PHYSIOLOGICAL AND NUTRITIONAL RESPONSES OF NAVEL ORANGE TREES TO DIFFERENT IRRIGATION AND FERTIGATION PRACTICES
A trial was established in drip irrigated Atwood Navel orange trees growing in Australia to compare daily irrigation with conventional practices. Trees were subjected to five treatments of combined irrigation and fertigation: conventional irrigation + conventional fertigation; pulses irrigation + conventional fertigation; conventional irrigation + advanced fertigation; daily pulse irrigation + advanced fertigation and continuous irrigation + advanced fertigation. The water relations responses of trees during the summer-autumn period and the nutritional status after three years of application of the treatments were studied. Trees were well irrigated in all treatments, even during the most water demanding periods, and no clear differences in leaf gas exchange were found within the different irrigation treatments. Conventionally irrigated trees had similar water potential values to daily pulse irrigated trees and the values of both were always above from the threshold for well-irrigated trees. When nutrients were applied in a conventional way, irrigation practices did not modify foliar NPK levels, while with proportional injected nutrition combined with pulse irrigation increased K and P foliar levels. As conventionally irrigated trees received lower amounts of water and had a similar yield to daily pulse irrigated trees, the former had the highest water use efficiency.
Josefa M. Navarro, and Steven G. Falivene, (2015). PHYSIOLOGICAL AND NUTRITIONAL RESPONSES OF NAVEL ORANGE TREES TO DIFFERENT IRRIGATION AND FERTIGATION PRACTICES. Acta Hortic. 1065, 1739-1747
mineral nutrition, photosynthesis, water potential, water use efficiency, yield