Effect of plant growth regulators on leaf area, chlorophyll content, carotenoids, stomatal count and yield of cashew (Anacardium occidentale L.) var. Bhaskara

Abstract

<p>An experiment was conducted to study the effect of exogenous application of growth regulators at three important growth stages<br />(flushing, flowering and fruiting) on leaf area, chlorophyll content, carotenoids, stomatal count and yield of cashew var. Bhaskara.<br />Irrespective of growth stages, foliar application of GA3 @ 50 ppm and ethrel @ 50 ppm was found to be superior in all the<br />parameters and on par with each other compared to other growth regulators. Out of nine treatments of different growth regulators;<br />the highest leaf area was recorded in trees sprayed with GA3 @ 50 ppm and ethrel @ 50 ppm. At flushing stage, spraying with GA3<br />@ 50 ppm resulted in highest stomatal number (21.9) and carotenoids (0.41) whereas unsprayed (control) trees recorded least<br />stomatal number (11.6) and carotenoids (0.19). Thus, leaf area, chlorophyll content, carotenoids and stomatal count increased in<br />trees sprayed with growth regulators than unsprayed trees. Spraying of ethrel @ 50 ppm recorded highest nut yield<br />(14.3 kg tree-1) followed by NAA @ 25 ppm + GA3 50 ppm (12.9 kg tree-1). This study demonstrated the potential of ethrel as well<br />as GA3 in improving various biochemical parameters viz., chlorophyll ‘a’, chlorophyll ‘b’, carotenoids and leaf area in cashew<br />which are important determinants in increasing nut production.</p>