تاثیر نوع و منبع کود مصرفی بر توزیع عناصر غذایی در برگ و میوه کیوی

انتخاب نوع و منبع کود در تغذیه درختان میوه نقش مهمی در افزایش عملکرد و بهبود کیفیت میوه‌ تولیدی دارد. پژوهش حاضر با هدف بررسی اثرات کوتاه مدت چهار نوع کود آلی شامل آزولا‏، آزوکمپوست، کود گاوی و ورمی‌کمپوست و نیز کود شیمیایی کامل و تیمار بدون کود، در قالب طرح بلوک‏های کامل تصادفی در مجموع با شش تیمار و چهار تکرار بر توزیع عناصر غذایی در برگ و میوه کیوی و ارتباط آن با عملکرد انجام شد. نتایج نشان داد که غلظت نیتروژن، فسفر، پتاسیم، کلسیم و منیزیم در برگ و میوه کیوی در تیمارهای کودی نسبت به تیمار بدون کود بیشتر بود و مقدار این عناصر در برگ و میوه در تیمارهای کودی در وضعیت بهینه قرار داشت. تیمار آزوکمپوست در بین تیمارهای کودی، بیشترین افزایش مقدار نیتروژن (2/57 درصد) و کلسیم (3/39 درصد) را در برگ نشان داد. در تجزیه همبستگی ارتباط معنی‌دار بین نیتروژن، فسفر و پتاسیم برگ با نیتروژن، فسفر و پتاسیم میوه به ترتیبب*0/76، *0/69 و *0/71 بدست آمد. همچنین در معادله رگرسیون گام به گام بین عملکرد تیمارها با مقادیر هر یک از عناصر نیتروژن، فسفر و پتاسیم در برگ و میوه ارتباط مستقیم وجود داشت. در مجموع مصرف کودهای آلی در خاک باغ کیوی موجب افزایش مقدار عناصر غذایی در برگ و میوه کیوی شد. با توجه به آبشویی کودهای شیمیایی و مشکلات زیست محیطی ناشی از مصرف این کودها، می‌توان از کودهای آلی بررسی شده در این مطالعه مانند ورمی‌کمپوست و آزوکمپوست در باغات کیوی به منظور تولید میوه در شمال کشور استفاده کرد.

Effect of Fertilizer Type and its Source on Nutrients Distribution in Kiwifruit Leaves and Fruit

Introduction: Type and source of fertilizer in fruit trees nutrition play an important role in increasing yield and fruit quality, shelflife prolonging and reducing waste in harvested fruit. Evaluation of the possibility of integrated use of organic and inorganic fertilizers or gradual replacement of chemical fertilizers with organic manures is necessary in nutrition of kiwi vines, due to environmental issues resulted due to application of chemical fertilizers as well as increasing market value of organic fruits. Studies in this regard, especially comparison between organic manure and chemical fertilizer effects in kiwi fruit production is very limited. Therefore,this research was performed to investigate the shortterm effects of four types of organic fertilizers as compared to chemical fertilizers over the amount of nutrients in leaves and fruits in Kiwi Hayward variety. Materials and Methods:This shortterm field research was conducted in a randomized complete block design with six treatments including (azola, azocompost,vermicompost, cow manure, chemical fertilizer and control treatments) and four replications inHorticultural Science Research Institute, Citrus and Subtropical Fruits Research Center in Ramsar.Fertilizers were mixed with topsoil in canopy,weed control and drop irrigation was performed. The amount of nutrients, including nitrogen, phosphorus, potassium, calcium and magnesium in kiwi leaves and fruits were measured. In addition, relationship between nutrients in leaves and fruit yield was examined. The correlation analysis between mineral elements and the characteristics of qualitative and quantitative fruit firmness, dry matter, total soluble solids, titratable acidity and ratio of soluble solids to titratable acidity was performed. Stepwise regression equation between treatments with nitrogen, phosphorus, potassium and calcium was written on kiwifruit leaves and fruit. In addition, stepwise regression, the overall equation between yield and nutrient content of kiwifruit were reported. Result and Discussion: The results showed that concentration of nitrogen, phosphorus, potassium, calcium and magnesium in leaves and fruits in Kiwi trees are higher than control treatment and the amounts of these elements in leaves and fruit werein optimum condition. Fertilization increased the amount of nitrogen, phosphorus, potassium, calcium and magnesium in leaves and fruit of kiwifruit trees in fertilizer treatments, compared to the control. Azocompost treatment had the highest amount of nitrogen and calcium in leaves and fruit compared to other treatments. Azocompost and vermicompost treatments had the highest potassium content in the leaf. As well as cow manure, vermicompost and Azocompost treatments resulted in the highest amount of potassium in fruit. Increasing theamount of nutrients in the leaves of kiwifruit had a direct impact. The correlation between the amount of elements in the leaves and fruit showed a direct and significant relationship between nitrogen, phosphorus and potassium leaves and nitrogen, phosphorus and potassium in fruits. Increasing of nutrients in kiwifruit leaves had a direct and positive impact on fruits. In stepwise regression equation there was a significant relationship between the yield andamounts of nitrogen, phosphorus and potassium and kiwi fruit trees, and by increasing of these elements and yield wasincreased. Correlation analysis between minerals and firmness in kiwifruit showed that there are negative correlations between the nitrogen content in mature fruit and firmness at harvest time at probability level 5 percent. In addition, positive and significant correlation between the calcium content in mature fruit and firmness, as well as between the percentage of dry matter and phosphorus and potassium contents of mature fruit at harvest time was obtained. Results showed that a significant negative correlation was between soluble solids with calcium and between titratable acidity with phosphorus, and of soluble solids ratio to titratable acidity with nitrogen and phosphorus the mature fruit at harvest mature fruit. Conclusion: In general, according to these research results we can say that use of organic fertilizers like chemical fertilizers in kiwifriut orchards increasethenutrient amounts in leaves and fruit of kiwifruit. In addition,there was a significant positive correlation between quantitative and qualitative characteristics of kiwifruit and its leaf and fruit nutrients. Nitrogen, phosphorus and potassium have significant positive effect in increasing fruit yield.Chemical fertilizers leaching and environmental problems caused by the consumption of these fertilizers, motivated to useof organic fertilizers, such as vermicompost and azocompost in kiwifruit orchards, in order to produce fruit in north of the country.