ẢNH HƯỞNG CÁC DẠNG PHÂN ĐẠM VÀ THỜI ĐIỂM BÓN ĐẾN NĂNG SUẤT VÀ HÀM LƯỢNG NITRATE TRONG QUẢ DỨA QUEEN

The present study on the effect of fertilizers types and application stage of nitrogen on the content of nitrate in Queen pineapple has been carried out at Tan Phuoc district, Tien Giang province. The results indicated that application of inorganic fertilizer Urea+DAP at stage 7and 15 days before fruit harvesting were increased nitrate (18,25mg/l - 26,02 mg/l) content in fruit over limiting standard. There were not significant differences in the fruit yield among stages of application such as 7, 15, 30, 40, 60 days before harvesting. High nitrogen rates were applied at stage 7 days before fruit harvesting due to increased nitrate residue on pineapple fruit.