Tractors out, oxen in for fuel-starved Cuban farms⁣ ⁣ Alexander Quesada was gifted a tractor for turning a Cuban rubbish dump into a model farm, but these days he is using oxen to pull his plow as a severe energy crisis worsened by a US blockade hobbles food production.⁣ The changing fortunes of Quesada's organic farm Finca Burgambilia -- named after the vibrant purple flowers that bedeck the entrance -- follow those of communist Cuba's relations with the United States over the past decade.⁣ Quesada, 52, looks back fondly on what he refers to as the "Obama years" a decade ago, when a historic detente with Washington helped spur a tourist influx.⁣ As visitors began pouring off cruise ships into Havana, restaurant owners began beating a path to Finca Burgambilia, once a local dump, for gourmet greens like salad rocket that were virtually unheard of on the island.⁣ ⁣ But since US President Donald Trump imposed a fuel blockade in January, which put a nail in the coffin of the already sputt...