this spring, they will seek a host upon which to lay their eggs. Since wheat is the principal host plant of the Hessian fly and they are not strong flyers, these fields may be susceptible to spring infestations. Please refer to the article “Management of Hessian Fly in the Spring” in WCU Volume 16, Issue 1 for sampling and possible control options.

Soybean Rust Update for 2008

Friday, March 28th, 2008

Bob Mulrooney, Extension Plant Pathologist;

Soybean rust continues to be a threat to soybean production in the US. Although we have not seen it here or in MD yet that does not mean that growers can let down their guard. It is important to continue to track its whereabouts and have an action plan in place should it appear. All it took was some heavy rainfall in LA, TX and OK last season to produce conditions that were very favorable for rust development. The rust spore production in those states was great enough that soybean rust was found late in the season in Iowa. Fortunately, it was too late in the season for rust to have any affect on yields in the northern states. All we would need is for the drought to be broken in northern FL and GA one of these years, and soybean rust could make it to DE and MD. Granted a lot depends on the weather, but the fungus continues to overwinter in southern FL and is infecting scattered patches of kudzu along the Gulf of Mexico at the present time. So it is important to know where it is during the growing season. The ipmPIPE website is still the best place to get your soybean rust info ( For more info and labels of registered fungicides for use in DE see the UD Extension soybean rust website at

In 2007 soybean rust was detected in one province in Canada, in two states (3 municipalities) in Mexico, and in 19 states and 334 counties in the U.S including: 40 counties in Alabama (19 soybean), 33 counties in Arkansas (soybean), 24 counties in Florida (11 soybean), 51 counties in Georgia (14 soybean), four counties in Illinois (soybean), one county in Indiana (soybean), 14 counties in Iowa (soybean), nine counties in Kansas (soybean), three counties in Kentucky (soybean), 21 parishes in Louisiana (18 soybean), 26 counties in Mississippi (21 soybean), 37 counties in Missouri (soybean), four counties in Nebraska (soybean), six counties in North Carolina (soybean), 12 counties in Oklahoma (soybean), seven counties in South Carolina (soybean), seven counties in Tennessee (soybean), 26 counties in Texas (25 soybean), and nine counties in Virginia (soybean).


As of March 27 there are 10 counties in Florida, two in LA, one in TX, and one in AL with rust on kudzu at the present time. In Mexico there are three counties with soybean rust on another legume called jicama bean. Kudzu is coming out of dormancy in much of the South so rust activity should be increasing in the coming weeks.

Delaware will continue to participate in the ipmPIPE sentinel plot system for detecting soybean rust in a timely manner for the 2008 season. At the present time seven sentinel plots are planned for Delaware, three in Sussex and two each in Kent and New Castle counties. USDA/APHIS and commodity funding is continuing to fund this effort at the present time. Each sentinel plot will be planted with a group III and a group VII variety so that susceptible plants are present throughout the growing season and into the late fall.

Scout Small Grains for Aphids, Winter Grain Mites and Cereal Leaf Beetle

Friday, March 28th, 2008

Joanne Whalen, Extension IPM Specialist;

Recently we are receiving reports of high levels of aphids in barley and wheat fields. The fluctuating temperatures as well as continued dry conditions have been favorable for aphids. As indicated in a previous newsletter, cool, dry conditions generally favor spring outbreaks of aphids. This type of weather allows the aphids to survive and reproduce. Although natural enemies can keep aphids under control, cool dry weather in the spring often allows aphids to reproduce rapidly whereas their natural enemies reproduce slowly. Beneficial insects that attack aphids reproduce slowly at temperatures below 65°F, whereas aphids can rapidly increase when temperatures exceed 50°F. A number of insecticides are labeled for aphid control in wheat including: Baythroid, Baythroid XL, Dimethoate 4E, Lannate LV, Mustang MAX, Penncap-M, Proaxis, and Warrior. Materials labeled for aphid control in barley include Lannate, Penncap-M and Warrior. Check the labels for restrictions and harvest intervals. The recent Virginia Ag Pest Advisory from Ames Herbert indicates that they are hearing of many wheat (and some barley) fields with unusually high aphid numbers. Please use the following link for his comments on aphid management in wheat. (

We continue to receive report of wheat fields with damage from winter grain mites. Remember, this mite is favored by cooler conditions. No thresholds are available for this mite pest. As indicated in the most recent Virginia Ag Pest Advisory written by Tom Kuhar, these mites have been found almost exclusively in no-till wheat situations. Very little is known about this sporadic pest; however, experience in Virginia this season indicates that that high densities of these mites can significantly affect plant vigor and growth. Although we have no experience with winter grain mite control in wheat, materials that have appeared to provide control in areas to our south include the pyrethroids (Warrior, Mustang MAX) and certain organophosphates (dimethoate). Note that dimethoate may not be effective when temperatures are below 60°F. Be sure to follow the rates and usage restrictions on the labels.

As temperatures increase in April, be sure to look for cereal leaf beetle adults, especially along field edges that border woods or in protected areas. Adult beetles feed along the veins of grain leaves leaving characteristic narrow linear holes parallel to the leaf veins. Although they do not cause much damage, you should routinely check these areas since this is where you are likely to find the first eggs and larvae. Larvae can feed heavily on leaves, especially flag leaves, and can quickly cause significant yield reductions if they exceed the economic threshold of 25 eggs/young larvae per 100 tillers.