The cultivars of NERICA (New Rice for Africa), which are characterized by early maturity and high yield potential under rainfed conditions, have the potential to increase rice production in Tanzania, where rice cultivation is greatly affected by a short rainy season. Trials were conducted in Zanzibar to examine the yield performances of 14 NERICA cultivars at five locations during the long-rains season (Masika) and at another five locations during the short-rains season (Vuli). The NERICA cultivars produced significantly higher yields than local cultivars at five locations. Yields of 12 NERICA cultivars were associated with rainfall (R 2 = 0.367 to 0.732) such that they yielded well during Masika (109 to 343 g m-2) and poorly during Vuli (11 to 68 g m-2). Spikelet number per panicle and percentage of filled spikelets (% filled spikelets) accounted for 70 to 90% of the yield variation in all cultivars, suggesting that yield was determined mainly during the later part of the growth period. In some cultivars, yield was associated with rainfall during the later part of the growth period but the yield of the remainder was associated with rainfall during the early part. A selected group of farmers, extension workers and researchers evaluated grain quality. Some cultivars scored well, especially NERICA 1. We conclude that NERICAs are generally suitable for production during Masika and that NERICA 1 especially should be promoted due to its high grain quality. However, for double cropping of NERICAs, measures must be implemented for increasing or maintaining the water status of the soil during Vuli.

Rice consumption in Tanzania has greatly increased since the 1960s; it is predicted to continue to increase owing to urbanization and changes in consumer preferences from traditional staples to rice. In this study, we review rice agroecology, its value chain, and price determinants, and the history of and challenges to rice research in Tanzania. Our main findings are as follows: (1) rice cultivation can be classified into three major categories: irrigated lowland, rainfed lowland, and rainfed upland. Irrigated lowland is then subdivided into the permanent river, seasonal water, dam, and groundwater subtypes, while rainfed lowland is subdivided into flood plain (fields near rivers), catchment (fields on gentle slope in catchment basin), narrow valley (fields on flat narrow valley bottoms), and plain grassland (fields on gentle slope in savannah grassland). (2) Various stakeholders are involved in production, storage, milling, wholesale, retail, and trade at local, urban, regional, and national levels, resulting in higher market prices of local rice compared to imported rice. However, consumers still choose local rice consisting of traditional cultivar because of its distinct taste and aroma. (3) Improving yield potential through the introduction of foreign elite lines/cultivars has been a major research target; however, farmers have been rejecting most of the new cultivars due to poor grain quality. (4) An integrated set of agronomic management techniques is effective in increasing the yield of traditional cultivars under irrigated lowland. Technical package effectiveness has yet to be tested in all subtypes of rainfed lowland. We propose a new research framework for rice production in Tanzania that is greatly oriented toward meeting consumer demands. In the framework, both breeding and agronomy should have specific research targets for each agroecosystem. Furthermore, genetic resources of traditional cultivars should be fully explored. This study shows the importance of multidisciplinary approach in improving rice production in Tanzania.

No abstract

The productivity of irrigated rice is low in Tanzania. We hypothesized that this is caused by the absence of a packaged application of basic cultivation techniques. A baseline survey of 31 rice irrigation schemes across the country revealed that a large proportion of fields were cultivated without a technical package. Thus, a package was introduced to each of the 31 schemes through a farmer-to-farmer (FTF) extension approach. First, selected key farmers (KFs) were trained with the basic cultivation techniques at agricultural training institutes. Second, the KFs transferred their knowledge to intermediate farmers (IFs) by working together at a demo-field established in each scheme. Third, the KFs and IFs exhibited the rice performance to other farmers (OFs). The paddy yield across the 31 schemes greatly increased from the pretraining level of 2.4 t ha -1 to 3.6 t ha -1 after the FTF extension. However, the farmer interviews in the four selected schemes suggested that the technical package was not adopted by all farmers owing to the time-consuming nature of the FTF extension. It was inferred from our study that the low productivity of irrigated rice is caused by the absence of basic cultivation techniques in Tanzania. However, the post-training yield remained relatively low compared with high-yields (4.3-8.4 t ha -1 ) recorded in cultivar selection trials and high-performing schemes in the county. This ''yield gap'' could be partly ascribed to the insufficient technical diffusion and the technique-dependent adoption among OFs.

No abstract