Extension Field Reports

Extension Field Reports

Soybean aphids on soybean leaves, Dodge County
Figure 1. Soybean aphid populations are growing in some fields this week with the cool weather. (Photo by Nathan Mueller)

Nathan Mueller, Extension Educator in Dodge County: Most corn is in the milk to dough stage across the county with replanted corn silking. Our current GDDs suggest a freeze is a real concern in our replanted corn crop. On August 11, I did two in-field yield estimates of irrigated corn in the northwest and central part of the county resulting in 235 and 239 bu/ac, assuming 75,000 kernels/bu. Four dryland fields in the same areas were estimated at 170, 180, 205, and 210 bu/ac, assuming 80,000 kernels/bu. These yields are very similar to current yield forecasts by the Hybrid Maize Model simulations for Concord. There has been some questions as to why not use the old fudge factor of 90,000 kernels/bu. The kernel weight from several corn fields in Dodge County over the past few years have been much heavier, ranging from 72,000 to 85,000 kernels/bu, which is similar to a recent report on kernel weight by Bob Nielson, Purdue University agronomist.

Soybeans are in the R5 to R5.5 stage while replanted soybeans are setting pods, R3. The lack of below normal rainfall in late July and early August is showing up through visible drought stress on dryland soybeans this week. Soybean aphid populations have been low, but increasing in frequency and population in fields over the last week (Figure 1). Growers in the area should be scouting their fields to determine aphid populations, especially on replanted fields. Bob Wright, UNL extension entomologist, discussed soybean aphids on the August 8 Market Journal episode.

Read the full Dodge County crop report at Crop Tech Cafe.