MSc.

Papaya (Carica papaya L.) belonging to the family Caricaceae is a popular fruit of tropical world. India is the largest producer of papaya in the world (NHB, 2011). The project entitled “Evaluation of papaya types” was conducted in the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara during 2013 - 2015. The major objective of the study was to assess the variability in papaya and to select the promising types/ varieties suitable for Kerala. The study comprised of two experiments, namely assessment of variability and evaluation of promising types/ varieties.
In experiment I, a preliminary survey was conducted in the homesteads of Thrissur, Palakkad and Ernakulum districts of Kerala. Seventy five plants were tagged in different locations consisting of twenty five plants in each district. Then forty plants were selected from the initial tagged ones based on the different biometric, fruiting and flowering characters. Fruits from these forty plants were collected and subjected to quantitative and qualitative analysis. Further screening was done with special reference to plant height, fruit weight, TSS, sugars and organoleptic characters. Based on the qualitative characters viz. flesh colour, fruit shape, sex expression of plant, time of flowering and petiole colour, forty collections were grouped into nine clusters by using the statistical tool of agglomerative hierarchical clustering.
Finally twenty five accessions were evenly selected from the forty collections of nine clusters for detailed evaluation in the field. Plant height of the selected twenty five accessions ranged from 2.1 to 5.6 m and fruit weight varied from 440.0 to 2105.0 g. Total sugar and TSS of the selected 25 accessions ranged from 6.44 to 12.12 per cent and 9.40 to 14 0Brix respectively.
In experiment II, the selected twenty five accessions along with five released varieties namely Arka Prabath, CO 8, CO 7, CO 2 and Pusa Nanha were subjected to detailed studies in the field. The experiment was laid out in RBD with three replications at spacing of 2 x 2 m.
Among the accessions/ varieties evaluated, Pusa Nanha, Acc. 15 and Acc. 13 were found to have lowest plant height of 1.79, 1.87 and 1.95 m respectively, at 12 months after planting. Highest fruit weight of 1830 g was recorded in Acc. 15 followed by CO 8 (1770 g), and Pusa Nanha (1621.67 g). Highest flesh thickness of 2.98 cm was recorded in Pusa Nanha followed by CO 2 (2.70 cm), Acc. 6 (2.68 cm) and Acc. 11 (2.67 cm).
Accession 25 produced higher number of fruits per plant (35.11) followed by Acc. 1 (32.66), Acc. 5 (32.33), Acc. 6 (30.11) and these three were on par. The highest yield per plant of 31.50 kg was recorded in Acc. 25 followed by Acc. 6 (27.63 kg/ plant), Acc. 1 (26.57 kg/ plant), Acc. 9 (25.77 kg/ plant), Pusa Nanha (25.12 kg/ plant) and these were on par.
Total soluble solids (TSS) of the fruits showed significant variation among treatments. The TSS of Acc. 21, Acc. 11, Acc. 22, Acc. 8, Acc. 3, Acc. 17, Acc. 23, Acc. 18, Acc. 19 and Acc. 6 ranged from 13.13 to 15.17 0Brix and were on par. Highest per cent of reducing sugar was recorded by Acc. 11 (10.49 %) followed by Acc. 14 (10.36 %), Acc. 22 (9.92 %), Acc. 3 (9.92 %) and Acc. 13 (9.90 %). Accession 3 recorded the highest per cent of total sugar (10.89 %), followed by Acc. 11 (10.65 %), Acc. 14 (10.63 %), Acc. 4 (10.51 %) and Acc. 13 (10.40) were on par.
The highest vitamin C was recorded by CO 7 (164.27 mg/ 100 g) followed Acc. 20 (120 mg/ 100 g), Acc. 6 (117.6 mg/ 100 g), Acc. 8 (114.67 mg/100 g) and
Acc. 11 (114.40 mg/ 100 g). Sensory evaluation of fruits indicated that the Acc. 8 scored highest mean rank for sweetness and taste.
Significant variability was observed during the survey and twenty five accessions were selected for detailed study. As a result of field evaluation of 25 accessions and 5 varieties, eight accessions and Pusa Nanha were found to be promising. These included Acc. 1, Acc. 6, Acc. 8, Acc. 11, Acc. 13, Acc. 14, Acc. 15, Acc. 25 and Pusa Nanha. Further evaluation of accessions is necessary to get confirmatory results.