Synthetic Mulches in Organic Hardneck Garlic (Allium sativum subsp. ophioscorodon) Production

Abstract

The demand for certified organic garlic (Allium sativum) in Canada is increasing; however, garlic can be challenging to produce organically, as it does not compete well with weeds, requires relatively fertile soils, and is grown in a biennial cropping system. Synthetic mulches have been adopted in organic production as they can be an economical method to improve vegetable production by reducing weed pressure and modifying soil conditions. We hypothesize that garlic quality and overall yield will be improved when using synthetic mulches. In 2017-18, we conducted a randomized complete block design experiment to compare garlic production of black plastic, white plastic, and Kraft paper mulch treatments to a control with no mulch at a certified organic farm in Krestova, British Columbia. We evaluated garlic characteristics associated with yield and quality, changes in soil nutrition, and weed control of the mulch treatments. We found that plastic mulches had the best weed control, and all synthetic mulches increased minimum and maximum bulb diameter, clove count, and yield compared to the control. Mulching materials did not influence soil nitrate concentrations. The results support the hypothesis that synthetic mulches increase the quality and yield of the garlic compared to the control. Our findings suggest that synthetic mulching may be a key component of improving garlic production systems.