Control of aggressive weeds in coffee-growing areas using coffee honey waters through aerobic and anaerobic fermentation.

Context: Coffee production in Colombia plays a vital role in the economy and sustains thousands of families, yet it faces challenges from weed competition for essential resources (water, light, and nutrients), which reduces productivity (Salazar & Hincapié, 2020). Conventional chemical herbicide use has led to weed resistance and environmental damage (Labrada & Parker, 1996), prompting the search for sustainable alternatives like coffee mucilage ("aguas mieles"), a byproduct rich in organic compounds with herbicidal potential.

Knowledge Gap: While previous studies have examined natural herbicides such as cocoa mucilage, limited research exists on coffee mucilage's effectiveness, particularly under aerobic and anaerobic conditions. Furthermore, the influence of fermentation duration and application rates on its efficacy remains undetermined. This study addresses these gaps by evaluating these parameters in the coffee-growing region of La Plata, Huila.

Objectives: The primary aim was to assess coffee mucilage as a weed control method. Specific objectives included: (1) characterizing prevalent weed species, (2) determining the effects of fermentation periods (8, 15, and 24 days) and application rates (1L and 5L) under aerobic/anaerobic conditions, and (3) monitoring its impact on broadleaf and grass-type weeds.

Methodology: Conducted at El Mirador farm, the study employed thirty-six 1m² bamboo quadrats. Fermented coffee mucilage was applied under two conditions (aerobic/anaerobic), three fermentation periods, and two application rates. Treatment efficacy was assessed through visual evaluation of wilting and necrosis symptoms, with damage percentages calculated by weed type.

Results and Conclusions: Extended fermentation (24 days) with high application rates (5L) under anaerobic conditions proved most effective, achieving 98.57% control of broadleaf weeds and 96.67% for grass-type weeds, with broadleaf species showing greater susceptibility. These findings position coffee mucilage as a viable alternative to synthetic herbicides, offering both economic and environmental benefits. However, further research is recommended to examine its chemical stability and long-term soil impacts.