Evaluation of scion and rootstock combinations for the sustainability of the citrus industry in the State of São Paulo

Abstract

The citrus industry of São Paulo State is the largest producer of sweet orange and its co-products in the world. The state is still the most significant Brazilian producer of mandarins and acid limes, with citriculture playing an important socioeconomic role. However, this industry is characterized by the low diversification of scion and rootstock cultivars, which results in the limited supply of high-quality fruits throughout the year and the exposure of the activity to various climatic and phytosanitary risks. For oranges, only four cultivars correspond to 75% of the production, whereas for mandarins two varieties account for 89% of the crops and, in the case of acid limes, only two Tahiti clones are cultivated. For rootstocks, three varieties make up more than 90% of the orchards and only one is used in half of the nursery trees. Traits that are currently necessary for the adoption of graft combinations include the induction of high yield of fruits with outstanding quality for both fresh market and NFC juice processing, reduced tree size that facilitates harvesting and other cultural practices, high tolerance to drought or water use efficiency due to the limited irrigation in the state, and good adaptation to cope with several pests and diseases, especially the huanglongbing. Giving this scenario, we propose to evaluate the performance of a set of 572 scion and citrus rootstock combinations, using especially new citrandarin hybrids, and their reaction to citrus diseases and drought in a set of 14 trials located in two environmental conditions of Sao Paulo State (Northern and Southern regions). Expected results include the recommendation of superior scion and rootstock varieties or with good comparative advantages, aiming at efficiency gains and aggregation of value to contribute to the sustainability of the citrus industry in São Paulo. (AU)