Evaluation of trap barrier system for rodent management In irrigated rice ecosystem in Mkindo village, Tanzania

Masters Thesis

Rodents are one of the major factors limiting crop production in Central-eastern Tanzania. A study was conducted at Mkindo village from July, 2016 to July, 2017 to evaluate the effectiveness of trap barrier system (TBS) as rodent pest management tool in rice, which enclosed a crop planted 2 weeks earlier (trap-crop). The trap barrier of 10 m by 10 m was constructed using poles dug 50 cm into the ground and standing 1.5 m above the ground. A polythene sheet measuring 45 m in length and 1 m in width was rolled around the staked poles of wood. Two live-multiple-capture traps were placed at the base of the polythene on each side of the trap barrier. Damage to tillers and yield loss were assessed within the trap-crop and at 0, 10, 20 and 30 m on each side of the trap barrier. The effect of TBS on mean yield increased up to 20 m and 30 m in dry and wet season respectively from the trap crop. Two crops were monitored: dry season crop when rat densities were high and wet season crop when rat densities were low. Results show that there were no significant differences in rodent abundance between seasons and crop growth stage in farmers managed rice fields where Mastomys natalensis was the most abundant rodent pest species. Higher yield was recorded during the wet season compared to the dry season. The cost benefit ratios for using a TBS were 1:1.1 for the dry, 1:6.7 for the wet season. This showed potential of TBS in rodent management for reducing population abundance and crop damage in lowland rice in Tanzania. TBS surrounding crops provided cost-effective protection against pre-harvest rat- caused losses to rice in the dry season when rodent densities are highest. It is recommended that small scale farmers use TBS to reduce pre-harvest rat losses of rice in the dry season as opposite to wet season. This will help them to maximize their profits and improve their living standards. Further studies are needed to test this new technology in other irrigation schemes in Tanzania.