Posts Tagged ‘17:14’

WCU Volume 17, Issue 14 – June 19, 2009

Friday, June 19th, 2009

PDF Version of WCU 17:14 – June 19, 2009

In this issue:

Vegetables
Vegetable Crop Insects
Phytophthora Blight on Cucurbits
Cucurbit Downy Mildew Update
Potato Disease Advisory #11 – June 18, 2009
Late Blight Present on Tomatoes in Maryland
Lima Bean Weed Control

Agronomic Crops
Agronomic Crop Insects
Black “Sooty” Head Mold on Wheat and Barley
Soybean Rust Update
Hail Hammers Corn and Soybean Fields – Do I Replant?
Corn, Wet Soils, Delayed Sidedressing and Crop Effects
Fields Not Treated Yet for No-Till Soybeans
Glyphosate Formulations
Grain Marketing Highlights

Announcements
Weed Science Field Day – June 24
On Farm Delaware Food Safety Training – Level I Certification – June 30

Weather

Grain Marketing Highlights – June 19, 2009

Friday, June 19th, 2009

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

Weather and June 30th Planted Acreage Report to Determine Price Direction
So far this month we’ve seen the publishing of a rather insignificant June supply and demand report with two exceptions: the projected yield per acre for U.S. corn was reduced slightly resulting in a lower carryout estimate; and ending stocks of U.S. soybeans were reduced for both the ’08/’09 and ’09/’10 marketing years. Those factors were price positive, along with the price of crude now climbing into the $70 (+) range and the dollar index trading near 80. The most negative factor influencing commodity markets since the release of the June 10 S/D report is the trailing off of the Dow, trading at 8,550 this morning. A few days before the release of the June report some analysts were suggesting that we could see a continuation of the seasonal rally for corn to continue for an extended time, beyond early June, due to the lateness of the ’09 row crop season. Instead, within a couple of days of the release, corn, soybean, and SRW wheat prices plummeted. There are likely to be reasons for the recent price drop occurring, among them, commodity prices may have been getting too high too soon, creating an overbought situation and the non-commercial speculative traders decided for the time being to take profits from their long positions. Another might be that commodity traders had already discounted the information in the June S/D report into the market. In the last five trading days Dec ’09 corn futures; Nov ’09 soybean futures; and July ’09 SRW wheat futures dropped about 50 cents per bushel, respectively. Nevertheless, the task at hand remains looking ahead.

USDA Export Sales Report 06/18 07:35
Pre-report estimates had weekly corn export sales at 650,000 to 1,000,000 metric tons (23.6 million bushels to 39.4 mb) combined old-crop and new-crop sales. The weekly report showed export sales of 767,300 mt (30.2 mb) in old-crop corn, well above the 236,000 mt (9.3 mb) that was needed to meet USDA’s projection of 1.75 billion bushels, while new-crop sales were 376,200 (14.8 mb). Total shipments of 817,900 mt (32.2 mb) were below what was needed this week. This report should be viewed as neutral to bullish.

Pre-report estimates for soybeans ranged between 50,000 mt and 250,000 mt of combined old-crop and new-crop sales (1.8 mb and 9.2 mb). The weekly report showed export sales of 145,700 mt (5.4 mb) in old-crop soybeans, above the 28,800 mt (1.1 mb) that was needed to meet USDA’s revised projection of 1.25 bb, new-crop sales were 105,000 mt (3.9 mb). Total shipments of 349,400 mt (12.8 mb) were below what was needed this week. This report should be viewed as bullish.

Pre-report estimates for wheat ranged between 200,000 mt and 500,000 mt (7.3 mb and 18.4 mb) of export sales. The weekly report showed export sales of 268,800 mt (9.9 mb), below the 411,900 mt (15.1 mb) needed to stay on pace with USDA’s projection of 900 mb. Shipments of 392,800 mt (14.4 mb) were below what was needed this week. This report should be viewed as bearish.

Market Strategy
Have commodity prices already peaked with the start of summer just around the corner? We’d all like to be able to answer that question definitively. However, there are a few factors that don’t add up to higher and higher prices occurring over the summer, according to Darrin Newsom, DTN Market Analyst who will be alluding to these factors during a Summer Market Outlook presentation to be given this afternoon.

For example the Dow has recently descended and now has a summer target in the vicinity of 7,800. The dollar index, having dropped 10 points since March, is now expected to strengthen – summer target 84.00.

The front-month corn price recently hit $4.50, putting the market in the upper third of the price range. Seasonally corn tends to fall 26% from early June through early August.

Soybeans tend to rally about 10% from early June through early July and then falls about 25% through August. An early seasonal high may have occurred in June. The carry in the new crop futures spreads suggests that the November soybean futures contract could begin to come under pressure.

SRW wheat is now in a seasonal down trend with the U.S. wheat harvest now underway. Seasonally SRW wheat tends to decline 4% from early June through mid-August.

The trend remains up for corn and soybeans, more so for soybeans than corn. The underlying current of a more bearish tone coming into play in these markets could be over shadowed by a surprise in the June 30th Actual Plantings report and questionable weather for new crop development. Considering the uncertainty in these markets, which makes more sense – pulling the sales trigger on a portion of new crop soybean sales now or waiting to see what the summer brings? It may be advisable to consider making a soybean sale prior to the release of the plantings report and waiting to see the report before advancing sales on new crop corn.

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

Glyphosate Formulations

Friday, June 19th, 2009

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

Penn State University has a table of various glyphosate formulations, based on amount of active ingredient and amount of adjuvants. With slight modifications, I have posted this on the UD Weed Science Website at: http://www.rec.udel.edu/weedscience/Glyphosates_09.pdf

If you do not find a glyphosate product that you use, let me know and I will update this list.

Fields Not Treated Yet for No-Till Soybeans

Friday, June 19th, 2009

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

Due to the rains a number of fields that will be planted to soybeans have not been burned down or need to be retreated. A few things to consider if the fields have not been treated yet: 1.) coverage is important due to dense vegetation, keeping gallons per acre in the 20 gallons per acre range is important; 2.) while 2,4-D can help with some highly sensitive species (primrose), replanting intervals and proximity to sensitive crops will limit its use now; 3.) don’t try cutting rates, weeds are large and often reduced rates will not effectively control them, even higher rates may not provide 100% control; 4.) choose your herbicides carefully; if multiple species are present more than one herbicide will be needed and be sure they are compatible with one another, and that they are going to provide benefit to your situation; and 5.) be realistic in your expectations, controlling large dense populations of weeds is difficult, prioritize those species that are of the biggest concern and be sure to address them first and remember a follow up in-crop application may be needed sooner than usual after planting to help control some species not killed by burndown treatments.

Some fields have been treated and horseweed was not effectively controlled, but the fields have not been planted yet. First, a few scattered plants will not reduce final yield, so determine if a treatment is needed in the first place. The two options are Ignite 280 or a product with chlorimuron (Canopy, Canopy EX, or Synchrony). If the chlorimuron products have been used in this spring, a second application is not advisable due to both concerns with crop safety and reports of inconsistent horseweed control with these products. Ignite 280 at 29 to 36 oz/A or chlorimuron products at a rate providing 1.7 oz wt of Classic (Canopy 4 oz; Canopy EX, 1.8 oz; Envive at 4.1 oz; or Synchrony at 2 oz). We do not have much experience with side by side comparison of these options, but both should provide over 75% control.

Corn, Wet Soils, Delayed Sidedressing, and Crop Effects

Friday, June 19th, 2009

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

Many corn fields are too wet to go across and recent rains have caused more delays to corn sidedressing. Corn is getting too tall for tractor drawn sidedressing equipment in many cases and high clearance applicators will be needed. Thousands of acres have stunted growth due to excessive water and many low areas are drowned out. The following are some answers to critical questions about corn in this wet season.

If I delay sidedress N application too long will there be a yield loss?
Research has shown that corn that is sidedressed late may have little yield loss. In a study by the University of Missouri, researchers evaluated the yield impact of delaying N applications until the late vegetative growth stages and as far as silking. They conducted 28 experiments with timing of a single N application as the experimental treatment. This was their results: “We found little or no evidence of irreversible yield loss when N applications were delayed as late as stage V11 (11 leaf stage), even when N stress was highly visible. There was weak evidence of minor yield loss (about 3%) when N applications were delayed until stage V12 to V16 (12 to 16 leaf stage). Only 3 of the 28 experiments had N applications later than V16-all were at silking and relative yields were 71%, 89%, and 95%. Though full yield was not achieved when N applications were delayed until silking, yield was still highly responsive to N application at this stage” [Corn Yield Response to Nitrogen Fertilizer Timing and Deficiency Level" by Peter C. Scharf, William J. Wiebold and John A. Lory, Dep. of Agronomy, 210 Waters Hall, Univ. of Missouri, Columbia, MO 65211 in the Agronomy Journal 94:435-441 (2002)].

How much nitrogen has been lost in wet soils?
The combination of leaching and denitrification losses in wet soils can be over 60%. Sidedress applications should be adjusted upward accordingly.

Corn appears to be going backward in some fields. Why?
In wet soils, root growth has slowed because of the lack of oxygen. When roots are not functioning, nutrient uptake will be limited and top growth will be affected. There will also be severe nutrient deficiencies as roots cannot supply essential mineral nutrients to support top growth. Some roots may have died due to lack of oxygen or to root diseases. In addition, considerable nitrogen has been lost in soils due to leaching and denitrification, so even if growth resumes in drier weather, there will not be enough nitrogen to support top growth.

Why does later planted corn and replanted corn seem to be impacted more than earlier corn?
Late planted corn has a much smaller root system and again that root system is not functioning well in wet soils so effects are magnified. Earlier planted corn established a larger root system before soils became overly wet. These roots serve as a storage area and can supply the plant with some nutrients when conditions are suboptimal. Replanted areas are normally in the wettest parts of fields and therefore you would expect them to perform poorly in a wet year.

Will corn in low areas and wet fields recover?
Recovery will depend on 2 factors – air getting to the roots and adequate nitrogen being applied by the time of silking. If soils stay wet, roots cannot get enough oxygen and no amount of fertilizer will help. If nitrogen is not applied, also expect poor performance. In addition, some roots have already died due to lack of oxygen, some roots have been infected by disease organisms, and some root rots have already become established. If diseases have started to attack roots, expect poor corn performance even with drier weather.

Hail Hammers Corn and Soybean Fields – Do I Replant?

Friday, June 19th, 2009

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

Over the past few weeks, a number of hail storms have impacted corn, soybeans, and small grains on Delmarva. In some of the wheat fields I’ve visited, the field sometimes appears to have heads remaining although when closely examined little grain actually remains while other fields appear to have been previously combined with a stripper head leaving the stem upright but little to no grain on the head. Barley fields have faired even worse with some flattened so badly that they appeared to have been previously combined with the straw baled off even though this was not the case. In most cases, these fields will be total losses; and if the rains continue, double-cropping to soybeans may not be possible. If any of the fields are successfully planted to soybeans, be aware that volunteer barley or wheat will be a major problem.

The real dilemma growers face is whether to replant corn and soybean fields that have been hard hit with hail. For corn, the impact of hail damage really depends on the type and severity of damage and the growth stage of the crop. Since all our corn is still in the pre-tassel stage, I’ll concentrate on that aspect. Keep in mind that if the damage is restricted to leaf shredding, grain yield reductions are not directly proportional to the amount of leaf area loss since there is an increase in dry matter production in the remaining leaf area and movement of dry matter from other plant parts later to the developing ear. Very young corn if able to grow through the damaged top will produce a fully functioning plant since many of the lowest leaves are lost to shading and leaf aging before the plant even tassels or silks.

Leaves beginning with the first rounded tip leaf are counted as each collar region becomes visible. Little yield loss occurs before about the 7th leaf stage (although many of the corn hail damage estimate charts actually count the upper most leaves as long as about 50% of the leaf is exposed from the whorl and the leaf tip points below a horizontal line). At this stage, which should equate to five to six leaves with collars visible, a one percent yield loss can occur if 40 to 45% of the leaf area is missing or dead but even at 100% leaf loss the yield loss will only be about nine percent. As another example at the 10 leaf stage which is about the size of the largest corn I saw with damage, yield loss is one percent at 25% leaf loss, six percent at 50% leaf loss, nine percent at 75% leaf loss, and 16% at 100% leaf loss (see photo 1).

hail damaged cornPhoto 1. Hail damaged corn with an estimated leaf loss of >50%.

An added complication occurs when the growing point is above ground and the hail damages the stem below the growing point (Photos 2 and 3). If the hail impacts the stem causing minor injury (Photo 2), the leaf loss tables from charts assessing hail damage to corn can be useful by themselves but if the hail either breaks the stem below the growing point (Photo 3) or causes such severe injury that disease issues become important, another factor must be considered. This added factor is the impact of stand reductions on yield losses. Many of the available fact sheets on assessing hail damage include this type of information and the two charts must be combined to estimate yield losses.

hail damaged cornPhoto 2. Hail damaged corn with injury to the stem from the impact of the hail but without clipping the stem (note that the plant was bent over to allow a better photo of the injury).

hail damaged cornPhoto 3. Hail damaged corn where the stem has been clipped below the growing point.

One of the most difficult decisions to make is when to evaluate a field to see if it will grow out of the hail damage. In most cases, in 7 to 10 days after the hail you should be able to see renewed growth and estimate whether the new leaves will successfully emerge. This is especially critical on very young (less than five leaves emerged) corn that has been totally flatted or clipped by hail. In older corn where only the leaves have been shredded (Photo 1), new growth can often be identified in as little as 3 to 5 days but wait about a week to get a better assessment.

Should the corn be replanted is the question most frequently asked and the answer almost always is no unless the stand loss is nearly 100%. The reason is that replanting corn in our area this late in the growing season seldom results in enough yield to justify the expense of more seed, more fertilizer, and more labor and time to plant. With the added delay of waiting to evaluate regrowth and, this year, for the field to dry enough to replant, I doubt if any replant decision will result in making you money.

What about soybeans that have been damaged by hail? In most cases, yield loss from hail will be primarily due to stand reductions. Generally, within 5 to 10 days after the hail damage occurs you can make an assessment of the recovering stand to estimate yield loss (Photo 4). In almost all cases, unless the stand has fallen well below about 75,000 plants per acre (one plant per foot of row on 7 inch drilled rows), replanting will not be profitable. The combination of yield loss from a delay in planting of several to many weeks from the ideal time plus the ability of soybeans to compensate in yield potential for low populations will make replanting unnecessary and unprofitable. Although I did see some plants clipped off below nodes where secondary buds can develop, many plants were pock marked from the hail damage and will quickly recover (photo 5).

soybean regrowth after hailPhoto 4. Hail damaged soybean in double-cropped barley showing bud development at the cotlyledonary nodes about 5 days after hail.

soybeans with leaves damaged by hailPhoto 5. Note pock marked (holed) leaves from hail damage in double-cropped soybeans.

Soybean Rust Update – June 19, 2009

Friday, June 19th, 2009

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

On June 17, soybean rust was found in three kudzu sites in Taylor County in the big bend area of the Gulf Coast of Florida. Taylor County is adjacent to Jefferson County where rust was detected in two kudzu sites on June 15. Soybean rust scouting continues in the U.S. and Mexico. In 2009, soybean rust has been found in five states and 22 counties in the United States, and in two states and five municipalities in Mexico. Soybean rust was found on soybean in Louisiana and Alabama about three weeks ahead of normal. There are also earlier than usual finds in South Georgia. These finds are cause for concern, but not alarm. Most of the soybean rust sentinel plots have been planted but the wet weather is continuing to hinder soybean planting.

Black “Sooty” Head Mold on Wheat and Barley

Friday, June 19th, 2009

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

Both barley that is still in the field and wheat that was not sprayed with fungicides are beginning to blacken in the field. The blackening of the heads is caused by several fungi that are referred to as “sooty molds”. Sooty mold fungi colonize wheat heads when wet, humid weather occurs during the latter stages of grain development and crop maturation. Molding is frequently most severe when harvest is delayed. In addition, heads that are shaded, weakened, undersized, or prematurely ripe are frequently affected by sooty molds. Head molding is also prevalent when plants are deficient in nutrients, lodged, or damaged by insects or other diseases. These molds are superficial and do not affect the grain directly or reduce test weight. This condition, although rough in appearance, does not significantly affect crop yield or test weight.

Agronomic Crop Insects – June 19, 2009

Friday, June 19th, 2009

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

Alfalfa
Continue to sample for potato leafhoppers on a weekly basis. We continue to see both the adult and nymph stage. As indicated before, the nymphs can cause damage very quickly so sample fields on a weekly basis for both stages. 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.

Soybeans
Be sure to sample fields in the seedling stage for bean leaf beetles, slug damage, grasshoppers and thrips. In the earliest planted fields, we can also find green cloverworm activity so be sure to scout soybeans for all of these defoliators.

We have started to find very low levels of spider mites in the earliest planted soybean fields. Although you would not expect to find spider mites under the current weather conditions, it is not unusual for us to start finding mites this early, especially in no-till situations. As we all know from past experience, early detection and control is needed to achieve spider mite suppression. In addition to dimethoate and Lorsban, we now have Hero (zeta-cypermethrin + bifenthrin) as well as a number of stand alone bifenthrin products (not all are labeled so be sure to check the label) available for spider mite control in soybeans. All of these products need to be applied before mites explode. Be sure to read the labels for use rates and restrictions – there is a limit on the number of applications as well as the time between applications on all of the materials labeled for spider mite control.

Lima Bean Weed Control

Friday, June 19th, 2009

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

A number of lima bean fields in 2008 were infested with pigweed biotypes resistant to Pursuit, Raptor, and Sandea. These biotypes are resistant to soil as well as foliar applications of these products. Few of the other herbicides labeled for lima beans provide significant pigweed control and often are not sufficient for full-season control. Soil-applied herbicide for lima beans include: Dual, Prowl, Micro-Tech/Intrro, and Treflan. Basagran, the only other labeled herbicide for postemergence weed control in lima beans will not control pigweed. Do not plant lima beans in fields with a history of poor pigweed control. Timely (pigweed less than 1 inch) and careful cultivation will help tremendously. Fields may need two cultivations.