Testing drought-tolerant plant types of upland rice in Ghana using participatory methods. Final Technical Report.
Abstract
Rice is economically very important in Ghana and West Africa. The lack of improved rice varieties, particularly upland varieties, is recognised as a constraint. The purpose of the project was: to analyse rainfall patterns and drought-spells in Ghana; to characterise the photothermal flowering responses of diverse varieties in order to understand adaptation; to understand farmers' indigenous technical knowledge of rice farming and varietal selection; to test and evaluate new droughtand weed-tolerant rice varieties with farmers using participatory techniques and formal replicated yield trials; and to disseminate participatory approaches to crop improvement in Ghana and West Africa. Long-term (30 years) daily rainfall data were analysed for selected locations in each of the forest, transition and moist and dry savanna zones. Rainfall patterns (start, end and duration of the growing season) and drought-spells were calculated. A Crop Performance Index (CPI) was used to examine the effect of toposequence on drought patterns. Photothermal flowering responses of 83 varieties were quantified from sowing date experiments in the field and a controlled environment experiment in the UK. PRA techniques were used to describe indigenous technical knowledge at two locations, Hohoe in the forest zone and Aframso in the transition zone. A Participatory Varietal Selection (PVS) programme with 60-100 varieties was initiated at Hohoe, Aframso and at Nyankpala in the moist savanna. Replicated yield trials with High Input (fertiliser + weeding) and Low Input (low fertiliser + no weeding) treatments were planted at four locations in 1998 and 1999. Rainfall patterns covering the major upland rice zones have been analysed. This analysis has shown that the savanna zone (i.e. Northern, Upper East and West Regions) and forest zone (Volta, Western Region) is favourable for rice production, with a minimum of a 100d growing season even in very shallow upland soils. In contrast, rice production is much riskier in the transition zone (Ashanti, Brong Ahafo Regions) because of the bi-modal rainfall pattern and the consequent break in the rains in August. There was considerable variation in photothermal flowering responses and hence adaptation to different rice ecosystems among varieties. Photothermal characteristics were clearly defined in terms of a basic vegetative phase (BVP) and a photoperiodsensitive phase (PSP). The participatory process has shown that farmers have a considerable knowledge of varieties and their characteristics. Traits which contribute to weed competition and drought-tolerance are important, as are post-harvest traits. A PVS programme was successfully implemented with male and female farmers, traders and consumers. Male and female farmers made many similar varietal choices, the most notable difference being for grain characteristics; women selected grain types suitable for home consumption while men preferred grain types with a high market value. The market prefers long, white grains which are similar to those of imported grains. At Hohoe, almost all farmers selected the same variety, IDSA85, both in the PVS trials and from paired-comparisons on-farm. At Aframso a larger number of varieties was chosen, including interspecifics and improved upland japonicas. At Nyankpala, improved japonicas, interspecifics and local glaberrimas were selected. A Regional Workshop has helped disseminate project findings and promote the participatory approach throughout the West African region
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