Effect of Pratylenchus zeae on the growth and yield of rice

• Published in: Philippine Journal of Crop Science Vol. 13
• Main Authors: Plowright R.A, Matias D.M, Aung T, Mew T.W
• Format: Journal Article
• Language: English
• Published: 1988
• Subjects: arroz de secano; crecimiento; croissance; crop yield; growth; pratylenchus zeae; rendement des cultures; rendimiento de cultivos; riz pluvial; upland rice
• ISSN: 0115-463X

The root-lesion nematode Pratylenchus zeae is widely distributed on upland rice though its importance has not been assessed. In a field trial, control of P. zeae with carbofuran improved the yield of upland rice UPLRi 5. Pre-sowing soil population densities of P. zeae were low (0-111 nematodes/100 ml soil) and there were no obvious and consistent symptoms of damage during the vegetative phase. At harvest although the total spikelet number was not affected, treatment with carbofuran increased the proportion of filled spikelets in a 24 hills sample and at 4 kg a.i/ha total grain yield was 29% of that of the untreated control. The population densities of P. zeae in roots at harvest ranged between 94 to 1720 nematode/g root and were negatively correlated with grain yield (r=-0.59, P<0.05). A second cultivar Kinandang Patong, was equally susceptible (in terms of host status) but did not exhibit a yield response to nematode control which may reflect tolerance to nematode damage in this cultivar. In a glasshouse experiment higher initial population densities (630 and 3000 nematodes)/100 ml soil) significantly reduced the rate of growth of rice cv IR36 in upland conditions and half the number of tillers (P<0.01). At harvest population densities of P. zeae were very high (means of 11705 and 13219/g root) and root systems were severely stunted with extensive grey lesions. The number of panicles (P<0.05) and the number of spikelets (P<0.001) were markedly reduced by the nematodes.