Effects of Different Potassium Levels in Nutrient Solution on the Fruit Quality in Bell Pepper

Document Type : Research Paper


1 Assistant Professor, Department of Horticultural Sciences, Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran

2 M.Sc. Graduated, Department of Horticultural Sciences, Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran


Bell pepper (Capsicum annuum L.), due to its high nutritional values, is one of the most important vegetable crops in the world. Optimum supply of nutrients particularly potassium, has important role in improving the quality of agricultural products. This research was conducted to study the effects of potassium levels (150, 235, 300, 400 and 500 mgL-1in nutrient solution) on fruit quality of bell pepper. The results showed that the effect of K levels on fruit length, fruit firmness, and biochemical traits was significant (P≤0.05), while there was no significant effects of potassium levels on fruit diameter. The highest fruit length and fruit firmness were observed in plants treated with 400 and 500 mg K L-1 nutrient solution, respectively. The highest amount of TSS and pH of fruit juice were recorded in 400 mg K L-1 treatment, whereas the highest titreable acidity and vitamin C were in plants treated with 500 mg K L-1 nutrient solution. Therefore, it can be concluded that for improvent of fruit quality of Bell pepper in hydroponic system, higher potassium concentrations (400 mgL-1) rather than normal concentrations (around 235 mgL-1) should be applied.


Main Subjects

پیوست، غ. ع. 1384. سبزیکاری. چاپ چهارم. رشت: دانش پذیر. 346 صفحه.
جلیلی­مرندی، ر. 1383. فیزیولوژی بعدازبرداشت .انتشارات جهاد دانشگاهی ارومیه، ارومیه.276صفحه.
جهان­بین، ر.، یاوری، س.، عشقی، س. و تفضلی، ع. 1378. اثر توفوردی و سولفات پتاسیم بر ویژگی‌های کمی و کیفی پرتقال نافی. مجله علوم باغبانی (علوم و صنایع کشاورزی)، 22 (20): 112-110.
حسینی، ک. ز. 1373. روش‌های متداول در تجزیه مواد غذایی. انتشارات دانشگاه شیراز. شیراز. 210 صفحه.
مردانلو، ص.، سوری، م. ک. و دهنورد، س. 1393. بررسی ویژگی­های کمی و کیفی میوه فلفل قلمی تحت تأثیر غلظت­های مختلف پتاسیم محلول غذایی در کشت بدون خاک. مجله پژوهش­های خاک، 28 (2): 398-406.
مسیحا، س. م.، کریمایی، ص. و مقدم، م. 1378. مقایسه اثر سه محلول غذایی بر میزان رشد و غلظت عناصر نیتروژن، فسفر و پتاسیم در کاهو با استفاده از سیستم هیدروپونیک. مجله نهال و بذر، 4: 375-389.
ملکوتی، م. ج.، کشاورز، پ. و کریمیان، ن. ع. 1387. روش جامع تشخیص، توصیه بهینه کود برای کشاورزی پایدار. چاپ هفتم، انتشارات دانشگاه تربیت مدرس. 755 صفحه.
Almeslemani, M., Pant, R. and Singh, B. 2009. Potassium level and physiologyical response and fruit quality in hydroponically grown tomato. International Journal of Vegetable Science, 16: 86-95.
Arancon, N. Q., Edwards, C.A., Lee, S. and Byrne, R. 2006.Effects of humic acids from vermicomposts on plant growth. European Journal of Soil Biology, 42: 65-69.
El-Bassiony, A. M. 2006. Effect of potassium fertilization on growth, yield and quality of onion plants. Journal of Applied Sciences Research, 2 (10): 780-785.
El-Bassiony, A. M., Fawzy, Z. F., El-Samad, E. A. and Riad, G. S. 2010. Growth, yield and fruit quality of sweet pepper plants (Capsicum annuum L.) as affected by potassium fertilization. Journal of American Science, 6 (12): 722-729.
Fawzy, Z. F., El-Nemr, M. A. and Saleh, S. A. 2007. Influence of levels and methods of potassium fertilizer application on growth and yield of eggplant. Journal of Applied Sciences Research, 3 (1): 42-49.
Gruda, N. 2005. Impact of environmental factors on product quality of greenhouse vegetables for fresh consumption. Critical Review in Plant Science, 24: 227-274.
Hartz, T. K., Miyao, G., Mullen, R. J., Cahn, M. D., Valencia, J. and Brittan, K. L. 1999. Potassium requirements for maximum yield and fruit quality of processing tomato. Journal of American Society for Horticulture Science, 124: 199-204.
Howard, L. R., Talcott, S. T., Brenes, C. H. and Villalon, B. 2000. Changes in phytochemical and antioxidant activity of selected pepper cultivars as influenced by maturity. Journal of Agriculture and Food Chemistry, 48: 1713-1720.
Johnson, C. D. and Decoteau, S. R. 1996. Nitrogen and Potassium fertility effects Jalapeno pepper plant growth, pod yield and pungency. Hort Science, 31: 1119-1123.
Khayyat, M., Vazifeshenas, M. R., Rajaee, S. and Jamalian, S. 2007. Potassium effect on ion leakage, water usage, fruit yield and biomass production by strawberry plants grown under NaCl stress. Journal of Fruit and Ornamental Plant Research, 17: 79-88.
Lester, G. E., Jifon, J. L. and Makus, D. J. 2006. Supplemental foliar Potassium applications with or without a surfactant can enhance netted muskmelon quality. Hort Science, 41 (3): 741-744.
Lin, D., Huang, D. and Wang, S. 2004. Effects of Potassium levels on fruit quality of muskmelon in soilless medium culture. Scientia Horticulturae, 102: 53-60.
Mapson, L. W. 1970. Vitamins in fruits. In: Hulme, A. C. (Ed.), Biochemistry of fruits and their products. London: Academic Press, 369-383.
Marschner, H. 1995. Mineral nutrition of higherplants. 2ndEdition. Academic press, London. pp: 889.
Okur, B. and Yagmur, B. 2004. Effects on enhanced Potassium doses on yield, quality and nutrient uptake of watermelon. In IPI regional workshop on Potassium and fertigation development in West Asia and North Africa.
Rubio, J. S., Garcia-Sanchez, F., Flores, P., Navarro, J. M. and Martinez, V. 2010. Yield and fruit quality of sweet pepper in response to fertilization with Ca2+ and K+. Spanish Journal of Agricultural Research, 8 (1): 170-177.
Tisdale, S. L., Nelson, W. L. and Beaton, J. D. 1985. Soil Fertility and Fertilizers. 4th Ed., Macmillan Pub. Co., NewYork.
Topuz, A. and Ozdem, F. 2007. Assessment of carotenoids, capsaicinoids and ascorbic acid composition of some selected pepper cultivars (Capsicum annuum L.) growen in Turkey. Journal of Food Composition Analysis, 20: 596-602.
Willumsen, J., Petersen, K. and Kaack, K. 1996. Yield and blossom-end rot of tomato as affected by salinity and cation activity ratios in the root zone. Journal of Horticultural Science, 71 (1): 81-98.
Wuzhong, N. 2002. Yield and quality of fruit of solanaceous crops as affected by Potassium fertilization better crops. Atlantatica, 13: 6-8.
Xisheng, G. 1999. Study on the K fertilizer responses of vegetables. Journal of Hebei Agricultural Sciences, 1: 91-95.