Losses in potato yields of 20-50% are commonly caused by potato-cyst nematodes (PCN; Globodera rostochiensis & g.pallida)in the Andes. Bolivian scientists have sought collaboration with two EC centres to develop a novel basis for lessening the impact of this pest on production systems. The Work will enhance traditionally based procedures, complement current work in Southamerica ondevelopment ofresistant cultivars andcontributeto reduce use of nematicides. Peruvian and Bolivian agronomists have established that two secondary traditional crops (a legume, tarwi, Lupinus mutabilis,and a grain, quinua, Chenopodium quinoa)reduce PCN infest at ions in soilwhenused in rotation with potato. Usually,unhatched juveniles of PCN can survive for up to 20 years in the soil as hatching occurs in response to specific factors released by the roots of potato plants. This effect does not normally occur on cropping with non-host crops.Both quinua and tarwi induce abnormally high declines apparently by releasing chemicals that affects hatch of PCN. Neither species is a host for PCN and so the nematodes die rapidly. The consequent decline in the density of soil infestation lessens crop loss and enables increased potato cropping within rotational control. The project will quantify the enhanced decline rates of PCN induced by the two non-host crops at field sites within Bolivia. The mode of action of chemical factors on hatch, dormancy and viability of PCN eggs will be defined in laboratory conditions and in Bolivian fields. Parallel work will isolate and characterise the hatching factors or other PCN-antagonistic compounds. The programme uses advanced biotechnology within EC centres to provide results for immediate application within South America. The data gained will enable an appropriate control strategy suitable for sustainable agriculture in the Central Andes. Identification of characterised chemical factors from the two non-hosts and optimised bioassays will provide a basis for screening germplasm banks for tarwi and quinua within south America. Identification of particularly PCN-antagonistic lines would provide a valuable resource for plant breeding programmes. Programme outputs will increase quality and food production in developing countries where potato is a staple food. This will be achieved by introducing pest management systems compatible with traditional practices. Promotion of secondary (marginal) crops will also increase the biodiversity of the agrosystem.
Funding SchemeCSC - Cost-sharing contracts