Reaction of rice cultivars to Meloidogyne graminicola as a function of irrigation management.

The objective of this study was to evaluate the reproduction of Meloidogyne graminicola in 22 cultivars of rice used in the southern region of Brazil according to the irrigation management. The design was completely randomized in a factorial scheme, being the factor A: rice cultivars and factor B: irrigation management (dry and flooded). The rice cultivars were kept individually in pot with sterilized substrate and inoculated with 5,000 eggs and juveniles (second stage - J2) of the nematode. Plants to rice cultivate BRS IRGA 410 was inoculated with M. graminicola and were used as controls. At 60 days after inoculation, the root system of each plant was evaluated number of galls (NG), number of nematodes per gram root (NNGR) and the reproduction factor (RF). The results demonstrate that M. graminicola can parasitize and develop in different rice cultivars that are commonly used in commercial crops in the Southern region of Brazil, and all cultivars evaluated were classified as susceptible to this nematode (FR> 1.00). The cultivation system under flood conditions showed significantly lower values for the NG, NNGR and RF. [ABSTRACT FROM AUTHOR]