Qualities of Soybean Grains Harvested on Crops Treated with Neem Seeds Extract in Field Conditions against Asian Rust

Abstract

In soybean production, qualities of grains harvested are usually affected according to the development of diseases and control methods used in the field. This study aims to evaluate the impact of neem seeds extract (AENS) on soybean grains health after crops treatment in field conditions for the control against Asian rust. Experiment was conducted in Mimetala and Nkometou, located in the agroecological zone V of Cameroun. Three varieties of soybean (“Locale”, TGX 1835-10E and TGX1910-14E) were used in a completely randomized blocks design containing five treatments: T0 (control), T1, T2, T3 (25, 50, 100 g/L of extract respectively) and T4 (5.33 g/L of Plantineb 80wp). The disease was identified on the harvested grains; its incidence on those grains was evaluated and some biochemical parameters were assessed by extraction and determination of their contents. Many grains were attacked by Asian rust. The highest incidence was obtained in the seeds from untreated plots (35 %), compared to those from T1, T2, T3 (1.14; 1.07 and 0.95 % respectively). The different doses of AENS improved the content of all biochemical compounds tested in harvested grains compared with the T0 and T4 treatments. TGX1910-14E variety presented the highest content. In T3,grain contents in biochemical compounds were 415.17; 118.83; 118.33; 44.43; 36.53 and 10.83 mg/g of dry matter from total proteins, globulin, albumin, Glutelin, prolamin and glucide respectively. Meanwhile, in T4 treatments, grain contents were 403.49; 112.95; 112.78; 40.58; 33.90 and 9.91 mg/g of dry matter from the same compounds respectively. This study shows that the application of neem seeds extract on soybean crops for the control of Asian rust in field conditions at the maximum dose (e.g. 100 g/L) can improve the qualities of harvested grains. The neem extract as a natural substance should be used in integrated pest management of soybean and other crops.