The Effects of Nitrogen and Zinc on Quantity and Quality of ‘Washington navel’ Orange (Citrus sinensic var. Washington navel)
A. Kazemi, A.R. Zakerin and C.A. Hassanpor
Book of Abstract. APEC Symposium on Assuring Quality and Safety of Fresh Produce, August 1-3, 2005, Bangkok, Thailand. 76 page.
2005
บทคัดย่อ
The Effects of Nitrogen and Zinc on Quantity and Quality of ‘Washington navel’ Orange (Citrus sinensic var. Washington navel)
This study was carried out during 2003-2004 in a commercial garden in Mohammad abad region, 5 Kilometers from Jahrom to study the effects of Nitrogen and Zinc on quality and quantity of Washington navel orange. Treated trees were 5 years old budded on Lime rootstock. In winter of every year 500 g of potassium sulphate, 250 g super phosphate triple, 200 g of manganese sulphate and 50 g of Fe sequestron were applied to the trees. The experimental design was RCBD factorial with 16 treatments and 4 replications. Treatments included 4 levels of N (0, 400, 600 and 800 g) Per tree in the first half of May as soil application and 4 levels of zinc in the from of zinc sulphate (0, 5, 8 and 10 g/L) sprayed on trees in second half of May. Results showed that, application of N and Zn had Positive effects on yield of Washington navel orange. Mean yield during two years increased by 59.6% in 800 g N and 10 g/L Zn treatment in comparison with control. In addition to positive effects of N and Zn on yield, most fruit quality factors such as Juice density, TSS, pH, total acid (TA) and vitamin C improved. Thus, Improvement of yield and fruit quality of Washington navel orange, additional application of N in early May and spray of Zn in late May is recommended.