Leaf Nutrient Concentrations and Dry Biomass of Fig Plants as Modified by the Application of NPK: A Preliminary Study

Abstract

Aims: The effect of a complete NPK matrix on leaf nutrient concentrations and dry biomass of ‘Black Mission’ fig plant organs was tested under an intensive culture system and protected environment. Study Design: A randomized complete block design with four blocks was employed. Place and Duration of Study: The experiment was conducted from April to November 2016 at the Campo Experimental La Laguna, located in Matamoros, Coahuila, Mexico. This research station belongs to the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) of Mexico. The experiment was set up under a macro tunnel equipped with a shade mesh with 50% sunlight attenuation. Methodology: Two-year-old fig plants (cv. ‘Black Mission’) previously propagated from stem cuttings were used. There were three application rates each for N (0, 80, and 160 kg ha-1), P (0, 40 and 80 kg ha-1), and K (0, 80, and 160 kg ha-1) arranged in a balanced factorial matrix of 27 treatments. After harvest, leaf samples were collected to determine nutrient concentrations and they were split into roots, shoots, leaves, and fruit Results: The greatest total dry biomass was produced by the interaction of 80 kg ha-1 N and 40 kg ha-1 P and yielded the following leaf nutrient concentrations (mean ± SD): N 2.9 ± 0.3%, P 0.11 ± 0.01%, K 2.1 ± 0.4%, Ca 1.4 ± 0.7%, Mg 0.34 ± 0.03%, Fe 166.4 ± 49.5 mg kg-1, Cu 6.3 ± 1.7 mg kg-1, Mn 83.3 ± 20.9 mg kg-1, and Zn 22. 6 ± 3.8 mg kg-1. Application of 80 kg ha-1 N and 40 kg ha-1 P could be suggested for commercial fig production. Conclusion: Application of 80 kg ha-1 N and 40 kg ha-1 P could be tested under similar commercial production systems; however, the addition of supplemental K deserves further study.