Abstract:
Potential predatory activity of the Collembolan Cyphoderus spp. on the infestation of roots by root-knot nematode, Meloidogyne incognita was determined experimentally using spinach and tomato plants. Adult Collembolans (n=100) were added to three-week-old plants grown in plastic pots. The plants which did not receive Collembolans served as untreated controls. One week later, all the plants were inoculated with 500 infective juveniles of M. incognita. Sixty days after inoculation of nematodes, shoot height and weight, root length, number of galls and egg masses per root system as well as number of Collembolans from 100 cm3 soil was recorded. There were five replications, and the experiments were arranged in complete randomized design in a screen house. Significant increase (P<0.05) in shoot height and weight, and root length was detected in both plant species grown with Cyphoderus spp. Compared to controls, spinach had 40% while tomato had 37% increase in root length. Number of galls and egg masses per root system was significantly lower (P<0.05) in both plant species when grown with Cyphoderus spp. compared to controls. Number of Cyphoderus spp. recovered from the soil was 27.60 ± 1.50 and 79 ± 5.36 in spinach and tomato respectively. These findings showed that Cyphoderus spp. reduced the root infestation caused by M. incognita which in turn promoted growth of the plants. The increase in the root length was associated with a reduced gall formation leading to increase in the shoot growth. The reduced infestation by M. incognita was most probably due to the predatory activity of Cyphoderus spp. on infective juveniles in the soil. Thus, there is a potential to use Cyphoderus spp. as a biological control agent in control programs of M. incognita.
