Impacts of climate variability on the production of Dwarf x Tall and Tall x Tall coconut (Cocos nucifera L.) palm hybrids planted on the coast in Côte d'Ivoire

Abstract

The Ivorian coast is the main coconut production area where agriculture is mainly rainfed. However, in this area, climate variability poses a great threat to the growth and sustainable development of agriculture. This study aimed at highlighting the impacts of climate variability on the production of the most popular Dwarf x Tall and Tall x Tall coconut palm hybrids in the world. It is based on the evaluation of the production of the hybrids from statistical tests (ANOVA, STUDENT's T-test at 5%) and the results of the standardized precipitation and evapotranspiration indices (SPEI) during the period of 2009 to 2018 of the study area. The results obtained revealed that the NJM×GOA+ hybrid was significantly differentiated by its good production potential of bunches (10 bunches), fruits (151 nuts) and copra (3.69 t). The maximum fruit production per year was observed in the Dwarf × Tall hybrids (101 nuts). The highest mass productions of copra per tree and copra per hectare were recorded in the Tall × Tall hybrids. The maximum productions of the ten hybrids were observed in 2012, 2015 and 2018 and the lowest in 2014 and 2017. Productions gradually increase or remain stable for consecutive wet years (2009 to 2011) prior to harvest. The onset of drought in one year (2012, 2013, 2015, 2016) and pronounced for two consecutive dry years (2012 to 2013 and 2015 to 2016) prior to harvest significantly decrease the level of production. These cumulative effects of drought are most pronounced in NRC×GRL+, NRM×GTN, NJM×GD001, NJM×GD002, and NJM×GD003 hybrids. NJM×GOA+, GVT×GTN, GSL×GTN, NRM×GVT, and NVS×GVT hybrids are developing abilities to express themselves better under this climate variability. They could be taken into account in the crop improvement program and proposed to growers to improve the yield of coconut trees under rainfed conditions.