Issue No. 14, Article 5/July 9, 2010
Soybean Condition Update
Most soybean fields appear to have green, or at least greener, color again. That is a very welcome sign, attributable to the excellent weather last week that offered great sunshine, cool temperatures, and little rainfall. The excellent weather not only perked up the existing crop, it also allowed most growers to finish planting in previously wet fields and to patch-in wet holes.
Many of the fields with green soybeans are peeking through dying weeds now, as many postemergence herbicides were applied last week in the favorable weather. Make sure to scout fields diligently following postemergence herbicide applications. If difficult-to-control weeds like waterhemp don't die, the options for a second herbicide application will get limited as soybean plants rapidly progress into more advanced growth stages. Also, if you have waterhemp escapes that appear unscathed by glyphosate applications, refer to the article by Pat Tranel and Aaron Hager last week offering screening for glyphosate resistance (July 1, issue 13).
The USDA NASS reported that 20% of soybeans are blooming, which is equivalent to the five-year average. With a return to warmer temperatures, many of the later-planted soybeans will start blooming as soon as they reach the third trifoliate leaf stage. So far, foliar diseases and insects have posed only minor concerns this year.--Vince M. Davis