Upland Rice Breeding in Uganda: Initiatives and Progress

Abstract

Until recently, there was limited research on breeding upland rice varieties. Moreover, there is an increasing expansion of rice production from traditional irrigated production areas to rain-fed environments in the East African region, where drought problem is a serious challenge. To date, several initiatives aimed at increasing rice production have been made. Of the initiatives, promotion of upland rice production has been the most important in Uganda, but yield penalty due to drought continued to be a major drawback. This article traces progress in the upland rice breeding that started with improvement of late maturing varieties that had nonpreferred cooking qualities. Initially, introduced lines were evaluated and released. These varieties are the 'New Rice for Africa' (NERICA) that had been generated from interspecific crosses involving Oryza glaberrima and Oryza sativa. Several studies to understand the mode of gene action and modified pedigree breeding approaches for drought tolerance were conducted and used to develop new rice varieties. Up to 11 improved upland rice varieties were released and deployed in the country from 2002 to 2011 as a result of this initiative.

Improved Upland Rice: Adaptability, Agronomic and Farmer Acceptability Assessment under Semi-Arid Conditions of South Western Uganda

“…Apart from genotype E22 (yielded 6443 -10,036 Kg/ha un-milled rice during 2017A and B), NamChe 4 and NamChe 5 released in 2013 displayed higher agronomic performance and tolerance to low soil moisture over NERICA 6 and local varieties (SUPERICA 1 and local Var.). The potential yields of NamChe 4 and NamChe 5 at the time of release were 4500 and 5800 Kg/ha [12], but in the current study, the average yield range of these varieties were 4889 -5449 Kg/ha and 9416 -10,547 Kg/ha of unmilled rice in 2017A and 2017B, respectively, in the SWAEZ. Combination of improved variety with fertilizer application plus appropriate agronomic management resulted in higher upland rice performance in the zone, whereby in some sites yield increased by ≥100%.…”

“…The current decline in the lowland rice yield in Uganda, which is partly attributed to prolonged drought, insufficient water availability and low soil fertility, is a threat to food security and income especially in regions that are highly dependent on this commodity. Effort to develop high yielding varieties that are adaptable to the diverse environments and tolerant to drought are on-going in Africa [17], and specifically in Uganda where many improved upland rice varieties have been recently released [12]. The current upland rice average yield of milled rice in Uganda is 1.7 t/ha, but it is projected to rise to 2.9 t/ha with increased use of improved technologies [18].…”

“…Rice blast can cause up to 90% yield loss on susceptible varieties, but germplasm evaluation studies have identified externally introduced genotypes with high to moderate resistance to M. grisea races existing in Uganda that can be used to improve the most preferred varieties with durable blast resistance gene pyramids [6]. Besides NamChe 3, which has been previously reported as a potential source of disease resistance [12], NERICA 10 consistently displayed higher resistance to rice blast. A combination of early maturity with high blast resistance qualifies NERICA 10 as a promising climate change and disease resilient variety, but because of its low yielding, it is best utilized as a source of genes to improve other high yielding and consumer/market preferred rice varieties.…”

“…A study by Haneishi (2014) showed that besides the high input requirement, growing high yielding NERICA upland rice varieties that were found to increase crop income by 40% -60% [11], may be more profitable especially to smallholder farmers than some other upland crops. The high demand and market price in urban areas makes rice a commodity farmers continue to invest in for income generation [2] [12].…”

“…NaCRRI) in Uganda in collaboration with other institutions[12]. Although farmers grow some of these improve upland rice varieties (NERICA and NamChe) plus other mixed local varieties, the agronomic performance of the improved varieties under farmers' conditions in SWAEZ is not well known.…”