Abstract
The investigation was carried out to explore the possibility of an interaction between the plant parasitic nematode Helicotylenchus dihystera (Cobb) and the Cowpea strain of Rhizobium, in or on the roots of the Southern Pea Vigna sinensis (L) Endl. Experiments were carried out in the greenhouse using the variety Knuckle Purple Hull, field collected nematodes, and the American Type Culture strain of Rhizobium No. 9931. Seed germinating in sand in the absence of nitrogen were exposed to three levels of Rhizobium and three levels of nematodes in all possible combinations for periods of 13 to 50 days. The levels of Rhizobium used resulted in an increase in all parameters measured (fresh weight, dry weight, nodule weight and total nitrogen content) except in regard to fresh weight in one 13-day and one 22-day experiment and for dry weight in one 13-day experiment. The F-test for the nematode component was significant only in the 13- and 33-day experiments. The nematodes consistently increased nodule weight over a 13-day experimentation time. The nematode component reduced significantly the fresh weight in two of the 33-day experiments. Dry weight and nodule weight were also reduced in some instances. On the whole the nematodes had no significant effect on the total nitrogen content of the plants except in one 13- and one 33- day experiment where a significant increase was recorded. In the 33-day experiments there was good evidence for an interaction between the nematodes and the Rhizobium, in regard to both fresh and nodule weights. It is speculated that the southern pea has a differential susceptibility to attack by nematodes which varies with the physiological age of the plant.
Brown, Oswald David Robert (1971). The influence of the plant parasitic nematode Helicotylenchus dihystera (Cobb) on the growth and nitrogen fixation in the Southern Pea Vigna sinensis (L) Endl. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -213465.