Allelopathic Effects of Sphaeranthus suaveolens on Seed Germination and Seedling Growth of Phaseolus vulgaris and Oryza sativa

This research article published by Hindawi, 2021Weeds with allelopathic effect have been reported to cause significant damage in agriculture particularly in smallholder farming systems. ,is study assessed the allelopathic effects of different concentrations of crude extract of a noxious weed Sphaeranthus suaveolens on seed germination and seedling growth of Phaseolus vulgaris and Oryza sativa by examining germination, seedling height, and total chlorophyll content after seven and fourteen days of crude extract treatment, respectively. Results showed that seed germination and seedling growth were significantly (p < 0.001) decreased with increase in concentration of crude extract, signifying concentration dependency. Highest concentration (100%) of S. suaveolens crude extracts resulted in 90% and 100% inhibition of P. vulgaris and O. sativa seed germination, respectively. Chlorophyll content, fresh weight, and root and shoot length of both P. vulgaris and O. sativa were also significantly (p < 0.001) affected by highest concentration (100%) of S. suaveolens crude extracts. Results from this study suggest that the extract of S. suaveolens contains water-soluble allelochemicals which significantly reduce growth and productivity of P. vulgaris and O. sativa

Farmers’ Knowledge, Perceptions and Practices in Managing Weeds and Insect Pests of Common Bean in Northern Tanzania

Weeds and insect pests are among the serious constraints in common bean production in most rural communities. A survey of 169 smallholder farmers was conducted in two common bean-growing districts in northern Tanzania. The aim was to assess farmers&rsquo; knowledge, perceptions, current management practices and challenges in order to develop sustainable weed and insect pest management strategies. The results revealed that 83% of farmers perceived insect pests as the major constraint in common bean production, while 73% reported weeds as the main drawback. Insect pest management was mainly achieved through the use of synthetic pesticides, however, only 24% of farmers were able to apply, the rest could not afford due to high cost, limited access and lack of knowledge. Only 6.5% of farmers were aware of non-chemical methods and 2.1% did not practice any method in managing insect pests, both in the field and during storage. Moreover, farmers generally relied on experience in managing insect pests and weeds, and about 43% did not see the need to consult extension officers. These findings indicate that there is a need to sensitize and train farmers on the sustainable methods for pest and weed management in common bean farming systems in northern Tanzania