Irrigation and nutrition as criteria for adequate management of Tahiti acid lime trees affected by a physiological disorder in tropical conditions

摘要

In Colombia, Tahiti acid lime production value ranks among the most important fruits in the country. Despite its economic importance, productivity loss in Tolima department orchards has been reported due to a physiological disorder or "phisiopathy", related to water and nutrition stress which causes descending tissue death. This study aimed to assess the response of Tahiti acid lime trees to three irrigation treatments (based on water retention curve) combined with two nutrition doses (based on balance index between soil and leaf nutrient concentration). Variables of photosynthesis, yield, and symptom expression caused by the phisiopathy were monitored during three experimental years. The number of affected order-5 branches was quantified in five trees per treatment on a biweekly frequency. Assessment of physiological behavior of Tahiti acid lime was conducted by monitoring leaf gas exchange. The results of the water retention curve indicated that the soil moisture must be maintained above 15.6 % (at 0.5 bars) and preferably at field capacity (FC), in order to avoid water stress and thus physiological disorder. Results showed that no treatment was highlighted in terms of reducing significantly the number of affected order-5 branches for trees without phisiopathy (WOP, classified as trees with less than 50 % of branches affectation). However, in trees with (WP, trees with more than 50 % of branches affectation), a decrease in affected order-5 branches was observed as a response to T2 (applied irrigation water is between 0.33 - 0.5 bars with 150 % of nutrients), T3 (applied irrigation water is between 0.5 -1.0 bars with 100 % of nutrients), and T6 (applied irrigation water is between 1.0-3.0 bars with 150 % of nutrients) treatments.