LUCKNOW, May 25 -- In a year when infestations have plagued mango orchards across Uttar Pradesh, Upendra Kumar Singh's harvest looks promising. He is among a small group of farmers, less than 1% across the state, who use butter paper bagging to protect their fruits. The practice, though effective, has not gained traction widely, mainly due to cost. According to the Uttar Pradesh horticulture department, while the state has nearly 3 lakh mango growers, just over 2,000 have adopted the butter paper bags (Mango 'Kavach'). P4...