Philosophy is a fine thing. Mr. President. but it will not cultivate or harvest perishable food crops. In his zeal to upgrade the wages and working conditions of domestic migrant labor. the Secretary of Labor has apparently overlooked the basic fact that millions of American consumers also deserve consideration. For that matter. so do the individual growers of such items as cantalopes. onions. tomatoes. and other produce. A melon field under a blazing hot sun at harvest timewhen timing and handling spell the difference between profit and lossis no place to wage a social revolution by the stubborn insistence of Federal bureaucracy.