A scientist checks a papaya orchard undergoing nutrition and population density studies. The Centre has successfully incorporated resistance to mosaic virus into the commercially cultivated species, Carica papaya, through hybridization. - - Tropical Horticulture. Tropical fruits cover about 90 percent of the total fruit crop area (over one million hectares) cultivated in India. However, poor quality yields, high production costs and heavy losses due to pests and diseases, have plagued the tropical fruit and vegetable industry. A centre for advanced studies in tropical horticulture was established at the Indian Institute of Horticulture Research in Bangalore with assistance by the Food and Agriculture Organization of the United Nations (FAO), to help improve, protect, produce and utilize more tropical fruit, vegetable, ornamental, medicinal and aromatic crops. Emphasis was on developing new varieties of tropical crops, plant nutrition, disease and pest control and irrigation and post-harvest technologies, with the main objective of improving the quality and quantity of horticultural produce in India. FAO also helped develop post-graduate courses in tropical horticulture at the Institute in collaboration with the University of Agricultural Sciences and provided international training programmes and specialized equipment and facilities. Extension programmes are training farmers in improved tropical horticulture.