Grafting in Coffea canephora: a strategy to enhance growth and photosynthetic rates for environments with contrasting water availabilities

Water deficit is one of the main limiting factors for the yield in most regions where Coffea canephora is cultivated. This problem has been amplified by the climate changes in recent years. The objective of this work was to study the response of grafting combinations between genotypes of C. canephora, cultivated in contrasting conditions of water availability, and their effects over the initial growth and photosynthetic rates of the plants. For this end, grafted plants with four combinations of genotypes (201/14, 201/RT, 02/14 and 02/RT) were submitted to two contrasting conditions of water supply (80% and 25% of available water in the soil). The initial growth, dry matter accumulation, and leaf gas exchanges were evaluated. Under abundant water supply, the grafting combination 02/RT achieved higher initial growth, whereas 02/14 maintained higher growth under conditions of water deficit. Under adequate water supply, the combinations 201/14 and 201/RT stand out regarding water use parameters, while in conditions of water deficit, the combination 201/14 was capable of keeping higher efficiencies.