INFLUENCE OF FOLIAR APPLICATION BY SALICYLIC ACID AND SOME MICRONUTRIENTS ON GROWTH, YIELD AND QUALITY OF ONION CROP

Document Type : Original Article

Abstract

Two field experiments were conducted at the Experimental Farm of Sakha Agricultural Research Station to study the effect of foliar application with salicylic acid with and without of some micronutrients (Fe, Zn and Mn) as well as their interaction, on the growth, onion bulbs yield and its quality as well as storability of onion bulbs variety Giza Red during the two successive winter seasons of 2012/2013 and 2013/2014. Strip-plot design with four replications was used in this investigation. The horizontal plots were randomly assigned by the three foliar application with salicylic acid rates (100, 200 and 300 ppm), whereas foliar application with micronutrients at the same dose, 2 ml L
 -1(spraying with water; spraying with Fe or Zn or Mn and spraying with Fe+ Zn+Mn) were randomly distributed in vertical plots. The obtained results could be summarized as follows:
·The maximum values of growth characteristics (No. of leaves/plant, bulb diameter (cm), dry weight of onion plant and leaf area/plant), average bulb weight, culls bulb weight, marketable and total bulbs yield (t fed.
 -1) were obtained under foliar application of salicylic acid at the rate of 200 ppm, while the lowest values were recorded under spraying salicylic acid at the rate of 100 ppm.
·Foliar application of onion plants with mixture of Fe, Zn and Mn markedly increased bulb yield and its components with best growth characteristics followed by that sprayed with Zn. Foliar application of salicylic acid at the rate of 200 ppm andmicronutrients (Fe + Zn + Mn, at the rate of 2 ml L 
-1 in combination) resultedin the tallest plants, the heaviest bulb weight, culls bulb weight, marketable and total bulbs yield (t fed. -1) and the highest leaf area/plant of onioncompared with control treatment.
·After storing for 180 days the lowest values of weight loss % was observed under combination of salicylic acid at 200 ppm with mixture of Fe, Zn and Mn which achieved the maximum values of remained bulbs% in both
seasons. Moreover, the obtained data revealed that, the highest nutritional values in onion bulb tissues were detected when mixture of the three nutrition elements (Fe, Zn and Mn) together. Generally, from the economic point of view, this study can be recommend that foliar application with salicylic acid for three times with the rate of 200 ppm in each once as well as spraying with a mixture of micronutrients (Fe+Zn+Mn at the rate of 2 ml L-1) to increase onion
productivity and storability as well as quality improvement.

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