Outcropping and yield prediction studies in grain amaranths
Outcropping and yield prediction study.. were conducted in four populations of grain amaranth, populations 1008 and 1024 ( hypochondriacs) nd 1034 and 434 (cruentus). The studies were conducted at Kabete Campus ot the University of Nairobi and National Horticultural Research Station, Thika during the lone rains and the short rains of 1988. A two-replicate alternate row .method where dominant red pia.ention parent was planted in the center with the recessive green placentation parent on either side was used. Both intraspecific and inter specific outcrossing rate estimates were determined and utilized to describe the breeding system of erain amaranth species (~ hypochondriacs and cruentus). Quantitative traits, plant height, head length of the mature plant, seed yield per plant, sun dried head weight of the mature plants, days to flowering and days to .maturity were used to determine yield predictors in the four grain amaranths. High intraspecific and interspecific outcrossing rate variations were noted in both the two species with a high ability to outbreeding exhibited by ~ cruentus. Intraspecific outcrossing rate for the two species oscillated around 10 per cent with interspecific outcrossing rate of about 3.87 per cent. There was sufficiently very high locational and seasonal variations for the outcrossing rate estimates. The probable factors contributing to the variations were believed to be locational, seasonal and pollinator density variations, and genetic structural differences alongside genotype x environment interaction. Hultiple regression and multiple correlation analyses showed that plant height and head length were constantly strongly correlated to seed yield per plant. Head weight offered good prediction levels for seed yield for the -Viitour populations. Day. to flowering and days to maturity did insignificantly correlate to leed yield per plant tor .ost ot the analyses hence were not regarded important yield predictor variable in the present study.LSD •of the .eans for the six quantitative traits investigated .howed variation between the .eans of the two seasons tor so.e of the traits and variation between the .earns ot the two locations for the four populations uled in the present study. Outcropping and correlation analyses indicated that breeding system of grain amaranths requires further research tor the establishment of marketing system that would exploit natural pollination for the crop improvement and development.