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. 12, June 28, 2007 |
||||
In this issue  Assessing drought stress effects on corn yield Custom machine work rates MSU Crop Diagnostic School Regional Reports Weather |
|
|||
|
||||
| Assessing drought stress effects on corn yield Effects of drought-stress on the corn plant To date, the 2007 growing season in Michigan can be characterized as widely variable in terms of rainfall. Some parts of the state have experienced near ideal precipitation levels while others remain quite dry. Inadequate moisture during any period of growth can result in reduced grain yield. Nutrient availability, uptake and transport are impaired without sufficient water. Plants weakened by stress are also more susceptible to disease and insects. Severe moisture stress is indicated by leaf wilting that is alleviated only when the plants receive additional water. Four consecutive days of visible wilting can reduce potential corn yield by 5 to 10 percent during the vegetative growth stage. Drought stress prior to tassel and silk appearance may result in small ear size. From approximately the 8-leaf to the 12-leaf stage (V8 to V12), potential kernel row number is determined in the corn plant. From the 12-leaf to the 17-leaf stage (V12 to V17), potential kernel number per row is determined. Moisture stress during the vegetative periods may reduce both ear length and the number of potential kernels on each ear. If ear size is reduced during this period, it cannot be corrected by relieving the moisture stress later in the season. |
||||
| During silking and pollination, yield reduction after four consecutive days of wilting can be as much as 40 to 50 percent (see Table 1). Moisture stress during this period can result in a lack of synchronization between pollen shed and silking at pollination, because pollen grains may not remain viable and silking may be delayed. If a plant has tasseled and shed pollen but no blisters have appeared, it will be barren. A common result of prolonged moisture stress or moderate moisture stress during late pollination is the production of ears with barren tips. This occurs because the tip kernels were not pollinated or were aborted after pollination. In order to determine harvest options for drought stressed corn, an assessment on potential grain yield should be conducted. Within one to three days after a silk is pollinated and fertilization is successful, the silk will detach from the developing kernel. Thus, you can carefully remove the husk leaves from an ear shoot, shake the cob, and estimate the degree of successful fertilization by observing how many silks shake loose from the cob. Table 1. Effect of drought on corn yield
Another method to determine whether drought-stressed corn plants have been pollinated and fertilized is to look for small white blisters on the ear seven to ten days after pollen shed. To identify the blisters, take ears from several areas in the field and break them in half. Using a knife, dig out several kernels on each ear. If you find kernels that resemble blisters on the ears, you can assume that kernel fertilization occurred. If you are unsure whether fertilization has occurred, observe the kernels again in five to seven days. If the kernels were fertilized, the blisters will have rapidly increased in size. If fertilization did not occur, the kernels will not have increased in size. It is also possible to tell if fertilization has occurred by slicing the kernels longitudinally through the embryo side and looking for the young embryo. Only fertilized kernels will produce embryos. Most kernels that have been fertilized will continue to develop and mature if the plants get water. Drought stress after pollination and fertilization can result in aborted kernels or poor kernel fill, causing low test weight and reduced yield. It may also predispose the plants to development of stalk rots. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
Custom machine work rates Many farmers either hire some farm work to be done or else perform custom work for others. What is a fair amount to charge or to pay for such work? Michigan State University has Extension Bulletin E-2131, Revised October 2002 available free of charge, which outlines labor, tractor and machine rental rates as determined by a survey of farmers from around the state of Michigan. Some spring custom rate numbers for the following items may be helpful for farmers as they settle up accounts. All rates are per acre unless otherwise noted. These numbers are average prices for the state. Rates in different areas of Fuel prices have increased dramatically since this MSU survey was taken.Farmers need to consider their current fuel prices and adjust their custom rate charge according to their actual costs.
For a free copy of this extension bulletin, contact your |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| Regional reports 1 -- Southeast Ned Birkey Weather The weather has generally been hot with storms coming in yesterday and up to four inches of rain reported from southern Monroe County. Most areas received an inch or less, which means we are still below normal precipitation levels for the year. Crop reports Alfalfa is regrowing with potato leafhoppers, though not at threshold levels. Corn is mostly very green with highly variable height fields still apparent. I do not see how these fields will ever “catch up” unless we have plenty of degree days in September and a late fall frost. Oats are headed out and will benefit from the rain and cooler temperatures forecast for the next five days. Soybeans seem to be growing slowly, with no fields above knee high. All soybean aphid and rust plots are established, and no aphids were found in the Lenawee County plot this week. Wheat will be ready to combine once the fields dry out from yesterday’s rain. Farmers will need to run plenty of air to blow out any light head scab kernels and weed seed. I expect lower than normal yields because of the hot June temperatures. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| 2 -- Southwest Bruce MacKellar Weather Rainfall was widely variable from thunderstorm events that occurred on June 26 and 27. Precipitation totals ranged from around not a drop to 1.5 inches in other areas. The rainfall amounts and coverage seemed to be more significant in the eastern portion of the region. Crop reports Irrigated commercial corn continues to look excellent. The most advanced fields are approaching tassel emergence (vt). Dry land corn continues to suffer in areas where rainfall has been hard to find. European corn borer larvae can easily be found in some areas and are quite rare in many areas. Japanese Beetle Adults are very common in many areas in the southwest. We are seeing Asiatic garden beetle adults, the new pest reported on last week, in our western bean cutworm traps. I can confirm that we have seen Asian garden beetles in southern Van Buren County. We would be interested in learning more about where uneven corn stands or fields with patches of missing corn plants have occurred in the southwest region to help gauge the potential range of the Asian garden beetle damage. The fields that we have seen stand loss in St. Joseph County were rotated fields where soybeans were raised in 2006. Contact the St. Joseph County MSU Extension office at (269)-467-5511 to report field locations where you believe stands have been reduced by this pest. So far, there have been no western bean cutworms in the traps. Seed corn fields range from V-12 + to V4. We are gearing up for detasseling, which may start this weekend. Corn leaf rust can be found in some fields in the area. Producers are beginning to apply fungicides to help protect the plant from this challenge. Irrigation continues to be a critical task. Cooler temperatures should help to reduce corn stress, which would be helpful as we begin to move into pollination season. Most soybean fields are beginning to flower. Japanese beetles are beginning to feed on soybean foliage. Soybean aphids continue to be found in very low numbers in fields. In most fields, we are not finding more than one to two aphids per plant. As the dry weather persists, continue to monitor for the bronzing symptoms caused by spider mites. Infested beans often show a stippled or sand blasted appearance. Watch you alfalfa re-growth carefully for this pest, because the early re-growth period is the most vulnerable to “hopper burn” injury. It does not take many leafhoppers to cause serious injury on 2-3 inch alfalfa. Wheat is approaching harvest. So far, we have seen little in the way of rain or wind to know the crop down or cause sprouting worries. That situation may not be accurate for areas where storms hit in southern Berrien County on Tuesday, June 26. Meetings The next St. Joseph County IPM Breakfast Meeting will be held on Wednesday, July 5 at the St. Joseph County MSU Extension office, 7:00 AM-9:00 AM. Cost is $7, which includes a catered in breakfast. Our guest speakers next time will be Steve Miller and Lyndon Kelley, who will talk about irrigation water management on field and vegetable crops. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| 3 -- West Central Fred Springborn Weather Much like last week and the week before, warm and dry sums up the weather for this past week with an emphasis on dry. Irrigation systems are running across Montcalm County as rain fall totals have been not much more than trace amounts. High temperatures have been in the upper 70’s to upper 80’s. Crop reports Wheat harvest will be soon upon us perhaps as little as a week to 10 days, as most fields are drying down. Many of the common wheat diseases were observed this year including a late appearance of cereal leaf rust in a few irrigated fields. The disease Take-all has also been seen frequently in many fields. There has been some evidence of head scab infection, but the incidence is very low. Oats are headed with few problems. One barley field was observed this week with cereal leaf beetle feeding. Corn growth ranges from V5 to tassel emergence with the majority in the range of V5 to V10. Irrigated corn is progressing exceptionally well. European corn borer trap catches are down this week with an average of one moth per trap at our Stanton site, and one per trap at the Trufant trap site. Dry bean planting is by-in-large complete with many fields emerged, stands are very good, where there was adequate moisture. A few soybean fields are V5-V6 –most are holding in the V3 to V4 range— and then it’s on down to just emerging. Soybean stands appear fairly uniform, but needs moisture badly. Round-up Ready spraying has occurred on most acres, but results are slow to be seen. Alfalfa second cutting is under way as the last of an overripe first cut is being finished. Leaf hopper feeding is above threshold in some fields. There is slow, spotty regrowth due to dry weather. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| 4 -- Central Paul Gross Weather Rain over the region on Wednesday, June 26, was very widely scattered. Some areas did not receive any while the highest reported amount was seven tenths of an inch. The cooler weather forecasted for the next few days will reduce stress on crops on lighter soils and in areas that did not receive any rain. Overall crops are off to a good start and are on track for good yields if we get normal rainfall throughout the summer. Crop report The corn crop is progressing normally with no insect or disease problems reported. What the crops need the most is rain. Fields on light soils are showing signs of drought stress. It appears some of the early planted fields will have some tassels by the Fourth of July. Soybeans are progressing normally with good stands, and there aren’t any serious problems at this time. There are a few soybean aphids in some fields, but at low numbers. Scout fields for this pest every few days. The wheat crop is in the dough stage, and harvest is expected to begin some time after the Fourth of July holiday. Thus far, we have seen nearly every foliar disease in fields, but the good news is head scab is not one of them. At this point, yields should be good. Wheat on light soils will have reduced yields due to lack of rain. Second cutting of alfalfa has begun in some areas. For the most part, farmers are reporting lower yields. Leafhoppers are out in large numbers and some fields are showing signs of “hopper burn.” The oat crop is all headed and looks good. The cooler weather predicted will really help this crop that likes the cooler weather. Dry beans are progressing, but could use a rain. Leafhoppers are a pest that needs to be managed in this crop as numbers are high. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| 5 -- Thumb Mark Seamon Weather High temperatures have finally subsided for a while. A nice rain before that would have helped more, however, the cooler temperatures will help to relive some crop stress. Crop reports Alfalfa regrowth is slow and fighting against potato leafhopper feeding. Sugar beets continue to add growth and are filling the rows in many fields. Other challenged fields are not progressing much without some rainfall. The wheat crop has dried down prematurely due to dryness. There are a few late planted fields that have significant green color and may benefit from rainfall. Most of this crop has lost a lot of its grain fill period. Corn is growing quickly with some field reaching 60 inches and more. Leaf rolling is variable among fields, but is pretty much the norm in this area. This drought stress ranges from severe to some fields having leaves rolled only in the hottest part of the day. Most fields have good stands with steady, but slow growth. Soybean aphids are widespread, but variable in populations. Most fields have one to five aphids per plant on average. Similar to soybeans, this crop has had good emergence but is progressing slowly due to dryness. Potato leafhoppers are causing “hopper burn” where they have not been controlled. |
||||||||||||||||||||||||||||
| back to top |
||||||||||||||||||||||||||||
| Weather news Jeff Andresen Agricultural Meteorology Geography A slow-moving cool front brought much-needed moisture to some sections of the state Wednesday, June 27 (mainly southern sections of Lower Michigan), but unfortunately many areas were also missed and remain unfavorably dry. During the next several days cool, dry weather is likely statewide as Canadian-origin high pressure moves into the region from the north. Temperatures will fall back to near or below normal levels Thursday, with highs ranging from the upper 60's or low 70's far north to the upper 70's south and low temperatures from the upper 30's north to low 60's south through Sunday. With clear, calm conditions and low humidity, some patchy light frost is even possible Friday morning across low-lying, interior areas of the Upper Peninsula. One positive aspect of the forecast for those missed by Wednesday's rainfall is that the forecasted cooler temperatures should lead to at least a temporary reduction in evapotranspiration rates, water demand, and moisture stress relative to recent levels. Cooler than normal weather will likely remain with us for the next week or two. As mentioned here last week, medium range forecast guidance is suggesting the formation of an upper air trough across the eastern United States next week with northwesterly flow across Michigan and the Great Lakes region. Both 6-10 day and 8-14 day outlooks covering July 3-7 and July 5-11, call for below normal temperatures statewide. Precipitation totals are forecast to increase to near normal levels during the 6-10 day time frame, and range from near normal levels in the south to above normal levels in the north during the 8-14 day period. New long lead outlooks Earlier this year, sea surface temperatures in the equatorial Pacific region were falling, and the development of an El Niño event looked possible. That surface temperatures trend unexpectedly stabilized during the spring season and has remained steady since, reducing the chance of an El Niño anytime soon. ENSO factors thus play little if any role in the new series of NOAA long lead outlooks for the upcoming months. For the month of July, the outlooks are directionless for Michigan and the Upper Midwest, with near equal chances for below-, near-, and above normal mean temperatures and precipitation. During July, warmer than normal temperatures are expected across eastern and western sections of the United States. Cooler and wetter than normal weather is expected to continue (due to abnormally wet soils) from the central Corn Belt region south- and westwards to Texas. During the 3-month (July-September) period, the outlooks suggests warmer than normal temperatures Michigan, with the equal odds scenario for precipitation. Warmer than normal temperatures are also forecast for the upcoming fall season as well. |
||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||
| Back to top | ||||||||||||||||||||||||||||
Email the web developer.