Neem oil encapsulated electrospun polyurethane nanofibrous bags for seed storage application

An ex-situ conservation of seeds is necessary to preserve the active germplasm of crops for longer period to protect their viability and longevity. The Indigenous seed storage systems causes considerable seed-grain losses which accounts nearly 1.3 billion tons worldwide. The primordial factors contributing in storage losses are nature of seeds, temperature and moisture which also promotes fungal or insect growth.

Present research attempts to overcome the qualitative and quantitative seed storage losses by designing the polyurethane based nanofibrous bags containing uniformly distributed neem oil.
The neem oil is a bio-pesticide effective over 600 species of pests including insects, nematodes, fungi and viruses. While polyurethane has been chosen for its excellent mechanical and thermal properties along with water resistivity.

The bags are fabricated by an easy and effortless technique called electrospinning. The material characterizations performed were, SEM, FTIR, TGA, contact angle, mechanical testing, water vapor transmission rate, and microbial assay. The as fabricated bags are hydrophobic, have high load carrying capacity and lower water vapor permeability due to their nano topography and the values are comparable to the commercially available bags. The real time application of as fabricated seed storage bags has been tested by storing seeds at normal room temperature and moisture conditions for 75 days and compared with commercial storage bags in terms of inhibition of seed borne fungi. The antifungal testing performed by incubating the stored seeds on Sabouraud Dextrose Agar infers that, less than 10% seeds from nanofibrous bags were infected with storage borne fungi, Aspergillus niger, whereas nearly 70% seeds iwere infected from commercial polypropylene bags.

An antifungal assay performed by incubating the seeds stored in neem oil loaded polyurethane nanofibrous bags (PUNO-10%)and commercial polypropylene bags (PP-Knitted and PP-Patterned) for 75 days at normal room temperature and moisture conditions.