Undoubtedly, this is evolving into a challenging wheat harvest. Soybeans range from 3rd trifoliate to knee high and podding. Weed control has been a challenge, with fields too wet in some areas to allow herbicide application. Relfex, Blazer and Basagran Forte supplies are non-existent. Rescue sprays in these wet fields will now have to shift to chemicals such as Basagran plus Assist, Classic and Pinnacle for broadleaf weed control.
Manganese deficiency is also evident in some soybean fields.
Manganese symptoms appear as interveinal chlorosis, with the veins in the leaf staying distinctly green. This contrasts with other nutrient deficiencies, such as nitrogen, which are a more general yellowing. Soybean cyst infestations and pH problems can also cause yellowing. Be sure to do some detective work to determine the actual cause of your yellow soybeans, then you will be able to take the appropriate management steps to correct the problem. Many growers are also questioning the addition of fertilizer nitrogen where nodules have been destroyed due to root rots in the soybean crop.