Assessing the Importance of Natural Regulating Mechanisms in Weed Management: The Case of Weed Seed Predation in a Winter Wheat Field and in Adjacent Semi-Natural Habitat in Northern Hungary

Abstract

Weeds are one group of pests that significantly reduce crop yields and qualities, while herbicide use poses a risk to human health and environment. Weed seed predation has been identified as a potential biocontrol approach offering sustainable weed management. It causes substantial seed losses on weed species in crop fields, and thus may result in a reduction in herbicide use. This study aimed to investigate the relevant seed predation patterns on important weed species, Galium aparine L., Papaver rhoeas L., and Apera spica-venti L., in a winter wheat field and the adjacent semi-natural habitat (SNH) near Gödöllő, Hungary, assuming that weed seeds are likely to be predated, but predation levels may differ by weed species and habitat type. Sampling rounds were performed twice, in 2019 and 2021, before crop harvest, by placing a total of 240 seed cards (120 cards/round) on the soil surface inside both crop field, and in the adjacent SNH. Seed predation was assessed on each card every 24 h, for 5 days in 2019 and 6 days in 2021. The results revealed high intensity (100%) of seed predation on the evaluated weed species, during the exposure periods in both years and habitat types, although weed seeds were significantly consumed (p < 0.001) in 2019 as opposed to 2021. Whereas, seed consumption levels were not significantly different (p = 0.802) among habitat types, and between habitats and years (p = 0.842). The optimum period for measuring weed seed predation was found to be after 48 h of field exposure. Our findings showed that seed predation reduced the number of exposed weed seeds on the soil surface, which may decrease the weed seed banks, and the number of weed seedlings the next cropping season.