Yield Response of Planting Corn in Early April

Corn is planted earlier each year, which is one important component in maximizing grain yield. Earlier planting dates can be attributed to larger farms, less spring tillage, improvements in corn hybrids, improved drainage systems, and better seed treatments. Research conducted at the ISU Northwest Research Farm from 2006 through 2009 showed that the planting window for 98 percent or greater yield potential in northwest Iowa is April 15 to May 9. A 95 percent or greater yield potential can be realized from April 15 to May 18. A study was conducted from 2009 through 2011 at the Northwest Research Farm to determine how corn planted in early April compares with corn planted in the recommended planting window for the area.

Soybean Planting Dates in Northeast Iowa

Soybean planting date studies of various types have been conducted at this site since 1976. Earlier tests included later planting dates (May through mid-June), differing variety maturities, and comparisons with starter fertilizer and Ridomil fungicide soil treatments. Research reports on these studies can be found in previous annual progress reports with the last summary in the 2001 and 2009 reports.

Converting Land from Poplar Tree Bioenergy Planting to Cropland: An Example

Many landowners ask about the process and costs for returning land to crop production after trees are cut for biomass. A field on the Squaw Creek bottom, Story County, Iowa was planted to hybrid poplar trees in spring 2000. The trees were planted in rows with a 10-ft spacing. The trees were cut in spring 2010. The resulting field was four acres, and this is the account of the first corn crop in 2011 on the area.

Second Year Performance of Honeycrisp on 31 Dwarfing Rootstocks in the Iowa Planting of the NC-140 2010 Regional Apple Rootstock Trial

To evaluate the adaptability and performance of new and promising apple rootstocks in the dwarfing size-control category, a NC-140 regional rootstock trial was established in 2010 at 12 sites in the United States (CO, IA, IL, IN, MA, MI, MN, NJ, NY, OH, UT, WI), two sites in Canada (BC, NS), and one site in Mexico (CHIH) with Honeycrisp serving as the test cultivar. The Iowa planting, located at the ISU Horticulture Research Station, includes 31 rootstocks with new selections from the Cornell-Geneva breeding program (G, CG.), Russia (Bud), Germany (PiAu), and Japan (Supp), with M.26, M.9 Pajam 2, and M.9 T337 serving as industry standards. Tissue cultured propagated (TC) rootstocks of G.41, G.202, and G.935 were included for comparison with normal (N) stool bed propagated rootstocks. This report summarizes the tree-growth characteristics of the Iowa planting during the 2011 growing season.

Effect of Date of Planting on Soybean Sudden Death Syndrome

The objectives of this project was to study the effect of planting date on the onset of soybean sudden death syndrome (SDS). It is believed, that avoiding planting soybeans into wet cold soil may delay or lower the severity of SDS. Planting date for soybeans is important and can have a large effect on yield potential.

Optimum Soybean Planting Date

Past research by Iowa State University has shown that the optimum planting date for soybeans, assuming favorable soil conditions, is the first week in May for the northern third of Iowa. The optimum date for the southern two thirds of Iowa is the last week of April. Given that rapidly changing soybean genetics have shown improvements in both yield and disease resistance, this trial was designed to demonstrate the planting recommendation under local conditions.

Early Planting of Tomatoes in a High Tunnel with Plant Coverings

High tunnels have been successfully used in Iowa to modify the climate and extend the growing season for tomatoes and other crops. Without the use of supplemental heat these ventilated, single layered plastic structures have typically increased average inside air temperatures by 10°F or more over outside temperatures for the growing season. The same tunnel, however, will only increase the daily low temperature by about 1 or 2°F, thus making early season high tunnel plantings without additional heat or plant coverings risky in Iowa. Fabric row covers are commonly used in high tunnels to provide for an additional 2-4°F frost protection during cold evenings. The recommended planting date for high tunnel tomatoes in Iowa has been about April 16 (4 to 5 weeks ahead of the recommended outside planting date). Producers are also advised to have some sort of plant covering material available to protect plants during a late spring frost.