KARACHI (PPI) - The ecological diversity of Pakistan holds immense comparative advantage for production of horticulture products, fruits, vegetables and floricultural products - for exploitation of the world's $80 billion plus annual fresh fruit and vegetable market. But country remains 'low level' producer and trades essentially for domestic markets, said Asian Development Bank's experts. In an updates on Agriculture Sector of Pakistan prepared by ADB consultants and experts, it said small quantities of exports are limited to two 'monopoly products', kinno and mango with small amounts of exports of potato, onions and lady fingers to regional markets like Sri Lanka and Middle East. The share of horticulture in agriculture value-added is about 12 but has further expansion potential. Punjab produces most fruits and vegetables compared to other provinces: 63 per cent of fruits and 60 per cent of vegetables. Horticulture sub-sector can be a good source of foreign exchange earnings as there is high demand for Pakistani vegetables and fruits in international markets, especially mango, apples, dates, citrus. Export values of fruits and vegetables as a proportion of world's revenues for fruits and vegetables are on up trend, albeit slowly- from 0.12 per cent in 1990 to 0.16 per cent in 2004, they added. Vegetables like broccoli, brussel sprouts, lettuce, all kind of green beans and asparagus grows very well in Pakistan's ecological conditions. Since these vegetables are not a part of local cuisine, there is no local market and export linkages have not been established. According to ADB studies, barring a few commercial vegetable farms, which are vertically linked to high-end local markets, bulk of vegetable production is concentrated around urban centres for supply to local fruit and vegetable markets for daily auction. Overall horticulture production in Pakistan has been rising steadily. This was primarily due to increase of area under production. Yield growth has been slow especially since early 1980s. Unlike major crops, vegetable, fruit farming received minimal research, development and extension services from Government. Horticulture farming is characterised by low input use and hence low output situation, leaving substantial improvement for yield improvement. Still nascent exporter of high value, perishable commodities like fruits, vegetables, Pakistan's horticulture sub-sector will have lot of catching up to do to become a competitive exporter of these commodities, starting from production of huge quantities of high quality and cost competitive products, which would require among others, compliance to stringent international standards. ADB experts say Pakistan has rich and vast natural resources base, covering various ecological and climatic zones. Based on physiography, climate, land use and water availability, Pakistan can be divided into ten agro-ecological zones. Agriculture remains important sector of Pakistan economy. From 2000-2008, it accounted for 23 per cent of GDP, 25 per cent of export receipts and 44 per cent of total labour force.