Author Archives: Charity Gichobi

A Study of the African White Rice Stem Borer at Mwea Irrigation Scheme in Central Kenya.

The African white rice stem borer (Maliarpha separatella Ragonot) is a major pest of rice in Kenya. To understand and develop appropriate management packages, its population dynamics were studied at Mwea irrigation scheme in Central Kenya. This was for two wet and two dry periods. Farmer fields located in different parts of the scheme and outside the scheme were sampled every fortnight. Farms sampled represented five water provision schedules (System of Rice intensification (SRI), rain fed, flood irrigated, sporadic irrigation, and fallow period). Five planting regimes (on season, off season double cropping, ratoon, and late planting) and three management styles (controlled by National Irrigation Board (N.I.B), not controlled by N.I.B and out-growers) were studied. During each sampling, a 1mx1m quadrant was used randomly and pest counted on all the plants within the quadrant. Results showed that the number of M. separatella varied significantly (p<0.05) in the scheme. Pest densities were highest in off season planted rice (13.1). High numbers were also found in Non N.I.B controlled fields with sporadic irrigation (8.1) and the lowest in the N.I.B, fallow (2.5) and this was significant (p<0.05). There were no significant differences in pest infestations on the normal season crop (0.3) and the ratoon crop (0.6) p<0.05 and SRI and conventional irrigated fields (p<0.05). From the results it is recommended that off season planting of rice be discouraged and that efforts are made to ensure that farmers synchronize planting dates and other cultural practices for the crop, within the scheme and in rice farms outside the scheme.

V. M., Kega, M, Kasina, J. H., Nderitu, F, Olubayo. .A Study of the African White Rice Stem Borer (Maliarpha separatella Rag.) Population Density Fluctuations

Agronomie Africaine article Correlates Farming Practices and Yield

According to a 2017 article by Bagayoko et al in Agronomie Africaine, an exploratory study was conducted from 2008 to 2011 in the Office du Niger to determine the feasibility of the System of Rice Intensification (SRI) cultural practice. The experiments consisted of 3 treatments: farmer practice (T1) ; SRI (T2) with 5 tons of manure and the recommended rate of mineral fertilizer and SRI with 5 tons of manure and half of the recommended dose of mineral fertilizer (T3). A total of 40 farmers were involved in the three year evaluation, in which large spatial and temporal variabilities were observed. Yields varied between 4.5 and 10 t /ha and more for SRI and between 3 and 8t t / ha for the conventional practice. There was a significant correlation between farming practices and yields, and between yields and soil factors (especially N and P). More than 60% of the variations in performance were due to the control of cultural practices and water management in both systems (conventional method and SRI). Because of large spatial variability of yields, it was concluded that the SRI can lead to low yields if proper cultural practices are not followed.

Government Promotes SRI in the District de Marovoay

Rice self-sufficiency in 2020 is one of the objectives of the Fisandratana Plan of the President of the Republic of Madagascar HE Mr. Hery Rajaonarimampianina. Conditions for improving rice yield and achieving this goal is the adoption and practice of modern rice crop cultivation techniques and the use of improved seeds. The Regional Directorate of Agriculture and Livestock (DRAE) Boeny has undertaken for this campaign 2017/2018 promotion of SRI in the District of Marovoay. A SRI demonstration site, with an area of 15 ares, has been set up in the rural district of Ankazomborona District Marovoay. Transplanting on April 19 and harvesting followed on August 6. The yield is estimated at 5 tons/ha.