Role of Nutrient Imbalance on Yellow Leaf Disease in Smallholder Arecanut Systems on a Laterite Soil in India.

On-farm trials in India investigated the role of nutrient imbalance on yellow leaf disease (YLD) in arecanut on a laterite soil using compositional nutrient diagnosis (CND) approach. Soil fertility status was imbalanced with high organic carbon status and low phosphorus (P) and potassium (K). The CND norms indicated that the order of nutrient demand was changed with nutrient application. Interventions increased yield by 50% during 2007–2010. The correlations indicated positive effect of nitrogen (N) and K and negative effect of manganese (Mn) on yield. The CND indices for NPK were important discriminators between yellowed and apparently healthy populations both in 2007 and 2010. Linear regressions between leaf nutrient concentrations and CND indices were significant for P, K, iron (Fe), Mn, and copper (Cu) (R2 = 0.44–0.53). Results suggest that the predisposing factor for YLD might be nutrient imbalance in the soil leading to deficit of major nutrients in plant. [ABSTRACT FROM PUBLISHER]