place-specific, although as we argue below the scope for transfer is large. Moreover, the scope for adaption – that is the scope for modifying Asian practices to suit African conditions is larger still.<sup>18</sup> The Green Revolution for rice in Asia started in 1966 when the International Rice Research Institute released IR8, the first modern variety of rice. Rice is the essential Green Revolution crop in southern Asia, and while the Green Revolution in Africa may include more than one crop as none dominates, rice will be important for several reasons.<sup>19</sup> First, Asia has already accumulated a huge stock of scientific knowledge and useful production methods that could well serve Africa if selectively and appropriately adapted to its socio-economic and agro-ecological environments. Second, as shown in Figure 2, there has been an increasing demand for rice but low self-sufficiency ratio of only about 60%. Third, lowland rice varieties, which propelled and sustained the Asian Green Revolution, have exhibited high yield potential in lowland areas in sub-Saharan Africa, e.g. a short-duration IRRI bred variety was selected by AfricaRice breeders in the 1990s and is now widely grown in the Senegal River valley. Fourth, and finally, there is a huge amount of farmlands that are agroclimatically hospitable to rice production. As discussed, Balsaubramanian et al. (2007) estimate that upwards of 240 million ha of wetlands is available, which is 1.7 times more than the 142 million ha of rice area harvested in Asia in 2008 (FAOStat, 2009).

Borlaug (2002) argues that what Africa essentially needs is a simple, effective farming system based on modern technology – chemical fertilizer, improved seeds bred for local conditions, and effective crop management practices. This is perhaps an overly simplistic, since it fails to take into account the complexity of Africa’s geography and rice production system. Nevertheless, it does reflect a commonly held view that a “seed-fertilizer” approach is also appropriate for Africa. In turn, this makes Asia’s stock of potentially profitable matured technologies especially relevant for Africa.

The Asian Green Revolution in rice did not happen overnight but was a long-term evolutionary process involving long and sustained efforts in rice research spanning more than four decades since 1966. The firstgeneration of modern rice (e.g., IR5 and IR8) were effective in dramatically increasing yield potential but were susceptible to various forms of pests and disease infestations. The second-generation of modern rice (e.g., IR36) incorporated a wide-spectrum of pests and disease resistant traits and early maturity period (Khush, 1995). Resistant modern varieties (MVs) contributed significantly to the acceleration of yield growth by reducing yield variability thereby increasing the expected yield particularly during the dry season (Otsuka et al., 1994). The shorter growth duration increases cropping intensity per year which results in more harvests from a given plot of land each year (Barker, Herdt and Rose, 1985). The third-generation of modern rice varieties

> 18 Often, the difference has to do with water availability and water management practices. See, for example, the discussion in Woperis and Defoer (2007).

> 19 Although there have been attempts to disseminate high-yielding varieties of sorghum and millet, which also have relevance for Africa, these efforts were confined largely in some parts of India (Deb and Bantillan, 2003).

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