تأثیر محلول‌پاشی پتاسیم در کاهش اثرات مضر شوری در گیاه اسفناج (.Spinacia oleraceae L )

نوع مقاله : مقالات پژوهشی

نویسندگان

مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اصفهان، سازمان تحقیقات، آموزش و ترویج کشاورزی، اصفهان

چکیده

در مناطق خشک و نیمه خشک، مقابله با تنش شوری و اثرات مضر آن ضروری به نظر می‌رسد. به منظور بررسی تأثیر محلول پاشی پتاسیم بر عملکرد و اجزای عملکرد اسفناج در شرایط تنش شوری، پژوهشی در سال‌ 1391 با استفاده از آزمایش کرت‌های خرد شده و طرح پایه‌ی بلوک‌های کامل تصادفی با چهار تکرار در ایستگاه تحقیقات کشاورزی و منابع طبیعی استان اصفهان انجام شد. شوری آب آبیاری در سه سطح شاهد (2 دسی‌زیمنس بر متر)، آب چاه (4 دسی‌زیمنس بر متر) و آب چاه (8 دسی‌زیمنس بر متر) به عنوان کرت‌های اصلی و دو سطح استفاده از کود پتاسیم شامل شاهد و محلول‌پاشی اکسید پتاسیم محلول در آب ( 5/2 میلی‌لیتر در هر لیتر) به عنوان کرت‌های فرعی بودند. نتایج نشان داد عملکرد تیمار محلول‌پاشی پتاسیم و شوری 4 دسی‌زیمنس بر متر معادل 35300 کیلوگرم در هکتار بود که با تیمار شاهد تفاوت معنی‌داری نداشت. افت عملکرد در تیمار محلول‌پاشی پتاسیم و شوری 8 دسی‌زیمنس بر متر و همچنین تیمار شوری 8 دسی‌زیمنس بر متر و بدون محلول‌پاشی پتاسیم به ترتیب برابر با 2/20 و 38 درصد بود. تعداد بوته در متر مربع در سه تیمار شوری 2، 4 و 8 دسی‌زیمنس بر متر به ترتیب 40، 1/38 و 1/29 بوته در متر مربع بود. محلول‌پاشی پتاسیم در شوری 8 دسی‌زیمنس بر متر، درصد ماده خشک برگ را 7/12 درصد بهبود بخشید. با توجه به نتایج بدست آمده، در شرایط تنش شوری، محلول‌پاشی پتاسیم می‌تواند به عنوان یک عامل تعدیل کننده شوری مورد استفاده قرار گیرد.

کلیدواژه‌ها


عنوان مقاله [English]

Impact of Potassium Foliar Application in Alleviating the Harmful Effects of Salinity in Spinach

نویسندگان [English]

  • Amirhooshang jalali
  • Peyman Jafari
Isfahan Agricultural and Natural Resources Research and Education Center, AREEO
چکیده [English]

Introduction: Spinach is an important leafy vegetable in the cold season, and despite the fact that is considered as low-calorie food source contains significant amount of minerals such as iron, and vitamin A and C. According to the University of Utah 3.8 dS m-1 is salinity tolerance threshold for the spinach and yield decrease that have been reported by 10%, 25% and 50% at 5.5, 7 and 8 dS m-1 salinity. The necessity to supply adequate potassium has been demonstrated in salinity conditions. In salt stress conditions, foliar application of K in spinach, reduces the harmful effects of salt and increase the ratio of potassium to sodium (1.61 to 2.72). Foliar application of K with prevent of potassium transfer from root to shoot is causing continuation of photosynthesis and reduce the effects of salinity. Absorption of potassium from the leaves depends on the type of used compound. In this context, characteristics of plant (leaves with a waxy composition, duration of growth and leaf area) are important. 100 kg ha-1 of potassium in salt stress conditions by reducing the absorption of sodium, increased salt tolerance on the sunflower.
Materials and Methods: In order to evaluate the foliar application of K on the yield and yield components of spinach in salt stress condition, a study was conducted in 2012 by using split plot randomized based on complete block design with four replications at Isfahan Agricultural and Natural Resources Research Station. Three levels of irrigation water salinity consisted of a control (2 dS m-1), well water with salinity (4 dS m-1) and well water with salinity (8dS m-1) arranged in main plots and two levels of control and foliar applications of potassium fertilizer containing potassium oxide solubility in water (2.5 ml per liter) arranged in subplots. Statistical analysis was conducted by using SAS software and statistical tests were compared with Duncan at 5 percent.
Result and Discussions: The results showed that the yield of spinach with foliar application of K and 4 dS m-1 salinity was equaled 35300 kg ha-1 which had not significantly different from control treatment. Foliar application of K and 8 dS m-1 salinity, and also 8 dS m-1 salinity and without foliar potassium, had 20.2 and 38% yield reduction, respectively. In salinity 2.1, 4 and 8 dS m-1 plants m-2 were 40, 38.1 and 29.1, respectively. Leaf dry matter percent was improved with foliar application of K in 8 dS m-1 salinity. Effect of potassium, as modulators of salt in spinach, by researches of Shannon and Greve (24) and Kaya et al (14) have also been emphasized. Spinach leaves number was from 11.4 to 16.7 in different treatments. Foliar application of K in 4 and 8 dS m-1 salt treatment was increase in the number of leaves. This increased in treatment of 4 and 8 dS m-1 was 15.3 and 28.9 percent, respectively. In both saline treatments of 4 and 8 dS m-1, leaf length was positively affected by the application of potassium but in salinity 4 dS m-1 (unlike the eight salinity dS m-1) leaf width was not affected by the potassium spraying. The ability of plants to maintain intracellular potassium to sodium ratio leaves in certain extent is necessary for a salt tolerance. In fact, the application of potassium in salinity conditions by increasing the concentration of the K in organs is a kind of acclimation to the salt stress and activates repair mechanisms of the damage against of stress agent. The length of tail leaves in 4 dS m-1 salt was not significantly affected by the spraying of potassium while in 8 dS m-1 salinity, spraying potassium led to an increase of 28 percent in length of leaf tail. The effect of K application on the dry matter content in the 8 dS m-1 salinity was statistically significant. Potassium is the most abundant cation-forming in many plants (typically more than 10% of dry weight) and less than 10 grams per kg-1 of dry weight appear deficiency symptoms in most plants.
Conclusion: According to the results, in salinity conditions, the foliar application of K can be used as a factor to reduce the harmful effects of salinity. While the lack of fresh water for irrigation in arid and semi-arid crops has become a challenge, attention to the moderated mechanisms of the harmful effects of salt, is one of the approaches to face the challenges ahead.

کلیدواژه‌ها [English]

  • Dry matter percentage
  • Length of blade
  • Modulators of salt
  • Sodium
  • Leaf width
1- Akram M.S. 2006. Influence of exogenously applied K from different sources on Sunflower under salt stress. University of Agric. Faisalabad, Pakistan.56pp.
2- Amacher J.K. 2000. Salinity and plant tolerance. Utah State University Extension. Electric Publishing, 30pp.
3- Asadi, H., and Hasandokht, M.R.2005. Study the genetic variation of genotypes spinach. Journal of Crop Sciences 38:257-265. (in Persian)
4- Ashraf M., and Harris, P.J.C.2004.Potential biochemical indicators of salinity tolerance in plants. Plant Science 166:3-16.
5- Ashraf M., Athar H.R., Harris P.J.C., and Kwon T.R .2008. Some prospective strategies for improving crop salt tolerance. Advances in Agronomy 97: 68-82.
6- Cachorro P., Ortiz A., and Cerda, A. 1993. Growth water relations and solute composition of Phaseoulus vulgaris L. under saline condition. Plant Science 95:23-29.
7- Citak S., and Sonmez, S. 2010. Effects of conventional and organic fertilization on spinach growth, yield, vitamin C and nitrate concentration during two successive seasons. Scientia Horticulturae 126: 415-420.
8- Cuin T.A., Miller A.J., Laurie S.A., and Leigh, R.A. 2003. Potassium activities in cell compartments of salt-grown barley leaves. Journal of Experimental Botany 54: 657– 661.
9- Delfine S., Alvino A., Zacchini M., and Loreto F. 1998. Consequences of salt stress on conductance to CO2 diffusion, rubisco characteristics and anatomy of spinach leaves. Australian Journal of Plant Physiology 25:395-402.
10- Eftekhari A., Hasandokht M.R., Fatahimoghadam M.R., Kashi. A. 2010. Iranian spinach genetic diversity using morphological traits. Journal of Horticultural Science 41: 89-93. (in Persian)
11- Gratan S.R., Grieve, C.M. 1999. Salinity –mineral nutrient relations in horticultural crops. Scientia Horticulturae 78: 127-157.
12- Gulser F. 2005. Effects of ammonium sulphate and urea on NO3 and NO2 accumulation, nutrient contents and yield criteria in spinach. Scientia Horticulturae 106: 330–340.
13- Jalali A.H. and Jafari P. 2013. Effect of potassium fertilizer on yield of three varieties of watermelons in salinity stress. Journal of Crops Improvement 14:31-41. (in Persian)
14- Kaya C., Higgs D., and Kirnak H. 2001. The effects of higher salinity and supplementary phosphorous and potassium on physiology and nutrition development of spinach. Bulgarian Journal of Plant Physiology 27:47-59.
15- Leigh R.A., and Johnston A.E. 1983. Concentrations of potassium in the dry matter and tissue water of field-grown spring barley and their relationships to grain yield. The Journal of Agricultural Science 101:23-31.
16- Maroufi K., Farahani H.A., and Moaveni, P. 2011. Effects of hydro priming on seedling vigor in spinach. Advances in Environmental Biology 5:2224-2227.
17- Marschner P. 1995. Mineral nutrition of higher plants. Academic press, London, 889pp.
18- Martino C., Delente S., Pizzuto R., Loreto F., and Fuggi A. 2003. Free amino acids and glycine betaine in leaf osmoregulation of spinach responding to increasing salt stress. New Phytologist 158:455-463.
19- Mengel K. 2002. Alternative or complementary role of foliar supply in mineral nutrition. Acta Horticulture 594:33-48.
20- Mirzapour M.H., Khoshgoftarmanesh A.H., Mirnia K., Bahrami H., Naeine M.R. 2002. Magnesium and potassium interaction effects on growth and yield of sunflower in saline soil. Journal of Soil and Water 17:1-12. (in Persian)
21- Pasternak D., and De Malach Y. 1994. Crop irrigation with Saline Water. In: Pessarakli, M. (ed), Handbook of plant and crop stress, Marcel Dekker, New York, pp. 599-622.
22- SAS Institute. 2010. SAS user’s guide. SAS Inst., Cary, NC.
23- Shahid Umar A., Iqbal E., and Abrol Y.P. 2007. Are nitrate concentrations in leafy vegetables within safe limits? Current Science 92:355-360.
24- Shannon M.C., and Grieve C.M. 1999. Tolerance of vegetable crops to salinity. Scientia Horticulturae 78: 5-38.
25- Storey R., and Wyn Jones, R.G.1978. Salt stress and comparative physiology in the Gramineae. 1. Ion relations of two salt- and water-stressed barley cultivars, California Mariout and Arimar. Australian Journal of Plant Physiology 5: 801-816.
26- Zhu J.K. 2003. Regulation of ion homeostasis under salt stress. Current Opinion in Plant Biology 6: 441–445.