Effect of date of sowing on flowering and incidence and damage of melon fruit fly in snap melon var. genotypes Cucumis melo momordica

The Journal of Plant Protection Sciences, (1) : , 2010 2 86-91 This Dipteran insect lays eggs in young ovaries just below the skin, only to hatch into maggots, which feed from within the fruits to cause fruit rotting and reduce fruit yield significantly. The experiment was carried out during 20042005, at the Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya, Gayespur, Nadia; it was set out in factorial RBD to evaluate the performance of eight genotypes (treatments) named as BCSM-1 to BCSM-8, with respect to three sowing dates (S =22 November, 2004, S =22 January, 2005 and S =22 March, 2005) with three replications. Each plot measured 3m x 1.5m and the spacing given was 1m x 1m, accommodating six plants per plot. The crop was raised following standard agronomic practices. Observations at weekly intervals on days to first male flower, days to first female flower, node number of first male flower, node number of first female flower, days to first harvest, total number of fruits per plant , number of fruit-fly infected fruits per plant and percentage of infested fruits were recorded and collected data were subjected to analysis of variance. Data on different parameters were recorded from randomly selected three plants per genotype in each replication. No insecticidal measure was taken. Number of infested fruits was counted and its percentage out of total number of fruits per plant was calculated and analyzed statistically. The data on flowering pattern, fruit fly incidence and damage in different genotypes in three different seasons have been furnished in the Table 1. Days to first male and female flowers ranged from 31.78 to 82.55 and 46.21 to 101.22, respectively, irrespective of sowing dates. The male flower always appeared in advance of female flower in all the seasons and genotypes tested. Appearance of first female flower took longer days (83.78–101.22 days) in the first sowing than in the following two sowings (49.33–79.44 days and 46.21–64.43 days, respectively). The same trend is also noticed in case of the first male flower production. Node number of 1st male flower did not vary significantly in different seasons. However, in case of 1st female flower, it varied significantly having lower values in January sowing (10.43–18.11). In case of days to first harvest, the earliest harvest was recorded in March sowing (76.6–100.9 days) followed by January sowing (81.8–115.1 days). In November sowing, days to first harvest (129.7–151.9 days) were much higher than other two sowings. When total number of fruits per plant is considered, it is found that highest number of fruit was obtained in January sowing (9.46/plant), closely followed by March sowing (8.20/plant) and the least in November sowing (7.01/plant). In all the three sowing dates, BCSM-4 took the least days (S -83.78, S 49.33, S -46.21) for appearance of the first female flower, which were significantly different from those in other genotypes. The appearance of earliest female flower was recorded in third sowing in BCSM4. BCSM-7 took longest days for appearance of the first female flower in all the sowings. In the first sowing, earliest female flower appeared on the node number 11.21 in BCSM-4, which was Materials and Methods