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NITRATE ACCUMULATION IN OKRA AND CARROT AS INFLUENCED BY FERTILIZER APPLICATION

ASLAM JOHN, MUHAMMAD IBRAHIM AND MUHAMMAD ISHAQ

Abstract: Excessive use of nitrogen fertilizers is a factor of nitrate accumulation in vegetables which causes health problems to the consumers. A study was conducted to assess the effect of NPK fertilizers on NO3 accumulation in okra (Abelmosclus esculentus) and carrot (Daucus carota) at Ayub Agricultural Research Institute, Faisalabad. For okra five N (0, 100, 150, 175, 200 kg ha^-1) and two P2O5 rates (0, 75 kg ha^-1) were tested with 60 kg K2O ha^-1 as basal dose. To carrot four N (0,25,50,75 kg ha^-1), three P2O5 (0, 50, 75 kg ha^-1) and two K₂O rates (0, 25 kg ha^-1) were applied. Increasing fertilizer rates increased NO₃ concentration over control in okra and carrot. However, the application of N with P reduced NO₃ concentration in okra. Conversely, the NO₃ concentration in carrot increased significantly over control either N applied alone or with P. A balanced use of N and P (2:1) fertilizers reduced the NO₃ accumulation. Additionally, the doses of NPK fertilizers applied in this study did not pose health hazards to the consumers.

Soil Chemistry Section, Ayub Agricultural Research Institute, Faisalabad 38950, Pakistan.