Managing the number of orthotropic stems in Coffea arabica as strategy for cultivation at low-altitude regions

The objective of this study was to better understand the implications of the management of the number of orthotropic stems in Arabica coffee for its cultivation in low-altitude regions (< 500 m), characterizing its effects over the canopy architecture, production and allocation of biomass, photosynthesis and crop yield, as possible strategy for mitigating the stresses of cultivation at low-altitude regions. The experiment was conducted in a region with 124 m of elevation above sea level, studying four treatments with different numbers of orthotropic stems per plant such as one, two, three and four stems. After planting, during the stage of sprout budding, a number of sprouts were established in accordance to the treatments. The experimental design was a randomized block design, with eight repetitions. Parameters of gas exchange, chlorophyll contents, canopy architecture, production and allocation of biomass, and crop yield were evaluated to characterize the plant development. Overall, increasing the number of orthotropic stems per plant promoted leaf density, number of plagiotropic branches per plant, available leaf area per fruit mass, photosynthetic rate, crop yield, proportion of large grains and, possibly, the de-acceleration of the stem aging rate, mainly for the management with four orthotropic stems. It is concluded that the management of the number of orthotropic stems has potential use as a mitigator for the cultivation of Arabica coffee in low-altitude regions, being able to promote higher canopy density and, possibly, enhance microclimate conditions at the canopy level.