Inoculation of symbiotic N2-fixing rhizobacteria (rhizobia) in legumes is an alternative to reduce synthetic N fertiliser input to crops. Even though common bean benefits from the biological N2 fixation carried out by native rhizobia isolates, the low efficiency of this process highlights the importance of screening new strains for plant inoculation. Two rhizobial strains (SEMIA 4108 and SEMIA 4107) previously showed great potential to improve the growth of common beans under greenhouse conditions. Thus, this study evaluated the growth and grain yield of common bean plants inoculated with those strains in field experiments. The rhizobial identification was performed by 16S rRNA sequencing and the phylogeny showed that SEMIA 4108 and SEMIA 4107 are closely related to Rhizobium phaseoli, within a clade containing other 18 Rhizobium spp. type strains. Common bean plants inoculated with SEMIA 4107 showed similar productivity to N-fertilised (N+) plants in the first experiment (2016/17) and higher productivity in the second experiment (2018/19). The development of inoculated plants was different from that observed for N+. Nonetheless, comparing inoculated treatments with N-fertilised control, no yield or productivity losses at the end of the growing process were detected. Our results showed that inoculation of the rhizobial isolates SEMIA 4108 and SEMIA 4107 improved the growth and grain yield of common bean plants. The observed agronomical performance confirms that both strains were effective and can sustain common bean growth without nitrogen fertilisation under the edaphoclimatic conditions of this study.

One ppm molybdenum produced the greatest height, fresh and dry weight per plant; number, fresh and dry weight of leaves; diameter, length, fresh and dry weight of stem; length, fresh and dry weight of roots; yield and yield-attributing characters (height, diameter, fresh and dry weight of curd), and N content of component parts of cauliflower plants (curd, leaf, stem and root). The lowest values for these characters were obtained in the control (nil Mo). Reducing and non-reducing sugars and vitamin C (ascorbic acid) were favourably enhanced (0·5 ppm Mo). The lowest values for sugars and ascorbic acid were observed under 1·0 ppm and nil Mo respectively. The quadratic response curve was drawn in terms of fresh weight of curd and rates of molybdenum application.

Four depth of tillage treatments were given by ploughing to 7 cm. depth by bullock-drawn plough and 14, 21 and 28 cm. depth with a tractor-drawn mouldboard plough in 1962–63. A significant decrease in bulk density was observed with the 21 and 28 cm. ploughing, negatively correlated with dry matter of crop roots and yield of grain. The effectiveness of 28 cm. tillage in reducing the population and dry matter of weeds was significant when compared to tillage at 7 and 14 cm. and there were significant relations between dry matter of weeds and yield of grain. Crop roots under tractor tillage were significantly greater than with 7 cm. tillage. Grain yield was maximum under 28 cm. tillage followed by 21, 14 and 7 cm. deep tillage in that order. The higher grain yields were associated with a greater number of fertile tillers per metre of row and higher yields per tiller.

On-farm experiments were used for assessing the processing and food value of four promising sorghum cultivars and the willingness of farmers to pay for the herbicide 2,4-D for controlling the parasitic weed Striga hermonlhica in coarse grains. The active participation of farmers in these experiments was useful in determining the conditions under which the improved sorghum cultivars and the herbicide would be most likely to he adopted by smallholder farmers in southern Mali.

A procedure is described in which variation in the attenuation of β-radiation by water held in nylon pads is used to show changes in the water content of soil. The method enables sequential measurements to be made in narrow zones of soil under field conditions; the results are not influenced by the presence of soluble salts.