Cotton Response to Salinity and Different Potassium‐Sodium Ratio in Irrigation Water

Abstract

AbstractThe present study was designed to investigate cotton response to different salinity levels at different K/Na ratios of irrigation water.The salinity levels in irrigation water were 3200 and 6400 mg/1 and the control treatment had a 320 mg/L. Potassium/Sodium ratios in irrigation water were 1: 9 and 1: 4.Some agronomic traits were studied as well as leaf water Potential (LWP), and leaf samples were taken for elemental analysis.Statistical analysis showed that increasing total salinity of irrigation water reduced seed yield and total dry weight of cotton but not number of total or open bolls. Lower K/Na ratio (1:9) was of benificial effects on most agronomic traits.Increasing salinity of irrigation water caused an increase in Na, but not K or Ca content of the cotton leaves; while decreasing K/Na ratio in the saline irrigation water decreased the K/Na ratio in the leaves. Lower leaf water potential was found to be associated with higher levels of both water salinity and K/Na ratio.A strong relationships were found between cotton seed yield, LWP and K/total bases content in leaves. Ionic content relations (K/Na and K/total bases content) were found to be of a strong association with LWP.In brief, it could be concluded that increasing K to certain extent; K/Na (1: 9) could be useful in irrigating cotton plant with high water salinity.The benificial effects of potassium additions to diminish the salinity effects in cotton may be the consequence of improved plant water relations, as well as the status of ion relationships.