Combine and Root Dig Field Day

University of Maryland Cooperative Extension in Queen Annes County in cooperation with the Wye Research and Education Center in Queenstown, Maryland are having an interesting field day on August 7, 2008 where they will go over setting up combines for fall harvest and also look at the impact of compaction on corn root systems. The following is information on this field day.

WREC & Queen Anne’s County Cooperative Extension Combine & Root Dig Field Day

Date: Thursday, August 7, 2008
Place: University of Maryland, Wye Research and Education Center, Queenstown, MD
Registration: Phone 410-758-0166 to register by July 31.

Schedule:

10:00 AM - Setting your combine, Marion Calmer, Calmer Combine Heads
Noon - Lunch provided
1:00 PM - Corn Root Dig - Three plots: Compacted, Compacted and No-Till Ripped, and No-Till Ripped

Do you know what your corn roots are doing?
Do you take time to correctly set your combine?
Have you ever entered a corn root dig pit?
Would you like to increase your farm profits?

Join us at the Wye Research and Education Center for an educational day looking at corn roots, looking at a root dig pit, and learning how to maximize harvest recovery and profits by setting your combine head and combine correctly.

Marion Calmer is an Illinois farmer and innovator in manufacturing corn heads for narrow rows and improved recovery of downed crops. Go to http://www.calmercornheads.com/index.htm for more information.

Organic Field Day on Field Crops at the USDA Beltsville Agricultural Research Center

The following is information on an upcoming Organic Field Day at the USDA - Beltsville BARC on July 30, 2008.

Organic Field Day

Location: USDA Beltsville Agricultural Research Center (BARC), Beltsville, MD
Date: July 30, 2008
Time: 9:00 am – 3:30 pm

BARC scientists and leading Maryland organic farmers will discuss research results and experiences growing organic field crops and forages.

Learn About:
-Optimizing your crop rotation
-Soil fertility management in organic hay
-Cover crop management and breeding
-Weed management
-And more…

The field day is FREE and includes lunch, but pre-registration is requested by Monday, July 21, 2008.

For more information or to register, contact:
Kate Mason at 410-841-5779 or masonkb@mda.state.md.us

The field day is hosted by the Maryland Department of Agriculture, USDA ARS-Beltsville, USDA Natural Resources Conservation Service, Maryland Cooperative Extension and Southern Maryland Resource Conservation and Development Board as part of a USDA NRCS MD Conservation Innovation Grant, with additional funding from the Wallace Genetic Foundation.

Delaware State Fair - A Gathering Place for Kent County Farmers - Starts Today

The Delaware State Fair is a gathering place for Kent County farmers and it officially starts today. Some things to enjoy at the fair:

• Look at the 4-H and FFA exhibits in the 4-H/FFA building (Ice Skating Arena). You will be impressed at the amount and quality of entries from vegetables to clothing.
• Go through all the animal barns. There are more exhibitors of goats, sheep, beef, dairy cows, and swine than ever before. Youth exhibitors and old fair hands bring their prized show animals. There are many livestock shows and of course the auction.
• Don't forget the poultry building. You will be amazed at the variety of show poultry that are exhibited.
• Visit the other departments including the open class vegetable and field crop sections, clothing, food, crafts, art and much more.
• Go through the Delaware Department of Agriculture Commodities building and interact with all the agricultural producer groups in the state from bee keepers to vegetable growers.
• Have a snack at the Delaware Farm Bureau stand and enjoy dinner at the Grange food area.
• Visit the farm machinary and agricultural supply exhibits.
• Visit the UD/DSU extension tent, the natural resources exhibits, the FFA childrens petting zoo, and other educational display areas.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Goats - Delaware State University is Taking the Lead

There is more and more interest in raising goats in Delaware. Delaware State University is taking the lead in this area and Dr. Dahlia Jackson is developing research and educational programs specifically on goats. The following is some information from Dr. Jackson on activities at Delaware State University.

Kidding this year went over much better than it had last spring. We still had our problems, but not as many as we experienced last time. For instance, we had one female go down with ketosis, and three others that had breeched deliveries and by the time we got to them at least one kid had already died.

In total, we had only 17 females that kidded with an average birth weight of 7.2 lbs with 2 kids per doe kidding. All of the females were bred to a 100% registered Boer buck that was purchased from the University of Maryland Eastern Shore early last year. All kids are growing really well and we expect to wean them in approximately 4 weeks.

With the parasite season here, we are gearing up to start work on our USDA and *NESARE projects. Two graduate students, Jodi Lynn Eierman (DSU graduate) and Elizabeth Crook (Berry College, GA) were accepted into our Masters (M.S.) program in Agriculture (name recently changed from Plant Science to Agriculture Science to include animal science students).

Jodi Lynn will be working on a project using timed-A.I in goats later this fall, while Elizabeth will be working on characterizing the level of resistance in sheep and goat parasites in the Mid-Atlantic U.S. (USDA funded project in collaboration with the University of Maryland Eastern Shore and the University of Georgia). In addition, the Small Ruminant Program at DSU has gained three undergraduate students for the summer to conduct research on the efficacy of natural plant dewormers in controlling internal parasites in sheep and goats (NESARE* funded) as well as on the impact of multi-species grazing (cattle and goats) in controlling parasites in goats. For the USDA project mentioned above (characterizing the level of resistance in sheep and goat parasites in the Mid-Atlantic U.S.) we are now getting in touch with producers who had expressed interest in determining levels of parasite resistance in their flock. We plan on starting this project in the next week or two. If anyone else is interested, please feel free to contact me in order to participate.

Again, the information gained from participating will help sheep and goat producers in implementing a chemical deworming strategy that is most effective on their farm in order to prolong the efficacy of available chemical treatments. We look forward to conducting these projects as well as assisting with others over the next couple of weeks. As we get results, look out for technical reports that we will be sending out to keep everyone updated on our results.

Again, if you would like more information on worm control or reproduction in sheep and goats please do not hesitate to contact me at (302) 857-6490 or djjackson@desu.edu. In addition, please contact me if you'd like to give your opinion about the type of research and programs that you would like to see conducted at Delaware State University.

Reprinted from the Summer, 2008 edition of the Wild and Woolly newsletter from the University of Maryland Cooperative Extension.

Controlling Weed Escapes in Roundup Ready Beans

The following is a good article on controlling weed escapes in Roundup Ready soybeans from the Ohio State University.

This is the time of year when we get phone calls about rescuing weed control in Roundup Ready soybean fields, and we hear most often about marestail, giant ragweed, and lambsquarters. Less than adequate weed control after several herbicide applications can often be attributed to failure to use the appropriate combination of herbicides and application timings for the weed population. However, adverse weather, crop replants, and slow crop development can also negatively impact weed control programs. Weeds that survive into mid-season can also be indicative of herbicide resistance, or a developing herbicide resistance problem. Before spending additional money on a late-season POST herbicide application, it’s important to consider what the goal of the application is, and whether any effective herbicide options remain based on what has already been applied this season.

For example, a marestail plant that has survived previous application of glyphosate plus an ALS inhibitor (FirstRate or chlorimuron) is not likely to be controlled by additional herbicide applications. A late-season application that does not control marestail will also fail to suppress it enough to make harvest any easier. On the other hand, small soybeans that are infested with late-emerging marestail plants, which have not been subject to a prior herbicide treatment, may merit an additional application where the marestail is known to be still sensitive to glyphosate or ALS inhibitors. Where someone is determined to treat marestail that have survived previous application, our recommendation is typically going to be something like a full rate of FirstRate or Classic plus up to 1.5 lbs ae/A of glyphosate. The cost of this, up to $25 or more based on current glyphosate prices, has to be weighed against its possible effectiveness.

For both lambsquarters and ragweeds, it is possible that a second POST application of glyphosate will control plants that survived a previous application. However, as we have stated in previous C.O.R.N. articles, this is most likely to occur where the first application greatly suppressed the weeds (70 to 80% control at least), and the second glyphosate treatment is applied about 3 weeks of the first. Where the previous glyphosate application had little effect on the weeds, an alternative to glyphosate would be required in the second application for control of ragweeds. There are essentially no consistently effective alternatives to glyphosate for control of large lambsquarters.

Choices for ragweeds include FirstRate, Classic, Cobra/Phoenix and Flexstar, and the decision here should be based on several factors. Classic or FirstRate would generally be the most effective option where the population is known to be still sensitive to ALS inhibitors. Where ALS resistance is known or suspected, we would suggest use of Cobra or Phoenix. Use of Flexstar should generally be curtailed as we move later into the season, since it has more restrictive guidelines for crop rotation. Where the glyphosate had substantial activity on the weeds in the first application, the second application should generally contain glyphosate plus one of the alternatives mentioned here. Keep in mind the following also: 1) expectations should be lowered for late-season applications to large weeds – plant death may not occur, but harvest problems may at least be reduced; 2) maximum labeled rates of the alternative to glyphosate are likely to be needed; 3) spray adjuvants should be optimized for the alternative; and 4) spray coverage should be maximized through use of slower application speeds, higher volumes, and nozzles that provide a greater number of relatively small droplets (for example, extended range flat fans instead of ai nozzles). As stated previously, the possible merits of a late-season application to large weeds have to be weighed against the cost and risk of soybean injury.

Reprinted in part from "Late-Season POST Herbicide Applications in Soybeans" by Mark Loux in the July 14, 2008 edition of the Crop Observation and Recommendation Network newsletter from the Ohio State University.

Corn Pollination

Corn has been pollinating throughout Delaware and will be continuing with later planted corn. The following is information on pollination in corn.

Pollen shed usually begins two to three days prior to silk emergence and continues for five to eight days with peak shed on the third day. Under very dry conditions, silk emergence may be delayed, and such “asynchronization” of pollen shed and silking may result in poor kernel set and reduced grain yields. However, in some years under favorable growing condition, silks may actually emerge before tassels fully emerge and pollen shed starts in certain hybrids. On a typical midsummer day, peak pollen shed occurs in the morning between 9:00 and 11:00 a.m. followed by a second round of pollen shed late in the afternoon. Pollen may be shed before the tassel fully emerges (“stretches out"). Pollen shed begins in the middle of the central spike of the tassel and spreads out later over the whole tassel with the lower branches last to shed pollen.

Pollen grains are borne in anthers, each of which contains a large number of pollen grains. The anthers open and the pollen grains pour out in early to mid morning after dew has dried off the tassels. Pollen is light and is often carried considerable distances by the wind. However, most of it settles within 20 to 50 feet.

Pollen shed is not a continuous process. It stops when the tassel is too wet or too dry and begins again when temperature conditions are favorable. Pollen stands little chance of being washed off the silks during a rainstorm as little to none is shed when the tassel is wet. Also, silks are covered with fine, sticky hairs, which serve to catch and anchor pollen grains.

Under favorable conditions, pollen grain remains viable for only 18 to 24 hours. However, the pollen grain starts growth of the pollen tube down the silk channel within minutes of coming in contact with a silk and the pollen tube grows the length of the silk and enters the female flower (ovule) in 12 to 28 hours.

A well-developed ear shoot should have 750 to 1,000 ovules (potential kernels) each producing a silk. The silks from near the base of the ear emerge first and those from the tip appear last. Under good conditions, all silks will emerge and be ready for pollination within 3 to 5 days and this usually provides adequate time for all silks to be pollinated before pollen shed ceases.

Pollen of a given plant rarely fertilizes all the silks of the same plant. Under field conditions 97% or more of the kernels produced by each plant may be pollinated by other plants in the field. The amount of pollen is rarely a cause of poor kernel set. Each tassel contains from 2 to 5 million pollen grains, which translates to 2,000 to 5,000 pollen grains produced for each silk of the ear shoot. Shortages of pollen are usually only a problem under conditions of extreme heat and drought. As noted above, poor kernel set is more often associated with poor timing of pollen shed with silk emergence – with silks emerging after pollen shed (poor “nick”). However, hybrids rarely seldom exhibit this problem unless they experience extreme drought stress.

Article by Peter Thomison in the July 14 issue of the Crop Observation and Recommendation Network newsletter from the Ohio State University.

Tissue Testing

Tissue testing is an excellent way to evaluate your nutrient management program during the growing season. In addition tissue testing may be an excellent diagnostic tool and a method to compare different soil fertility programs. The following is information on tissue testing.

The optimum time to measure nutrient levels in a plant is when nutrient demand is high and before the crop starts removing nutrients from the leaves. For corn, this time is at initial silking and for soybeans, initial flowering – so we are fast approaching the optimum time. In addition, select the tissue that has the greatest demand for nutrients at this time, ear leaves for corn and the upper fully developed leaf for soybeans. Most labs will need 15 – 20 leaves to complete the test. Randomly select leaves from areas that are representative of the field (avoid drowned out areas or areas that are distinctly different). Send them to a reputable lab that analyzes plant samples.

Contact your selected lab prior to collecting the leaves. Each lab may have slightly different instructions on mailing samples or the number of leaves that need to be collected. Lab results may be used to see if specific nutrients are within the sufficient or marginal categories.

Sufficiently ranges for tissue nitrogen in corn are between 2.90 – 3.50%, phosphorus – between 0.30 – 0.50%, and potassium – 1.91 – 2.50%. Environmental factors may often be the cause of levels below the sufficiently range, such as drought or excess rainfall. In some cases, leaves collected too late may have values below the sufficiency range.

If you are using tissue testing for diagnostic reasons, collect leaves from the area showing nutrient deficiency and an area not showing the symptoms as well as a soil sample from both areas. The soil test will assist in determining whether the soil has adequate nutrient levels or the proper pH for crop growth. For example, if the soil test shows adequate potash levels for crop growth, but the tissue test shows potash deficiency – adding more potash will not correct the problem. Environmental factors (drought, excess moisture, unusually low or high temperatures) have most likely limited root development so the crop is unable to remove adequate nutrients from the soil. If environmental, the deficiency symptom will most likely disappear when adequate growing conditions return.

Tissue testing when completed for several years will provide valuable information on the need for sulfur or micronutrients in a field. University research has consistently shown that micronutrients and sulfur generally do not increase crop yields on medium to fine textures soils (loams, silts and clays) with adequate organic matter and proper soil pH. In contrast, sandy soils often do respond to sulfur (and manganese if soil pH is elevated). A tissue test would show if a certain field has a history of a micronutrient deficiency and if not, a producer could save fertilizer dollars by not adding it to starter or in foliar programs.

Reprinted in part from "Benefits of Tissue Testing" by Edwin Lentz and Robert Mullen in the July 14 edition of the Crop Observation and Recommendation Newsletter from the Ohio State University.

Roundup Injury in Roundup Ready Corn

Glyphosate application to Roundup Ready corn does not cause injury normally. However, the following are pictures of damage by Roundup on Roundup Ready corn. The area affected was around an irrigation pivot point and received 2-4 times the recommended rate. Note the yellowing of the whorls.




Gordon Johnson, Extension Agriculture Agent, UD, Kent County

More on Arrested Ear Develoment in Corn

Last year I came across a field with arrested ear devlopment in corn. The following is additional information on this problem from Purdue University and pictures that I took last year.

The primary common thread that linked all of the affected fields with arrested ear development was the timing of a chemical application during the 1 to 2 week period preceding the onset of pollination. Applications of foliar fungicides captured most of the attention. Most of the reported fields were indeed treated with foliar fungicide, but many were treated with a combination of foliar fungicide plus insecticide, and some were treated with foliar fungicide plus fertilizer. Anectdotal reports suggested the worst of the arrested ears occurred in fields where the chemicals were applied with high-clearance spray applicators versus aerial applications. Use of adjuvants such as surfactants with these chemicals has also been implicated in causing these problems.





Information by Bob Nielson, Agronomy Dept., Purdue Univ. Photos by Gordon Johnson, Extension Agriculture Agent, UD, Kent County.

Watch for Stink Bugs

Stink bugs are starting to increase in field and vegetable crops. Scout for these pests as they can cause significant yield reductions if in high enough numbers. The following is information from Joanne Whalen, UD IPM extension specialist.

As full season beans start to set pods in the next week to 10 days, you will also need to consider stink bugs. We have started to see an increase in both brown and green stink bug populations. Economic damage is most likely to occur during the pod development and pod fill stages. You will need to sample for both adults and nymphs when making a treatment decision. Available thresholds are based on beans that are in the pod development and fill stages. We are currently following the same guidelines that are being used in Virginia. Thresholds are also based on numbers of large nymphs and adults, as those are the stages most capable of damaging pods. As a general guideline, current thresholds are set at 1 large nymph/adult (either brown or green stink bug) per row foot if using a beat sheet, or, 2.5 per 15 sweeps in narrow-row beans, or 3.5 per 15 sweeps in wide-row beans.

In corn, as far as stinkbugs, we have no thresholds for our area; however, the following is information from Georgia: “Corn is most sensitive to stink bug injury during ear elongation before pollen shed. The treatment threshold at this stage is 1 bug per 4 plants (25% infested plants). Once pollination occurs, feeding though the husk causes damage to individual kernels. Kernels are susceptible to damage up until the milk stage (R3) and possibly early dough stage (R4). The threshold at this time is 1 bug per 2 plants (50% infested plants).”

In lima beans we are staring to see an increase in stinkbug and plant bug populations. As soon as pin pods are present, be sure to watch carefully for plant bug and stinkbug adults and nymphs. As a general guideline, treatment should be considered if you find 15 adults and/or nymphs per 50 sweeps. Bifenthrin (Brigade and a number of generics), Mustang MAX, Proaxis and lamda-cyhalothrin (Warrior and a number of generics) are labeled for both insects. The higher labeled rates will be needed if stinkbugs are the predominant insect present.

Green stinkbug nymph. Photo by Herb Pilcher, USDA Agricultural Research Service, Bugwood.org

Brown stinkbug adult. Photo by Russ Ottens, University of Georgia, Bugwood.org

Information from Joanne Whalen, Extension IPM Specialist, UD.

Current Grain Market Information

The following is current grain market information from Carl German, Extension Marketing Specialist, UD.

Corn Analysis

USDA projected an increase in ‘08/’09 ending stocks for U.S. corn to 833 million bushels, above the average pre-report guess of 820 mb and 160 mb more than last month’s estimate. This report incorporated the June harvested acreage estimate of 78.9 million acres and cut average yield from the June estimate by one half bushel to 148.4 bushels per acre, resulting in estimated production of 11.715 billion bushels. This is 20 million bushels less than the June production forecast. Feed and residual use was cut 100 mb for ‘07/’08 but was raised 50 mb for the ‘08/’09 marketing year. Ethanol use was cut 50 mb for both the ‘07/’08 and ‘08/’09 marketing years. Exports were left unchanged for both years. The season average farm price estimate was increased by 20 cents per bushel on both ends of the price range, now placed at $5.50 to $6.50 per bushel. World ending stocks of corn were projected at 105.31 mmt, 2.02 mmt larger than last month.

Soybean Analysis

U.S. soybean stocks are projected to decline to 140 million bushels for the ‘08/’09 marketing year, down 35 million bushels from the June report. Harvested acreage is placed at 72.1 million bushels (taken from USDA’s June 30 Acreage Report). The yield estimate was decreased by one half bushel per acre from the June estimate and is now placed at 41.6 bushels per acre. U.S. soybean production is now forecast at 3 billion bushels for the ‘08/’09 marketing year, 105 million bushels less than the June estimate. Adjustments to ending stocks for the ‘07/’08 marketing year were left unchanged due to counterbalancing adjustments to exports and residual use. For the ‘08/’09 marketing year, crush was cut 10 mb, export projections were reduced 50 mb and residual use was cut 6 mb. The season average farm price projection was increased $1.00 per bushel on both ends of the price range, now placed at $12.00 to $13.50 per bushel. World ending stocks for soybeans were reduced 1.54 mmt from last month and are now placed at 48.87 mmt.

Wheat Analysis

All U.S. wheat production is forecast at 2.461 billion bushels, an increase of 29 mb from the June estimate and below the average of pre-report estimates. U. S. ending stocks for all wheat for the ‘08/’09 marketing year, now projected at 537 million bushels, are 50 million bushels larger than last month. The season average farm price was unchanged from the June estimate at $6.75 to $8.25 per bushel. Global wheat production is projected at a record 664 million tons. World ending stocks are now placed at 133.06 million metric tons, reflecting a 1 mmt increase from the June estimate.

Marketing Strategy

There are currently two primary driving forces that are influencing commodity prices: the price of crude oil (currently trading at $146.40 per barrel) and the lateness of the growing season which suggests that any yield estimates being made at this point in time are basically educated guesses with the outcome not likely to be known until harvest. We can expect commodity prices to remain extremely volatile throughout the summer.

Dec ‘08 corn futures are currently trading at $7.02 per bushel; Nov ‘08 soybeans at $15.93; July ‘08 SRW wheat at $8.17; and Dec ‘08 SRW wheat at $8.43 per bushel.

For technical assistance on making grain marketing decisions contact: Carl L. German, Extension Crops Marketing Specialist clgerman@udel.edu.

Avoiding Antagonism Between Glyphosate and Manganese

Many Delaware fields will need an application of manganese in soybeans because soils are prone to manganese deficiencies. This micronutrient is often low, especially in sandier soils. It is a common practice to apply manganese as a foliar treatments when spraying glyphosate (Roundup and other products) to Roundup Ready soybeans. However, an antagonism can occur between the two materials. The following is an article on the subject.

Manganese (Mn) deficiency is the most common crop micronutrient problem in Delaware, particularly in soybeans and small grains. The availability of manganese to the plant generally decreases as soil pH levels increase. Consequently, soybeans grown in the sandy soils of lower Delaware where pH has been elevated above 6.2 with liming often show manganese deficiencies. When possible, producers prefer to tank-mix manganese micronutrient solutions with foliar applied herbicides to eliminate an extra trip across the field. As glyphosate is estimated to be used on more than 90 percent of Delaware soybean acreage, reported reductions in weed control on some of these acres caused by tank-mixed manganese applications is an important issue. The cold wet weather experienced in May, may have exacerbated manganese deficiency problems in full season soybeans due to poor soybean root growth.

Researchers have shown that weed control can be antagonized when some manganese fertilizers are tank-mixed with glyphosate. Field experiments showed a significant antagonism in common lambsquarters and velvetleaf when glyphosate was tank-mixed with ethylaminoacetate- manganese, and slight antagonisms in tank-mixes with lignin sulfate- manganese and MnSO4-powder (TechMangam). Greenhouse studies have shown that an EDTA- manganese formulation enhanced glyphosate efficacy (by 25 percent in giant foxtail and 40 percent in velvetleaf). However, tank-mixes of each of the other manganese products caused significant antagonisms, reducing weed control by 10 to 30 percent when compared to glyphosate alone. Manganese chelated with EDTA did not affect the performance of glyphosate, but other forms of manganese did.

One method for avoiding the antagonism is to apply the manganese fertilizer at a different time than glyphosate. In a greenhouse study the ethylaminoacetate- manganese fertilizer was applied six, four, and two days before-, two days after-, and at the same time as glyphosate. There were no differences in herbicide efficacy in giant foxtail for any of the two-pass timings. In velvetleaf, manganese sprayed two days before the glyphosate application reduced weed control by 15 percent. But this was not as severe as the 30 percent reduction when glyphosate and ethylaminoacetate- manganese were tank-mixed.

A second method for avoiding the antagonism is to add an adjuvant to the spray tank that will prevent the antagonism by preventing the manganese from binding to the glyphosate molecule (by adding ammonium sulfate). In greenhouse experiments, ammonium sulfate improved herbicide efficacy in all glyphosate- manganese tank mixes.

In summary, if conditions are optimal for glyphosate control of weeds, i.e. weed pressure is low, and weed size is small, you may get adequate weed control with glyphosate tankmixes with commercially available manganese formulations. However, even under these optimal conditions it is still advisable to add ammonium sulfate (17 lbs per 100 gallons of water) to minimize the antagonism imposed by the manganese. If weed control conditions are marginal, i.e. moderate weed pressure or moderate weed size, a chelated form of manganese such as an EDTA- manganese formulation, plus ammonium sulfate is recommended with glyphosate tankmixes.

Finally, if weed control conditions are poor, i.e. heavy weed pressure (especially lambsquarters and velvetleaf) or large weed size, manganese should not be tankmixed with glyphosate. Rather, in these tough weed control conditions, manganese should be applied in a separate application following the glyphosate application.

Adapted from "Tips to avoid weed control antagonism when applying manganese fertilizer with glyphosate" by Kurt Thelen, Crop and Soil Sciences, Michigan State University.

Dairy and Beef - Silage Heating

Excessive heating in silage can cause deterioration of feed quality. The following is an article on the subject.

The production of heat is a normal occurrence during silage fermentation. If silage is well packed and sealed immediately, the average temperature of the mass should not rise to more than 10 to 20 F above the ambient temperature at filling. However, it is common to measure temperatures as high as 110-130 F in the upper most layers of silages during silo filling. These high temperatures are a result of excessive amounts of air trapped in the top layers of forage. The key is that these temperatures should decrease quickly as further packing removes air from the mass. Prolonged high temperatures above 115-120 F can lead to heat damaged protein. Temperatures in this range are often detrimental to many lactic acid bacteria that are needed to achieve a successful fermentation. Thus, chop forage adequately, pack quickly and tightly and seal as soon as possible to keep the air out of the forage mass. When the active phase of fermentation is complete, temperatures in the core of the silo often fall to 70 to 85 F . However, a second wave of heat can be produced in silos because of aerobic deterioration. Penetration of air into the silage mass allows spoilage yeasts to metabolize lactic acid. As a result of this, the mass reheats and silage pH increases. Molds and opportunistic bacteria that thrive on oxygen cause more heating and spoilage. In some cases we have measured temperatures in silage faces in excess of 145 F. Signs that silage is aerobically spoiling include measuring temperatures in excess of 100 F four to eight inches in back of the silo face at feed out, reheating in the bunk, visible mold, lack of a sharp or sweet smell to the silage and/or a flat or moldy/musty smell. If a pH meter is available, a moldy smell coupled with a high pH may also be a good indicator that a feed has undergone aerobic deterioration. Aerobic deterioration is of course more commonly found during warmer weather.

Information from Limin Kung, Jr., Ph.D., Department of Animal and Food Sciences, University of Delaware.

Poultry - More on Nightime Cooling Issues in Hot Weather

This is a continuation of information on nighttime cooling issues in hot weather. This article will cover thermostat/temperature sensor location effects.

Make sure tunnel fans operate off of thermostats/sensors no further than 100' from the tunnel fan end wall for nighttime cooling. During the day when all the tunnel fans are operating, there is typically less than a five degree difference in temperature between the pad and fan ends of a house. But, in the evening this temperature difference can increase to harmful levels if the house’s environmental controller is not set properly. For instance, let’s say we had two identical houses, one where the tunnel fans operated off the average of the sensors located throughout the house and the other where the tunnel fans operated only off the sensors nearest the tunnel fans. With tunnel fans operating off the average of all the sensors it is fairly likely if the outside temperature dropped into the low seventies that you could end up with the situation where the inlet end of the house is 72 F, the center is 76 F and the tunnel fan end is 80 F. This is because the average house temperature is 76 F and the controller is set to operate only half the tunnel fans at 76 F which would tend to lead to large temperature differences between the two ends of a tunnel house when older birds are present. Though 72 F is not a problem for the birds near the tunnel inlet, the birds on the tunnel fan end would not receive adequate nighttime cooling because they would be subjected to an 80 F environment with high humidity and very little air speed. Conversely, if tunnel fans were set to operate off the sensors on the tunnel fan end of the house, the higher air temperature at the tunnel fan end of the house would have resulted in more fans operating, resulting in significantly cooler temperatures for the birds in the back half of the house. Though it is true that operating the tunnel fans off of the sensors on the tunnel fan end of the house will tend to result in lower air temperatures at the inlet, the fact of the matter is that during hot, humid weather we are not that concerned with overcooling the birds at the inlet end because temperatures will tend to stay in the seventies.

Information from "Maximizing Nighttime Bird Cooling" in the August 2005 edition of Poultry Housing Tips from the University of Georgia, Cooperative Extension.

Ozone Air Pollution Damage on Vegetable Crops

The following are photos of ozone air pollution damage in vegetable crops that we are seeing at this time.

Ozone damage interior an crown leaves in watermelon.

Note how leaves initially turn white color. They will darken in watermelon as the injury progresses.

Ozone injury in muskmelons. Note that the yellowing of the older leaves.

Ozone injury in melons often is seen as a yellow strip down the middle of melon beds where interior leaves have been damaged.

Ozone injury on asian melons.

Ozone injury on summer squash.

Photos by Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Fusarium Crown Rot and Wilt of Summer Squash

There are a number of reasons for plant collapse in squashes including bacterial wilt, squash vine borer, squash bug feeding, Pythium root rot, and Phytophthora root and crown rot. Another reason for squash collapse is Fusarium crown rot and wilt, a common soil-borne fungus disease. The following are some pictures I took recently from the field.

Zucchini plant collapse and wilt caused by Fusarium crown rot.

Fusarium rot of the crown area of squash. Note the pinkish or orange color of the crown interior when it is cut open.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Cutting Teff Hay

I was recently asked about when to cut teff, a relatively new forage crop to Delaware. The following is some information.

For the best combination of yield with optimum forage quality, teff should be harvested in the late vegetative stages - preboot to early-boot stage - before the seed head emerges. The teff will be well above Knee height usually. Earlier harvests can be done if higher protein hay is needed. First harvest will occur approximately 50 to 55 days after planting and subsequent harvests should be expected in 40 to 45 days depending on moisture and temperature. In a multiple-cut system a 3 to 4 inch cutting height is necessary to promote vigorous regrowth; cutting lower than this will stunt the crop. Feeding value of Teff is comparable to Timothy, making it an good forage for horses and other livestock. Protein content of Teff hay ranges from
12-17% depending on the growth stage or maturity.

Information from Cornell University and Target Seeds.

Options for Volunteer Roundup Ready Corn in Soybeans

I was recently asked about how to control volunteer Roundup Ready corn in soybeans. The following are some recommendations.

If you have volunteer Roundup Ready corn in soybeans you can control it with one of the following grass herbicides:

Select Max
Arrow
Assure II
Targa
Fusion
Fusilade DX

Rates will vary from 4-12 ounces per acre depending on the product and the size of the corn. Check individual labels for specific rates.

Each of these can be mixed with glyphosate (Roundup) when spraying Roundup Ready soybeans or used alone in conventional (non RR) soybeans. Adjuvant recommendations may vary. Check the product labels for specific recommendations for what to add with these grass herbicides when mixing with glyphosate.

Poast plus is less effective than the grass herbicides above on controlling volunteer corn.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Irrigating Soybeans

If you have not started already, it is time to start irrigating full season soybeans. The following is an article on soybean irrigation.

With double-cropped soybeans going in the ground and full-season beans either closing the canopy or about to begin blooming, it’s time to consider how to irrigate beans. Full-season beans yield best if not irrigated early unless severely impacted by drought, require irrigation to activate soil-applied herbicides, or require additional moisture for germination and emergence. But, about this time of year when the beans begin to bloom, it is time to begin irrigation of full-season beans. The beans are probably using about 1/4 inch of water per day and this will rapidly increase to about 1/3 of an inch per day. Irrigation should raise the soil moisture to near field capacity throughout the rooting depth and then replace the amount of soil moisture loss to evapotranspiration until about the R7 growth stage (physiological maturity designated by at least one pod on the main stem turning to the mature pod color).

For double-crop soybeans, irrigation should begin immediately after planting and continue until the R7 growth stage. In most situations, the soil is quite dry when double-cropped beans are planted so be sure to apply adequate water early in their growth to rewet the deeper soil layers. This will provide the beans with an extra cushion if you experience a long period of very dry, hot weather.

Information from Dr. Richard Taylor, Extension Agronomist, UD

Soybeans - Know Your Soybean Diseases.

This is the time of the year that we start seeing some foliar diseases in soybeans. Septoria leaf spot may already be found in soybeans in wetter areas. The following are pictures of downy mildew, Septoria brown spot, and frogeye leaf spot in soybeans.

Downy mildew on soybean leaf.

Septoria leaf spot or brown spot on soybean leaf.

Frogeye leaf spot on soybean leaf.

All photos by Bob Mulrooney, extension plant pathologist, UD

Powdery Mildew Control in Cucurbits

Powdery mildew is now being found in susceptible cucurbits including summer squash, pumpkins, and certain melon varieties. Start control programs now. The following are some recommendations.

Usually powdery mildew occurs from mid-July until the end of the season. Symptoms typically begin on older, lower leaves and can spread rapidly under dry, humid conditions. Control of powdery mildew begins with regular scouting for symptoms and weekly fungicide applications. Begin a fungicide program when PM has been found in the region and/or when 1 lesion is found on the underside of 45 leaves. Fungicide resistance management of the fungus which causes powdery mildew is critical in the mid-Atlantic region! Fungicides with a high risk for resistance development, such as the strobilurins (Pristine, FRAC code 11) and Nova or Procure (FRAC code 3), should be tank mixed with a protectant fungicide such as chlorothalonil (M5) and rotated with fungicides of a different chemistry.

Powdery mildew in summer squash.

For control of cucurbit powdery mildew in:

Pumpkin and winter squash fields:

Nova or Rally (myclobutanil, 3) at 5 oz 40WP/A plus chlorothalonil at 2-3 pt 6F/A,orProcure (triflumizole, 3) at 4-8 oz 50WS/A plus chlorothalonil at 2-3 pt 6F/A
Alternated with:
Micronized Wettable Sulfur (M2) at 4 lb 80W/A Sulfur may injure plants, especially at high temperatures. Certain varieties can be more sensitive. Consult label for precautions.orA tank mix containing chlorothalonil plus Pristine (pyraclostrobin + boscalid, 11 + 7) at 12.5-18.5 oz 38WG/A

If powdery mildew has become well established in the mid to late part of the season, only apply protectant fungicides such as chlorothalonil or sulfur.

Summer squash and cucumber fields:
Nova or Rally (myclobutanil, 3) at 5 oz 40WP/A plus chlorothalonil at 2-3 pt 6F/A,orProcure (triflumizole, 3) at 4-8 oz 50WS/A plus chlorothalonil at 2-3 pt 6F/A
Alternated with a tank mix containing:
Chlorothalonil plus Pristine (pyraclostrobin + boscalid, 11 + 7) at 12.5-18.5 oz 38WG/A

Muskmelon and watermelon fields:
Nova or Rally (myclobutanil, 3) at 5 oz 40WP/A plus chlorothalonil at 2-3 pt 6F/A,orProcure (triflumizole, 3) at 4-8 oz 50WS/A plus chlorothalonil at 2-3 pt 6F/A
Alternated with a tank mix containing:
Quintec (quinoxyfen, 13) at 6 oz 2.08F/A plus chlorothalonil at 2-3 pt 6F/A,orChlorothalonil plus Pristine (pyraclostrobin + boscalid, 11 + 7) at 12.5-18.5 oz 38WG/A

Information from Bob Mulrooney, Extension Plant Pathologist, UD

Is it Too Late for Fungicides in Corn?

Fungicide use has increase in high management corn across Delaware in recent years. The window for application for maximum yield benefits is the period prior to full tassel emergence. Can you still get benefits from fungicide applications? Later planted corn entering tasseling will have the most likelihood for having maximum yield benefits from fungicide applications. Target irrigated fields, high yield potential fields, and hybrids with weaker disease packages. If corn has fully tasseled, then potential yield benefits will be reduced. However, in fields starting to show signs of foliar diseases, there is still a good chance of receiving significant benefits from a fungicide application now. Many of our corn diseases actually come somewhat later and you still can have an impact on seed fill.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Rainfall Again Overnight

Kent county received additional rainfall over night. Amounts ranged from 0.25 inches to 0.75 inches depending upon location. While some corn was hurt by the dry weather prior to the Fourth of July weekend, for much of the county, the rains came in time to preserve yields. Irrigated corn growers are reminded that corn will be using over a third of an inch a day now.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County

Pumpkin Spray Programs

Pumpkins are running now and a good fungicide program is essential for good yields and particularly for good fruit quality. The following is information on spray programs for pumpkins.

I frequently am asked for a “good” spray program for pumpkins. This is always a difficult program to design because it depends on field history (i.e. has Phytophthora crown rot occurred in the field), production practices (no-till vs. bare ground), and the grower’s philosophy about control (Cadillac treatment program vs. minimal inputs). Keep the following in mind to design a good spray program:

Ø Know what diseases are the most common on your farm. Previous problems with black rot, Phytophthora blight, anthracnose, scab or other diseases may indicate that these diseases are likely to be problems again.

> Know if downy mildew is present on Delmarva. When downy mildew is present your spray program should include effective downy mildew materials. Note: downy mildew is not known to be present on pumpkins as of July 19, 2007.

> Scout 50 old leaves in your field for powdery mildew lesions. If powdery mildew is present in the field, apply materials that are targeted for it.

> Even after implementing a program, scout your fields frequently and modify your program if new disease problems occur.

> Familiarize yourself with the Commercial Vegetable Production Recommendations section on pumpkins. Many fungicides are available for controlling different diseases.

An example of a good spray program is to alternate chlorothalonil plus Nova 5 oz/A or Procure 8 oz/A with Pristine 12.5 oz/A plus copper or Micronized Wettable Sulfur 4 lb 80W/A (Beware that sulfur can injure plants when applied at high temperatures, so read the label carefully.) If downy mildew is present on pumpkins, an application of Previcur Flex 1.2 pt/A or Tanos 8 oz/A may be applied in rotation with chlorothalonil plus Nova or Procure. If conditions favor Phytophthora blight, apply Forum 6.0 fl oz/A plus copper, Ranman 2.75 fl oz/A or Tanos 10 oz/A.

A good fungicide spray program will increase yields and improve quality. The single best way to improve handle quality is to control foliar and fruit diseases in season.

Information from Kate Everts; Vegetable Pathologist, University of Delaware and University of Maryland.

Alert - Downy Mildew Found in Cucumbers

The following is a downy mildew alert for pickle and other cucumber growers. Start fungicide programs now if you have not already done so.

Downy mildew was observed on cucumber in our sentinel plots this morning (July 9) near Georgetown, DE by Emmalea Ernest. She found several small spots on 3-4 leaves on the susceptible slicing variety “Straight Eight”. This indicates that we had a transport event of spores from the south over the weekend as predicted by the NC State Plant Disease Forecast Center. We are recommending that cucumbers be sprayed at this time to protect plants that are at a vulnerable stage of development. We are recommending fungicide programs that utilize fungicides that have provided very good control in the past several years. Previcur Flex or Ranman combined with Bravo and alternated with Tanos combined with mancozeb or Bravo have done well in regional trials. Ranman/Bravo alternated with Previcur Flex/Bravo has also been a very effective combination. Other fungicides that are good alternating partners have been Curzate and Gavel. Another very good product that was just registered is Presidio from Valent. It had very good activity against downy mildew in tests conducted in North Carolina and could be used in a program as you would Previcur Flex or Ranman, or in alternation with these products. Presidio also needs to be tank mixed with a protectant fungicide. Be sure to check the labels for specific instructions and resistance management strategies.

For other cucurbit crops we are suggesting that you wait until the disease is seen on crops other than cucumbers. Be sure to be checking your fields daily especially in areas that had heavy rainfall Sunday. Our sentinel plots have other cucurbits including cantaloupe, pumpkin, watermelon and winter squash. To repeat, downy mildew was only seen on cucumber near Georgetown, DE and it is not present on any crop in the sentinel plots in Salisbury, MD. To track disease development visit the Downy Mildew Forecast website often http://www.ces.ncsu.edu/depts/pp/cucurbit/

Information from Bob Mulrooney and Kate Everts, Extension Plant Pathologists, UD and UMd.

Green Cloverworms are Heavy Earlier this Year

The following is some information on green cloverworm, a common pest of soybeans in Delaware. They are at higher numbers this year for this early in the season.

In some fields, growers and consultants are reporting significant defoliation from green cloverworm (over 30% in some fields). Green cloverworm larvae are light green with three pairs of white stripes running the length of the body. In addition to the three pairs of legs near the head, they have three pairs of fleshy legs near the middle of the body, and one additional pair at the end of the body. Larvae wiggle vigorously when disturbed. Smaller larvae may drop from the leaf when disturbed. Young larvae skeletonize the underside of the leaf. Older larvae chew irregular shaped holes in the leaves and can eat all of the leaf except large veins.

Green Cloverworm on Soybean. Photo from Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org

Green cloverworm feeding on soybeans. Photo from David Jones, University of Georgia, Bugwood.org

Information from Joanne Whalen, Extension IPM Specialist, UD

Current Pest Alerts

The following are pest and crop considerations that we are currently concerned with.

DEFOLIATORS IN SOYBEANS including grasshoppers, green cloverworms, Japanese beetles, and velvet bean caterpillars are at moderate to high levels in some full season soybeans and pose a high risk for double-cropped soybeans following small grains.
MITES were on the increase in soybeans and vegetables last week. Recent rainfall may help keep crops keep ahead but fields should be scouted. Early control is critical.
STINK BUGS are on the increase in soybeans, vegetables, and possibly later corn.
SQUASH BUG numbers are high this year in squashes and pumpkins
VEGETABLE DISEASES The recent thunder showers and increased humidity have produced conditions favorable for foliar and fruit diseases of vegetables. This includes anthracnose, Septoria, Alternaria, gummy stem blight, Plectosporium, bacterial spot, powdery mildew, Phytophthora, Pythium, and many others. Maintain fungicide applications and tighten spray schedules.
CORN DISEASES Check susceptible varieties and consider fungicide programs where not already applied in high management corn. Fungicides should already be applied (early tasseling) for yield and plant health benefits.
POWDERY MILDEW is now active on vine crops in the region.
DOWNY MILDEW WATCH Potential exists for downy mildew spores moving into the area from the south with weather systems. Cucumber crops may be at risk. Keep up to date on downy mildew alerts to start fungicide programs.

Gordon Johnson, Extension Agriculture Agent, UD, Kent County