Balanço de água no solo em pomar de laranjeira ‘pêra’ com e sem adensamento de plantio sob diferentes porta-enxertos

Abstract

Bahia's citrus industry, second largest in the country, has some peculiarities as climate and soil conditions. The citrus orchards are deployed mainly along the coast of the state, called the tableland. These regions are characterized by presenting a dry period and another humid, dividing the agricultural year almost by half. Apart from this, these regions soils are represented almost entirely by Latosols and Argissolos Yellow Distrocoesos, which present a cohesive layer that prints high resistance to root penetration and changes the water movement in the soil profile. The density of planting is being studied as a strategy to improve productivity and profitability in the citrus industry. Rootstocks to induce the canopy equivalent or higher production efficiency and which have lower canopy volume may be as or more interesting than those with the greatest canopy and greater production of fruits per plant, indicating that this production can be compensated with increasing plant density per area. Considering that the water factor in the soil the main limitation to citrus in the ecosystem of the Coastal Tablelands and considering the research directed to the evaluation of new hearts interactions / rootstock aimed at densification planting, the study of the water balance in the soil, monitoring all incoming processes and water outlet in the soil-plant-atmosphere system, it becomes a very useful tool in the characterization of water and evaluation processes of canopy interactions/rootstock. Therefore, the study was conducted in Agricultural Sparrowhawk, Municipality of Inhambupe-BA, a block consists of 'Pera' orange grafted on the following rootstocks: TSKC x (CSF x TR)-059, LVK x LCR-038, TSKC x CTSW-041, 'Rangpur lime Santa Cruz', tangerine 'Sunki Tropical', Citrandarin Riverside and Trifoliata Flying Dragon. The results showed that actual evapotranspiration (ET) of the orange crop during the period of a year, ranging from 1.270 mm to 1.306 mm depending on the assessed rootstock, and daily values ranged from 0.95 a 8.63 mm for periods of lesser and greater need for water; the water storage in soil reflected variations in rainfall throughout the monitored period. During the rainy season, average evapotranspiration were higher, showing that the supply of rainfall was great, keeping the soil moist, and therefore with greater availability of water during this period; there was no significant difference of evapotranspiration in different rootstocks, either dense or conventional spacing, indicating that the use of planting density technique and dwarfing rootstocks and semi-dwarfing is advantageous, as it has an increase in planting density and consequent increase in productivity.