Effect of foliar application of seaweed extract and micronutrients on growth, yield and nutritional quality of chickpea

Abstract:

Data gap: while seaweed extract has been tested extensively as a biostimulant on vegetables and cereals, its combined use alongside conventional micronutrient foliar spray on chickpea remains almost entirely absent from the published record, a gap this two-season field research set out to address directly. Five treatments, an untreated control, seaweed extract (SWE) at 0.5%, SWE at 1.0%, a standard micronutrient mix (zinc, boron, and molybdenum), and a combined SWE 1.0% plus micronutrient mix spray, were compared for their effect on chickpea growth, nodulation, yield, and grain nutritional quality. The combined SWE plus micronutrient treatment produced the highest seed yield at 1846 kg per hectare, a gain of 38.6% over the control, and also delivered the highest nodule number, pods per plant, and grain protein content among the five treatments. Seaweed extract alone at 1.0% outperformed the micronutrient-only treatment on nodulation and vegetative growth parameters, while the micronutrient-only treatment showed a slight edge on grain mineral content specifically, suggesting the two inputs act through at least partially distinct physiological pathways rather than one simply substituting for the other. Benefit-cost ratio was highest under the combined treatment at 2.86, exceeding both single-input treatments despite its higher combined material cost, since the yield and quality gains more than offset the added spray expense. These findings support combined seaweed extract and micronutrient foliar application as a genuinely synergistic, cost-effective strategy for improving chickpea productivity and nutritional quality beyond what either input delivers alone.