Status and yield loss assessment of Rice root knot nematode, Meloidogyne graminicola infestation in Siddharthnagar District, Uttar Pradesh

Abstract

A total of 80 paddy fields from 14 blocks, located in five tehsils, were surveyed. Meloidogyne graminicola was found widely distributed in most of the rice fields in all the blocks. In nurseries, the frequency of occurrence of rootknot was recorded in 12.2% (Naugarh), 12.1% (Shohratgarh) and 12.3% (Bansi), whereas in the fields, highest frequency of disease was observed in the tehsil Shohratgarh (17%), followed by Bansi (16%), Itwa (12%) and Naugarh (3%). Similarly, the maximum disease incidence was observed in Itwa (28%) tehsil followed by Shohratgarh (24%), Naugarh (22%), Domariayaganj (21%) and Bansi (19%). Gall and root-knot indices (at 0–10 scale) were highest in Shohratgarh (3.4 & 2.8, respectively) followed by Itwa (2.4 & 1.8, respectively) and Naugarh (2.2 & 1.8, respectively). Average soil population of M. graminicola was highest in the tehsil Shohratgarh (1518 J2/kg soil), followed by Itwa (1214 J2/kg soil) and lowest population was recorded in Domariayaganj (714 J2/kg soil) at the time of harvesting. The relative yield loss was also determined during the survey and highest yield loss was recorded in Itwa (17.9%), followed by Domariyaganj (9.7%) and Shohratgarh (9.5%) tehsils.