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

Document Type : Original Article

Authors

1 Phytopathology Department, National Research Centre

2 Department of Agricultural Zoology and Nematology, Faculty of Agriculture, University of Cairo, Giza, Egypt

3 Department of Entomology and Nematology, IFAS, University of Florida, USA.

Abstract

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

Keywords