Abstract:
Pots experiment was conducted, during the summer season 2018, at the College of Agricultural Studies (CAS), Shambat, Sudan University of Science and Technology (SUST), Bahri Locality, Khartoum State. The experiment was carried out to determine the effects of the Hargel (Solenostemma argel), Jatropha (Jatropha curcas) aqueous extracts, each applied alone or in their combinations with Nitrogen 40 Ib/fed and the effect of Nitrogen applied alone on S. hermonthica incidence and growth and yield of Sorghum (cv.Asareca-w2). Treatments were arranged in a randomized complete block design (RCBD) with three replicates. The results of the experiment showed that, Striga emergence increased with increasing number of weeks from crop sowing. At 6, 10, 14 weeks after sowing (WAS), all the botanical aqueous extracts each applied alone or in their combinations with Nitrogen and Nitrogen applied alone significantly reduced Striga emergence by 29.1-100%. At 7 WAS, all the botanical aqueous extracts each applied alone or in their combinations with Nitrogen and Nitrogen alone significantly reduced Striga shoot fresh weight (g) and shoot dry weight (g) by 42.1-91.9% and 31.8% - 96.6% respectively .At 7 and 14 WAS all treatments increased plant height (cm) by 26.6-113.5. All treatments except (Hargel at 2.5%, 5% and Jatropha at 2.5% and 5%) gave plant height comparable to that obtained by Striga free control treatment. The medium and high concentrations of Hargel aqueous extracts and high concentration of Jatropha aqueous extract significantly increased plant shoot fresh weight (g) by 120.8, 122 and 127.8%, respectively. Hargel and Jatropha aqueous extract in combination with Nitrogen 40 Ib/fed and all levels of Nitrogen significantly increased plant shoot fresh weight by 97.4-170%. Hargel and Jatropha at 10% and their combination with Nitrogen 40 Ib/fed and all levels of Nitrogen significantly increased plant shoot dry weight by 87.5-110%. Hargel aqueous extracts at concentrations 5% and 10% significantly increased grain yield (g)/plant and grain yield (kg)/fed by 122.9%-128.6% and 122.3 - 128.7%, respectively. All concentrations of Jatropha aqueous extracts applied alone significantly increased grain yield (g)/plant and grain yield (kg)/fed by 116.2%-138.1% and 114.1-138.2%, respectively. Hargel applied in combination with Nitrogen 40Ib/fed significantly increased grain yield (g)/plant and grain yield (kg)/fed by 142.9% - 145.7% and 143-219.2%, respectively. However, Jatropha applied in combination with Nitrogen 40Ib/fed significantly increased grain yield (g)/plant and grain yield (kg)/fed by 151.4%-179% and 137.4-178.5% respectively. Nitrogen at all levels significantly increased grain yield (g)/plant and grain yield (kg)/fed by 106.1-133.4% and 106.1-133.1%, respectively. The best treatments among the botanical aqueous extracts, each applied alone or in combination with Nitrogen 40Ib/fed were Hargel and Jatropha aqueous extracts in combination with Nitrogen, concentrations of Hargel and Jatropha at 5% and 10% and Nitrogen doses at 80 and 120 Ib/fed.