Agricultural weed and rotational crop spp., common to the high hill potato produc ion areas  in  Nepal, were  tested  to  determine  their  potential  as  hosts of  race 3 of Pseudomonas solanacearum, the causal agent of bacterial wilt or brown rot of potato. Tests were conducted under screenhouse and glasshouse conditions in Nepal and the UK respectively and a survey was conducted in Nepal to explore the incidence of natural infection. Artificial inoculation was performed by drenching cut roots of potted seedlings with a suspension of a potato isolate of biovar 2 of the bacterium.  Brassica juncea (mustard cv. Fine White), Portulaca oleraceae, Drymaria cordata and Cerastium glomeratum were susceptible to infection when artificially inoculated with the bacterium. Surface sterilised roots of these   plants contained an estimated 1ct to 108  colony­ forming units (cfu) per g of fresh root. One of 12 mustard seedling developed typical wilt symptoms, whereas other infected spp. remained symptomless. In C. glomeratum, infection tend .to localise in roots two months after inoculation whereas, it spread systemically into the stems of the other infected spp. Systemic root infection was also detected in Solanum xanthophyllum after one month but not after two months. Other spp., such as Polygonum capitata and Galinsoga paNiflora, although not infected systemically maintained high rhizosphere populations of the pathogen. Whereas P. so/anacearum declined to an undetectable level in unplanted soil within one month of inoculation, the bacterium could be recovered from the rhizosphere of all test plants for up to two months. Under natural conditions in bacterial wilt affected potato fields, infected plants of G. paNiflora, G. ciliata and P. capitata were identified although the frequency of infection was often low.

Agricultural weed and rotational crop spp., common to the high hill potato produc ion areas  in  Nepal, were  tested  to  determine  their  potential  as  hosts of  race 3 of Pseudomonas solanacearum, the causal agent of bacterial wilt or brown rot of potato. Tests were conducted under screenhouse and glasshouse conditions in Nepal and the UK respectively and a survey was conducted in Nepal to explore the incidence of natural infection. Artificial inoculation was performed by drenching cut roots of potted seedlings with a suspension of a potato isolate of biovar 2 of the bacterium.  Brassica juncea (mustard cv. Fine White), Portulaca oleraceae, Drymaria cordata and Cerastium glomeratum were susceptible to infection when artificially inoculated with the bacterium. Surface sterilised roots of these   plants contained an estimated 1ct to 108  colony­ forming units (cfu) per g of fresh root. One of 12 mustard seedling developed typical wilt symptoms, whereas other infected spp. remained symptomless. In C. glomeratum, infection tend .to localise in roots two months after inoculation whereas, it spread systemically into the stems of the other infected spp. Systemic root infection was also detected in Solanum xanthophyllum after one month but not after two months. Other spp., such as Polygonum capitata and Galinsoga paNiflora, although not infected systemically maintained high rhizosphere populations of the pathogen. Whereas P. so/anacearum declined to an undetectable level in unplanted soil within one month of inoculation, the bacterium could be recovered from the rhizosphere of all test plants for up to two months. Under natural conditions in bacterial wilt affected potato fields, infected plants of G. paNiflora, G. ciliata and P. capitata were identified although the frequency of infection was often low.