Combinações copa - porta-enxerto alternativas para produção de laranja doce na região metropolitana de Manaus-AM

Abstract

Brazilian citrus culture uses a limited number of rootstocks, although the diversity of citrus species and clones is great. The diversification of rootstocks is an alternative to increase productivity and improve fruit quality, while also ensuring the survival of plants against adverse factors. Studies on the performance of citrus rootstocks in the state of Amazonas are scarce. Thus, the objective of this research work was to evaluate the agronomic performance of rootstocks in the conditions of the Metropolitan Region of Manaus. The experiment was installed in February 2013 in the municipality of Rio Preto da Eva, in a 6 x 2.5 m spacing. The orange canopy varieties used were 'Rubi', 'Pera CNPMF D6', 'Valencia Tuxpan' and 'Pineapple', grafted on rootstocks: lemon tree 'Cravo Santa Cruz', tangerine 'Sunki Tropical', citrandarins 'Indio’ and ‘Riverside' and hybrids BRS Bravo, BRS Pompeu, LVK x LCR -038. The experimental design was in entirely randomized blocks, with 28 treatments, three replications and four plants in the plot. Fruit production was in the period from July to September 2019. For the evaluation of fruit quality, the following characteristics were used: weight, diameter, length, juice yield, soluble solids, titratable acidity, ratio, pH and technological index. The results were submitted to variance analysis and the means werw grouped by the Scott-Knott test (P≤0.05). The rootstocks provided higher yields than the others according to the canopy variety. Thus, the lemon tree ‘Cravo Santa Cruz’ induced greater productivity to the ‘Rubi’, ‘Pera CNPMF D6’, ‘Valencia Tuxpan’ and ‘Pineapple’; BRS Bravo with ‘Rubi’, ‘Pera CNPMF D6’ and ‘Valencia Tuxpan’; citrandarins ‘Riverside’ with ‘Rubi’ and ‘Pera CNPMF D6’ and ‘Indio’ with ‘Pera CNPMF D6’. The rootstocks BRS Pompeu and the hybrid LVK x LCR - 038 under the 'Pera CNPMF D6' and 'Valencia Tuxpan' crowns, did not produce fruit, while with the 'Rubi' and 'Pineapple' crowns the yield was lower than all the other combinations. The quality characteristics of the fruit varied according to the canopy - rootstock combination. The survival of the plants in the field was considered good, except for the rootstocks BRS Pompeu and hybrid LVK x LCR - 038 in combination with the 'Pera CNPMF D6' and 'Valencia Tuxpan' canopies.