Archives of Phytopathology and Plant Protection
Effects of nitrogen fertilisers on the Javanese root-knot nematode
Meloidogyne javanica and its interaction with cucumber
Muwaffaq R. Karajeha* and Farah M. Al-Nasirb
aFaculty of Agriculture, Plant Protection and IPM Department, Karak, Jordan;
bFaculty of Agriculture, Plant Production Department, Mutah University, P.O. Box 7, Karak 61710, Jordan
(Received 10 May 2012; final version received 15 May 2012)
Abstract:
The influence of different nitrogen salts at five electrical conductivity levels (EC 2, 4, 6 and 8 mmhos/cm) on the Javanese root-knot nematode (RKN) (Meloidogyne javanica) and its interaction with cucumber was evaluated under in vitro, growth chamber and greenhouse conditions. Percentages of egg-hatching and second stage juvenile viability of M. javanica were greatly reduced when NH4Cl, (NH4)2SO4 and NH4NO3 were used especially at the higher levels of EC and accompanied with reduction in cucumber root galling. The lower root galling (less than 2.5) was accompanied with NH4Cl, (NH4)2SO4 and (NH4)2HPO4, while KNO3 and NH4NO3 resulted in moderate root galling. In contrast to the nitrogen salts, NaCl caused a reduction in both nematode infection and root growth especially at higher EC levels and this could be due to salinity effect. Diammonium phosphate was superior over the tested salts in increasing plant and root fresh and dry weights and cucumber phosphorus content, while KNO3 was superior in increasing in plant content of potassium.
