Bitter cassava and women: an intriguing response to food security

... Cassava is classified as sweet or bitter (manihot utilissimaor manihot palmate) respectively[6]. Farmers often prefer the bitter varieties because they deter pests, animals and thieves[7]. Like other tubers and roots both bitter and sweet varieties of cassava contain ant nutritional factors and toxins[8]. ...

... The cyanogenic content of cassava cultivars can be as small as less than 10 mg/kg for some cultivars and can be as high as more than 500 mg/kg fresh weight basis[9]. Nonetheless, some farmers from cassava growing countries often desire the bitter varieties as they deter pests, animals, and thieves[10]. The more-toxic varieties of cassava are a fall-back resource in times of scarcity in some places[11]. ...

... While many Malawian MHHs are typically advantaged compared with FHHs, in the same way as in many other developing countries, i.e., in terms of access to land and access to other resources (see e.g., Chipande 1987;Chiwona-Karltun et al. 2002;Due and Gladwin 1991;Gilbert et al. 2002; Peters Takane 2008Takane , 2009), this is not uniform. The southern and central parts of the country are dominated by ethnic groups which have historically had matrilinear inheritance traditions; this might conceivably improve FHHs' access to at least some productive assets such as land (FAO 2011;Peters 1997). ...

... These adverse social developments are claimed to have necessitated the reorganization of society into ever more complex social forms, leading ultimately to the formation of the centralstate. 23 Motivated by comparing the political structures that evolved in the valleys of Peru with those in the Amazon Basin, Carneiro (1970) o §ers a variant of the conáict theory. He contends that states could not emerge in the Amazon Basin, with its ìalmost unlimited agricultural land,î because ìin Amazonia. ...

... .. the vanquished could áee to a new locale, subsisting there about as 22 See for example Kellyís (1995, p. 294) list of such correlates that distinguishes between simple and complex hunter-gatherer societies. 23 For leading advocates of this theory see Johnson and Earle (2000). This ìpopulation pressureî approach seems to us inconsistent with the Malthusian argument that there would (almost) always be population pressure. ...

... agriculture, yet their analysis appears to be perfectly consistent with our appropriability theory on the distinction between tubers and cereals and how cereal farming led to hierarchy. Chiwona Karltun et al. (2002) provide another pertinent example that illustrates how farmers may protect themselves against expropriation by choosing ine¢cient crops. They report that women in modern Malawi, and particularly single women, prefer to grow a bitter and toxic cassava variant that requires signiÖcantly more processing after harvest than the available non-toxic variant. ...

... Nevertheless, farmers often prefer the bitter varieties because they deter pests, animals and thieves. Karltun et al. (2002) Cassava is sometimes spelled cassaba or cassada. Darwin and Charles (1839) In Englishlanguage publications, the plant may be occasionally called by local names, such as mandioca, aipim, or macaxeira (Brazil), yuca (El Salvador, Bolivia, Costa Rica, Colombia, Cuba, Ecuador, the Dominican Republic, Haiti, Panama, Peru, Puerto Rico, Venezuela), mandi´o (Paraguay), akpu, ege, ugburu, nto-roro or ukuduk (Nigeria), bankye (Ghana), bananku (Mali and other parts of West Africa), mogo or mihogo (Swahili-speaking Africa), pondu in (Lingala-speaking Africa), kappa (India), maniokka (Sri Lanka), singkong (Indonesia), ubi kayu (Malaysia), kamoteng kahoy or balanghoy (Philippines), mushu (China), man sampalang (Thailand), karapendalam (Telegu), củ sắn or khoai mì (Vietnam) and manioke, tapioka or manioka (Polynesia) (Gade, 2002). ...

... As in Amazonia, processing of bitter manioc is often women's work in Africa as well. Karltun et al. (1998Karltun et al. ( , 2002 ) asked how African women manioc farmers themselves feel about this activity that consumes so much of their time: ''Interestingly enough, the women that are the custodians of this crop do not perceive the processing or the toxin to be a problem'' (Chiwona-Karltun et al. 2002). They found that farmers, particularly women, preferred bitter manioc, because it conferred greater food security than sweet manioc in three ways. ...

... As in Amazonia, processing of bitter manioc is often women's work in Africa as well. Karltun et al. (1998Karltun et al. ( , 2002 ) asked how African women manioc farmers themselves feel about this activity that consumes so much of their time: ''Interestingly enough, the women that are the custodians of this crop do not perceive the processing or the toxin to be a problem'' (Chiwona-Karltun et al. 2002). They found that farmers, particularly women, preferred bitter manioc, because it conferred greater food security than sweet manioc in three ways. ...

... Acyanogenic cassava has been produced using RNAi technologies (Siritunga & Sayre 2003; Jørgensen et al. 2005) but it is unclear whether they will be as productive under field conditions, particularly in the light of the newly discovered role for cyanogenic compounds in N metabolism and transport (Jenrich et al. 2007). The preference for high cyanide varieties by the predominantly female subsistence farmers in parts of Africa also raises doubts about the acceptance of completely non-cyanide producing cultivars (Chiwona-Karltun et al. 2002). With increasing population density, declining soil fertility , expansion into marginal farmland, together with the predicted increase in extreme climatic events, reliance on robust crops such as cassava will increase. ...