Variation among some mungbean germplasm for late summer planting

Nineteen mungbean genotypes were evaluated under Giza conditions, in three sowing dates (1st , 15th and end of August), in three separate experiments during 2006 and 2007 seasons. The objectives were to explore the performance and stability of mungbean genotypes across kharif sowing environments. The results showed that sowing dates (SD) significantly affected mungbean traits except seed Index (SI) during both seasons moreover, genotypes (G) significantly affected all studied traits during both seasons. The interaction of G x SD was highly significant in both seasons except for 50 flowering date (50 FD) (significant) in 2006 season and SI.(non significant) in 2007 season. The magnitude of variances due to sowing dates were much higher than those of genotypes followed by G x SD interaction for all traits except no. of branches, SI and Protein % (P %) for both seasons and plant height in the second one. Interaction of genotypes with seasons and sowing dates [G x SD x (S)] recorded highly significant mean squares and exhibited lower mean squares than genotypes for all traits. The three sources of variation, viz. Environments (E), Genotypes (G) and G x E were highly significant for all traits except for SI (significant) with (E). The mean squares of environmental effects recorded huge compared to these genotypes for onset of flowering date (OFD), (50 FD), onset podding date (OPD), 90 % podding date (90 PD), pod filling duration (PFD), number of seeds /pod (S/P), seed yield (SY), biological yield (BY) and protein yield (PY). Contradicting higher variances due to genotypes than environments were recorded for the rest traits; plant height (PHT), branches, pods, HI, P % and SI. Seeding mungbean at the beginning of August (SD1) significantly produced taller plants with more branches, pods/plant seeds/pod, SY, BY and HI with shortened flowering and maturity days during both seasons. Medium-sowing date (SD2) during both seasons affected mungbean yield and yield componehts intermediately between both early and late ones. The calculated measurements of stability indicated that variable performance among genotypes and parameters for SY and BY. Overall, the results can be great benefit in the development and recommendation of mungbean genotypes during the late summer in Egypt.