ZINC-BORON INTERACTION EFFECTS IN OILSEED RAPE

The interaction effect of applied zinc (Zn) and boron (B) on early veg etative growth and uptake of Zn and B by two oilseed rape (canola) (Br assica napus L.) genotypes was investigated in a sand culture experime nt under controlled environmental conditions. Two genotypes (Yickadee and Dunkeld) were grown at three Zn levels (0.05, 0.25, and 2.0 mg kg( -1) soil) and two B levels (0.05 mg kg(-1) soil and 0.5 mg kg(-1) soil ). Dunkeld produced significantly higher shoot and root dry matter tha n Yickadee at low Zn and low B supply indicating the superiority of Du nkeld over Yickadee for tolerance to both low Zn and low B supply. Chl orophyll content of fresh leaf tissue was increased significantly by a n increase in Zn and B supply. Zinc deficiency enhanced B concentratio n in younger and older leaves. Boron concentration was higher in older leaves than in the younger leaves irrespective of B deficiency and su fficiency indicating immobility of B in two oilseed rape genotypes tes ted. Zinc concentration was higher in younger leaves than in the older leaves indicating mobility of Zn. An increased supply of Zn enhanced B uptake under high boron supply only. Zinc uptake in Dunkeld was enha nced significantly with an increased rate of B supply under high Zn su pply, while the effect was not significant in Yickadee. Dunkeld proved to be more efficient in Zn and B uptake than Yickadee.