Usha Ghatowar smiles wryly when asked about the pay she earns picking leaves at a colonial-era tea garden in India's Assam.

"Do you think 3,000 rupees ($48) are enough when your monthly expenses can be double that?" she mumbles, as she puts on her jaapi hat of woven bamboo and palm leaves and takes a sip of tea from a steel mug.

As the women workers around Ghatowar nod in agreement the heavens open — it has started raining heavily in recent days after three largely dry months.