Production of the yellow passion fruit and the mechanical resistance of the soil with biofertilizer under irrigation with saline water

Abstract

The study aimed to evaluate the effects of irrigation water with increasing salinity levels and the application frequency of bio-fertilizer on the production of yellow passion fruit and soil resistance to penetration (RSP). The experiment was conducted in the municipality of Remígio (PB), Brazil, with treatments distributed in a 5 x 4 factorial design corresponding to levels of electrical conductivity (EC) of the irrigation water of 0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1 and to four frequencies of the application of bovine bio-fertilizer: no biofertilizer (WB); with the application of bovine bio-fertilizer one week before transplanting (1 WBT); with an application every 90 days after transplanting (90 DAT); and bovine bio-fertilizer applied one week before and every 90 days after transplanting (1 WBT + 90 DAT). The increase of the EC of the water compromised the productive capacity of the passion fruit in terms of fruit number and yield per plant. The largest losses were recorded in plants irrigated with water with an EC equal to or greater than 2.5 dS m-1. The highest frequency of organic raw material application promoted an increase in production per plant. The values of the RSP to a depth of 40 cm, although increasing with the depth profile, were below 2000 kPa which does not impair root growth or the productivity of passion fruit. The application of saline water increased mechanical resistance, with lower values in soils where organic raw material was used (1 WBT + 90 DAT).