Volume 6, Issue 2 April 3, 1998


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


Aphid activity has started to increase in overwintered spinach. With the warmer temperatures, parasites have also been active resulting in parasitized aphids being "glued" to the leaves. In order to prevent losses in quality, fields should be treated as soon as you see an increase in aphid activity. Dimethoate, Provado, or Thiodan will provide control.


Asparagus beetles are active now. Edge treatments should be applied before egg laying increase and beetles move into fields. Ambush, Pounce, or Sevin will provide control. v

Section 18 Request For Reflex on Snap Beans Withdrawn By Zeneca - Ed Kee, Extension Vegetable Crops Specialist ; kee@udel.edu

Zeneca, manufacturer of the herbicide Reflex, has asked the Delaware Department of Agriculture to withdraw the request we submitted for emergency labeling on snap beans. Reflex has been shown to be effective for postemergence broadleaf weed control in snap beans. Zeneca stated that the theoretical "risk cup" is full and they do not want to endanger their other uses, especially on soybeans. EPA representatives indicate that the "risk cup" overflow is due to ground water concerns with the product. Zeneca is moving ahead with data collection this year to support full registration of the product on snap beans.

Reflex will not be available for use on snap beans in Delaware or Maryland in 1998. The same scenario has occurred in Virginia. v

Pea Planting - Delayed But Catching Up - Ed Kee, Extension Vegetable Crops Specialist ; kee@udel.edu

Cool, wet weather delayed pea planting by 30% until recent warm, dry weather prevailed. Significant acreage has been planted in the last seven days, narrowing the gap between intentions and actual planted acreage. Approximately 9,000 acres will be planted in Delaware in 1998. Nationally, over 230,000 acres will be planted, with the upper Midwest and the Pacific Northwest being the two major production areas. Delmarva is the first region harvested each year, therefore the first new crop to hit the market. v

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

Fungicide Storage.

Fungicides, if stored properly can have a long shelf life. For growers who farm small acreages, knowing when a chemical is still efficacious, and when it is not, is important. Like most pesticides, fungicides should be stored at moderate temperatures (between 40 and 80F), in a room with low humidity and good ventilation. The containers should be sealed and fungicides should always be stored in their original containers. In general, shelf life is longer if a product is unopened. Dr. David Ross, University of Maryland has compiled some information on shelf life of fungicides. The following chart combines his information, and includes some additional information on fungicides used in vegetable production.

Bayleton DF 2 years Cool and dry, no freezing problem.
Benomyl WP 2 years Must be stored tightly sealed and dry.
Benlate and Benlate SP 5 years Keep dry and avoid heat.
Captan 50 and 80 WP 3 to 4 years Must be sealed tight, at temperatures below 100F.
Captan WP 3 years Keep cool and dry.


After 2 years, it will begin to lose potency at 1% per year Heat may result in chemical changes in product that may reduce efficacy.
Nova indefinite Store between 32 and 100F. Keep water soluble pouches in container until use.
Quadris 2 years Do not allow to freeze
Rovral 4 years if unopened, 2 years if opened No problem if frozen
Ridomil 3-5 years Be careful to keep outer package intact until use.
Ziram 3 years if unopened Keep tightly sealed and avoid cross-contamination. No freezing problem.


Field Crops

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

Field Corn.

At this time, white grubs can be easily found in the top four to six inches of soil. Although this may be interpreted as a heavier overwintering population, the incidence of grubs is more likely the result of mild winter conditions resulting in grubs overwintering closer to the soil surface. Factors favoring grub problems include: 1.) planting into old sod or pasture fields, and 2.) planting into double crop or full season soybean stubble, especially if grass weed pressure was heavy the previous season. Fields can also be scouted for grubs before planting. Sampling should be done before the field is tilled when soil temperatures at 6-inches deep are at least 45 degrees F. At each site, sample one square foot of soil dug six inches deep. A minimum of two samples should be taken for every 10 acres with no less than 10 samples per field. A treatment is recommended if you find one or more grubs per square foot. Counter, Force, or Fortress will provide grub control. If populations are heavy, be sure to use the higher labeled rate.

A Special Local Needs Label 24(c) has been approved for the use of Mesurol 50 Hopper Box Treatment (HBT) on field corn and sweet corn for prevention of plant losses from birds feeding on seeds and seedlings in newly planted fields. Mesurol 50HBT is a non-lethal bird repellent; however, birds must consume some Mesurol 50HBT before repellency develops. Birds quickly acquire a learned aversion to Mesurol treated corn seed after consuming only a few kernels and quickly leave fields. It should be applied at a rate of 8 – 14 ozs per 100 pounds of corn seed. The high rate is only needed when pheasants or other large birds are expected to be a problem.

Small Grains.

Aphid populations are starting to increase in barley and wheat; however, the warm temperatures have resulted in fairly good beneficial insect activity. However, this situation could change with the predicted cooler temperatures. If temperatures turn cooler for an extended period of time, beneficial insect activity will start to lag behind. At this time, fields with aphid populations close to the threshold level (150 per linear foot of row) and low beneficial insect activity should be watched carefully for increases in populations. We have also been asked about the likelihood of aphids transmitting barley yellow dwarf virus (BYDV) at this time. Information from Kentucky indicates that it is possible for spring sprays to have an affect on BYDV but it can not be guaranteed. You might expect a return from a spring spraying if BYDV pressure is heavy in your area, aphids were not killed by winter conditions and they overwintered in the field, you have a yield potential of 90-100 bushels per acre, and virus symptoms are not visible yet. Cereal leaf beetle adults have begun to lay eggs in small grain fields. If you plan to use the new threshold of 25 eggs and/or larvae per 100 tillers, no treatment should be applied before at least 50% of the population is in the larval stage. v

Be Sure To Consider Last Year - Mark VanGessel, Extension Weed Specialist ; mjv@udel.edu

In planning your weed management for a given field, consider what happened last year in that field. A number of fields throughout the state did not get a rain shower to activate the soil-applied herbicides and growers could not get a handle on the weeds. Fields that had a large number of weeds go to seed last year, will need a more aggressive weed management program this year. So plan accordingly.

Remember, many of our hard to control weeds require a postemergence herbicide for effective control. Knowing that you are going to be spraying a postemergence herbicide allows you to adjust your soil-applied herbicide program. The result can be less money in a preemergence program knowing you will need a postemergence spray. v

Should You Alter Your Burndown Program This Year? - Mark VanGessel, Extension Weed Specialist ; mjv@udel.edu

With the warm weather we have been having weeds are further along than normal. When you start to burndown your weeds prior to no-till, be sure you check your weed stage first. Some fields have winter annuals that are getting large and starting to bolt. You may need to increase the rate of your non-selective herbicides, or add a non-selective herbicide if you usually do not use one. The key here is to check the field before you start. A wet spring like this year usually means heavy grass pressure. Either Bladex or Princep are often include in no-till corn tank mixes for residual control of fall panicum and crabgrass. Bladex has good burndown activity while Princep does not, this can be a bonus for burndown. At the same time, Princep will provide longer residual control. As with everything else, there are trade-offs.

REMINDER- Timing for Small Grain Herbicides - Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

The following are the timing limitations for small grain herbicides. The timing restrictions are based on crop safety.

Herbicide Small Grain Growth Stage
2,4-D up to jointing stage (pre-jointing)
Banvel up to jointing stage (pre-jointing)
Buctril up to boot stage
Harmony Extra up to flag stage (pre-flag leaf)


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

Executive Summary.

-USDA Planting Intentions

-USDA Quarterly Grain Stocks Report

March 31, 1998


The March 31, 1998 "Prospective Plantings" and "Quarterly Grain Stocks" reports have set the stage for grain and soybean complex price action this spring. Given in this summary is a recap of the reports.


* Average trade guess for U.S. corn going into the report was 82.062 million acres

- Producers intend to plant 80.781 million acres, 1% above last year)

*Average trade guess for U.S. soybeans was 72.005 million acres

- Producers intend to plant 72.0 million acres U.S. soybeans, 2 % above last year

- Producers intend to plant 67.0 million acres of U.S. wheat, down 6 % from last year


* Average pre-report trade guess for March 1, U.S. corn stocks was 4.827 billion bushels

- Total stocks in all positions for U.S. corn reported at 4.937 billion bushels

* Average pre-report trade guess for March 1, U.S. soybean stocks was 1.223 billion bushels

- Total stocks in all positions for U.S. soybeans reported at 1.202 billion bushels

* Average pre-report trade guess for March 1, U.S. wheat stocks was 1.142 billion bushels

- Total stocks in all positions for U.S. wheat reported at 1.166 billion bushels

Plantings and Stocks Report Highlighted

 Corn: U.S. producers intend to plant 80.8 million acres in 1998, corn for all purposes. If realized, the estimate represents the largest planted acreage since 1985. The March 1 corn stocks estimate was nearly 110 million bushels higher than the average trade guess.


 Soybeans: U.S. producers intend to plant 72.0 million acres in 1998, 2 % above last year. If realized, this estimate represents the largest planted acreage for soybeans on record! Growers across the Southeast and Mid-Atlantic states show a general decline in planted acres for 1998. The March 1 soybean stock estimate was only about 20 million bushels below the average trade guess.

  Wheat: The 1998 all U.S. wheat planted area is expected to total 67.0 million acres, down 6 % from last year. This estimate represents the lowest planted acreage for wheat in ten years. Partially offsetting the bullishly construed wheat plantings estimate is the March 1 all wheat stocks estimate of 1.166 billion bushels, 24 million bushels above the average trade guess.

Basis: A Key Indicator to All Grain Marketing Decisions - Carl German, Extension Crops Marketing Specialist ; clgerman@udel.edu

Basis is among the most important relationships to understand in grain and soybean marketing. As a price relationship between local cash prices and futures prices, basis provides the grain marketer with clues on when to sell and when to wait; when to forward price; or simply whether to accept or reject a particular price or basis contract offering, on a given day.

Basis is calculated as B = C – F (Basis = cash – futures). On the Eastern Shore, the grain trade typically refers to basis as the local cash price being over or under futures. A good definition of basis is the continuous and ever-changing relationship between cash grain prices and futures prices.

Basis: Described Further

What is basis?

The amount, on any given day, that the local cash price of a commodity is above or below the current price for a particular futures delivery month. For spot prices, the basis is the difference between the local cash price and the nearby futures contract.

For forward prices, the basis is the difference between the local cash price offering and the distant futures contract (December for corn, November for soybeans, July for wheat).

How and Why Does Basis Fluctuate?

Basis fluctuates for several reasons. Some are more common than others are. A recent guidebook published by the Chicago Board of Trade gives four components of the basis: basis differs partly due to location, partly due to storage, handling & profit (and at times due to protection).

On any given day, the cash price of grain in Chicago is determined by active competition between a large number of buyers and sellers. Processors, merchandisers, exporters, and retailers are continuously bidding (in cents per bushel over or under the nearby futures price) for grain for immediate or deferred delivery. When basis strengthens it narrows, conversely, when it weakens it widens.

Common Producer Applications

Two of the more common applications of basis in cash marketing are:

  1. To accept or reject cash bids (spot)
  2. To accept or reject forward cash contracts

Spot cash or basis bids of 30 under means that the market is telling you to wait, it does not want your grain right now. A basis bid of 30 over or better means that the market is telling you to take an immediate sale, the market wants your grain right now.

Historical basis records are necessary to determine if a forward cash contract offer is acceptable.

As a guideline, the general rules of thumb regarding basis apply to any time throughout the marketing year; to every marketing decision; and to every marketing alternative used in making grain marketing decisions. v

General Planting Reminders…. Derby Walker, Extension Ag Agent, Sussex County; derby@udel.edu

* check planting equipment :double check seeding depth, and adjust equipment for seed size and field conditions

* Fertilizer placement is very important to crop growth; 2 inches down & 2 inches off to the side of the seed; too close and salt injury can occur, too far away and plants can not take full advantage of the nutrients provided

* go over your sprayer ; inspect hoses and nozzles and check your spray pattern. A few minutes now could save you money later.

* Recent weather has caused delays in planting, but remember mudding in crops leads to: compaction problems, ruts in the field and often poor stands. Replanting can be expensive. Waiting for the soil to warm up and dry up enough to plant will improve your profit margin.

When To Plant Corn - Richard W. Taylor, Extension Agronomist ; rtaylor@udel.edu

At a recent irrigation meeting, growers asked about what the soil temperature should be before beginning to plant corn. In response to this question, I sent out an e-mail message to all university corn agronomists across the country asking them what criteria they use to decide if it’s time to plant corn. Their replies were even more varied than our opinions at the irrigation meeting. The two temperatures sited were 50 and 55 F. The temperature was measured at either 7 am, 8 am, 10 am, or 1 p.m., needed to remain at or above the chosen temperature for 1, 3, or more days, and had to be measured at the seeding depth, at a 2-inch depth, or at a 4-inch depth to trigger the decision to plant. Several avoided the use of soil temperature altogether and relied strictly on calendar date.

Despite all the conflicting opinions, I feel that it is possible to synthesize a few reasonable guidelines you can follow in deciding if conditions will permit corn planting. Above all else be sure the soil conditions will support your use of equipment without causing severe compaction problems. After that the first guideline to follow is calendar date. In this area, the optimum planting date is around May 1 but little change in yield occurs between April 20 and May 10. Therefore, if the date is earlier than April 20, you should use more conservative soil temperature criteria, 55 F at 10 am for several days. After April 20, use a more liberal soil temperature criteria, 50 F at 7 am plus the forcast of 3 to 5 more days with air temperatures at or above 50 F.

The next guideline to use is to measure the soil temperature in soil under the same conditions in which the crop will be sown. If no-till in a cover crop, measure soil temperature in the same situation. If conventional-till, measure soil temperature in bare soil and so forth. Another guideline is to measure soil temperature at the same depth as you intend to plant corn.

Finally, when planting early in soil barely warm enough for corn to germinate, the agronomist from Purdue University said that if the soil temperature falls below 50 F. during the 21 to 28 days before emergence and the soil is wet, emergence will be very variable while under dry soil conditions emergence will remain good. Another agronomist suggested increasing the seeding rate by 2,000 seed per acre when planting early under marginal conditions.

What can you use to measure soil temperature? We report it for bare soil in this newsletter and it is also available on-line from the University of Delaware Research and Education Center http://www.rec.udel.edu under the local weather option. Otherwise, you can buy a regular outside type of thermometer or a probe-type of metal tipped thermometer to use. Be sure it measures temperatures in the range of 40 to 60 F. It can be installed in a field for the few weeks you’ll need to check it or with the probe-type it can be carried around with you to check multiple fields each day. Just match sample and planting depths and use bare soil for conventional or chisel plowed fields and sod covered soil for no-till fields or fields with heavy residue. 

Before Planting Forage Crops, Calibrate Your Seeder and Save Money - Richard W. Taylor, Extension Agronomist ; rtaylor@udel.edu

Dr. Marvin Hall at The Pennsylvania State University recently reported on a study that examined how different alfalfa seed flowed through the same forage seeder. Coated seed flowed through the seeder easier than uncoated seed; and, even accounting for the reduction in seed per pound (due to the increased seed size with the coating), coated seed resulted in higher seeding rates.

When different alfalfa varieties were evaluated in the same seeder, the seeding rates ranged from 14 to 21 lb./acre without changing any of the settings on the seeder. If you thought you were planting at 15 pounds per acre and instead the actual rate was 20 pounds per acre, the additional cost (a 33 percent increase) per acre for seed would be substantial.

What caused these differences? Varieties vary in number of seed per pound. In one study, it ranged from 196,000 to 224,000 seeds per pound. Another variety effect comes from seed shape. Some varieties are slightly rounder than others are and this rounder seed flowed through the drill’s metering device faster than the non-rounded seed.

Are varieties consistent in these treads? No, the growing conditions when the seed was produced can effect these seed characteristics so each lot of seed should be evaluated separately.

How can you check your seeding rate? One way is to drive the seeder either over a tarp or a smooth hard surface and then count the number of seed in several square foot areas on the surface or tarp. Generally, recommended seeding rates in pure stands will result in 75 to 90 seeds per square foot. If you are concerned more with the pounds of seed planted per acre, use a tarp, measure the area of the tarp seeded, and then weigh the amount of seed on the tarp. You can then calculate the pounds per acre knowing that an acre has 43,560 square feet of area and a pound of seed weighs 454 grams or 16 ounces.

Even with these quick checks, you should plan to calibrate your seeder annually before the planting season since even slightly worn seed metering devices can cause large changes in seeding rates.


Week of March 27 to April 2

0.01 inches: April 1
Readings taken for the previous 24 hours at 8 a.m.
Air Temperature:
Highs Ranged from 88 F on March 31 to 68 F on March 27.
Lows Ranged from 52 F on April 2 to 38 F on March 27.
Soil Temperature:
64 F average for the week.
(Soil temperature taken at a 2 inch depth, under sod)


Compiled & Edited By:

Tracy Wootten, Extension Associate - Vegetable Crops

Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State College 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, color, sex, disability, age or national origin.

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