This year, we undertook research to further und Ralph Lauren Mens Polo Shirts Australia off started withÂ erstand the dynamics of the relationships among factors affecting banana and plantain production in Africa such as pest and diseases, biotic and abiotic stresses, and farmersâ€™ preferences. This is to establish some of the underlying causes why bananas and plantains in Africa are as they are. More importantly, this would help us plot a more effective course for our Musa research-for-development efforts.
In East Africa, we conducted large-scale diagnostic surveys with our partners particularly in the major production areas of Uganda, Rwanda, Burundi, Eastern DRC, and central Kenya. We mapped yield levels, crop management practices, pest and disease pressure, nutrient deficiencies, and ecological parameters such as rainfall and altitude.
Our surveys came up with some surprising facts:
- Yield levels (t/ha), taken from measurements of hundreds of farmers fields, were more than double the figures reported by national statistics and cited by FAO;
- Uganda, which has been traditionally regarded as the regional champion of banana production, actually had lower average yields (around 15 t/ha) than neighboring Rwanda, Burundi, and East DR Congo (more than 20 t/ha);
- Sigatoka disease pressure, which had been the primary focus of breeders, was generally low, especially in the higher altitudes;
- Nematode and weevil pressure was still important in the lower parts of the highlands (less than 1200m above sea level), but were not a primary yield constraint in most production areas;
- Nutrient deficiencies were widespread. With the exception of young and volcanic soils near the Albertine rift, the dominant Acricols and Ferralsols were low in nutrient stocks.; and
- Soil organic matter management is a key factor, and often explained the large production differences observed when moving 50 meters away from the relatively fertile soil adjacent to houses to banana plots farther away and less likely to receive discarded kitchen waste.
Our on-farm fertilizer trials across Uganda showed that modest fertilizer doses (average 71N, 8P, 32K kg ha-1 yr-1) doubled yields from 10 to 20 t/ha per year in areas such as Central Uganda. Fertilizer use proved highly profitable near large urban centers such as Kampala, but at farther distances (>150km) from the market, the increased transport cost reduced farm gate prices to levels that would make fertilizer investments too risky (marginal rates of return <100%).
Besides soil fertility, regional production gradients seemed also strongly correlated to rainfall gradients. To prove this, we explored data from past field trials, relating inter-annual yield variations to rainfall variations. Drought proved to be one of the biggest yield constraints, with an estimated 50% yield loss in large production areas in the highlands that received â€onlyâ€ 1000 mm of rainfall per year. Pot trials confirmed that even moderate drought stress (pF 2.8) resulted in strongly reduced growth (>63%) compared to pla stole helene de shopbust baugignyÂ nts that remained well watered (pF 1.8). Drought stress does not result in obvious visual stress symptoms, explaining why farmers and researchers in the East African highlands had not given it much attention.
We are planning to conduct similar diagnostic surveys for the plantain systems in West and Central Africa, as well as setting up irrigation trials in West and East Africa, in 2010.
Our plant health researchers are also conducting studies to probe deeper into the complex relationships between pest and disease resistance and abiotic and biotic stresses, and develop appropriate solutions to optimize Musa production in Africa.