Planting Date and Genotype Effect On Morpho-agronomic Traits of Burkina Faso Sweet Grain Sorghum

Sweet grain sorghum is an under-exploited crop mainly grown around dwelling houses. Its production faces harsh environmental conditions. This study aims to assess sowing date effect on morpho-agronomical traits of sweet grain sorghum. Thus, 30 genotypes of sweet grain sorghum were assessed under 2 planting dates (June 26 and July 20) 24 days apart in a Randomized Complete Block Designs with 3 replications using 10 traits. The results showed a significant effect of sowing date on most of the traits, except internode length. All genotypes were sensitive to photoperiod variation by reducing their sowing-flowering cycle from 08 to 20 days, size and yield at the second planting date. Delayed sowing also resulted in a decrease in plant height (66.4 cm), 100 grain weight (8.3%), panicle weight (16.84%) and grain yield per plant (18.93%). The genotypes expressed a differential sensitivity to photoperiod variation with a mean coefficient of 0.59. Finally, a clustered flowering of all genotypes between September 11 and 27 was observed for both sowing dates. These results could be exploited by sweet sorghum breeding programme in the definition of the cropping calendar

Assessment of Genetic Variability of Three Types of Sorghum Cultivated in Burkina Faso Using Morphoagronomic Quantitative Traits and Brix

In Burkina Faso, three types of sorghum are mainly grown. Despite their genetic proximity revealed by molecular markers, the identification of distinctive agro-morphological traits between sweet grain sorghum, sweet sorghum and grain sorghum could contribute to better management of their genetic resources. Thus, 42 genotypes consisting of the three sorghum types were evaluated in a three replicate Fisher incomplete block design using 20 quantitative traits. The results showed a high variability of traits within each sorghum type and a greater closeness between sweet grain sorghum and sweet stalk sorghum. In addition, nine traits clearly discriminated sweet grain sorghum from the other sorghum types. Sweet grain sorghum expressed the highest values of the sowing-heading cycle, leaf sheath length, stem diameter, productive tillers, and panicle width and the lowest values of mean heading-flowering difference, 100-grain weight, and Brix. Moreover, the ‘sorghum type’ factor is less preponderant than the ‘genotype factor’ in expressing the variability of all traits. Therefore, the 42 genotypes are organized into three genetic groups independently of the sorghum- type factor, where the group I contains all sweet grain sorghum genotypes and three sweet stalk sorghum genotypes. These results could be exploited in sorghum breeding programs