This episode's headline: Farm Crisis; Lebanon: After Israel Leaves. The guests include In Washington: JOHN BLOCK, Secretary of Agriculture; In Denver: Father DONALD BATTIATO, Verdigre, Nebraska, Pastor; DONALD BUTLER, Cattleman; In Des Moines: DIXON TERRY, Farmer; Reports from NewsHour Correspondents: CAROL LEVINSON (KTCA-Minneapolis-St. Paul), in Minnesota; ANN MEDINA (CBC), in Lebanon; BRIAN STEWART (CBC), in Sudan. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor