Resistance level of some citrus cultivars to the citrus nematode (Tylenchulus semipenetrans cobb) in West Java, Indonesia

Abstract

This study aimed to determine resistance level of some citrus cultivars to the citrus nematode (Tylenchulus semipenetrans Cobb). Number of T. semipenetrans female penetrated per cm root not significantly different on all citrus cultivar. Number T. semipenetrans female per cm root on all citrus cultivar was < 1 nematode per cm root. This fact showed that Citrus jambhiri, C. reticulate, C. aurantium, C. nobilis, C. medica, C. macrocarpa, and C. hystryx ABC showed resistant reaction on T. Semipenetrans. Citrus cultivars have effect on T. semipenetrans female development. Number T. semipenetrans female that penetrated root system on C. medica, C. microcarpa, C. aurantium, C. hystrix ABC, C. nobilis, and C. reticulata that were 1.25- 4.25 nematodes. This fact showed that the sixth citrus cultivars retarded T. semipenetrans development. Resistance level of citrus cultivar toT. semipenetrans could determined based on reproductive index (R). Citrus cultivar have effect on number J2 T. semipenetrans in the soil. C. jambhiri, C. reticulata, C. aurantium, C. nobilis, and C. medica have reproductive index was low (< 1), mean that final population T. semipenetrans in the soil decrease. This fact showed that cultivars resistant on T. semipenetrans. On the contrary, C. microcarpa and C. hystrix ABC have reproductive index hight (>1), mean showed that cultivars susceptible on T. semipenetrans. Some citrus cultivars have resistance level that different on T. semipenetrans attacking. C. jambhiri, C. reticulata, and C. aurantium were resistant to T. Semipenetrans