COW MANURE INCREASES THE CHLOROPHYLL CONTENT (SPAD) AND IMPROVES CABBAGE YIELD UNDER FULL AND DEFICIT IRRIGATION

Chlorophyll content is a pivotal physiological characteristic of plants that is affected by water restriction

and organic fertilization. The present study examined the effect of three irrigation levels on chlorophyll

content (SPAD) in white cabbage plants under three different fertilization treatments over a period of

two years. The irrigation levels were W100 (full irrigation), W75 (25% less than W100), and W50 (50%

less than W100). The fertilization treatments were F0 (mineral fertilization), F1 (cow manure

fertilization providing 3% organic matter content in the topsoil), and F2 (cow manure fertilization

providing 4.5% organic matter content in the topsoil). When two-year means are considered, a

substantial decline in SPAD values is observed in response to water scarcity. The W100 treatment

resulted in a higher SPAD value of 42.6% in comparison to the W50 treatment. Applying manure

demonstrably increased the SPAD value. The maximum value of 62.3% was observed in the F2-W100

treatment. This signifies a 52.7% increase compared to the F0-W100 treatment. At the W50 irrigation

level, the F2 treatment had a SPAD value similar to the F0-W100 treatment. A similar outcome was

observed in the F1-W75 treatment, which produced a significantly higher SPAD value than the F0-

W100 treatment. A substantial linear relationship was identified between cabbage marketable yield and

SPAD values. In conclusion, the findings of this study demonstrate that applying cow manure is more

effective than mineral fertilization for achieving high plant yields under water-scarce conditions due to

increased chlorophyll content.