Physiological traits as determinant of yield in muskmelon under field conditions

During the explorative trial, basic information on physiological attributes and its relationship with yield attributes were recorded. Based on the observation under explorative trial, the critical observation on the association of physiological attributes as determinant to biological and economic yield of muskmelon was further studied during summer. Seven muskmelon genotypes were tested in field condition to correlate the effect of significant variation of leaf net carbon assimilation rate (leaf NAR), leaf conductivity to water and CO₂, stomatal resistance (SR) and transpiration rate (E) on economical yield and yield attributing parameters. The pooled mean value (n = 63) of leaf net carbon assimilation rate ranged from 11.82 to 18.37 mmol m⁻²s⁻¹ at flowering stage (42 ± 2 days after sowing) at an average photosynthetic active radiation (PAR) of 1500 ± 50 mmol m⁻²s⁻¹. Economic yields across seven genotypes were correlated significantly with leaf NAR (r = 0.87). The economic yield was positively correlated to leaf CO₂ conductivity, transpiration rate and negatively to stomatal resistance in the tested muskmelon varieties. Genetic variability alone and with environmental interaction was directly and positively correlated to yield. Genotypes having high photosynthetic rates were found to have high yield. High leaf net assimilation rate at flowering stage could preliminary predict genotypes expected to give a high economic yield.