PENGARUH PEMUPUKAN KALIUM TERHADAP TOLERANSI FISIOLOGI TANAMAN JAGUNG KULTIVAR ARJUNA PADA KONDISI CEKAMAN AIR

Abstract

The research was conducted at Experimental Station, Faculty of Agriculture, Jambi University. Factorial experiment with three replications was arranged in a randomized complete block design. First factor was potassium fertilizer, consisted of five levels, namely no potassium fertilizer, 25, 50, 75 and 100kg K2O ha-1. Second factor was level of water stress, i.e. 100, 75, 50 and 25% of available soil water content (ASWC). Results indicated that leaf water potential and carbohydrate content were increased by application of 50 kg K2O ha-1 at water stress levels of 100 and 75% ASWC, whereas those of 50 and 25% ASWC increased those variables by application of 75kg K2O ha-1. Abscisic acid (ABA) increased along with increase of water stress, but it was not affected by potassium fertilizer. Free proline content at water stress level of 50% ASWC was significantly higher than those of 100 and 75% ASWC by application of 50 and 100kg K2O ha-1. With 75 and 100kg K2O ha-1, free proline content at water stress level of 25% ASWC did not significantly differ from those of water stress levels of 100 and 75% ASWC.