Season‐specific varietal management as an option to increase rainfed lowland rice production in East African high altitude cropping systems

Abstract

Due to land expansion and an increase in productivity, rice production in sub‐Saharan Africa has been growing at a rate of 6% in the past decade. Rainfed rice production systems have accounted for a large share of this expansion. In these systems, the potential growing period not only depends on the length of the rainy season and thus water availability, but is often, especially in the highlands of East Africa, bordered by the onset of the cool period of the year, when low minimum temperatures compromise rice yields. The objective of this study was to investigate the yield potential of 30 rice varieties contrasting in crop duration and cold tolerance in the highlands of East Africa, with its limited length of growing period. A field trial was conducted in the cropping seasons in 2016 and 2017 at the Fogera rice research station, Ethiopia. As a function of the onset of rains, rice was sown mid‐July in 2016 and early July in 2017. Early sowing in 2017 led to an extended crop duration and significantly lower yields of the short‐duration varieties, and to a shortened duration and significantly higher yields of the medium‐ and long‐duration varieties, when compared to late sowing in 2016. Late sowing compromised yield of the medium‐ and long‐duration varieties because of low temperatures during booting stage, which led to high spikelet sterility. Early sowing resulted in low yields of the short‐duration varieties, probably due to low solar radiation during the cloudy rainy season, which coincided with the vegetative stage. Therefore, choice of variety should be a function of the variable onset of the rainy season and related sowing date. However, crop models precisely calibrated for potential varieties and the respective environmental conditions could fully support the selection of a suitable variety, depending on the date of sowing, for example with the help of online tools or smartphone applications.

Low‐temperature stress during the flowering period alters the source–sink relationship and grain quality in field‐grown late‐season rice

“…Nevertheless, direct evidence is still lacking. Addressing this evidence gap is also important for rice production in the temperate and high‐altitude areas in the tropics, where low temperature stress is a major factor affecting the growth and development of rice (Abera et al., 2020; Razafindrazaka et al., 2020; Wainaina et al., 2015).…”

Farm yard manure application mitigates aluminium toxicity and phosphorus deficiency for different upland rice genotypes

“…Hence, when both FYM and mineral P are combined, yields are closer to their potential, with fewer environmental limitations contributing to the genotypic variation (i.e. cold tolerance) (Abera et al., 2020; Raboin et al., 2014). Under combined TSP and FYM amendments, the genotypes Chomrong Dhan and FOFIFA 172 generally outperformed other tested genotypes in terms of yields.…”

Creating the data basis to adapt agricultural decision support tools to new environments, land management and climate change—A case study of the RiceAdvice App

“…More detailed information on crop and site‐specific management and data collection is provided in Abera et al. (2020), Boschuwenda et al (2020) and Razafindrazaka et al. (2020).…”

“…Details of the individual studies are available from Abera et al. (2020), Boschuwenda et al (2020) and Razafindrazaka et al (2020). Here, we focus on the links these studies provide for assessing the influence of temperature dynamics and genotypic performance on resource use, development and productivity of lowland rice grown in high altitudes and discuss the next steps required to adapt the West Africa‐calibrated RiceAdvice tool to East African conditions.…”