| dc.description.abstract | A field study to determine the distribution and population densities of
plant parasitic nematodes associated with beans was undertaken in
Kakamega, Kiambu, Machakos and Siaya districts of Kenya. Meloidogyne
spp. and Pratylenchus spp. were the most predominant endoparasites,
occurring in 86 and 61% of the root samples, respectively. Ectoparasitic
nematodes in the genera Scutellonema and Helicotylenchus were
recovered in 86 and 59% of the soil samples, respectively. Field
experiments were conducted to determine the efficacy of organic
amendments (chicken manure, compost, neem leaves, baobab remains
and farm yard manure) in the control of root-knot nematodes. The
amendments showed varying levels of nematode suppression with
chicken manure being rated as the most effective with galling index of
2.4 while sisal wastes were least effective with galling index of 5.1.
Another study was undertaken to determine the reaction of 35 bean
genotypes to Meloidogyne incognita. Ten genotypes were rated as
susceptible while 3 and 22 genotypes were rated as resistant and
moderately resistant, respectively. The potential of different Bacillus
isolates to suppress galling by root knot nematodes in beans was
investigated using sterile sand in Leonard jars under greenhouse
conditions. The isolates had varying effect with the majority (93%) of
the isolates causing a reduction in root galling when compared to the
control (water). Twelve percent of the isolates were more effective
than carbofuran (nematicide). In another greenhouse experiment
investigating the interaction between Bacillus spp. and Rhizobium strain
inoculations using N-free sterile sand, 4 out of the 20 Bacillus isolates
significantly promoted nodulation in bean plants. | en |
