UTJECAJ BILJNE PROIZVODNJE I NAČINA SUZBIJANJA KOROVA NA NJIHOVU POJAVU, RAST TE PRINOS KUKURUZA (Zea mays L.) I STOČNOGA GRAŠKA (Vigna unguiculata L.)

The effects of cropping system and weed management practice on weed seedling emergence, weed biomass production and yield of maize and cowpea were examined at Ilorin, in the southern Guinea savanna (9°29\u27 N, 4°35\u27 E and 307 m ASL) of Nigeria. Weed emergence occurred throughout the 3-15 weeks after planting (WAP). Forty-three weed species belonging to 38 genera within 20 families were encountered. Fimbristylis littoralis Gaudet, Tridax procumbens L and Eleusine indica Gaertn were the most prevalent weed species. Cropping system and weed management practice significantly affected weed emergence. Significantly (p≤0.05) lower number of weeds emerged in the intercropped and herbicide treated plots while higher weed densities and weed biomass were recorded in the uncropped and unweeded control plots than in the other plots. While aggregate crop yields were significantly higher in the intercropped than in the sole plots, component crop yields were higher under the sole cropping than in the intercrop. The implication of the results on weed management is discussed.Utjecaj sustava biljne proizvodnje i načina suzbijanja korova na njihov rast, proizvodnju biomase te prinos kukuruza i stočnoga graška ispitivao se u Ilorinu, u savani južne Gvineje (9°29\u27 N, 4°35\u27 E and 307 m nadmorske visine) u Nigeriji. Korov se pojavio 3-15 tjedana nakon sadnje (TNS). Utvrđeno je 43 vrste korova i 38 rodova unutar 20 porodica. Fimbristylis littoralis Gaudet, Tridax procumbens L i Eleusine indica Gaertn bile su najzastupljenije vrste korova. Sustav biljne proizvodnje i način suzbijanja korova značajno su utjecali na njegovu pojavu. Značajno manji broj korova (p≤0.05) zabilježen je u međuusjevima i parcelama tretiranim herbicidima, dok su veća gustoća i biomasa korova zabilježeni u neobradivim i zakorovljenim kontrolnim parcelama u odnosu na druge parcele. Ukupni prinosi usjeva bili su značajno viši na površinama s međuusjevom u odnosu na one bez, a komponente prinosa usjeva bile su veće kod sjetve bez međuusjeva u odnosu na one s međuusjevom. U radu se raspravlja o mogućim primjenama rezultata ispitivanja na suzbijanje korova

Phosphorus And Nitrogen Fertilization Of Soybean In The Nigerian Savanna

Soybean (Glycine max) is a major cash crop in the savannas of Nigeria although productivity is typically constrained by poor soil fertility. The objective of this research was to determine the interactive effect of N and P on soybean productivity in the northern Guinea and Sudan savannas of northeast Nigeria. Experiments were conducted using locally adapted early and late maturing cultivars. Two rates of N and three rates of P fertilizer were also compared at both sites over two years. At both sites, pods plant−1 and seed yield were higher in 2006 than in 2007, possibly due to better rainfall distribution in 2006. Nitrogen fertilizer had no significant effect on seed yield or pods plant−1. Application of P fertilizer increased pods plant−1 by 40–66%. Averaged across site and year, seed yield with no P was 1057.2 kg ha−1 while yield with 20 and 40 kg ha−1 P were 1941.0 kg ha−1 and 2371.5 kg ha−1, respectively. No significant interaction effect between N and P fertilizer on seed yield and pods plant−1 was observed. The late maturing cultivar yielded less than the earlier maturity group cultivar in 2007 likely due to moisture stress. For optimum seed yield 40 kg of P fertilizer ha−1 is recommended for soybean production in both locations. Our results suggest that N fertilizer is not critical for soybean production in this area

Electronic support tools for identification and management of rice weeds in Africa for better-informed agricultural change agents

International audienceWe developed an interactive electronic weed identification tool, AFROweeds, and an online network, Weedsbook, for agricultural change agents to aid communication and offer assistance to rice farmers with specific weed problems. We collected quantitative and qualitative data to assess effectiveness and usefulness of these products with potential users. With the online version of AFROweeds, used on an electronic tablet, average weed identification time in the field was 7 min 6 s with 44% successful identifications. Poor mobile network coverage and slow internet were the main reasons for the relative long identification time and low success rate. A second trial was done with the offline version, pre-installed on a tablet. The average identification time was 6 min 34 s, with a success rate of 75%. The online network Weedsbook, established alongside AFROweeds, was assessed by the test users as a useful additional aid, enabling agricultural change agents and agronomists to exchange information or request assistance on all aspects of weeds and weed management. The potential improvements of both products are discussed

INFLUENCE OF CROPPING SYSTEM AND WEED MANAGEMENT PRACTICE ON EMERGENCE, GROWTH OF WEEDS, YIELD OF MAIZE (Zea mays L.) AND COWPEA (Vigna unguiculata L.)

The effects of cropping system and weed management practice on weed seedling emergence, weed biomass production and yield of maize and cowpea were examined at Ilorin, in the southern Guinea savanna (9°29' N, 4°35' E and 307 m ASL) of Nigeria. Weed emergence occurred throughout the 3-15 weeks after planting (WAP). Forty-three weed species belonging to 38 genera within 20 families were encountered. Fimbristylis littoralis Gaudet, Tridax procumbens L and Eleusine indica Gaertn were the most prevalent weed species. Cropping system and weed management practice significantly affected weed emergence. Significantly (p≤0.05) lower number of weeds emerged in the intercropped and herbicide treated plots while higher weed densities and weed biomass were recorded in the uncropped and unweeded control plots than in the other plots. While aggregate crop yields were significantly higher in the intercropped than in the sole plots, component crop yields were higher under the sole cropping than in the intercrop. The implication of the results on weed management is discussed