Parasitology, Harold W. Manter Laboratory of
Date of this Version
1989
Abstract
Path analysis was used to assess the efficacy of the fiddleneck flower gall nematode as a weed biocontrol agent of coast fiddleneck in competition with wheat during 2 yr of field experiments. The path analysis revealed that the number of inflorescences/plant for fiddleneck and the number of heads/plant for wheat were the most important yield components that determine fecundity and seed yield. The density of fiddleneck had a much greater impact on the yield components of fiddleneck than did the density of wheat or the nematode rate of inoculation. The nematode had its greatest negative impact on the number of seeds/flower of fiddleneck and its greatest positive impact on the number of heads/plant of wheat. Path analysis predicts that a biocontrol agent that has a large negative direct effect on the number of inflorescences/plant for fiddleneck would be more efficacious in decreasing fecundity and seed yield than an agent that only impacts the number of flowers/ inflorescence, seeds/flower, or biomass/seed. Nomenclature: Coast fiddleneck, Amsinckia intermedia Fischer and Meyer #3 AMSIN; wheat, Triticum aestivum L. 'Anza'; fiddleneck flower gall nematode, Anguina amsinckiae (Steiner and Scott, 1935) Thorne, 1961.
Comments
Published in Weed Science, 1989. Volume 37:778-783