Nematode distribution in roots of banana (Musa AAA cv. Valery) in relation to plant height, distance from the pseudostem and soil depth.

摘要

The horizontal and vertical distribution of plant parasitic root nematodes on banana (Musa AAA cv. Valery) was determined in a sandy clay loam in Costa Rica. Root samples were taken from soil blocks at distances of 0 to 30, 30 to 60, and 60 to 90 cmfrom the pseudostem, from 0 to 120 cm depth at intervals of 15 cm, and from plants of 120, 150, 180 or 210 cm high (non-flowering), plus a set from plants at flower stalk. The horizontal distance from the pseudostem affected the percentage of Radopholussimilis, Pratylenchus spp., and total nematodes (R. similis + Helicotylenchus spp. + Meloidogyne spp. + Pratylenchus spp.). There was a significant effect of soil depth on the density of each genus. An interaction between soil depth and plant height andwith horizontal distance was found for R. similis and total nematodes. For the three horizontal distances from the pseudostem, the percentage of each genus decreased with soil depth. Higher percentages of R. similis and total nematodes were found at 0 to 30 cm horizontal distance from the pseudostem than at greater distances in the upper 30 cm of the soil profile. Therefore, samples for monitoring nematode populations in bananas should be taken within a horizontal distance of 0 to 30 cm from the plantbase and down to 30 cm deep from the soil surface. Additional studies are needed to relate the nematode population density at this sampling point to yield.