Evaluation and selection of citrus scion and rootstock varieties in the presence of huanglongbing

• Grant number: 23/11955-3
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2023
• End date: November 30, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Eduardo Augusto Girardi
• Grantee: Eduardo Augusto Girardi
• Host Institution: Estação Experimental do Agronegócio de Bebedouro (EEAB). Bebedouro , SP, Brazil
• Associated researchers: Alécio Souza Moreira ; Eduardo Augusto Girardi ; Marcelo Eiras
• Associated scholarship(s): 25/01667-6 - Assessment of horticultural performance of scion and rootstock varieties in the Brazilian citrus belt, BP.TT; 24/16452-2 - Assessment of horticultural performance of scion and rootstock varieties in the Brazilian citrus belt, BP.TT; 24/04103-3 - Assessment of horticultural performance of scion and rootstock varieties in the Brazilian citrus belt., BP.TT

Abstract

The citrus industry in the State of São Paulo (SP), Brazil, is responsible for the largest production of sweet orange, its processed juice, and other co-products in the world. SP is also the largest Brazilian producer of citrus for the fresh market, with a significant socioeconomic importance. Only four sweet orange cultivars correspond to 83% of production. For tangerines, two varieties account for 86% of the crops and, in the case of acid limes/lemons, 89% refer to Tahiti. For rootstocks, three varieties are used in 91% of the nursery trees currently. Selecting and recommending new citrus scion/rootstock combinations is challenging and complex, as there are several attributes of interest: induction of high production of high quality fruits for fresh market or processing as pasteurized juice; more regular distribution of production throughout the season, notably for earlier varieties; reduction of the canopy size that facilitates cultural practices and harvesting; high tolerance to drought/high temperatures in critical periods of the phenological cycle, given the climatic changes and restricted availability for irrigation; greater resistance to various pests and diseases; and adaptation to climate and soil conditions of each region. Particularly, the evaluation of citrus scion and rootstock varieties must consider their performance under the pressure of huanglongbing (HLB) disease, which became prevalent in the citrus belt affecting both the tree healthy and the production system. A project is proposed to evaluate the performance of scion/rootstock combinations in 34 experiments across 10 locations in the citrus belt. New scion and hybrid rootstock varieties pre-selected by EEAB-FUPAB, Embrapa and Instituto Agronômico will be selected, according to their technological maturity with comparative advantages to commercial standards in the presence of HLB. Their adoption by citrus growers will enrich the citrus varietal framework, aiming at the sustainability of the industry. (AU)