Detection of Suppressiveness against Rotylenchulus reniformis in Soil from Cotton (Gossypium hirsutum) Fields in Texas and Louisiana.
Rotylenchulus reniformis is a major problem confronting cotton production in the central part of the cotton belt of the United States of America. In this study, the hypothesis that natural antagonists in some cases are responsible for unusually low densities of the nematode in certain fields was tested by assaying soils from 22 selected fields for the presence of transferable agents in pots containing cotton plants. In one field, soil from four different depth ranges was tested. In the first of two types of assays, 1 part nematode infested soil was added to 9 parts test soil that was left untreated or autoclaved before mixing; this mixture was used to fill pots. In the second type of assay, 1 part test soil was added to 9 or 19 parts pasteurized fine sand, and nematodes were introduced in aqueous suspension. In three experiments representing both types of assay, transferable or autoclavable agent(s) from four fields in South Texas suppressed nematode populations by 48, 78, 90 and 95%. In one experiment, transferable agents in five fields in Louisiana suppressed populations from 37 to 66%. Identification and evaluation of these agents for biological control of R. reniformis merits further study.
Robinson
A Forest
AF
USDA-ARS, 2765 F & B Rd, College Station, TX 77845 Lilly Hall of Life Sciences, Purdue University, West Lafayette, IN 47907-2054 LSU AgCenter, Department of Plant Pathology, Louisiana State University, Baton Rouge, LA 70803 LSU AgCenter, 212 Macon Ridge Rd, Louisiana State University, Winnsboro, LA 71295 USDA-ARS, 2413 East Highway 83, Weslaco, TX 78596 Texas Agricultural Experiment Station, Rt. 3, Box 219, Lubbock, TX 79403 USDA-ARS, P.O. Box 345, Stoneville, MS 38776-0345.
Westphal
Andreas
A
Overstreet
Charles
C
Padgett
G Boyd
GB
Greenberg
Shoil M
SM
Wheeler
Terry A
TA
Stetina
Salliana R
SR