Potassium and Phosphorus

Abstract

Mustard (Brassica campestris L. var. Pusa bold) was grown in sand culture at different K levels. Plant parts (leaves, stems and petioles) were collected at 6 growth stages. Relations between K concentrations in plant parts and grain yield indicated that plant analysis performed at either vegetative (30 d) or bloom (65 d) period could be used to diagnose K. The computed critical K levels were 3.0% in leaves, 5.0% in stem and 7.6% in petioles at the vegetative stage (30 d), 3.7% in leaves, 4.5% in stems and 7.8% in petioles at bloom stage (65 d). At all stages, K in leaves correlated better with grain yield than stem and petioles. The relation between K content in plant and in the media revealed that bloom stage (65 d) was the most sensitive. Further at this stage higher correlation coefficients were recorded between K content in plant parts and yield.

Key words:

• Potassium deficiency and sufficiency