Effect of Foliar Application of Water Soluble Fertilizer (WSF) on Growth, Yield and Nutrient Uptake in Little Millet

Abstract

A field experiment was conducted during rabi 2021–22 and 2022–23 to evaluate the effect of different levels of the recommended dose of fertilisers (RDF) in combination with foliar application of water-soluble fertilisers on the growth, yield, and economics of rice. The experiment consisted of 13 treatments comprising different RDF levels with foliar sprays of water-soluble fertilisers at panicle initiation, flowering, and grain development stages. Plant height was significantly influenced by the treatments, with 100% RDF applied to the soil recording the highest plant height during 2021–22 and in the pooled analysis, while 75% RDF + 2.0% KNO₃ foliar spray produced the tallest plants during 2022–23 and remained statistically comparable with 100% RDF. Productive tillers per plant were not significantly affected by the treatments. Panicle length was highest under 100% RDF during the first year and in the pooled mean, whereas no significant differences were observed during the second year. Thousand-seed weight remained unaffected in 2021–22 and in the pooled analysis, but was significantly higher with 100% RDF during 2022–23. The highest pooled grain yield was recorded with 75% RDF + 2.0% KNO₃ applied at panicle initiation, flowering, and grain development stages, which was statistically on par with 100% RDF and several other treatments. Foliar application of KNO₃ at critical reproductive stages improved nutrient availability, enhanced grain filling, and increased yield. Economic analysis revealed that 75% RDF + 2.0% KNO₃ recorded the highest gross returns, whereas 100% RDF applied to the soil achieved the highest net returns and benefit-cost ratio. The results indicate that foliar application of 75% RDF + 2.0% KNO₃ at critical reproductive stages can help maintain little millet yield with reduced soil-applied fertiliser.