Phosphonate fertilizers suppressed root knot nematodes Meloidogyne javanica and M. incognita

摘要

The ef?cacy of the phosphonate fertilizers, Calphos (a.i.calcium phosphonate), Magphos (a.i.magnesium phosphonate and potassium phosphonate) and Phosphoros (a.i.potassium phosphonate) against two species of root knot nematodes (RKN), Meloidogyne javanica and M.incognita is evaluated.Laboratory experiments showed that Calphos, Magphos and their main components inhibited egg hatching and caused 100% mortality of the second stage juveniles (J2s) of the two RKN species; the hatchinginhibitioneffects persisted after transferring the eggmasses of both species to water.However, Phosphoros (0.5%) did not suppress egg hatching or the survival of J2s of both RKN species.No hatching occurred when egg masses were treated for one week with the nematicide Vydate L (2 ml/l), however, J2s hatched when the Vydate L treated egg masses were moved to water.The glasshousestudyindicatedthatMagphos,Calphos andPhosphoros reducedrootgallingcausedbyM.javanicaby98,66and47%, respectively, in comparison to the untreated controls.Magphos resulted in the lowest number of root galls formed by M.incognita, the reduction was 84%.In contrast, Calphos and Phosphoros reduced galling by 47 and 39%, respectively.The Magphos treatment resulted in the lowest numbers of egg masses and the lowest reproductive factor (RF) of both nematode species.However, plants treated with Phosphoros resulted in higher foliage weights compared with the application of the other two fertilizers and the untreated plants.