Sicklepod (Cassia obtusifolia) is a leguminous weed species that has b
ecome a severe problem in soybean production throughout the Southern U
nited States. Economic incentives, such as premiums for low levels of
foreign matter from cleaning soybeans prior to sale, could generate a
large source of sicklepod seed in that area. This study was undertaken
to evaluate C. obtusifolia seed for potential applications. As much a
s 41% of the seed was extractable. Some extracts were strong inhibitor
s of wheat, velvetleaf and sicklepod root growth, causing discoloratio
n of the root meristems in a manner similar to that caused by naphthoq
uinones such as juglone and plumbagin. Some extracts increased weight
gain in fall armyworm (Spodoptera frugiperda) causing them to grow to
50-100% larger than controls in a 7-day trial. Survival of Columbia ro
ot-knot nematode (Meloidogyne chitwoodi) in the soil was inversely cor
related to the amount of ground whole sicklepod amendment. No phytotox
ic effects of the meal amendment on tomato plants or inhibition of ger
mination for several crop seeds was observed at the levels tested. (C)
1998 Elsevier Science B.V. All rights reserved.