EFFECTS OF ROOT-KNOT NEMATODES (Meloidogyne spp.) ON THE GROWTH OF BLACK PEPPER (Piper nigrum L.) UNDER NURSERY CONDITIONS

Abstract

Root-knot nematodes (Meloidogyne spp.) have been identified as one of the major pests affecting black pepper (Piper nigrum L.). These nematodes are capable of infecting and damaging pepper plants from the seedling stage in nurseries to maturity in the field. This study was conducted to evaluate the infestation level and impact of Meloidogyne spp. on the Vinh Linh pepper variety under greenhouse conditions. The experiment was arranged in a randomized complete block design (RCBD) with three replications, using different nematode inoculation levels: 0, 50, 100, 150, 200, 300, 400, 500 juveniles per 100 g of soil. Results showed that Meloidogyne spp. were capable of infecting and reproducing rapidly, as indicated by the increase in nematode density in both soil and roots over time compared to the initial inoculation levels. The nematodes significantly affected plant growth, particularly in terms of reduced main stem length and the severity of root damage. From the inoculation level of 100 juveniles per 100 g soil and above, growth and physiological indicators began to decline significantly compared to control after 150 days of infection. The proportion of galled roots increased markedly, reaching 88,67% at the inoculation of 500 juveniles per 100 g of soil. The study determined that the damage threshold of Meloidogyne spp. for the Vinh Linh pepper variety under net house conditions is from 150 juveniles per 100 g of soil and above. From the density of 100 juveniles per 100 g of soil, it is determined as the warning threshold of nematodes for plants. These findings provide a critical basis for evaluating resistance, screening breeding materials, and developing effective nematode management strategies for black pepper production.