Assessment of the most suitable nematode inoculum density and plant growth period to screen coffee genotypes for their reaction to Meloidogyne incognita

Abstract

Summary One of the concerns for nematological research is the absence of information on standard nematode population densities to be used when screening to assess resistance/susceptibility levels of a genotype. In addition, the length of the growth period, especially for perennial crops such as coffee, must also be known. The objective of this work was to evaluate the ideal evaluation periods and population densities of the root-knot nematode, Meloidogyne incognita, for phenotyping Coffea arabica genotypes. Seedlings of coffee ‘Mundo Novo’ with five leaf pairs cropped in 700 cm3 plastic pots were inoculated with population densities of 700, 1400, 2800, 5600 and 11 200 eggs of M. incognita per plant and evaluated at 90, 120, 150 and 180 days after inoculation (DAI) to determine the nematode reproduction factor (RF). The use of population densities of M. incognita from 700-2000 nematodes with evaluations between 90 and 180 DAI was the most suitable to obtain higher RF values and allows earlier and more accurate evaluations, which reduces the time for phenotyping in genetic screening programmes.