Low temperature stress induced changes in the seedling growth and nutrient content of papaya genotypes

The major problem of subtropical papaya cultivation is its susceptibility to low temperature stress. The present study was conducted to investigate the effect of different low temperature regimes on nutrient content and growth parameters in five papaya genotypes namely, Pusa Nanha, Red Lady, P-7-2, P-7-9, P-7-14 and one wild cold tolerant relative, i.e. genus Vasconcellea cundinamarcensis. It was observed that there was a higher reduction in plant height, stem diameter, leaf fresh and dry weight at all the low temperature regimes. The genotype V. cundinamarcensis had higher (5.42%) leaf potassium (K) content followed by P-7-9 (5.28%). The genotype V. cundinamarcensis also showed the highest mean calcium (Ca) level in both leaf (3.82%) and root (3.92%) tissues. However, genotype P-7-9 had the highest Mg content in both the tissues, i.e. leaf (0.97%) as well as root (0.90%). Low temperature stress, in most of the cases, significantly affected the leaf and root nutrient contents, although the degree of change in nutrient content was genotype specific.