SINGLE AND CONCOMITANT EFFECT OF SULPHUR DIOXIDE AND MELOIDOGYNE JAVANICA ON PUMPKIN

M. R. Khan, M. H. Khan, K. Singh

Abstract


Intermittent exposures of SO[sub2] and 200 and 300 µg m[sup-]³ caused chlorosis of the leaves of pumpkin whether or not infected with Meloidogyne javanica. At 100 µg SO[sub2] m[sup-]³, a mild chlorosis appeared only in the infected plants. SO[sub2] at 200 or 300 µg m[sup-]³ and root-knot nematode, separately caused significant suppression of plant growth, dry matter production, flowering, fruit setting and chlorophylls. In the combined treatments of SO[sub2] and the nematode, the suppression were relatively greater. The interactive effects of the nematode and SO[sub2] were synergistic at 100 µg m[sup-]³ and antagonistic or addictive (slightly synergistic/antagonistic) at 200 and 300 µg m[sup-]³. Root galling and egg mass production were enhanced by about 11% and 6% at 100 µg m[sup-]³ and declined by 23% and 24% at 300 µg m[sup-]³. The fecundity was 16% lower at 300 µg m[sup-]³, whereas at rest of the concentrations it was more or less equal to the control.

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