Crossing of Food Beans (Phaseolus Vulgaris L.)

Abstract

The cultivars used in the trial were GLP-11 a so called" Mwezi moja" bean with purple speckled, large sized and oblong seeds, and GLP-707, a so called" Mwitemania" bean with grey-green flecked, small and rounded seeds resembling the pinto bean. Of each cultivar five seeds were sown in each of 24 buckets of 16 1 capacity which had been filled for about three-quarters with a mixture of 5 parts top soil, 2 parts manure and 1 part gravel to which 9 g double superphosphate had been added. The buckets stayed in the open! till flowering started and were then transferred to a shade house with an estimated light reduction of 40 per cent. Three crosses were made per bucket daily for a period of four subsequent days, from 14-17 December 1976. The rubbing method of pollination as described by Buishand (1956) was used thrughout. The notation for the days is D1–D4. Three chemical treatments were compared: C1—A small cut was made in the calyx with a needle, and a mixture of lanoline+ potassium gibberellate+ naphthalene acetarnide in a ratio of 97: 02: 01 was applied to the little cut. C2–A 2 per cult solution of potassium. gibberellate in water was brushed over the stigma immediately after pollination. C3—Control treatment without the use of chemicals. Two treatments affecting the relative humidity around the crossed flower buds and flowers were included in the study: H1—The flowers bud after crossing was wrapped in glass-wool which was kept moist by means of an atomizer (Fig. 1), and H2—Control treatment.