The underlying cause of the 2009 sorghum failure in Kongwa district and its implications for Tanzania's vulnerability to climate change.

摘要

Low rainfall has been blamed for the recent crop failure in Kongwa district, within Tanzania's Central Zone, when 310 out of a total of 331.2 mm of rainfall were concentrated into the first 4 months (November to February) of the 2008-09 cropping season. In May 2009, farmers in this district, expected yields from early maturing (short/intermediate) varieties of sorghum, such as Macia and Pato that were late planted in January and February, to be less than 250 kg/ha. They complained that late delivery of seed of these varieties had led to the poor yields. Records kept by thirty seven subsistence farmers throughout the cropping season indicated that an average of 62 kg of sorghum grain of both early and late maturing varieties was harvested per household by June 2009. This is sufficient for just 14 day's food supply for an average household comprising three adults, two adolescents (aged 10-18 years) and two children (aged less than 10 years). In addition, each household had accrued financial losses, averaging Tsh64, 527.65 (Euro 33.79) from expenditure on wasted inputs. Furthermore, the high incidence of Covered Kernel Smut in sorghum fields suggested that farmers had been supplied with contaminated seed, while the limited availability of seed of the Striga-resistant sorghum varieties, Hakika and Wahi, had allowed this parasitic weed to flourish in their fields. It was estimated that these two pests could have caused sorghum losses in excess of 50%. Each household that was impoverished by this crop failure will have to raise an average of Tsh436, 070 (Euro 228.36) to cover its grain deficit until June 2010.