Regional reports on Michigan field crops – June 30, 2011
MSU Extension educators’ pest and field crop updates for Michigan.
This week’s regional reports:
- Southwest Michigan – Bruce Mackellar
- West Central Michigan – Fred Springborn
- Central Michigan – Paul Gross
Cool and dry conditions marked the past week in southwest Michigan. Last week’s heavy rainfall refilled most of the drowned-out portions of fields back up to near the seasonal high mark. However, drier conditions allowed field work to continue much of this week. Sidedress nitrogen applications are continuing on corn and will continue with the spread-out growing season for the next couple of weeks. Pleasant conditions are expected to give way to air conditioner weather over the Fourth of July weekend. Chances for rainfall are expected to be limited to thundershower activity over the next seven days.
A quick look around the region shows that we are at 853-900 GDD’s Base 50 since May 1, depending on the proximity to Lake Michigan. The average GDD accumulation Base 50 in the region for the next five days is 20.2 and the following five days is 20.5. The 6-10 day outlook has the region in the below normal temperature range, and the 8-14 day outlook is calling for near normal temperatures.
Rainfall total over the last week averaged about 0.3 inches. Both the 6-10 day and 8-14 day outlooks has southwest Michigan in the slightly above normal precipitation range.
Wheat is turning pretty fast now. The crop has benefited from the sunshine and drier conditions. We should see wheat harvest progress just slightly behind normal. The crop condition generally looks good with good yield potential. The incidence of Fusarium head blight is fairly low, with low severity in most instances. However, it can be found in some locations over the region. It would be a good idea to check over your fields to consider how best to harvest the crop and to check for Fusarium head blight. Another good reason to check fields is that some fields have lodging issues following last week’s thunderstorm’s wind-driven rainfall. We also have a few fields where weeds are below the canopy for now, but may not stay that way for long. Overall, the crop looks good.
Alfalfa. There is a lot of hay down right now with the favorable forecast. Good drying conditions should mean that most of the second cutting will find a decent harvest window. Potato leafhopper numbers are pretty high right now, so watch regrowth carefully and be prepared to protect your fields. Alfalfa regrowth thresholds for treatment are pretty low – two potato leafhoppers per sweep, 1- to 3-inch alfalfa. Even on more mature alfalfa, it is important to watch for signs of leafhopper feeding injury. View MSU Extension Bulletin E-1582 for Dr. Chris DiFonzo’s recommendations for potato leaf hopper control.
Well, it is official. Some early planted corn fields are shoulder high as we head into the Fourth of July weekend. Unfortunately, there is also a pretty significant chunk of corn acreage that will not be knee-high by that traditional benchmark date. The majority of fields are at 8 to 12 leaf collars, which puts them just above the traditional cutoff for sidedress nitrogen applications. A lot of producers have been working really hard to stay ahead of the developing crop, with wide variations in planting dates plant sizes.
Stink bug damage was fairly evident across many fields this spring. A few growers haveasked about this, concerned it was herbicide damage. The elongated holes across the leaves are a pretty distinctive indication that stink bugs have been the culprit. Western bean cutworm moth flight is just beginning in Michigan. MSU Extension will have traps set in Van Buren, Allegan, Kalamazoo and Cass counties this season. Corn water and nitrogen uptake will be rapidly on the increase as we move into the next three to four weeks. Corn entering the rapid growth phase will ramp up evapotranspiration rates 0.15 to 0.2 inches per day over the next couple of weeks. As corn reaches pollination, water usage will move 0.22 to 0.28 inches per day of removal for optimal plant growth. High temperatures, high winds and low humidity days are conditions that trigger the most water demand in corn.
Overall, the corn across the region looks good, with the caveat that we need some warm conditions to help the later-planted fields to reach maturity. One thing is becoming pretty evident, however. 2011 will be a much longer and more challenging harvest season than we saw in 2010.
All of the earlier planted soybeans are flowering. Later planted soybeans are moving towards R1. Weed control in soybeans is all over the board, with herbicides going on late in a lot of situations. I would not be surprised if we see a good number of second applications of glyphosate needed on quite a few fields. Soybean aphid infestations are spotty, but we do have a fair number of fields with at least some aphids. I have seen at least one field where there were pockets of 25 to 40 aphids per plant. This is about 10 percent of threshold, but bears watching. Japanese beetles are beginning to emerge this week. We have also seen silver spotted skipper larvae damage on soybeans. The threshold for treatment for all types of soybean defoliators is 50 percent of leaf tissue damage in the vegetative growth stages, and 25 percent at early pod fill.
We are beginning to see the signs of early onset sudden death syndrome damage at our soybean disease research site at Decatur. We normally see the initial symptoms on sudden death syndrome in patterns that seem to correlate with soybean cyst nematode heavy infestation. The plants in these areas begin to have signs of yellowing and exhibit stunted growth, starting before the plants begin to flower. Before long, the distinctive inter-veinal yellowing and browning become visible. If the progression of the disease is the same as the last couple of years, the disease will spread out from the heaviest cyst concentration areas to infecting the surrounding areas. MSU’s field research sites will hopefully identify soybean breeding lines and commercially available varieties that exhibit tolerance to the disease. Dr. George Bird also has a seed treatment study looking at different soybean seed treatments impact on sudden death syndrome control. A field day program is slated for Wednesday, August 24, for producers and agri-business professionals to learn more about sudden death syndrome.
With only light rain this week, many producers on well-drained soils were able to get back into fields to apply fertilizer, herbicides and perform other crop maintenance operations. Areas in many fields remain very wet. High temperatures have been in the upper 60s to upper 70s.
Corn growth stage ranges from V3 to V10 and over. Western bean cutworm traps are beginning to catch the first moths of the season.
Alfalfa second cutting will begin next week on many farms as regrowth has been excellent in many fields. A few are still finishing first cutting. Continue to scout field for potato leafhopper adults and nymphs.
Wheat is filling kernels and starting to turn in some fields. A few scattered fields are lodged. Head scab symptoms can be found in some locations.
Soybean growth stages are variable. We are seeing soybean aphid in several fields at very low levels. Natural predator numbers are also building.
Dry bean planting is nearly complete with some replanting planned on poorly drained soils
Things are beginning to dry out after the heavy rains last week that resulted in ponding in many fields. There are a number of field operations that are going on all at once. Farmers are forced to pick and choose where fields are dry enough for field activities. Crops are progressing with the warmer weather this week. Growing degree day totals are getting closer to normal averages. The late planting and normal temperatures are causing concern as to whether the crops can mature in a timely fashion. We will need a nice, long, warm fall.
The warm weather this week has been great for corn growth. Corn has nearly doubled in size in the past week. The early planted fields are almost shoulder high and most will make the “knee high by the Fourth of July” thumb rule. There are plenty of challenges with weed control and sidedress nitrogen applications. The first western bean cutworm moths have been caught this week. Nothing has been easy this year.
Soybeans are progressing and early planted fields that were drilled will be canopied by the weekend. Weed control is still a challenge with wet fields and big weeds. Due to the excessive rains, weeds have gotten big enough to cause yields loss. Farmers need to consider strategies in the future to prevent this problem. There are reports of soybean aphids in low numbers in most fields. Scout fields for this pest.
The wheat crop is beginning to turn, but harvest is still a couple of weeks away. The fields that have had fungicide treatments are generally disease-free. Some lodging occurred with the heavy rains and winds of last week. Rust has been reported in southern Michigan counties.
Second cutting alfalfa harvest is just getting underway for farmers with aggressive cutting schedules. Rain and warm weather has been nearly ideal for crop growth. Scout fields for leafhoppers and other pests. It appears yields of second cutting will be very good.
Dry bean planting is nearly complete and most of the crop has emerged. Wet fields have kept farmers from making weed control applications.
Sugarbeets are nearly filling the rows in the early planted fields. The crop has had its challenges this year.