Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 2, 1997
Publication Date: N/A
Interpretive Summary: Sicklepod is a weed that has become a serious problem in soybean production areas throughout the Southern United States. Economic incentives to clean soybeans prior to sale should generate a large source of sicklepod seed in the Southeastern United States. This research found that as much as 41% of the sicklepod seed was useful as weed inhibitors and feeding stimulants in fall armyworm. Ground whole sicklepod seed, when added to the soil, prevented Columbia root-knot nematodes from growing but didn't hurt tomato plants. This is the preliminary work which could turn a weed problem into an agricultural benefit.
Technical Abstract: Sicklepod (Cassia obtusifolia) is a leguminous weed species that has become a severe problem in soybean production areas throughout the Southern United States. Economic incentives to clean soybeans prior to sale should generate a large source of sicklepod seed in that area. This study was undertaken to survey C. obtusifolia for potential industrial and agricultural applications. As much as 41% of the seed was extractable as useful components. Some extracts were strong inhibitors of wheat, velvetleaf and sicklepod root growth, causing discoloration of the root meristems in a manner similar to that caused by naphthoquinones such as juglone and plumbagin. Some extracts appeared to act as feeding stimulants in fall armyworm (Spodoptera frugiperda), causing them to grow to 50 to 100% larger than controls in a seven day trial. Survival of Columbia root-knot nematode (Meloidogyne chitwoodi) in the soil was inversely correlated to the amount of ground whole sicklepod amendment. No phytotoxic effects of the meal amendment on tomato plants was observed at the levels tested.