Insecticide-releasing LLDPE films as greenhouse cover materials

Abstract

The use of chemical pesticides is limited by several public health concerns regarding their toxicity levels and indiscriminate use. Nevertheless, they are still vital components of agricultural industry since no other competitive equivalents to chemical pesticides still exist in terms of efficiency. This study describes the preparation and biological assessment of an insecticide releasing plastic film for agricultural covering purposes. The formulation was prepared by incorporation of deltamethrin loaded, nano-sized halloysite nanotubes into polymeric films. Thermal, morphological, and mechanical properties of films were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Universal Testing Machine UTM. Sustained release profiles of the films were evaluated by Thermogravimetric Analysis (TGA). Results reveal that deltamethrin was successfully loaded into halloysite nanotubes and nanotube incorporation enhances the elastic modulus of linear-low density polyethylene (LLDPE) films. In addition, films exhibit controlled release function of the active agent for 32 days. Bioassays of the nanocomposite films with varying deltamethrin doses tested on grasshoppers showed that the LD50 values of the films are 1.85 10 !! g/cm 2 . Insecticidal activities of films were tested in greenhouse on Medicago Sativa plants contaminated with thrips and aphid. Nanocomposites are observed to repel mature aphids and kill young aphids and thrips.

Environmental Sustainability of Greenhouse Covering Materials

“…Sustainability concerns in crop production and the need for ideal pest control management systems and organic cultivation [15] have informed the development of greenhouse materials with customized properties such as higher photo-selectivity and slow insecticide release capabilities [32,33]. Other properties associated with modern greenhouse materials are limited droplet formation, reduced heat losses, accumulation of dust, and transmission of a particular wavelength of light [14,31,32,34].…”

“…The Chinese prefer fired clay blocks and compacted clay as shown in Figure 1 [21] while the construction of greenhouse walls and roofs using one material such as glass or plastic films and sheets is common in other countries [14,34,36]. Zhang and co-researchers reported low conductivity in the clay bricks constructed with agricultural waste (0.280 W m −1 k −1 ) compared to porous clay blocks.…”

“…Secondary materials include semi-transparent solar panels [1], plexiglass (rigid polymethyl methacrylate PMMA) [34], and PP nonwoven fabric Agril [24,36]. The ecological sustainability of plastics and glass was emphasized in the current review article because these materials offer distinct benefits and are affordable and commonly available.…”

Environmental Sustainability of Plastic in Agriculture

“…The main challenge is to achieve similar capabilities using bio-based polymer films/covers. The data reported by Antón, Torrellas, Raya, and Montero [39] and Seven, Tastan, Tas, Ünal, and Ince [40] is based on polycarbonate and LLDPE films, which are not biodegradable. However, the degradation process can be augmented by UV light and oxidizing agents [41].…”

Chitosan as a coating material in enhancing the controlled release behaviour of zinc hydroxide nitrate–sodium dodecylsulphate–bispyribac nanocomposite

“…Therefore, to minimise the incorporation of the pesticide residues into food and water cycle, extensive research on controlled release formulation (CRF) of agrochemicals has been reported in the previous studies (Kah and Hofmann 2014;Cao et al 2019;Seven et al 2019;Song et al 2019;Tang et al 2019;Wani et al 2019). The pesticide with CRF was fabricated by incorporating or intercalating the pesticide into a host material which acts as a carrier for the pesticide (Bugatti et al 2019;Rebitski et al 2019;Sarijo et al 2019;Wang et al 2019).…”