**10. Longevity of weed control by encapsulated herbicides**

Encapsulated herbicide formulation delivers active material to the target environment in a sustained pattern thus protecting active molecules from environmental vulnerability and eventually resulted in an efficient and extended period of weed control. Ethyl cellulose-based microencapsulated alachlor formulation showed greater herbicidal activity even after 30 days of application achieving long-term weed control [143]. Efficacy of free and encapsulated metribuzin in poly (3-hydroxybutyrate) was tested against *Avena fatua* as target species [96]. The results revealed that encapsulated metribuzin offered prolonged weed control of 70 days against *Avena fatua*, whereas 40% of germinated weeds were observed at 42 days with application of conventional metribuzin formulation. Similarly, metazachlor and pendimethalin were encapsulated separately using terpolymer (L-Lactide/Glycolide/PEG) where the weed control was effective against target weed species for 2–3 months [163]. Encapsulated formulation of pendimethalin herbicide delivered herbicide sustainably during the period of forty days to achieve season-long weed control [88].
