Second to Black Sigatoka (Mycosphaerella fijiensis), Moko (Pseudomonas solanacearum race 2) is the most threatening disease to plantains and bananas. No resistance has been found on commercial varieties. It is present throughout Central America, as well as in Trinidad, Grenada, Brazil, Surinam, Venezuela, Colombia, Ecuador and Peru and suspected in the Dominican Republic. Its detailed distribution in Mexico, Nicaragua, Costa Rica, Venezuela, Colombia, Ecuador and Peru is described. Symptoms, pathogenesis and survival of race 2, which is pathogenic and divided into SFR, the major disease agent on bluggoe, and A and B are described. Disease control by elimination of diseased plants by glyphosate injections is detailed. Good control was achieved in 70 % of infected farms with a 90 day fallow after injection

Important features of the disease Pseudomonas solanacearum or Moko, affecting banana and plantain are reviewed. The history and distribution, host range, symptoms, causal organisms and dissemination, pathogen cycle, disease resistance and control based on sanitation methods are briefly described

The strategy is preventative based on a climatic forecasting system which receives data from 14 agroclimatic stations, complemented by biological assessments. The method used is termed 'state of evolution', an expression of the speed of disease development which varies with inoculum potential and climatic conditions. Benzimidazole and sterol-inhibiting fungicides are applied in rotation

Phytosanitary practices are recommended to reduce the incidence in the Windward Islands of banana pests and diseases: leaf spot (Mycosphaerella musicola), crown rot (Fusarium roseum), virus diseases (bunchy top), moko disease (Pseudomonas solanacearum), banana borer (Cosmopolites sordidus), rust thrips (Chaetonophothrips signipennis), flower thrips (Frankliniella parvula), Lachnopus beetle and nematodes

The advantages of shoot tip planting material in banana production are briefly outlined. The production scheme and ongoing research at IRFA/Vitropic are summarised

Research is directed towards study of host-parasite relations. The 3 Sigatoka leaf spot pathogens, Mycosphaerella musicola (Yellow Sigatoka), M. fijiensis (Black Leaf Streak) and M. fijiensis difformis are compared morphologically and pathogenically. Species identification by electrophoresis on acrylamide gels has been studied, the species also differ in host range, geographical range, symptoms and distribution of lesions. Early tests of susceptibility of plantlets from meristem culture suggest that they react to infection in the same way as observed in the field

The leaf spot diseases of bananas and plantains, Sigatoka and Black Sigatoka, caused by Mycosphaerella musicola and M. fijiensis var. difformis are distributed worldwide and only in Central America respectively. Epidemiological studies are described in detail including seventy of the pathogens at different sites and correlation with climatic data. Susceptibilities of different banana and plantain genomic groups were found to be nearly identical for both diseases except that Black Sigatoka is more virulent so that both pathogens occupy the same ecological niche. A method developed to test the susceptibility of musa clones to Black Sigatoka using plantlets derived from shoot tip culture is described

Poor phytosanitation affects banana quality through physical defects, harbouring of pests and diseases. The implications on marketing are briefly discussed

A diseased mat eradication programme in which mats are injected with Round up, followed by cygon spray and the area sprayed with Gramoxone has been successful. 216,812 mats were destroyed between 1978 and July 1985. Findings of research funded by the EDF include early detection of infected mats by examination for corm discolouration, possibility of Ricinus comunis, begonia jumbie tomato (Solanum sp.) and Xanthosoma sp. as alternative hosts, a recommended fallow period between injection of mats and re-planting of 9-12 months, optimum weed killer and application rate (Round up at 20 mls 2 % soln) and a buffer zone of more than 8 in. in radius

The disease is endemic in Guyana and both the B and SFR strains of Pseudomonas solanacearum race 2 are present. Four resistant varieties have been introduced viz. Pilipita, Enano, Congo and Mari Congo, the first of which was best adapted to the conditions but has fruit of limited marketability