Breaking the stranglehold of striga
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CTA. 1996. Breaking the stranglehold of striga. Spore 65. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/47442
Dipping maize seeds in a very small amount of herbicide blocks the ability of Striga hermonthica to parasitize and kill crops. Experiments over the past two years m Kenya have shown that dipping seeds in the herbicide imazapyr can triple the yield...
Dipping maize seeds in a very small amount of herbicide blocks the ability of Striga hermonthica to parasitize and kill crops. Experiments over the past two years m Kenya have shown that dipping seeds in the herbicide imazapyr can triple the yield of maize. The results of the trial were announced earlier in the year at the Sixth Parasitic Weed Symposium in Cordoba, Spain. The technique has been developed by researchers at the Kenyan Agricultural Research Institute (KARI) at Kisumu, Kenya, together with plant geneticists from the Weizman Institute of Science in Rehovot, Israel. Currently, the technique is based on using a herbicide-resistant strain of maize developed by an American seed company, Pioneer International. Pioneers strain of maize can withstand herbicides which block the action of an enzyme called ace to lactate synthase . Without this enzyme, striga is unable to make vital amino acids, and dies. Trials showed that, on average, a plot of treated seed yielded almost 3.5 times as much maize per plot compared to plots of untreated seeds which had five times as much striga growing in them as the treated plots. As the dipped seeds grow, the herbicide diffuses into the growing tissue and surrounding soil, killing the striga before it can get a hold. By the time the maize is harvested the herbicide in the soil has broken down. The use of this seed-dipping technique cuts out the need for potentially harmful spraying and eliminates the buildup of residues in the soil. Additionally, the cost of using such small quantities of herbicide is so little that even the poorest subsistence farmer could afford the technology. Just 15 grams of herbicide costing $5 is enough to treat one hectare, and could bring a farmer an extra $100 of income per hectare in improved yields. At present this Pioneer strain of maize, which was developed for use in the US, is susceptible to African fungi and viruses. The KARI researchers are now crossing the Pioneer strain with African varieties to produce a herbicide-resistant maize that is suited to local conditions. George Odhiambo and Gordon Abayo Kenyan Agricultural Research Institute Kisumu, KENYA