I can barely hear Esther Ngumbi over the roar of greenhouse fans as she shows me around her rooftop laboratory in Morrill Hall. The benches are full of tomato plants, and the tomatoes don't look good. Half of the plants are submerged in bins of water. Their leaves are yellow and withering. Some of the dying tomatoes have flowered. I see one or two baby tomatoes on a couple of spindly plants.
