Search

Consortium culture can be a relatively cheap and environment-friendly technology for producing secondary metabolites like pesticides (herbicides). This study produced some metabolites from a consortium culture of fungal isolates obtained from the rhizospheres of Panicum maximum, Ipomoea involucrata and Amaranthus viridis. The isolates from rhizospheres of the above-named plants were co-cultured using Czapek broth and were incubated in an incubator shaker for 28 days. The co-culture combinations were: Aspergillus welwitschiae and Trichoderma hamatum (consortium 1), Aspergillus welwitschiae and Aspergillus aculeatus (consortium 2), and Aspergillus aculeatus and Trichoderma hamatum (consortium 3). Crude extracts from each consortium were characterized using Fourier Transform Infrared Spectroscopy (FTIR). The FTIR results showed that consortium 1 had peak spectra range from 418.57 cm−1 (S–S stretch of aryl disulfides) to 3462.34 cm−1 (alcohol, aliphatic primary amine), consortium 2 had peak spectra range from 420.5 cm−1 (halo compound) to 3456.65 cm−1 (alcohol, aliphatic primary amine) and consortium 3 had peak spectra from 457.14 cm−1 (halo compound) to 3448.84 cm−1 (alcohol, aliphatic primary amine). Some of the compounds produced by the consortia were pesticidal in nature and are hence, considered a potential technology in developing organic pesticides. [ABSTRACT FROM AUTHOR]

In spite of okra's importance to food security in developing countries, its production is limited by low soil nutrient and health status. A screenhouse study examined soil chemical properties, okra growth and yield under complementary application of biochar, organic and inorganic fertilizer in an Ultisol. The treatments comprised 5 kg soil each amended with 5 t biochar ha−1, 5 t poultry manure compost (SPM) ha−1, urea at 56 kg N ha−1, urea (28 kg N ha−1) + 5 t biochar ha−1, 5 t ha−1 (2:1, PM: biochar) (SPMB), urea (28 kg N ha−1) + 5 t ha−1 (2:1, PM: biochar) (SPMBF2). The treatments, replicated thrice, were arranged in a completely randomized design. There were two sets of plants terminated at 50% flowering (dry matter yield (DMY) and nutrient uptake) and at 10 wk post-planting for growth and yield determination. Results revealed that soil chemical properties, okra growth and yield increased responsively to the organic amendments. The SPM, followed by SPMB and SPMBF, enhanced soil pH (0.18–0.19 unit), total N (79–100%), organic carbon (75–100%), available P (55–58%) and exchangeable cations over the control and others (p < 0.05). These treatments also increased the plant's agronomic parameters: plant height (10–19%), number of leaves, leave area (21–31%), stem girth (33–51%), DMY (59–67%), and tissue Ca, Mg and K. The SPMBF2 – treated soil had the highest fruit yield (45 g pot−1). Conclusively, sole and complementary applications of biochar and compost improved soil chemical properties, and okra growth and yields. [ABSTRACT FROM AUTHOR]

An acid Alfisol (Typic Paleustalfs) was amended in triplicates at the rate of 5 g kg−1 soil (12 t/ha) with organic amendment (cow dung (CD), corn cob (CC) and 1:1 CD:CC (CDCC), and 20 kg N ha−1 as urea, respectively, and planted to cowpea in the screenhouse. At flowering stage, plant shoots, roots and nodules were harvested. N2 fixed was estimated by N-difference method using maize planted and treated the same way as the cowpea as non-fixer. Considering average data for two planting periods, the increases (p < 0.05) obtained with the application of both organic manure with and without N over the control ranged from 125–775% for number of nodules, 96–296% for N2 fixed, 36–99% for dry matter yield and 160–460% for seed yield. The parameters were higher (p < 0.05) in the organic –inorganic N than in sole manure treatments. The organic amendments increased the pH, organic carbon (OC) and available P contents of the soil at both plantings, with CDCCN and CDCC recording the highest values. Average tissue N and P at the end of the two plantings were similar among all treatments, but average N and P uptakes were higher (p < 0.05) with than without amendments by 26–100% and 238–340%, respectively. Therefore, 5 g kg−1 cow dung:corn cob (1:1) or 5 g kg−1 cow dung in sole application or combined with 20 kg N ha−1 can promote cowpea growth, N2 fixation and yields with resultant positive effects on soil chemical properties. [ABSTRACT FROM AUTHOR]