Scheduling Irrigation of Pecans in Louisiana

Abstract

Research to alleviate moisture and nitrogen stress was conducted. An eleven year old pecan orchard near Baton Rouge, Louisiana was trickle irrigated. Fertilizer was injected into the irrigation system on the irrigated trees and applied on the surface by hand on the non-irrigated trees. Soil moisture was monitored with gypsum blocks and daily irrigation amount determined with a Class A evaporation pan. Irrigation was initiated at an estimated 30 percent soil moisture depletion. Nitrogen fertilizer at the rate of 0.9 kg per year tree age was applied to all trees and an addtional 110 g per year tree age was applied as sidedress to half of the trees. The tests were run for three years. Results indicate an interaction between cultivar, irrigation and side-dressing. Therefore, fertilizer injection through the trickle irrigation system may be used to advantage on select cultivars. The removal of either moisture or nitrogen stress makes the other factor important. ‘Sumner,’ ‘Caddo,’ and ‘Candy’ were the top producers, while ‘Cherokee,’ and ‘Tejas’ were the low producers.