West central Michigan field crops regional report – Aug. 9, 2013
Cool temperatures are comfortable for people, but many crops need more growing degree days.
High temperatures ranged from the low 80s to the upper 60 s this week at Entrican, Mich. Average relative humidity levels have been in the mid-70 percent to mid-80 percent range. Variable rainfall amounts were recorded in the west central area over the past week with many areas receiving well over an inch of rainfall while some received 0.5 inches or less for the week.
The vast majority of the corn crop has completed pollination; however, there are a number of late planted fields that are entering pollination now.
Soybeans continue to bloom and set pods.
Alfalfa cutting continues with most producers harvesting third cutting.
Dry beans are setting pods and closing rows.
Soybean aphids are present in many fields; however, the population is very low.
Flight of western bean cutworms continues this week. In the 10 traps that I monitor, the average moth capture is over 180 per trap for the season, with some areas having a bit larger flight than others. However, egg masses are scarce in corn fields, but natural predators seem to be abundant in many of these fields. Dry beans will need to be scouted for feeding injury as the optimal spray window is this week and next.
Japanese beetles are easily found in many crops, but are doing little meaningful damage for the most part. Michigan State University Extension advises crop scouts to continue monitoring this pest in corn that has not yet pollinated as this pest dose have the potential to clip silks. The damage to dry beans and soybeans should also be monitored, but remember that the thresholds take the leaf area of the entire plant into account, not just individual leaves. It is uncommon for fields to have threshold injury from this pest.
Potato leafhopper levels should also be monitored for another few weeks. Potato leafhopper adults and nymphs are present in nearly all fields and should be monitored closely.
White mold is present in soybean and dry bean fields where conditions were suitable for disease development. While it is generally getting too late to treat for this disease, it is well worth the effort to scout fields to evaluate disease pressure and to evaluate control of fungicides that were used earlier in the season.
Other Michigan State University Extension field crop regional reports from this week: