| dc.description.abstract | Tomato (Solanum lycopersicum) is one of the most important vegetables grown in Kenya. It
is grown for the domestic market under both rainfed and irrigated conditions. Due to the high
demand for tomato in the domestic market and for processing, farmers have extensively
adopted high yielding varieties and modern technologies like greenhouse production to
ensure year round production and increase production. Intensive tomato cultivation in Kenya
has resulted in build-up of soil borne diseases, especially root - knot nematodes and Fusarium
wilt particularly in greenhouses where monoculture and limited crop rotation are practiced.
The control of root- knot nematodes and Fusarium wilt is basically by use of nematicides and
fungicides which are toxic and expensive for the small scale farmers. Therefore, this study
was conducted to determine the efficacy of the use of chemical and biological agents in
management of root - knot nematodes and Fusarium wilt in tomato under intensive
cultivation. Greenhouse experiments were conducted over two cropping cycles. Tomato
seedlings were planted in sterilized growth media inoculated with root - knot nematode,
Fusarium, or a combination of the two. The products were Marshal® a chemical agent,
Neemraj® (Azadiractin) a neem-based product and Pl plus® (Paecilomyces lilacinus) a
microbial-based product against root - knot nematodes; Phosphite® a fungicide, Root guard®
(Trichorderma, Bacillus, Aspergillus, Chatomium, Escherichia, Azotobacter spp), and
Neemraj® against Fusarium wilt; Root guard® , Neemraj® and Pl plus® applied either singly
or in combination against the dual infection inoculation of seedling with root- knot nematode
and Fusarium wilt Fungus. The experiment was laid out in a randomised complete design.
Data on plant height, plant dry matter, number of galls per plant, number of nematode
juveniles in potting media, and the number of plants showing Fusarium wilt symptoms was
determined. The results showed that the effectiveness of the biological products in reducing
ot- knot nematodes and Fusarium wilt infection was comparable to that of the chemical
agents. The neem-based product Neemraj® was more effective than the microbial-based
product Pl plus® in reducing severity of root- knot nematodes infection. Neemraj® reduced
the number of galls by up to 77% and the number of juveniles by 94%. Microbial based
product (Root guard®) was the most effective against Fusarium wilt and it reduced the
severity of the disease by 100%. In dual inoculations with root- knot nematode and Fusarium
wilt, the biological products increased shoot biomass and plant height resulting in a reduction
of the number of galls, nematode juveniles number of plants with wilt symptoms and stem
vascular discolouration. Combined application of Root guard® and Pl plus®, Pl plus® and
Neemraj® or Root guard® and Neemraj® reduced the number of galls per plant and number
of juveniles by up to 93% while severity of vascular discolouration due to Fusarium
infection was reduced by up to 100%.
The study indicated that pre-treatment of seedlings with biological and botanical agents is
effective in managing root- knot nematode and Fusarium wilt in tomato. The combined
application of these products have a synergistic effect and improves their efficacy against the
root – knot nematode - Fusarium disease complex than when the products are applied alone | en_US |
