The Influence of Organic Fertilizers on Flowering, Leaf Characteristics, Nutrient amount, Branch Growth, and Yield Quality of Cocoa

Abstract

This study aims to investigate the effects of organic fertilizers on flowering, leaf characteristics, nutrient content, branch growth, and yield quality of cocoa. A completely randomized design (CRD) was employed, consisting of five treatments, with five replicates per treatment and three trees per replicate, totaling 75 four-year-old cocoa trees. Organic fertilizer was applied at rates of 0, 0.5, 1.5, 2.5, and 3.5 kilograms per tree, broadcast around the canopy every two months from the pre-flowering stage to the harvest stage. The study was conducted on an organic cocoa plantation managed by the Bua Yai Subdistrict Organic Agriculture Community Enterprise in Na Noi District, Nan Province, from 1 October 2023 to 30 September 2024. The results revealed that the average fruit set percentage per cluster, fruit count per tree, fruit width, fruit length, fruit weight, seed width, seed length, shell thickness, seed weight, protein percentage, and fat percentage differed significantly (P < 0.01). Applying 1.5 kilograms, 2.5 kilograms of organic fertilizer per tree and 3.5 kilograms of organic fertilizer per tree resulted in statistically significant differences (P < 0.01) in the fruit set percentage per cluster, fruit count per tree, fruit width, fruit length, fruit weight, seed length, and shell thickness. The application of 1.5 kilograms, 2.5 kilograms and 3.5 kilograms of organic fertilizer per tree significantly affected protein and fat percentages (P < 0.01). Organic fertilizer application at 2.5 kilograms and 3.5 kilograms per tree yielded the highest productivity per hectare, at 1,412 and 1,421 kg/rai, respectively. All fertilizer application rates increased soil pH, electrical conductivity, organic matter, total nitrogen, available phosphorus, potassium, carbon-to-nitrogen ratio, complete decomposition, and magnesium levels over time. The findings from this study can enhance cocoa yield efficiency and provide supporting data for organic fertilizer application in organic cocoa cultivation.

Keyword: Organic agriculture, organic fertilizer, growth, cocoa, Nan Province.