RELATIVE HUMIDITY AND PHOTOSYNTHETICALLY ACTIVE RADIATION INFLUENCE THE Vanilla planifolia FRUIT YIELD

Abstract

Background: Fruit yield in vanilla cultivation depends on climatic and genetic factors and management practices; however, studies on the influence of the environment on management systems for vanilla production are still limited. Objective: To evaluate the yield of vanilla fruit in three different management systems in correlation with their climate parameters. Methodology: 16 fruit yield components were evaluated in at least 10 repetitions; in addition, temperature, relative humidity, photosynthetically active radiation, and accumulated precipitation were recorded during the production cycle. The analysis of variance, Tukey´s test (α=0.05), and canonical correlation between yield components and climate parameters were performed under a randomized complete block design. Results: Vanilla fruit yield was influenced by the management system. The intensive system in shade mesh with an inert tutor (Barriles) had the highest yield of three evaluated sites, however, its fruits had lower weight and size than the system in acahual (20 Soles) and shade mesh with a living tutor (Solteros de Juan Rosas). The acahual system had a middle yield and the largest and heaviest fruits. The cultivation in shade mesh with living tutors in Solteros had low yield, attributable to high relative humidity and low photosynthetically active radiation during the cultivation cycle due to excessive shading of living tutors that as a whole could cause low floral induction and environmental stress promoting the development of diseases and premature fruit drop. Nevertheless, the fruits harvested in Solteros had physical characteristics similar to those of acahual (20 Soles). The effect of climate parameters was mainly reflected in inflorescences and fruit density. Implications: The incorporation of more study sites and cultivation cycles are necessary to extend the research, however, the information provided may be useful for producers to modify some of their management practices. Conclusions: The yield and size of vanilla fruits is influenced by the management system, since the highest yield occurred in the intensive system of shade mesh with inert tutors. The presence of diseases is a factor that could influence low fruit yield. Relative humidity and photosynthetically active radiation are the climate parameters with the greatest influence on fruit yield, particularly on fruits and inflorescences density in vanilla cultivation.