Rhamphicarpa fistulosa in Lowland Rice Production in Africa: a Review

Abstract

Rain fed agriculture is a common practice in most tropical regions. With a huge potential which unfortunately remains underexploited, Africa is constantly faced with the problems of self-sufficiency. Rice became especially since 1990 one of the most important food crops in Africa. Since colonial times, many governments of least developed countries have adopted policies to promote the introduction of rice as a staple food for urban populations growing. Considering harvested area, rice is the fifth most important cereal in Africa and the fourth in terms of production. In Africa, rice production is increasing at the highest rate of any cereal. The inherent problems in upland rice production are mostly due to climatic change conditions prevailing in ecological production areas, declining soil fertility, low availability of land and many other factors. In this context, lowland agriculture production is the best and offer potential in rain fed agriculture which can be practice with less difficulty and risk, because water is more available. However, farmers are facing to important phytosanitary problems and one of the most important is the angiosperm parasite rice: Rhamphicarpa fistulosa (Hochst.) Benth. Rhamphicarpa fistulosa is a parasitic weed of Orobanchiacea family. Six species of Rhamphicarpa genus were mainly native to Africa, India and Australia. Two species are native to southern Africa. On those two species, we have Rhamphicarpa fistulosa and Rhamphicarpa bredivepedicillata. Rhamphicarpa fistulosa,a facultative parasite, can cause yield losses ranging from 40% to 100%. Little information is available on the parasite and its host interaction. Rhamphicarpa fistulosa connects its xylem system to the host plant through haustorium. Parenchyma cells building were towards differentiated with cells provided by the periphery of the haustorium. According to certain scientist, a non polysaccharidic material staining dark red with saframin has been founded for different scrophulariacea. The interface between Rhamphicarpa fistulosa and the roots of its hosts never showed a secretion even if on semithin sections, a darkly staining could be observed.Little control option is also available in the management of this pest.