Seleção de porta-enxertos para genótipos promissores do programa de melhoramento genético do cajueiro (Anacardium occidentale L.)

Abstract

The cashew tree is a fruit tree of Brazilian origin, cultivated mainly in the Northeast region of the country. The cashew production chain generates thousands of direct and indirect jobs annually, playing an important role, both socially and economically. It can be propagated sexually, using seeds, or asexually. However, for commercial purposes, asexual propagation is recommended, through grafting, using rootstocks obtained from seeds for the production of seedlings. Thus, the objective was to select cashew rootstocks to be used with the recently launched genotypes, as well as the promising ones from the Cashew Genetic Improvement Program. The research was developed in two stages, during the period from July 2024 to February 2025, at the Pacajus Experimental Field (CEP), belonging to Embrapa Agroindústria Tropical, located in the municipality of Pacajus, Ceará, Brazil. For the production of rootstocks, a completely randomized experimental design (DIC) was used, consisting of five dwarf cashew clones (CCP 06; CCP 09; CCP 76; Embrapa 51 and BRS 275), with 20 replicates. For the production of grafted seedlings, the same experimental design was used, in a 5 × 5 factorial scheme, with five dwarf cashew clones as rootstocks (CCP 06; CCP 09; CCP 76; Embrapa 51 and BRS 275) and five clones used as scions (BRS 555; BRS 805; SLC 12/20; Capi 17 and Comum 28), with 10 replicates. In both phases, each experimental unit was formed by one seedling. Plant height (AP), stem diameter (DC), number of leaves (NF), dry matter of leaves (MSF), stem (MSC), roots (MSR) and total (MST) and the Dickson Quality Index (IQD) were evaluated. The rootstock BRS 275 showed the best performance in terms of growth and seedling quality. The clone BRS 275 has greater potential for the production of cashew seedlings with superior quality when grafted onto the genotypes BRS 555; BRS 805; SLC 12/20; Capi 17 and Comum 28.