Abstract:
Field surveys were conducted during the rainy season 2008 2009 in Gadarif area Eastern Sudan to investigate variability within S hermonthica populations Five locations Galabat Sumsum Gadarif Butana and El Fau were selected at random in S hermonthica endemic area Variability among S hermonthica populations was determined by measuring morphological and floral characters Data on S hermonthica morphology were collected and subjected to descriptive analysis and analysis of variance Means were separated for significance using Duncan s Multiple Range Test at p ? 0 5 Data on floral characters were subjected to descriptive analysis and compared with the taxonomic key The results of the surveys revealed that S hermonthica was pre-dominant on sorghum genotypesin Gadarif area S hermonthica populations showed significant differences in morphological characters However differences in flower shape size and colour were often not significant Average Striga height ranged between 49 7and76 6 cm leaves production ranged between 42 4 and 81 7 number of internodes ranged between 21 3 and 41 4 and density ranged between 17 4 and 33 8 plant m2 Average of capsules per plant ranged between 42 2 and 109 5 seeds per parasite ranged between 29516 5 and 76626 7 and Striga shoot dry weight ranged between 1 01 and 9 02 g The average of ribs per calyx ranged between 5 3 and 5 7 flower cross ranged between 1 8 and 2 cm length of corolla tube ranged between 1 7 and 1 9 cm width of bracts ranged between 2 2 and 2 5 cm and spikes had pink flowers that turn dark at drying The variability in morphological and floral characters revealed by this study could be attributed to a multitude of variables including initial size of Striga seed bank Striga species strains or variants crop genotype management and climatic and edaphic condition including spacing soil fertility and moisture status
