Posts Tagged ‘19:11’

2011 Delaware Cooperative Extension Short Course: BENEFICIAL INSECT IDENTIFICATION

Friday, June 3rd, 2011

Wednesday, June 8     6:00 – 8:00 p.m.
Sussex County Extension Office
16483 County Seat Hwy
Georgetown, DE 19947

Cost: $10

Instructors: Brian Kunkel and Tracy Wootten

Using Integrated Pest Management (IPM )in your business?  Correct I.D. is key to control of pests in the landscape.   Enhance your skills at identifying beneficial insects in the landscape.

To register call any County Extension Office

302-831-2506; cjmurphy@udel.edu

302-730-4000;carolm@udel.edu

302-856-7303; wootten@udel.edu

Hope you can join us!

Credits:
2 Pesticide, (Category 03,02, 06), and 1 CNP

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.

 

Palmer Amaranth is in the Area

Friday, June 3rd, 2011

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

Last year I saw a few fields in the area (Delaware and Maryland) with infestations of Palmer amaranth. Palmer amaranth is a pigweed, which looks similar to the smooth pigweed that is so common (and often called redroot). However, Palmer amaranth is a very aggressive species that grows very rapidly. It is native to the southwest region of the US, and does better than most plants under dry conditions. Palmer amaranth has been described as pigweeds on steroids because of its ability to grow very rapidly, get very tall, and be very competitive with crops. Palmer amaranth is found throughout the southern US and is moving northward. Palmer amaranth is not as sensitive to Group 2 herbicides as smooth or redroot pigweed (this includes Pursuit, Sandea, Accent, Matrix, etc.). It is sensitive to PPO herbicides (Reflex, Valor, etc); atrazine, and HPPD (Callisto, Impact, and Laudis. Furthermore, glyphosate-resistant Palmer amaranth is present in Georgia, North and South Carolina and other southern states. I am not aware of any herbicide-resistant Palmer amaranth in our area.

It is critical that you control plants early; and that you do not allow the plants to produce flowers. Plants will produce a very high number of seeds that will quickly infest fields. In the southern cotton growing regions where they have herbicide-resistant Palmer amaranth, they have had to resort to hand weeding.

To help identify Palmer amaranth, see the chart, websites, and photos below.

Characteristics Redroot Pigweed Smooth Pigweed Palmer Amaranth
Stem hairs Hairy Hairy No hairs
Stems Often ridges running length of stem Often ridges running length of stem Mostly smooth
Leaf petioles Petioles no longer than length of the leaf Petioles no longer than length of the leaf Long drooping petioles
Seed head Short, stout, prickly Long, slender, slightly prickly Very long, thick, very prickly

A couple of good publications include:

http://mulch.cropsoil.uga.edu/weedsci/HomepageFiles/PalmerBiologyEcology.pdf
http://www.extension.iastate.edu/Publications/PM1786.pdf
http://www.ksre.ksu.edu/library/crpsl2/s80.pdf

 

Smooth pigweed

 

Palmer amaranth

 

Grain Marketing Highlights – June 3, 2011

Friday, June 3rd, 2011

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

Outside Market Forces and Fundamentals at Odds

Corn Analysis
As of May 29, U.S. corn planting progress was reported to be 86 percent complete, 9 points behind the five year average and 11 percentage points behind last year. The U.S. corn crop was also reported to be 66 percent emerged, 12 percent behind the five year average. The initial weekly condition report for the corn crop was placed at 53 percent good and 10 percent excellent. The condition for the U.S. corn crop at the same time last year was 61 percent good and 15 percent excellent. The Linn group, a private forecasting firm, estimated corn plantings at 87.233 million acres, well below USDA’s 92.178 million acre projection. While the final USDA projection won’t be updated until June 30, the general consensus is planted acreage will decline due to late plantings, and flooding along the Mississippi and Missouri Rivers.

Soybean Analysis
U.S. soybean plantings were reported at 51 percent complete, as compared to the five year average of 71 percent. Emergence of the soybeans crop was reported to be about 12 points behind the five year average. Debate continues to grow as to whether bean acres will increase due to less corn being seeded or decline due to the late planting pace and flood concerns. Linn Group’s estimate for soybean planting came in at 74.894 million acres, well below USDA’s 76.609 million acre March 31 projection.

Wheat Analysis
Winter wheat conditions were reported at 26 percent good and 7 percent excellent, compared to 51 percent good and 14 percent excellent last year. Spring wheat plantings were reported at 68 percent planted as compared to the five year average of 95 percent. Emergence reported at 40 percent is 41 points behind last year’s pace.

Market Strategy
2011 U.S. planted acres remain a big unknown? Will we see less U.S. corn acres and/or more or less soybean acres than previously estimated? Until those acres become known the market is likely to move in a sideways to higher trading pattern for corn and soybeans. The underlying assumption is that crop acres are likely to decline from the March intentions report. Fundamentally, this would be price positive for commodity prices.

The primary outside market force working against this argument is the general state of the economy. For example, the Dow has taken a big hit this week due to general economic concerns weighing negatively upon commodity markets. Jobless claims are running higher than expected. This sent commodity markets into a nose dive in yesterday’s trading.

It is reasonable to expect these markets to be driven by fundamentals in the near term, bearing in mind that at some point acreage concerns will become considered as factored into new crop commodity prices. It might be wise to consider incremental sales for new crop corn and soybeans. Dec ‘11 corn futures are currently trading at $6.87; Nov ‘11 soybean futures at $13.87; and July SRW wheat at $7.72 per bushel.

For technical assistance on making grain marketing decisions contact Carl L. German, Extension Crops Marketing Specialist.

 

Harvest Aids for Small Grains

Friday, June 3rd, 2011

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

A number of glyphosate products such as Roundup and Touchdown are labeled as harvest aids in winter wheat and barley. Check the label for other formulations of glyphosate. Applications must be made after the hard-dough stage and at least 7 days prior to harvest. Aim is labeled as well, but the spectrum of control is limited to velvetleaf, morningglory, pigweeds, and few other weeds. Apply at least 3 days before harvest. Use of 2,4-D (or products containing 2,4-D) is generally not recommended as a harvest aid due to its volatility, and potential damage to the crop during application.

 

Soybean Planting

Friday, June 3rd, 2011

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

Since barley harvesting has already begun in Kent County, I would encourage anyone who has not planted their full-season soybeans to place a high priority on planting them. Soybean prices are some of the best in recent memory, so keep the following tips in mind to help maximize yields.

On soils with a history of crusting and when planting in conditions too dry for germination, avoid planting too deep since a heavy downpour can easily cause the soil to seal over before the soybeans emerge. Shallower planted soybeans seem to be able to break through the crust more easily than deep planted beans.

Even in dryland fields I like to shoot for about 175,000 pure live seed per acre as my target population. When seed to plant was expensive and the price you received for the beans you harvested was low, reduced populations made economic sense. With today’s prices, I think targeting for higher yield potential is worth the extra seed cost.

Plant as early as possible for full-season beans. Yield potential quickly declines as we move further and further into June. For double-crop soybeans, again planting as quickly after barley or wheat harvest as possible is best although be sure you are placing the seed in the soil and not on top of small grain straw where they possibly will die during germination from lack of moisture or an inability to peg themselves into the soil. If the field is so dry you can’t place the seed properly, your best choice will be to wait for rain to soften the ground and allow fast germination.

Once soybeans have emerged, scout them frequently for micronutrient deficiency, especially in fields that showed micronutrient deficiency on the small grain crop. Again, as with corn, the micronutrient you should be most concerned with is manganese (Mn). To maximize yields, apply Mn in a foliar spray as soon as you spot the characteristic interveinal chlorosis on the newly emerging leaves. You can confirm deficiency with either or both a soil test and a whole plant or leaf tissue test. If plants are very young when Mn deficiency shows up, you may need two foliar applications of Mn as manganese sulfate or a chelated Mn.

 

Dryland Corn and Nitrogen Sidedressing

Friday, June 3rd, 2011

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

I was asked recently for thoughts on sidedressing corn during the recent heat we’ve been experiencing. I thought I would share some arcane, although still relevant, information from my soil fertility and plant nutrition class at the University of Delaware. This concerns an old proven principle called (by me at least) the Sprengel-Liebig Law of the Minimum. Essentially what P. Carl Sprengel in 1828 and J. von Liebig, also, in the 1900s stated in various papers they published was that yield will be determined by whatever factor is most limiting to the crop.

For growers who irrigate their corn, chances are that the limiting factor will be something other than water availability. It may be a disease that impacts grain fill or it may be a lack of one of the essential nutrients or even a lack of enough sunlight during the growing season. We often see the latter in years where it’s cloudy or hazy for much of the summer. With respect to nitrogen (N) sidedressing, irrigated growers can easily apply a small amount of water to incorporate the N into the soil and therefore prevent ammonia volatilization losses from the urea component of the UAN (urea-ammonium nitrate) solution.

However for dryland corn producers who may feel the need to sidedress N on their rapidly growing corn crop, what likely is the most yield limiting factor their crop faces. Is it N availability? No in my opinion, the most limiting factor will always be water availability throughout the growing season. If it isn’t the total amount of N, it will be the distribution of the rainfall/moisture during the growing season. For these producers, the decision to sidedress N will come down to the speed of corn growth versus their ability to cover all the corn acreage before the corn runs out of starter N or becomes too tall to sidedress without causing crop damage.

Within the activity of sidedressing, there are some choices to minimize N loss as ammonia volatilization such as knifing in the UAN, using anhydrous ammonia rather than UAN, or using one of the urease inhibitors. Some of the old research suggests only about a 7 to 10 percent loss in N from dribbling the UAN solution on the soil surface. Even with this amount of loss, your most limiting yield factor will still be water availability throughout the growing season.

 

Scout Corn Fields for Micronutrient Problems

Friday, June 3rd, 2011

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

With the recent heat, corn development has been proceeding rapidly and before the corn develops past the point where you can get into the field to treat for the most common micronutrient deficiencies we see in Delaware fields you or your consultant-scout should check your most developed corn fields. Pay particular attention to fields that have had a history of micronutrient problems in corn and small grains and in fields where the soil pH is close to neutral (pH of 7.0). Many fields in Delaware begin to show manganese (Mn) deficiency as our soil pH rises towards neutral or alkaline. Application of even a ¼ of a pound of actual Mn per acre up to 1 or 2 lbs/acre in with a post-emergence weed control spray often will restore plant vigor. Mn deficiency in corn like most micronutrients shows up as an interveinal chlorosis meaning the parallel veins remain green and the tissue in between the veins turns yellow to white. The symptoms occur first on the newest growth since the plant is unable to take Mn from older tissue (the first leaves to appear and that will die soon anyway) and move it to the newly developing leaves and ears. The fact that corn is setting its ultimate yield potential even as early as the fifth leaf stage is something we often forget. Micronutrient deficiencies during this early vegetative growth will certainly reduce yields since the active growing points, such as the developing ear, are the first to suffer from a deficiency since micronutrients are not mobile in the plant.

 

Agronomic Crop Disease Updates

Friday, June 3rd, 2011

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

Soybeans
The dry conditions combined with high soybean cyst nematode (SCN) egg counts could mean we will see more stunting from SCN this season. Be on the lookout for stunting in irregular areas. The SCN females can be seen on the roots of infected soybeans around 28-32 days after planting.

Barley
Barley harvest is fast approaching and the crop looks pretty good. Besides some leaf rust, net blotch, powdery mildew on ‘Thoroughbred’, and a little head scab, diseases have not been bad this season.

Wheat
A few diseases were observed during a recent check of the variety plots near Middletown in New Castle County. Low levels of tan spot and powdery mildew were seen in a few varieties, but all but one of the 45 entries had some head scab. Most of the infections were under 1% of the heads infected and many of those heads were only partially infected. Wheat in NCC was the most at risk according to the scab predictions. Some shriveled grain with the white coating of the Fusarium fungus was observed on some of the infected heads. Increasing fan speed on the combine will blow the light chaffy “tombstones” out the back and not contaminate the rest. Planting multiple wheat varieties with different flowering times (maturity) will decrease the risk of scab for next year. Statewide, overall scab levels are low compared to several years ago. I had mentioned in last week’s WCU that several varieties in the variety trial had genetic flecking or a resistance reaction including Merl, USG 3209, USG 3251, USG3665, Sunburst, and Grow Mark FS627. These symptoms are not an active disease.

Flecking on USG3409 that looks like a disease

Head scab on wheat

Healthy kernels and Fusarium head scab infected “tombstones”

Tan spot on wheat

 

Harvesting Grain from Scabby Fields
The following are tips to reduce the amount of scabby kernels in the harvested grain and to avoid potential health problems for combine operators and grain handlers. Scabby grain is contaminated with mycotoxins, especially vomitoxin, which is harmful to humans.

Harvest tips:
1. Avoid breathing in dust from scabby fields by using a high quality dust mask. Spores of the scab fungus (Fusarium graminearum) and small pieces of contaminated plant parts are present in the dust. Inhaling these particles may cause health problems.

2. Harvest the most severely scab damaged areas, such as low areas or double seeded headlands, separately. Don’t co-mingle the most damaged grain with sounder grain.

3. Turn up the air on the combine to blow out the lightest, scabby kernels back into the field.

4. If rain is forecast, it may be better to harvest scabby fields at slightly higher moisture content than to wait for grain to dry down. However, this grain still needs to be dried down and maintained below 15% moisture after harvest to prevent fungal growth in storage.

5. After harvest, gravity table grain separation can be used in removing more of the light-weight, scabby kernels.

6. Get grain from scabby fields tested for vomitoxin before feeding, before blending, or before making a decision to discard suspect grain.

From http://www.scabsmart.org/harvest%20practices.html

 

Agronomic Crop Insects – June 3, 2011

Friday, June 3rd, 2011

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

Alfalfa
Continue to sample for potato leafhoppers on a weekly basis. Although adults are the main life stage present, we are starting to see the first nymphs. Both life stages can damage alfalfa but the nymphs can cause damage very quickly. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

If you have planted a glandular haired variety, we do not have any local data but here is some information from Ohio State regarding treatment thresholds on these varieties:

“If the alfalfa is one of the glandular-haired, leafhopper-resistant varieties of alfalfa, the economic threshold is three leafhoppers per inch of growth (24 leafhoppers for 8” tall alfalfa, for example). However, if the resistant alfalfa is a new planting this spring, growers should use thresholds meant for regular alfalfa during the first growth from seeding. Because resistance improves as the seedling stand develops, research suggests that the threshold for a resistant variety can be increased after the first cutting. More information on potato leafhopper, including how alfalfa growing conditions might affect the threshold, is available at http://ohioline.osu.edu/ent-fact/pdf/0033.pdf.”

Soybeans
Be sure to sample fields starting at emergence for bean leaf beetles and grasshoppers. In the earliest planted and emerged fields, we have started to see an increase in activity for both insects. As barley is harvested and soybeans are planted, these fields will be especially susceptible to attack from grasshoppers and feeding can often cause stand loss. If stand reductions are occurring from plant emergence to the second trifoliate, a treatment should be applied. Although no precise thresholds are available, a treatment may be needed if you find one grasshopper per sweep and 30% defoliation from plant emergence through the pre-bloom stage. As a general guideline, a treatment may be needed for bean leaf beetle if you observe a 20 – 25% stand reduction and/or 2 beetles per plant from cotyledon to the second trifoliate stages.

 

Cultivation and Postemergence Herbicide Treatment

Friday, June 3rd, 2011

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

Questions have come in about whether to cultivate first or spray first for weed control. Keep a few things in mind. Weeds are easier to control when they are small but consider which option is going to be more effective when weeds get larger. Cultivation will control the weeds between the rows but not in the row. Those weeds in the row are the ones you need to base your decision on whether to spray first. More often than not, it is better to spray first then cultivate. In addition, weeds not completely killed with cultivation are more difficult to control with herbicides. **Note this assumes that the herbicide is the right herbicide for the weed(s) in your field. The weeds that emerge after cultivation are going to be much smaller and have less impact on yield (in any impact at all). Setting your cultivator so it runs only 1 to 2 inches deep will slice through the weeds and not disrupt the herbicide layer from you preemergence herbicides. This in turn will limit the number of weeds that will emerge due to cultivation. It is recommended to wait a minimum of 5 to 7 days between herbicide treatment and cultivation.