Richard Taylor, Extension Agronomist; rtaylor@udel.edu
With the increase in bean prices you might automatically assume that beans will be a profitable enterprise this year, but since most beans are grown dryland you still will be at the mercy of the weather, in particular in need of timely rainfall. However, even if a profitable season might be likely, there are many agronomic practices that can be used to improve the chances of success.
The first one that comes to mind relates to the yield curve as affected by planting date. In an article for the April 2008 issue of Soy News, Bob Mulrooney, UD Extension Plant Pathologist, suggested that a seed treatment might be a good idea this year due to the fragility of the seed coats of last year’s seed production. In research conducted in Delaware and surrounding states in the past, early planting under cold temperatures did demonstrate the value of seed treatments as well as indicated that the earlier soybeans are planted in May, the higher the ultimate yield potential for full-season soybeans.
For double-cropped beans planting as soon as possible following the removal of the small grain crop is a key to success. In addition, for dryland beans controlling weeds either just prior to planting or as early after emergence as the herbicide label permits is essential to limit water loss and promote early vigorous growth.
Another key to maximizing soybean yields is to know the yield potential for each field you are planting and use this knowledge to decide which fields get planted first. For both full-season and double-crop beans, the fields with the highest yield potential should be planted first using the best adapted variety or varieties available and the best management possible. Next on the list should be the fields that may not produce outstanding yields but still are good fields. Last on your list of fields to plant should be the marginal fields, most drought-prone fields, or any fields with known limitations. If you run out of seed of the best varieties or you won’t be able to plant some fields until very late, it should be on these very marginal fields.
Other tips that should be kept in mind include the following:
*Seeding rate trials often point to small increases in yield with higher populations; and although the increase didn’t always pay at earlier soybean prices, current conditions suggest increasing your target population to 225,000 seeds per acre.
*For no-till seedings or following small grains where crop residue is a potential problem, boost seeding rates by 10 percent, set the planter to be sure seed is into moist soil or at least into soil, and use row cleaners or sweeps when possible.
*Inoculate your soybeans with one of the new strains of Bradyrhizobium.
*Plant a range of maturity group beans so that a short drought at the wrong time does not severely impact your farm yield.
*Observe beans carefully around the V5 to V9 growth stages (about 5 to 9 trifoliate leaves visible) for symptoms of manganese (Mn) deficiency (interveinal yellowing of the younger leaves) and treat promptly with either chelated Mn or techmangam at about 0.5 lb Mn/A. Manganese is the most common nutrient deficiency found on soybeans in this region. A second application sometimes is required when soybeans reach the bloom stage; scout appropriately.
*If you have the ability to irrigate double-crop beans, apply adequate irrigation to maintain rapid, non-stressed growth right through the seed fill stage.