Cabbage genotypes for internal tipburn resistance: a calcium related non-pathogenic disease under rain shelter in Kerala

Cabbage (Brassica oleracea L. var. capitata) is more susceptible to internal tipburn a calcium related physiological disorder, especially under protected conditions. Being a genotype specific disorder, the present experiment was carried out inside rainshelter with seven cabbage F1 hybrids and three levels of calcium foliar applications (0%, 0.5% and 1.5%). The interaction effects of calcium treatments were also observed. There was a significant difference among the genotypes with respect to number of wrapping leaves, non-wrapping leaves, stalk length, gross head weight, net head weight, head breadth and yield per plot. Different levels of Ca foliar application and interaction effect also exhibited non-significant difference. However calcium foliar application can minimize the internal tipburn incidence. All the genotypes were resistant to internal tipburn except the F1 hybrid NS 43(G1).Internal tipburn symptoms were noticed only in the plots sprayed with 1.5% CaNO3 while control treatments and plots with 0.5% CaNO3 foliar spray did not exhibited tipburn symptoms.