Effective and Sustained Control of Soil-Borne Plant Diseases by Biodegradable Polyhydroxybutyrate Mulch Films Embedded with Fungicide of Prothioconazole.

Ge Chen,Fengmin Li,Lidong Cao,Chong Cao,Bo Xu,Qiliang Huang,Pengyue Zhao

doi:10.3390/molecules26030762

Abstract

Soil-borne diseases and plant rhizosphere nematode have caused many crop yield losses. Increased environmental awareness is leading to more restrictions on the use of certain fumigants and root irrigation methods due to their impact on human health and soil system. Therefore, it is necessary to find alternative treatments to maintain crop economic yields and environmental sustainability. In the present work, biodegradable antifungal mulches were prepared by blending poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHB) with fungicide of prothioconazole (PRO), which were used for effective and sustained control of soil-borne plant diseases. To reveal the application prospect of the PHB/PRO composite films in the management of soilborne plant diseases, some physical and biological properties were evaluated. The proper mulch film of PHB/PRO was assessed based on its mechanical and optical properties, while water solubility and the film micromorphology was further characterized. The release patterns of composite films under different pH levels were investigated. Moreover, the in vitro antifungal bioassay and pot experiment showed satisfactory bioactivity of the PHB/PRO films against Sclerotium rolfsii Sacc., a soil-borne disease in peanut fields. This study demonstrated that the biodegradable mulch films containing PRO fungicide are capable of inhibiting soil-borne plant pathogenic fungi effectively, and this facile but powerful strategy may find wide applicability in sustainable plant and horticulture protection.

Highlights

With the rapid development of protected agriculture and intensive cultivation, the occurrence of soil-borne diseases and nematodes is becoming more and more serious
It is highly desirable and promising to use biodegradable antimicrobial mulch films embedded with fungicides to manage soil-borne diseases
The main goal of this work is to propose novel, environmental-friendly mulch films embedded with fungicides, which can control soil-borne plant diseases effectively, and offer ecological and economic advantages, alleviating the environmental pressure brought about by non-biodegradable agricultural plastic films and pesticides

Summary

Introduction

With the rapid development of protected agriculture and intensive cultivation, the occurrence of soil-borne diseases and nematodes is becoming more and more serious. The main treatment is root-irrigation of pesticides or root spray These methods can control the soil-borne diseases efficiently, a sizable quantity of pesticides would leach into the soil, which inevitably causes serious impacts on the soil and groundwater. Other physical or soil fumigation techniques commonly use plastic films [3,4] These agricultural plastic mulch films are typically composed of polyethylene [5] and other non-biodegradable polymer materials, which accumulate for a long time in the soil, affect the development of plant roots, hinder soil gas exchange and water infiltration, and change the structure of the soil microbial community [6,7]. Biodegradable antifungal mulch films can prevent and control soil-borne diseases as they degrade in soil to release active ingredients

Objectives

Results

Conclusion