Title: کاربرد کلروفیل فلوئورسانس برای ارزیابی دقیق میزان نیتروژن گیاه گندم و ذرت
Author: 12345

The effect of phosphate solubilizing bacteria and chemical phosphorous on quantitative and qualitative yield of potato cultivars 
Abolfazl Sefidgaran^a, Mojtaba Yousefirad^b and Majid Majidian^*c
^aMinistry of Jihad-Agriculture, Arak, Iran ^bDepartment of Agronomy, College of Agriculture, Islamic Azad University, Saveh Branch, Saveh, Iran. ^cDepartment of Crop Production and Plant Breeding, College of Agriculture, University of Guilan, Rasht, Iran
E-mail:ma_majidian@guilan.ac.ir

Abstract
Biofertilizer application in crop production in sustainable agriculture with aim of remove or reduce the chemical input in order to reach to quality increasing and sustainability of yield is very important. Phosphorus is second only to nitrogen as an essential macronutrient for plant growth and it is one of the essential nutrients for plants influence on growth and function. Deficiency of phosphorus can be compensating with the use of chemical fertilizer. This fertilizer has an injurious effect on environment and reduces the quality of agricultural products. This experiment was conducted to evaluate the phosphate solublizing bacteria and chemical phosphorus on three varieties of potato. A completely block randomized design with a split-split plot with three replication was used. A field experiment was conducted at Arak University research farm, during 2008 cropping seasons. The results showed that the use of phosphate solublizing bacteria and interaction with other factors, were significantly affected wet weight shoot, wet weight of tubers, dry weight of tubers, the  phosphorus content of tubers and harvest index. It caused significantly increasing in yield parameters, especially tubers yield comparing to chemical treatment at 1% level. Also The result showed that the interaction effect of phosphate solublizing bacteria and chemical phosphorus, showed significant effects on wet weight, dry weight shoot, dry weight of tuber, number of main stems per plant, biological yield, and the phosphorus content per plants at 5% level. There was no significant difference at application treatment of phosphate solublizing bacteria with 75 kg ha^-1 of chemical phosphate with application of 150 kg ha^-1 chemical phosphate fertilizer. Based on the results obtained from this study application of 150 kg ha^-1 chemical phosphate fertilizer in the most quantitative such as yield of tuber, the percentage of absorbed phosphorus, phosphate content of plant, dry weight of aerial part biomass yield, Showed significant difference at 1% level. Among potato varieties, Leidi Razita in most agronomic characteristic, especially tuber yield, harvest index, phosphorus content in plant, and wet weight of tuber, the highest amount to itself. According to the results of this study, application of last levels of biofertilizers or treatment of phosphate solublizing bacteria, consumption of 75 kg ha^-1 of chemical phosphate prepared the best condition in order to reach to the highest qualities and quantitative yield in a sustainable agroecosystem.
         
Keywords: phosphate solublizing bacteria, potato, phosphorus, yield.