Tailored Lignocellulose-Based Biodegradable Matrices with Effective Cargo Delivery for Crop Protection

Abstract

Controlled release and targeted delivery of agrochemicals are crucial for achieving effective crop protection with minimal damage to the environment. This work presents an innovative and cost-effective approach to fabricate lignocellulose-based biodegradable porous matrices capable of slow and sustained release of the loaded molecules for effective crop protection. The matrix exhibits tunable physicochemical properties which, when coupled with our unique "wrap-and-plant" concept, help to utilize it as a defense against soil-borne pests while providing controlled release of crop protection moieties. The tailored matrix is produced by mechanical treatment of the lignocellulosic fibers obtained from banana plants. The effect of different extents of mechanical treatments of the lignocellulosic fibers on the protective properties of the developed matrices is systematically investigated. While variation in mechanical treatment affects the morphology, strength, and porosity of the matrices, the specific composition and structure of the fibers are also capable of influencing their release profile. To corroborate this hypothesis, the effect of morphology and lignin content changes on the release of rhodamine B and abamectin as model cargos is investigated. These results, compared with those of the matrices developed from non-banana fibrous sources, reveal a unique release profile of the matrices developed from banana fibers, thereby making them strong candidates for crop protection applications.

Figure 1

Effect of pulp refining on (A) the appearance of handsheets (the refining time for each is shown on the arrow indicating increase in refining), (B) variation in thickness and air resistance with refining, and (C) strength in terms of burst and tear indices of the respective handsheets.

Figure 2

(A) SEM images (at various magnifications) of the fibrillar structure in raw banana fiber. (B) SEM micrographs of handsheets prepared from 2 min (a, e), 5 min (b, f), 10 min (c, g), and 30 min (d, h) refined pulp. Fiber quality analysis showing (C) fiber count and % length weighted fines and (D) mean kink index and coarseness of the pulp refined for 1, 2, 3, 5, 10, 20, and 30 min.

Figure 3

(A) Rhodamine B release profile of P1 (liner paper), P2, P3, and P4 (different banana papers), and P5 (copy paper). The points are connected through lines as a guide to the eye (error bars indicate standard deviation, n = 3). (B) Lignin content, density, contact angle, and air resistance of P1, P2, P3, P4, and P5. (C) SEM micrographs of surface sections (a–d) and cross sections (e–h) of P1 (a, e), P3 (b, f), P4 (c, g), and P5 (d, h). SEM images of surface and cross sections of P2 are displayed in Figure 2B.

Figure 4

(A) Abm release from P1 (liner paper), P2, P3, and P4 (banana fiber-based samples), and P5 (copy paper). (B) Schematic of the experiment design for in vitro study to measure bioavailability of Abm. (C) Time-dependent bioavailability of Abm from P1, P2, P3, P4, and P5. (Error bars in parts (A) and (C) indicate standard deviation, n = 3.)