Whether bean pod mottle virus is the primary disease agent for green stem remains to be determined. To date, the evidence is circumstantial and based on correlations, but the trend is such that bean leaf beetle is thought to be the primary vector of this soybean virus. Tall and short corn, large within-row gaps, and groups of crowded plants characterize fields that exhibit stand uniformity problems. Lack of stand uniformity is a problem involving uneven seedling emergence and within-row spacing of plants. Uneven emergence can also have a major impact on potential yield even if within-row spacing is relatively uniform.
Corn sometimes emerges unevenly because of environmental conditions beyond the control of growers.
However, timely planter servicing and adjustment, as well as appropriate management practices, can help prevent many stand uniformity problems. The following are some tips for improving the uniformity of seed placement during planting. Avoid excessive tillage trips and tilling wet soils. Check seed depth and seed soil contact periodically during planting. Distribute residues over row areas evenly.