He arrived there as a refugee in 1981, fresh from earning a degree in agriculture at Kabul University. He had focused on agriculture at the urging of his mother, who used to grow vegetables to help feed their family of 10.

It was an eventful period. In 1979, when Mr. Aslami was two years into his studies in Kabul, the Soviet Union invaded, toppling Afghanistan’s nascent republic and installing a communist government. As Afghanistan descended into chaos, Mr. Aslami said, his class of 120 students dwindled to 15. Some fled the country, others were disappeared by the brutal new regime, often taken away from the lecture hall.

“If someone came to the class and read your name, you knew you were gone,” he said.

At his family’s urging, Mr. Aslami left for Iran, where he would remain for more than a decade, carrying out research and working with villagers to improve cultivation techniques. That was also where he began to see the promise saffron held for Afghan farmers.

Saffron is harvested from a fall-blooming variety of the crocus flower, a hardy perennial that grows from bulbs and can withstand Afghanistan’s harsh climate. The flowers, each containing three red stigmas that will become the spice, have to be picked by hand in the early morning, before the blossoms open to the sun.

The plants bloom for only about three weeks a year, in late October and early November. After being plucked, the flowers are dried and the stigmas separated later. Harvesters must wear clean clothes, gloves and masks, because the slightest odors can be absorbed by the flower, reducing the quality of the spice.