Development of Plant-Parasitic Nematode Populations on Forage Crops under Field Conditions

Abstract

The continuous increase in cost and scarcity of mineral fertilizers resultingfrom the use of high-cost energy sources has renewed interests in organic recyclingand biological nitrogen-fixation to improve soil fertility and productivity. Foragelegumes can fix nitrogen from atmosphere which has the merit to offer nitrogen forboth crop production and soil fertility. However, plant-parasitic nematodes (PPNs)interactions with leguminous crops can be agronomically damaging under variousconditions. The present study examined population development of each of thePPN genera Meloidogyne spp., Paratrichodorus spp., Criconemella spp.,Pratylenchus spp., Tylenchorhynchus, and Tylenchus spp. on fourteen legumecultivars (i.e. 'Florida' red clover, 'Nolin' red clover, 'Kenland' red clover, 'Kenstar'red clover, 'Tibbee' crimson clover, 'Dixie' crimson clover, 'Mt. Barker' Subterraneanclover, 'Amclo' arrowleaf clover, 'FL - 77' alfalfa, 'Abon' persian clover, 'Wood ford'big flower vetch, 'Seqrest' ball clover, 'Kondinin' rose clover, and 'Chief' crimsonclover). The nematode initial and final populations varied considerably among thelegume cultivars. Therefore, we adjusted for the rate of nematode multiplication byusing analysis of covariance. However, we could not use one of the statisticalmultiple comparison methods because each treatment had different mean ofsquares for the experimental error. Consequently, a matrix was designed to test thesignificance of nematode populations on the cultivars using the t-test. Using acomputer program, the exact (numerical) level of statistical significance fornematode densities among the cultivars could be established. Relatively lowerpopulations of the nematode genera were found on 'FL-77' alfalfa plants.