Evaluation of Papaya Ring Spot Disease Resistant Lines under Western Maharashtra Conditions

The papaya cultivation in the country has recorded a continuous increase; however its productivity is decreasing. This is due to the losses from different diseases caused by fungi, bacteria, phytoplasma and viruses. The most important among them is a papaya ring spot (PRS) disease caused by aphid transmitting papaya ring spot virus (PRSV). In order to develop a PRSV resistant papaya type, an hybridization programme was conducted between cultivated papaya cv Washington (Carica papaya L) and wild type Vasconcellea cauliflora at NARP, Ganeshkhind, Pune. The genotype GKPS-2-7 developed through this breeding programme was found resistant against this disease in very effective manner. This genotype recorded lowest per cent disease index (PDI) as 5.22, 11.74, 20.91, 21.50 22.01, 22.16, 29.73, 40.00, 49.73 and 50.27 at 6^th, 7^th 8^th, 9^th, 10^th, 11^th, 12^th 13^th, 14^th and 15^th month after planting. This genotype also recorded significantly maximum fruit yield (43.05 kg/plant and 76.54 Mt/ha) where as commercial check cultivars viz. Red Lady, Coorg Honey Dew were susceptible to PRSV and recorded 100 per cent PDI at early age i.e. at 5^th months after planting.