Christmas trees
Field crops
Fruit
Home and yard
Nursery and landscape
Turfgrass
Vegetable
Diagnostic Services
Soil/Plant Nutrient Lab
Enviro-weather
Regional IPM Center
Pesticide safety
Organic: New Ag Network
Invasive species
Sustainable ag & food systems
MSU ANR departments
MSU Extension
Site index
Contacts/permissions
| Field Crop Advisory Team Alert newsletter | ||||
|
||||
 |
||||
| Vol. 22, No. 16, August 23, 2007 |
||||
In this issue  Benefits of wheat in a rotation Charcoal rot Free screening for herbicide-resistant weeds in soybean production systems Third edition of Managing Cover Crops Profitably released Drought online resource now available Regional reports Weather Next issue September 6 |
|
|||
|
||||
| Benefits of wheat in a rotation With the enthusiasm for producing ethanol from corn and biodiesel from soybeans, wheat has become the forgotten field crop. However, including wheat in a corn-soybean rotation can provide some real benefits for the quality and productive of the soil. The price of wheat makes it an economically attractive crop as well. In the 1990’s, Dick Harwood did considerable research evaluating the effects of wheat in rotation with corn and soybeans. Including wheat in the rotation was found to increase corn yields by at least 10 percent. In Michigan studies, when wheat was followed by a cover crop, such as frost seeded red clover, corn yields were always increased by at least 15 percent over continuous corn. This effect is valid for soils with low and high yield potential. The exact reasons for this enhancement in corn yield are not well understood, but are likely a combination of several effects. A well established wheat crop provides good ground cover through the winter months to prevent wind erosion. One of the keys to improving and maintaining soil quality is to have vegetation growing in the soil for as many months of the year as possible. Growing winter wheat after soybeans or another crop and then following wheat with a cover crop makes this possible for as long as 22 months. Plant roots contribute to enhancing microbial activity, nutrient cycling and improving soil aggregation. Red clover may be frost seeded into wheat or some other cover crop may be seeded after wheat harvest to continue active rooting in the soil. The long term decomposition of wheat roots and stubble contributes to cycling of nutrients, and a legume cover crop provides nitrogen for the following corn crop. At 50 cents per pound, a 60 lb N/ acre credit is worth 30 dollars per acre. In Michigan studies, nitrogen credits have ranged from 40 to 120 lbs N/ acre. Wheat is effective in utilizing residual soil nitrogen and reducing nitrogen loss by leaching. If strategically planted, wheat can also serve as effective filter strips and wind buffer strips. |
||||
| The physical condition of the soil tends to be preserved during the wheat production cycle because there is minimal tillage, and trafficking is usually done at times when the soil is not as susceptible to compaction. When sown in September or October after the harvest of soybeans, wheat breaks the cycle of pests and weeds that tend to become problems with continuous summer annual crops. The need for pesticides is generally less with wheat than summer annual crops. The period after wheat harvest provides an opportunity to control troublesome perennial weeds. Soil moisture after wheat harvest is usually favorable for sub-soiling where there is a need to loosen compact soil conditions. This is also an excellent time for establishment of cover crops if none were interseeded. Green wheat growing in the spring provides a good habitat for insect predators, such as ladybird beetles, that can then move into corn and soybean fields for controlling pest insects. An established cover crop can continue to serve a similar role throughout the summer. Wheat in the rotation spreads the production cost and weather (growing conditions) risks across another crop and distributes farm operations on time. There is little or no demand during the critical April-May corn-soybean planting period. The post-harvest period is ideal for making lime, manure or corrective nutrient applications. With increased emphasis on corn production, farmers need to recognize the benefits wheat can provide in improving long term corn yields. In summary, benefits from having wheat in the crop rotation include improving soil quality, cycling nutrients and providing nitrogen credit, breaking the cycle of annual and perennial weeds, protecting soil from soil erosion, distributing farming operations and providing a good return on investments. Therefore, as cropping rotations are being planned, be sure to consider wheat and its benefits. |
| back to top |
| Charcoal rot Although drought conditions aren’t especially conducive to the development of root diseases on soybean, there is one notable exception – Charcoal rot (Macrophomina phaseolina). (view photos)Although this disease organism survives in the soil and in crop residue from year to year, it develops when there is a high level of the pathogen in the soil, and plants are stressed by weather that is hot and dry. Recent rainfall and cooler temperatures should help to reduce plant stress, but plants damaged by this disease are likely to have already suffered some loss of yield. This pathogen can also cause a stalk rot in corn. I have visited fields and looked at samples from Clinton County, Sanilac County and Ingham County in the last two weeks and confirmed charcoal rot in all of them. Soybean samples with charcoal rot have been confirmed by MSU Diagnostic Services, and charcoal rot has been identified by extension educators in other counties in the state. One field I visited had a large number of dead and dying plants, particularly in low areas. Many of the remaining plants were stunted, and the upper leaves were yellowing. There were a few pods at the upper nodes and many of those were flat. Symptoms in the other fields weren’t quite as severe, but stunted and yellowed plants appeared in patches in the field. The confirming field symptom was the numerous, tiny black fruiting structures (sclerotia) in the root and stem tissue. To the naked eye, the infected tissue has a grayish-black color, as if it had been sprinkled with powdered charcoal. If you use a hand lens or field microscope, you can clearly see the tiny, individual sclerotia. It is interesting to note that several of the fields I visited had two different soybean varieties planted side by side in the same field, and that there was a noticeable difference in how the varieties were affected by the disease. The less affected variety had considerably fewer dead and stunted plants, was much greener and appeared to have better pod set than the other variety. Charcoal rot can infect soybean plants early in their development, but symptoms don’t usually show up until plants begin to flower, or even later as plants’ water needs increase during pod formation and filling. Early symptoms, such as yellowing of upper leaves and premature leaf drop, may be attributed to other causes, including drought. Symptoms develop in the driest areas of the field first. The fungus is most active when soil temperatures are in the 80-95°F range. If you have charcoal rot in your field, it is advisable to rotate out of soybeans for two years. Small grains or corn can be planted during the rotation away from soybeans. According to the University of Wisconsin Soybean Plant Health website, even though corn is a host for the charcoal rot pathogen, it can’t support as high a population of the microsclerotia as soybean. Plowing or tillage is not an effective means of controlling the disease, as the sclerotia can survive in the soil for a long time. Cultural practices that limit plant stress, such as optimum fertility levels, moderate planting rates and good weed control practices can help to reduce disease severity. Choose soybean varieties that are less susceptible to charcoal rot. Also, plant later maturing varieties (to the extent that is practical) that will be in the less vulnerable vegetative growth stages during the hottest, driest weather. |
| back to top |
| Free screening for herbicide-resistant weeds in soybean production systems Herbicide resistance in weeds is a growing concern for growers, due largely to the recent occurrence and spread of glyphosate-resistant horseweed and the occasional failure to control common lambsquarters, common ragweed and giant ragweed in Roundup Ready crops. (view photos) Confirming herbicide-resistant weed populations is the first step of any resistance management program. Verification will provide producers with the knowledge to implement the best possible management strategies, with the ultimate goal of preventing or limiting the spread of herbicide-resistant weeds. Because of the many benefits that glyphosate offers Michigan soybean growers and the high potential for selecting for glyphosate resistance; an ongoing herbicide resistance screening program has been expanded for 2007. Diagnostic Services at Michigan State University will conduct free glyphosate resistance screening for soybean producers. The program is funded by the Michigan soybean checkoff program and covers four weed species: horseweed/marestail, common lambsquarters, common ragweed and giant ragweed. Samples will also be screened for ALS and triazine resistance. Through this screening project and others, MSU Diagnostic Services has documented ALS-resistant horseweed in 35 field crop locations and seven Christmas tree plantations spanning 14 Michigan counties. Triazine-resistant horseweed has been documented in two field crop locations, 12 Christmas tree plantations and 4 blueberry plantations spanning five Michigan counties. Seedheads from mature plants should be collected in late summer to early fall following appropriate guidelines listed in the weed resistance submittal form available at MSU county Extension offices and agricultural retail facilities. Clip several seedheads and place them in a paper bag. Note both common and giant ragweed seeds are found in the leaf axils. They are not found at the very top of the plant. If you have any questions about field criteria or seedhead collection, please call Steven Gower at 517-432-9693 or by email at sgower@msu.edu. |
| back to top |
| Third edition of Managing Cover Crops Profitably released A revised third edition of Managing Cover Crops Profitably has just been released by the Sustainable Agriculture Network (SAN). Andy Clark, SAN Coordinator, has done an excellent job improving and upgrading this book. I’m excited to announce that several Michigan farmers are cited throughout this publication as well as Kellogg Biological Station cover crop research. I would encourage anyone working with cover crops to purchase a copy; it is well worth the $19 cost. Read more about this publication at: http://sare.org/publications/covercrops.htm |
| back to top |
| Drought online resource now available With this season facing drought conditions, a new online resource offering helpful tips and information has been established. Please visit http://www.ipm.msu.edu/drought2007.htm. Topics include: general drought and crop information and effects on corn and forages. This site will be updated as articles come in from the Field Crop Area of Expertise Team and CAT Alert authors. –Andrea Buchholz, asst. editor. |
| back to top |
| Regional reports 1 -- Southeast Ned Birkey Weather The weather in southeast Michigan has been unsettled, with rain every week and sometimes every day. Some areas, particularly near the Ohio state line have had up to ten inches of rain since storms with hail on July 26. Most of southeast Michigan had three or more inches of rain on Sunday, August 19 and Monday, August 20 this week. The race at Michigan International Speedway was rained out Sunday and Monday, and finally ran on Tuesday. Then later on Tuesday, the trucks hauling racecars going south to Bristol, Tennessee were stalled on I-75, which had over three feet of water on the roadway near Lima, Ohio. Northern and north central Ohio is having flooding right now. Crop report Alfalfa will be a nice third cutting whenever the rain quits and the soil dries out. Some fields were cut prior to the recent rains and some are in full bloom now. Potato leafhoppers continue to feed. Some new alfalfa seedings have gone in during August and more will as soon as the soil conditions permit. Corn is in the milk to dough stage and most fields still have nice, dark green leaves. The rains will help on kernel fill, though nothing more. European corn borer numbers are still low, though corn earworm numbers have spiked this week in trap counts. Several local dealers have applied Headline fungicide as a preventative and added some Lorsban for any insect control. I have not seen any field corn that has required any fungicides or insecticides. Soybeans are at the R3 to R5 growth stage, with continued growth, flowering and podding. Japanese beetles and bean leaf beetles continue to feed, though not at threshold levels. Spider mites are disappearing due to disease from the humid weather. Soybean aphids can be found, as well as soybean cyst nematodes. Sudden death syndrome seems to be more common this year than ever before. The rains since Sunday will finish off any further spraying for insects or diseases in soybeans this year. Wheat acreage may increase this fall based upon what some farmers are saying at field days. Miscellaneous This is fall field day “season” with lots of good agronomic information available from university and private company sources. There appears to be lots of new seed company releases for next year. Farmers interested in the 2007 soybean yield contest can still submit entries through the month of August to the Monroe County Extension Office. Their number is 734-240-3183. |
| back to top |
| 2 -- Southwest Bruce MacKellar Weather Sometimes when the weather breaks, it really breaks. That has been the situation in the southwest Region over the last couple of weeks. Thunderstorms, some severe, have brought copious amounts of rain to many portions of the southwest region on over the last two weeks. Rainfall totals over the two week period of 6.0-7.0 plus inches are not uncommon. We have finally began to see rainfall in the northern portion of Kalamazoo County, which was one of the areas hardest hit by the drought and that had received little way in relief until the rains over the weekend of August 21-22. The highest rainfall totals over the last week were in Berrien, Cass, St. Joseph and Branch counties. Crop report This year has been the most challenging for producing a non-irrigated corn crop in decades in the southwest region. Since we have started to see rainfall in the area following the first week in August, the corn crop has definitely regained color. Unfortunately, that has been the most significant improvement in many fields. Virtually all of the rainfall that fell in the region in June and July was associated with isolated to widely scattered thunderstorms. Corn plants are showing symptoms of moisture stress ranging from little vegetative growth and ear abortion (drought impact in the vegetative growth stages) through poor pollination and kernel abortion (drought stress in the early reproductive growth stages). The cumulative effects of the drought have most certainly reduced yield potential of the crops in the region, and have particularly devastated non-irrigated corn crop in the five counties most significantly impacted by the drought in the southwest region, Allegan, Van Buren, Cass, St. Joseph and Kalamazoo. Yield reductions will most likely range from 50-70 percent in many areas in these counties. The impact is very hard to see from the road. Plants that benefited from the “edge” effect along the edge of the road seem to have at least fair ear development. However, when you walk into the field and look at plants where the population is even, there are much smaller ears, and in some instances, many barren stalks in fields. We also have been seeing many ears with shallow kernel depth, so I think we can expect to see poor test weights on grain harvested from these fields. In addition, there is a lot of smut developing in the hardest hit fields. Stripper plate adjustments will most likely be in order to harvest the 2007 non-irrigated corn crop in the southwest. The irrigated corn crop looks good, but I would not be surprised to see a bit of yield reduction effect on fields where irrigation fell even slightly behind during the season. Producers were struggling to keep a zone of soil moisture just two to three inches thick on most fields because of the lack of any precipitation for extended periods of time. For those who had the capacity and were able to keep up, this year has provided excellent levels of sunlight and heat and should deliver exceptional yields. Seed corn has looked pretty good all season, and the early planted inbreds are beginning to dry down now. Because of the staggered planting, we are still working on male row destruction on a few fields. The drier conditions in late June and July helped to reduce the potential for leaf diseases earlier in the season. Rainfall and high humidity, coupled with high temperatures, provided favorable conditions for the development of gray leaf spot in some of the later planted fields. Insecticide applications to control spider mites were also prevalent. We anticipate the beginning of seed corn harvest during the next week. The soybean crop was anticipated to have a better chance than corn to at least somewhat recover from the drought stress. We have seen that happen in many areas of the southwest region. There is new growth on the top of the plants, especially on later planted fields or where full season variety soybeans were planted. Some plants are adding additional flowers and new pods, especially in areas where soil moisture levels began to improve by late July. I think that we can expect to see bean size improve on all pods, which can have a significant positive impact on soybean yields across the board. Spider mites were the most significant pest challenge to soybeans in the southwest region in 2007. Many fields were treated. With the benefit of hindsight, many more fields probably should have been treated. I think that most producers were waiting to see what if any rainfall was in the cards before they wanted to commit to treating non-irrigated fields. Irrigated producers have been used to not having to treat for the pest, thinking that increased water availability and canopy moisture would help keep spider mite populations in check. While there was less damage in irrigated portions of fields, there was enough in many that it may have warranted an application of an insecticide. We can see many little “hotspots” in fields where spider mites apparently dropped into areas and a near circular pattern developed in many places in irrigated fields. Soybean aphid numbers were on the increase in August, but it appears as though their numbers will remain well below threshold in the remaining weeks of the growing season. If you were to pick a crop that has improved the most with the rainfall, alfalfa and grass pastures would win hands down. We have seen an explosion of growth in these crops. The challenge with benefiting from the improved conditions of the forages will lie in finding acceptable harvest conditions. We anticipate that many producers will be forced to harvest alfalfa in the period that we normally would like to avoid harvest to allow for the roots to store energy for the winter and early spring growth. In a year with higher grain prices and short hay supplies, the decision to harvest in September may be easier to make this year than in most. Harvesting during this time period can have a detrimental effect on alfalfa stand longevity. |
| back to top |
| 3 -- West Central Fred Springborn Weather Some much needed rain has fallen in Montcalm and the surrounding area. In the past five days, many areas have received over 2.0 inches. Parts of Newago received 3.5 inches of rain. High temperatures have been moderate to quite cool with high in the 60s to low 80s for much of the two week period. Crop report Much of the dryland corn crop looks better than one might expect considering the lack of rain this growing season. There has been lots of variability within fields and from field to field. Until combines go to the field and a significant part of this crop has been harvested, it will be difficult to get an estimate of overall yields. Corn silage harvest has begun in a few drought-stressed fields as well as some irrigated corn. In the insect traps, European corn borer numbers remain low as well as corn ear worm moths. No western bean cutworm moths were caught this year. Soybean crop development is variable from bloom to late pod fill. Most fields are in late stages of pod fill. Noted insects have been spider mites, Japanese beetles and soybean aphids. Soybean aphid levels are variable with most fields having very low levels, with only a very few fields approaching threshold. The dry bean crop is as variable as possible. Growth stage varies from bloom with young pods to turning. Some irrigated fields have excellent yield potential, while some dry land beans will not be harvested. Several fields have feeding injury from bean leaf beetle as well as Japanese beetle. White mold is present in a few irrigated fields. Alfalfa is responding to the recent rainfall. Potato leafhopper numbers have declined in many areas. Many are hoping to get one more cutting in before September, as forage supplies remain tight. Oat harvest is complete with variable yields reported, most were below normal. |
| back to top |
| 4 -- Central Paul Gross Weather The region has received up to 3.5 inches of rain over the past two weeks that has broken the drought conditions at least for the time being. We are still well below average rainfall for the year. The rains was nice and gentle allowing maximum utilization for growing crops. The rain has perked growing crops and given a good fall, we should have a crop to harvest. Crop report The corn crop should benefit from the recent rains adding quality and test weight. Harvest of corn silage is underway with most of the drought stressed field already harvested. Silage yields have been well below average with yield reports of five to six tons per acre. We will have to wait until fall harvest to determine actual yields. Most farmers feel the yields will be below average, but better than they should be based on rainfall this summer. The soybean crop should benefit from the rains filling post and increasing bean size. There has been a problem with spider mites in many fields. Some insecticide applications have been made. The warm and humid conditions should help manage this pest as a fungal pathogen can collapse the populations under these weather conditions. Scout fields for this pest. Alfalfa harvest is underway with yields generally poor. The rains will be of great benefit for third and fourth cuttings. Leafhopper populations seem to be falling. Continue scouting fields for this pest. New seedings have emerged and are doing just fine. Drybeans are beginning to turn. Yields are expected to vary widely. Some fields will be very good, some very poor. Only time will tell. The sugarbeets are just loving the moisture and adding tonnage as we move into fall. |
| back to top |
| 5 -- Thumb Mark Seamon Weather Some areas received up to 2.0 inches of rain, while others only got 0.1 of an inch on Monday, August 20 of this week. This moisture along with cooler temperatures has improved the appearance of some crops. Crop reports Sugar beets have perked up with the moisture and break from high temperatures in most areas. The northern thumb area received limited rainfall and is still struggling with drought effects. The rainfall has created significant leaf wetness, which is a critical factor in the infection and development of cercospera leafspot. Be sure to check specific data for a site near you. This can be found at www.MichiganBeets.com The rainfall will have limited benefits in many corn fields due to the advanced drought stress. Some other fields seem to have improved visual plant health, hopefully this will translate into increased kernel size and weight. Corn silage is being harvested with reduced yields. This is increasing the acres needed to be chopped for feed. A short hay crop in most areas is also increasing the acres of corn harvested for silage. In soybeans, bean leaf beetles are feeding in most fields with those slow growing fields showing defoliation up to 20 percent. Most soybeans should benefit from the rainfall in bean size. Dry beans have been affected by the drought conditions as they blossom with poor pollination and pod set. Some fields have put on new blossoms and growth, which may make harvest more of a challenge. |
| back to top |
| Weather news Jeff Andresen Agricultural Meteorology Geography Thursday morning, a nearly stationary frontal boundary stretched from the central High Plains eastward through Iowa, Illinois, Indiana and Ohio into the mid-Atlantic Region. For almost one week, this front has served as a focusing mechanism for heavy rainfall across much of the Upper Midwest including the Lower Peninsula of Michigan. Some locations in Minnesota, Wisconsin, and Ohio recorded more than 10 inches of rain since last weekend with severe flooding. The front is forecast to edge northward through Michigan as a warm front Thursday, then return south- and eastward once again as a cool front Friday. Showers and thunderstorms will continue to be a threat through early Saturday. Best chances for rainfall will be across the Lower Peninsula Thursday and Friday evening, with lesser chances in the Upper Peninsula, where severe drought conditions continue. Daily rainfall totals through Friday are generally expected to range from 0.25-0.50 inches, with 1.0-2.0 inches possible in heavier storms. By late Saturday, the frontal system is expected to finally move south and east of Michigan, leading to drier and somewhat cooler weather Sunday into early next week. Temperatures during the next few days will fall back from above normal values Thursday and Friday to near normal levels by Sunday. Highs are expected to range from the low and mid 80's north to low 90s south Thursday and Friday, falling back to the upper 60's north to upper 70's south by Sunday. Low temperatures will fall back from the mid- and upper 60's Friday morning to the low 50's north to low 60's south Sunday. Following dry weather early next week, the next chance for rainfall across the state will come late Tuesday or Wednesday. The medium range forecast guidance suggests a relatively fast, zonal (west to east) flow along the United States./Canadian border through the middle of next week, gradually transitioning to a troughing pattern across the eastern United States. by next weekend. This type of pattern would shut off low level moisture to the region from southern sources once again, and both 6-10 day and 8-14 day outlooks, covering August 26- September 1 and August 30- September 5, call for below normal precipitation totals statewide. Mean temperatures during the 6-10 day time frame are expected to remain near normal statewide, while temperatures during the 8-14 day period are forecast to fall back to below normal levels. It is important to note that forecaster confidence in both these outlooks is considered lower than normal due to disparities in some of the forecast model guidance (take them with a grain of salt). |
|
| Back to top |
Email the web developer.