Humic acid as foliar and soil application improve the growth, yield and quality of coffee (cv. C × R) in Western Ghats of India.

Background: Humic acid is a promising natural resource to be utilized as an alternative for increasing soil fertility and crop production. A field experiment was conducted on the loamy sand soil at the Central Coffee Research Institute research farm, Karnataka, India for 2 years to evaluate the influence of humic acid on yield and bean quality of coffee with six treatments. The treatments comprised of recommended dose of fertilizer (RDF), humic acid soil application and foliar spray along with nutrient mixture and growth hormones.

Results: The data of the yield attributes of coffee revealed that the highest total nodes per branch, crop nodes per branch, flower buds, total number of fruits per branch and fruit set percentage of 17.45, 9.4, 208.65, 153.31 and 3.28, respectively, were recorded by T , which consists of RDF + humic acid granules at 10 kg acre  + nutrient mixture spray (1 kg urea, 1 kg SSP, 0.75 kg MOP, 1 kg ZnSO  + 75 mL Planofix 200 L  + humic acid at 600 mL 200 L as foliar application 25 days after blossom) during the both years of study. Humic acid application significantly improved the yield in both seasons of research. The same trend was observed in coffee bean quality and tree nutrients status. Postharvest nutrient status in the soil did not show any significance.

Conclusions: The study emphasized that application of humic acid as soil and foliar application improves the yield attributes, yield and quality of coffee apart from the economic profitability. © 2020 Society of Chemical Industry.