Effect of Different Pre - Sowing Seed Treatments on Germination and Growth of Papaya (Carica papaya L.) Seedlings cv. Arka Surya

A study on effect of pre-sowing seed treatments with organics, chemicals and plant growth regulators on seed germination and seedlings growth of papaya cv. Arka Surya was carried out at YSRHU- College of Horticulture, Anantharajupeta during the year 2021 - 2022, under complete randomized design with eighteen treatments and replicated thrice. The papaya seeds were subjected to various organic, chemicals and plant growth regulators treatments. Papaya seeds soaked in KH2PO4 @ 0.5% (T7) had recorded minimum days for initiation of germination (8.67) and 50% germination (10.34). The treated seeds had also recorded maximum germination percentage (86.66), germination index (1.16), dry weight of shoots (2.00 g), tap root length (26.33 cm), number of lateral roots per seedling (22.84), dry weight of roots (0.79 g), quality index of papaya seedlings (0.47) and seedling survivability (100.00%). In addition the same treatment exhibited higher chlorophyll content (3.51 and 3.91 mg/g), photosynthetic rate (15.32 and 17.76 µmol Co2m-2s-1), transpiration rate (4.61 and 5.69 mmol m-2 s-1) and stomatal conductance (2.73 and 4.12 mol m-2 s-1) at 35 and 45 DAS, respectively. While the lowest values for germination and growth parameters were observed in treatment salicylic acid @ 2 mM (T16). Among all the treatments, KH2PO4 @ 0.5% (T7) was found to be superior to the other treatments followed by KNO3 @ 0.5% for the enhancement of germination, growth and physiological traits.