Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/3/2009
Publication Date: 2/24/2009
Citation: Jifon, J.L., Lester, G.E. 2009. Foliar potassium fertilization of muskmelons on calcareous soils in south Texas: Effects on yield and quality. Proceedings of the Annual Conference of the Fluid Fertilizer Foundation, February 15-17, 2009, Scottsdale, Arizona. 26:130-137. Interpretive Summary:
Technical Abstract: Among the essential plant nutrients, potassium (K) has the strongest influence on crop quality parameters. However, many soil and plant factors often limit adequate soil K uptake to satisfy plant requirements during fruit development stages. The objectives of this multiyear field study were to determine if this apparent K deficiency and the associated fruit quality problems can be alleviated by supplementing soil-derived K with foliar K nutrition and whether differences exist among K salts for foliar feeding. Even though pre-plant soil K concentrations were high, foliar K treatments resulted in higher plant tissue K concentrations, suggesting that K uptake from the soil solution was not sufficient to satisfy plant requirements. Fruits from treatments receiving foliar K had higher soluble solids, concentrations, total sugars, and bioactive compounds (ascorbic acid and B-carotene). Among the different K salts, KNO(3) consistently resulted in non-significant effects on fruit quality compared to control treatments. Yields were significantly affected by these late-season foliar K treatments only in one year (2007) with unfavorable growing conditions, and potentially due to increased stress tolerance associated with adequate K nutrition. The results demonstrate that carefully-timed foliar K nutrition can improve muskmelon fruit quality by alleviating the apparent K deficiency during fruit development. The data also reveal differences among potential foliar K salts and suggest a reassessment of K management strategies aimed at improving fruit quality.