Evaluation the effect different rate of potash application On the quality and quantity of page mandarin CV on the poncirus root

Secound important factor in fruit production is the nutritional elements providing(climatic factors are the first). Agricultural improvement is achieved by basical and scientifical recognitionof growth factors which provide the best plant production. Potassium is one of the mineral elements which has a great importance in fruit growing in large scale. So we have conducted a field trial for determining the effects of potassium in different amounts (0,750,1500,2250 and 3000 gr/tree) on quantitative and qualitative parameters of citrus fruits. This study was conducted on Page mandarin trees in Randomized Complete Block Design(RCBD) with 5 replications and 2 trees for each treatment in Kotra station of Citrus Research Institute. All experimental trees were grafted on Poncirus and had 15 years old. Potassium deficiency symptoms was shown on these trees. These trees had similar cultural practices and were fertilized with Superphosphate triple and Ammonium sulfate in quantity of 750 gr. And 3000 gr. Respectively. Total yield of trees and important values of harvested fruits include: length, diameter, juice content, vitamin C, total acidity, total soluble solids, peel thickness and shelf life was estimated and analyzed according to statistical model of RCBD. Essential factors of nutritional statuse of orchard soil such as: texture,EC, pH, total nitrogen, absorbable phosphorous and potassium was estimated before beginning of this study. Fruit harvesting was carried out in December according to common low qualitative characteristics were determined with a sample of 25 fruits per tree. Result of this study showed that potassium fertilizer in quantity of 1500 gr per tree can cause the highgest yield and the best quality of fruits in this variety of mandarin at 1% of significance. Key words: Potassium, Yield, Quantity, Shelf life, Quality