Progress on the Soybean Seed Quality/Damage Front

Damage to mature soybean seeds can affect the economic value of those seeds when delivered to the buyer. Soybean seed that are maturing during the hottest part of the growing season are more susceptible to damage from weather events that may occur during this time. However, inclement weather during soybean maturity at any time or when mature soybean seed are not harvested in a timely manner can result in excess damage to mature seed. Click here for an article that describes such an occurrence in 2018, and here to access an article that provides information about the economic loss this damage can cause. Click here for an article that provides information about how delayed harvest of soybean can contribute to losses that are attributed to mature seed damage [MSD].

There does not appear to be a short-term solution to this problem since there are no apparent effective preventive measures to protect maturing/mature seed from MSD. This leaves only a genetic solution, or identifying and incorporating seed traits that will impart a level of protection against the cause/causes of MSD in soybeans.

In a Jan. 2009 article titled Registration of soybean germplasm SS93-6012 and SS93-6181 resistant to Phomopsis seed decay, information is provided about the development of two soybean germplasm lines that exhibit resistance to Phomopsis seed decay [PSD] that is caused by Phomopsis spp. Both lines have a relative maturity of early MG IV and are available for the development of PSD-resistant soybean varieties. The authors concluded from the evaluation of these lines in various environments that the most effective method for PSD management in soybeans is to use PSD-resistant soybean varieties.

In an article titled Registration of soybean germplasm DS1260-2, with improved tolerance to mature seed damage and Phomopsis seed decay that is authored by Dr. James R. Smith and colleagues, further progress is shown in the production of resources that can be used to develop soybean varieties that have improved tolerance to MSD.

•   The release of the above conventional MG IV germplasm line is an effort to increase soybean seed tolerance to MSD.

•   This line has lower levels of MSD than varieties that were used for comparison in trials that were conducted over 4 years in Mississippi. This should result in less dockage when harvested seed are delivered to the buyer.

•   This improved line is resistant to southern stem canker, frogeye leaf spot, and race 3 [HG type 0] of soybean cyst nematode.

Private company soybean breeders and geneticists must recognize that the adverse effects of weathering and other causes of MSD in soybeans can and will affect the economic yield of a crop. After all, producing a high yielding soybean crop will not be economical to the producer of that crop if it is subject to significant dockage due to the negative effects from weather vagaries and pathogens at or soon after seed maturity. Thus, a high seed yield that is not manifested in maximum income to the producer will in effect result in a lower economic yield, and this is what matters. The above developments should be viewed as incremental steps that should be incorporated into new varieties so that the high seed yield potential of today’s soybean varieties is manifested in the highest possible economic return to the producer when harvested seed are marketed.

Composed by Larry G. Heatherly, Apr. 2025, larryh91746@gmail.com