estates usually required two months’ labour a year from adult men, one month for rent, the second for Hut tax. However, on some estates the obligations of labour tenants were extended. The demand for estate labour declined in the 1920s, and British Central Africa Company was the first estate owner to modify thangata. The company issued seed to African tenants so that they could grow cotton or tobacco under supervision, and then sell their crops to the company at low prices. The Natives on Private Estates Ordinance 1928 formalised this arrangement by allowing landlords to receive rents in cash, in a fixed quantity of acceptable crops or by direct labour. The term thangata applied both to rent in kind, common on tobacco and cotton estates, and to the older form of labour thangata, which persisted on the tea estates that required direct labour. By 1946, those estate companies that had formerly relied on labour tenants for their workforce complained that thangata was virtually unenforceable, as the workers ignored their contracts with impunity and refused to pay rent. A proposed rent increase in 1953 led to further resistance, and riots in August 1953, leading to eleven dead and seventy-two injured. Following these riots, the Governor Colby urged that estate land should be acquired through voluntary purchase, and the colonial administration purchased 142,000 hectares by 1954. At independence in 1964, only 171,000 hectares of estates remained, mostly tea plantations. After independence At independence in 1964, the cultivable area of Malawi was estimated at 3.42 million hectares (net of the remaining estates), about 90% of which was cultivated. Most of the land in Malawi suitable for farming food crops was available at the time of independence to Malawians without an obligation to pay cash rent or provide labour services. From 1950 to the mid-1980s, Malawi exported substantial amounts of maize. Initially, this was the result of a policy change to promoting maize as a cash crop after the 1949 famine, but it continued despite later indecision on whether such surpluses should be promoted. Smallholders’ estimated average yields from local maize rose from 0.6 tonne a hectare in the 1950s to 0.8 tonne a hectare in the 1960s, then to 1.2 tonnes a hectare (1.8 tonnes with moderate fertilizer) in the 1980s. Up to the mid-1980s, Malawi was a net maize exporter; its agricultural growth rate was 6% a year between 1973 and 1982.