Biobased Sprayable Mulch Films Suppressed Annual Weeds in Vegetable Crops

Abstract

Biobased sprayable mulch (BSM) films are a potential alternative to herbicides, polyethylene plastic mulch film, and hand weeding for specialty crops. We developed a series of BSM films using locally available biomaterials [including corn (Zea mays) starch, glycerol, keratin hydrolysate, corn gluten meal, corn zein, eggshells, and isolated soy (Glycine max) protein] and tested their effects on weeds and crop yield during a total of seven greenhouse or field trials between 2017 and 2019 in Nebraska, USA. Application rates of BSM films applied in pots (greenhouse), planting holes in plastic film (field), or bed tops (field) ranged from 0.9 to 18.2 L⋅m−2; they were applied before and after the emergence of weeds. Weed control efficacy was variable, and results of greenhouse pots were rarely replicated under field conditions. Increasing the viscosity of the final suspension tested [BSM7; a mix of corn starch (72.8 g⋅L−1), glycerol (184.7 mL⋅L−1), keratin hydrolysate (733.3 mL⋅L−1), corn zein (19.8 g⋅L−1), and isolated soy protein (19.8 g⋅L−1)] reduced weed biomass by more than 96% in field-grown kale (Brassica oleracea var. sabellica) when applied to bare soil bed tops before or after weed emergence, but kale yield in treated plots was not different from the weedy control. The results demonstrated the potential for postemergence applications of BSM films, which increase application timing flexibility for growers. Further research is needed to explore the effects of BSM films on soil properties and crop physiology and yield.

A spray-on environmentally friendly degradable mulch material and its weed suppressing effect in greenhouse experiments

“…In our study, Elymus repens, although most of the leaves were necrotic, developed some new sprouts through the mulch. A similar effect was also shown by Gloeb et al (2023) [51]. In this study, a sprayable material made of starch, glycerol and soy protein was used on Guillenia avescens under eld conditions.…”

“…We also found a good control of this weed species, but we examined the post emergence effect of the mulch material. Information about weed control of well-established weeds by mulch lms is rare [51]. In this study the above ground biomass of Sorghum bicolor and Abutilon theophrasti was reduced by an application of a biodegradable spray mulch after the emergence of the weeds.…”

Characterization of sprayable mulch film from yam nagara starch for agricultural application

“…Weed control is still a major problem in agricultural activities. In general, weed management is done by using plastic mulch [4,15]. Currently, the use of plastic mulch is used in vegetable production, but the use of plastic mulch in horticulture causes serious impacts in the form of waste [14,16].…”

“…Plastic mulch used is generally made of polyethylene and synthetic polymers derived from petroleum (non-renewable resources) [17][18][19]. These materials are not biodegradable and need to be removed with special measures [15,17,[20][21][22][23][24]. Therefore, it is necessary to control weeds without waste by using biodegradable mulch.…”

“…The advantages of sprayable biodegradable mulch film are its efficient use, its end-of-life can be removed naturally without high costs and no negative effects on the environment [29][30][31]. Previously, Gloeb [15] has conducted research on the effectiveness of weed control from biobased sprayable mulch films in special crop systems. This research used corn starch as a material for making sprayable biodegradable mulch film.…”