Black plastic mulch affects soil temperature and yield of sweet potato under short season temperate climates

ABSTRACT Temperature is critical for the plant growth and yield of sweet potato (Ipomoea batatas L.) in northern cool season climates. Few studies have quantified the effect of temperature using different crop systems to improve the growth of sweet potato (Ipomoea batatas L.). Our study examined the impact of black mulch on raised beds for sweet potato (Ipomoea batatas L.) production in open field conditions in Manitoba. Black mulched plots were compared with non-mulched plots over 3 years for effects on soil temperature and commercial yields. Three year mean soil temperatures (19.9°C) were significantly higher under mulched plots compared to non-mulched soil (19°C). Higher total, marketable and US#1 yields were harvested from mulched plots than non-mulched plots; however, no differences were recorded for US#2, jumbo and cull yields over 3 years. Marketable yield increases of 47, 39 and 30%, were recorded for mulched plots over non-mulched plots in years 2018, 2019 and 2020, respectively, with a 3-year average yield increase of 39%. Use of black mulch contributed to increased sweet potato commercial yields in short season-temperate climates.