Variability in Striga hermonthica (Del Benth Populations in Gadarif Area Eastern Sudan

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