Cataloguing and identification of promising ashgourd ecotypes in relation to season and maturity

Abstract

An experiment was conducted during 1995-96 in the Department of Olericulture, College of Horticulture, Vellanikkara to catalogue and identify promising ashgourd ecotypes in relation to season and maturity. 1birty ecotypes of ashgourd were studied for their variability. The experiment was laid out in randomised block design with three replications. High heritability along with high genetic gain was observed for the characters primary branches per plant, fruit yield per plant, seeds per fruit and average fruit weight. Yield was positively and significantly correlated with length of main vine, nodes on main vine, primary branches per plant, internodal length, leaves per plant at 30 days after sowing, male flowers per plant, female flowers per plant, per cent of female flowers, average fruit weight, fruits per plant, percent of fruit set, circumference of fruit, length of fruit, seeds per fruit and 100 seed weight. Average fruit weight exhibited the highest positive direct effect on fruit yield per plant. The ecotype BH 21 possessing highest values for characters like length of main vine, number of nodes, number of female flowers, fruit yield per plant and number of seeds per fruit was selected to study the effect of sowing time and periodicity of harvests on yield. This experiment was laid out in split plot design taking months of sowing as main plot treatments and intervals of harvesting as subplot treatments. All biometric characters were significantly influenced by the sowing time. The crop sown in October was superior to other crops with regard to number of

nodes, earliest node at which the first female flower was formed and fruit retained, number of female flowers, per cent of female flowers, number of fruits per plant, number of seeds per fruit and fruit yield per plant. In general the crops sown during August, September and October performed better in yield contributing characters when compared to the crops raised during other months of the year. The plants under the harvest interval of 14 days produced the highest number of female flowers and fruits per plant. Average fruit weight, circumference, fruit shape index, flesh thickness and number of fully developed seeds were highest for fruits harvested at full maturity. Though more number of fruits were obtained from plants' under a harvest interval of 14 days the highest yield in terms of total fruit weight was realised from plants harvested at full maturity. The crop was succumbed to the attack of pests and diseases throughout the year. Fruit fly infestation was severe in April, May and June sown crop. Incidence of pumpkin beetle was severe 111 February, March, April and May sown crop. Mosaic was severe 00 crops sown in November, December, January and February. June and July sown crops exhibited downy mildew disease. The better expression of yield contributing characters and lower incidence of pests and diseases tor the crops sown during August, September and October indicated that these months are most ideal for raising a crop of ashgourd. The crop weather relationship revealed that maximum temperature during first and second weeks after anthesis had a significant positive correlation with' yield at full maturity. Minimum temperature and sunshine hours also have a positive correlation though not significant. A negative correlation exist between relative humidity and yield.