EVALUATION OF CHLORIDE FORM AS A PARTIAL SOURCE FOR POTASSIUM FERTIGATION OF BANANA PLANTS GROWN ON A SANDY SOIL

Document Type : Original Article

Authors

Soils Department, Faculty of Agriculture, Ain Shams University, Shoubra Elkhiema, Cairo, Egypt

Abstract

A field experiment was carried out in sandy soil to elucidate the possibility of using chloride form as a partial source for potassium in fertiga-tion of banana plants grown on a sandy soil. Growth, fruit yield and quality as well as plant nutritional status and Cl accumulation within both plant leaves and rhizosphere beside an economical elucidation were taken in to consideration to ac-complish such evaluation. Eleven gradual increas-ing KCl: KNO3 (0:100 - 100:0) ratios were applied with maintaining the concentration of all macro and micro nutrients except Cl constant. Obtained data indicated that increasing Cl existence didn’t adversely affect plant growth under this experi-ment. Treatments of 10:90 followed by 50:50 as well as 70:30 followed by 80:20 and either 90:10 or 10:90 (KCl:KNO3) were most stimulating treatments for increasing pseudo stem diameter and leaves number, respectively. Although total fruit yield bunch as well as number and length of fingers are less sensitive to increasing KCl:KNO3 ratio, number of hands/bunch and diameters of fingers were significantly and positively affected by increasing KCl existence. Treatment of 80:20 KCl:KNO3 was the most significant superior one for all measured fruit yield parameters. Although Cl content increased significantly in banana leaves and root surrounding area with increasing Cl ex-istence in the fertigation solutions, recorded con-tents seemed to be in safe ranges whereas no chlo-ride necroses symptoms were appeared at banana leaves. Contents of N, P and K as well as Cl in plant leaves were significantly, although in fluctu-ating manner, affected by increasing chloride oc-currence in fertigation solution. The encountered response of N, P and K contents seemed to be not only a resultant of increasing Cl occurrence in the root media but also as a reflection to changing the N form (NH4 and urea) compensating N-NO3 de-cline in the fertigation solutions having high Cl concentrations. The relatively high supplements of Cl (80:20 followed by 70:30 KCl: KNO3) recorded the highest economical net return. It could be con-cluded that KCl can be perfectly used in fertigat-ing banana plants grown on sandy soils. To in-crease safety of using chloride under such condi-tions, more work could be suggested particularly what concerns with calculating irrigation and leaching water requirements to prevent chloride accumulation in the root zone.

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