For years, Zimbabwe's white farmers have felt the wrath of Robert Mugabe, as they have been thrown off their land to make way for soldiers and ruling party cronies. Now, black farmers have also become the focus of his unwelcome attentions. Lot Dube's crops of onions, tomatoes and sweet potatoes were growing nicely when soldiers marched into Insiza district, in the south of the country, set up camp and declared that all crops other than maize would be destroyed.