Combinações da limeira-ácida Tahiti com porta-enxertos, sob estratégias de irrigação com água salinizada.

Abstract

Brazil is the second largest producer of citrus fruits and the largest exporter of concentrated juices, with the Southeast being the most important region in the agribusiness chain. In the Northeast, it plays an important economic and social role, especially in the cultivation of lemons. However, plant productivity rates in this region are lower than those obtained in orchards in the Southeast. The explanation lies in the use of scion/rootstock combinations that are less suited to the soil and climate conditions in most areas of the Northeast, which are usually affected by droughts and long dry spells, coinciding with high temperatures. Another factor to consider is the presence of salts in the water from wells and reservoirs, at levels that impair the growth/development and production of citrus plants. In this context, the objective was to evaluate the growth, production and fruit quality of the 'Tahiti' acid lime tree, grafted onto five rootstocks, in the third year of cultivation, under irrigation management with saline water. To this end, an experiment was carried out in an open environment, using drainage lysimeters with a capacity of 150 L, where the application of four irrigation water managements was studied on the Tahiti acid lime tree grafted onto five rootstocks (Citrandarin 'Indio', Citrandarin 'San Diego', TSKC x CTARG - 019, Limoeiro 'Cravo Santa Cruz' and BRS 'Bravo' [TSKC x (LCR x TR) - 059]). The irrigation treatments were as follows: treatment 1 - irrigation with water of 0.3 dS m-1 during the study period; treatment 2 - irrigation with water of 3.0 dS m-1 during the study period; treatment 3: irrigation at staggered intervals, with water of 0.3 dS m-1 for two months and water of 3.0 dS m-1 for a further two months, consecutively, during the third year of production; and management 4 - irrigation at staggered intervals, with water of 0.3 dS m-1 for four months, followed by irrigation with water of 3.0 dS m-1 for a further four months, successively, in the third year of production. During this period, the scion/rootstock combinations were evaluated for growth, production and quality. Salinity of 3.0 dS m-1 reduces the growth rates of 'Tahiti' acid lime combinations grafted onto the five rootstocks. The highest fruit yields were observed in combinations of 'Tahiti' with the rootstocks Citrandarin 'Indio', 'Cravo Santa Cruz' and BRS 'Bravo', when using water with low salinity (0.3 dS m-1). These same combinations were the most sensitive to irrigation with saline water of 3.0 S m-1. Plant production was higher with alternating irrigation, over periods of two and four months, compared to treatments with continuous irrigation of 3.0 dS m-1, in all scion/scion combinations, except for the combination with Citrandarin 'San Diego'. The chemical quality of 'Tahiti' acid lime fruit is positively affected by the evaluation period.