Effect of Heterodera sacchari on growth and yield of selected upland NERICA rice in Nigeria

Abstract

Pot and field trials were conducted in 2012 and 2013 cropping seasons in Nigeria to determine the damage of Heterodera sacchari on the growth and yield of upland New Rice for Africa (NERICA) derived from hybridisation of Oryza sativa and O. glaberrima. NERICA rice (NR) cultivars selected were NR1, NR2, NR3, NR8 and NR14. In screenhouse experiments, rice seedlings were inoculated with 2500, 5000 and 10000 eggs and second-stage juveniles of H. sacchari, three weeks after sowing. In addition, two consecutive field experiments were carried out on a naturally infested field. Data on plant growth, yield, and final H. sacchari population densities were taken at the end of the experiments. Significant reductions of 34, 60 and 78% were observed in plant height, fresh root and total seed weights, respectively. Infected plants also produced chlorotic tillers and showed delayed panicle emergence. In field experiments, rice yield was reduced by approximately 50 and 85% in the first and second cropping seasons, respectively. Nematode population densities in soil and roots of rice plants increased significantly in infected plants compared to the controls. The results of this study indicate that H. sacchari is a serious pathogen of susceptible upland NR cultivars and may cause total crop failure when NR is continuously cultivated in cyst nematode infested fields.