Phosphonate fertilizers suppressed root knot nematodes Meloidogyne javanica and M. incognita.
The efficacy 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 hatching inhibition effects persisted after transferring the egg masses 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 glasshouse study indicated that Magphos(®), Calphos(®) and Phosphoros(®) reduced root galling caused by M. javanica by 98, 66 and 47%, 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.
Department of Plant Protection, Faculty of Agriculture, University of Jordan, Jordan, Amman, Queen Rania Street.
Samer
S
Habash
Luma
L
Al-Banna