New Delhi, May 22 -- You can read a coconut tree like a document. Smooth bark means a tree never tapped; notched footholds, called khapa in Goa, signal a history stretching back to Portuguese-era law, when every plantation palm was required to be tapped. "All the old marked trees are at least 50 years old," says Hansel Vaz of Cazulo Feni, who tends a 160-acre farm he revived from decline, "and that points to a serious problem: an ageing population of coconut trees, and very few new ones being planted."

The notches also record who climbed and how, hands-up for the coconut plucker, toes-first for the toddy tapper, who moves before dawn because the sap waits for no one. That first collection, around 4.30am, yields neera/nira, known as kallu...