By Ardee NAPOLITANO and Sybille de La Hamaide BOUVINES, France (Reuters) – Emmanuel Lefebvre produces thousands of tonnes of endives on his farm in northern France annually, but this year he may abandon his crop because of the crippling energy costs required to freeze the harvested bulbs. Across northern and western Europe, vegetable producers are contemplating halting their activities because of the financial hit from Europe’s energy crisis, further threatening food supplies. Surging power and gas prices will impact crops grown through the winter in heated greenhouses such as tomatoes, pepper…