Because maize is so sensitive to weeds, weed control is an important factor in maintaining yields. The scarcity of manpower means that chemical weed control is the most commonly used method. The aim of the study was to assess the effectiveness of a post-emergence herbicide on weeds in maize crops. A completely randomised Fischer block design with nested control was used. The design consisted of seven treatments repeated four times. The floristic list, based on the «tour de champ» method, showed that broadleaf weeds predominated (78.36%). According to the European Weed Research Society rating scale, the herbicide based on Amicarbazone 74.667 g/l, Mesotrione 77.333 g/l and Nicosulfuron 40 g/l at doses of 0.75 l/ha and 1 l/ha was the most effective, with no signs of phytotoxicity. Yields were 8580 kg/ha at 0.75 l/ha and 9240 kg/ha at 1 l/ha of the product tested, compared with the reference controls 2,4-D amine salts (1 l/ha) and Nicosulfuron 40 g/l (1 l/ha) respectively, 5940 kg/ha and 5214 kg/ha, and the weed control (4620 kg/ha). Consequently, 0.75 l/ha of the product tested is recommended for post-emergence application to maize.

The misuse of mineral fertilizers is cause of the low production of cotton crops in Côte d’Ivoire. Thus, the adequate application of the mineral manure is necessary to boost the growth and vegetative developement of cotton plants. The present study carried out in Mankono in the Center north of the Côte d’Ivoire falls within this framework. The objective is to determine the optimal method of application of mineral fertilizers. The treatments consisted of different methods of applying mineral fertilizers to the cotton plant: T1 (0 kg/ha of NPKSB and urea), T2 (100 kg/ha of NPKSB and 30 kg/ha of urea respecttively applied at 29 and 57 days after sowing without burial) and T3 (200 kg/ha of NPKSB and 50 kg/ha of urea respecttively applied at 15 and 45 days after sowing with closed pocket). In a Fisher block device dispersed in six repetitions, the height of cotton plants 45 and 60 days after sowing, the number of fruiting branches and flower buds per plant 65 days after sowing weree the parameters measured. The results revealed that the T3 treatment allows to obtain the best parameters of growth and vegetative development of the cotton plant. However between T2 and T3 treatment there was no significant difference for all the variables measured except for the number of fruiting branches per plant. The recommended method of application of mineral manure (T3) will make it possible to compensate for the production deficit in cotton cultivation.