Effect of Seasonal Drought on the Agronomic Performance of Four Banana Genotypes (Musa spp.) in the East African Highlands

Brigitte Uwimana,Sebastien Carpentier,Yasmín Zorrilla-Fontanesi,Rony Swennen,Hassan Mduma,Allan Brown,Jelle Van Wesemael

doi:10.3390/agronomy11010004

Abstract

Banana (Musa spp.), a perennial (sub-)tropical crop, suffers from seasonal droughts, which are typical of rain-fed agriculture. This study aimed at understanding the effect of seasonal drought on early growth, flowering and yield traits in bananas grown in the East African highlands. A field experiment was set up in North Tanzania using four genotypes from different geographical origins and two different ploidy levels. The treatments considered were exclusively rain-fed versus rain supplemented with irrigation. Growth in plant girth and leaf area were promising traits to detect the early effect of water deficit. Seasonal drought slowed down vegetative growth, thus significantly decreasing plant girth, plant height and the number of suckers produced when compared to irrigated plants. It also delayed flowering time and bunch maturity and had a negative effect on yield traits. However, the results depended on the genotype and crop cycle and their interaction with the treatments. “Nakitengwa”, an East African highland banana (EAHB; AAA genome group), which is adapted to the region, showed sensitivity to drought in terms of reduced bunch weight and expected yield, while “Cachaco” (ABB genome group) showed less sensitivity to drought but had a poorer yield than “Nakitengwa”. Our study confirms that seasonal drought has a negative impact on banana production in East Africa, where EAHBs are the most predominant type of bananas grown in the region. We also show that a drought-tolerant cultivar not adapted to the East African highlands had a low performance in terms of yield. We recommend a large-scale screening of diploid bananas to identify drought-tolerant genotypes to be used in the improvement of locally adapted and accepted varieties.

Highlights

The success of agricultural production depends crucially on water availability since over 80% of global cropland is rain-fed [1]
The East African highlands in northern Tanzania experience relatively mild temperatures due to elevated altitude
East African Highland bananas such as the genotype “Nakitengwa” used in this study, are the most suitable for cultivation because they are already adapted to the region

Summary

Introduction

The success of agricultural production depends crucially on water availability since over 80% of global cropland is rain-fed [1]. From South East Asia, bananas and plantains have spread through Africa and Latin America and are grown in about 130 countries around the tropical belt [13], where the frequency of seasonal drought is likely to increase considerably due to climate change [6,14]. The major banana production area worldwide falls in marginal zones, where bananas are grown by small-scale farmers with limited ability to install irrigation systems. This is the situation in the East African highlands where bananas undergo seasonal drought, contributing to the poor performance of the crop and causing considerable yield losses [17,18]

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