Guava, the apple of tropics, is one of the most common fruits in Pakistan. Mature and freshly plucked fruit has a sweet and attractive flavour. It is largely eaten fresh, but is also used in jams and jellies.
The fruit contains 82 per cent water, 0.7 per cent protein, 11 per cent carbohydrate and a fair to good amounts of vitamins A, B and C, plus some minerals and high amount of pectin.
It contains three to six times more vitamin C than the oranges, 10-30 times more than the bananas and about 10 times more than the papaya. The fruit is also a useful source of calcium, nicotinic acid, phosphorous and soluble fibre.
These are good for immune system and in reducing cholesterol thus protecting the heart. Like other fruits and vegetables, guavas contain no saturated fat, sodium or cholesterol. There are about 25 calories per guava. Experts give maximum marks to this fruit in terms of its nutritional value.
It is extensively grown in Sindh and Punjab. It adapts to the most conditions of soil and climate, prevailing in the country. This fruit occupies third position after citrus and mango in terms of area and production.
About 194 thousand hectares are under citrus and 99 thousand hectares under mango and 64 thousand hectares under guava. The area and production of guava increased significantly during the 1990's.
Data indicates that the area has increased from 55 thousand to 64 thousand hectares from 1995-96 to 2001-02 and production has gone up from 442 thousand tons to 539 thousand tons during the same period.
Yield of guava is quite low, 10-12 tons/ha, considerably less than the potential. The gap between the potential and actual yield is wide due to poor management practices and post-harvest losses.
It is also found that its production system has been passed down from previous generations and is still dominant among growers. Traditional methods are commonly used in guava management and labour is an important input in production process. The process is not mechanized but labour-intensive.
Majority of growers do not follow modern practices like the proper use of the FYM, inter-culturing, fertilizer application, sprays and timely irrigation. The problems of post-harvest losses include improper handling, immature fruit harvesting and inadequate transport and storage facilities. The post harvest losses are estimated at about 20 to 40 per cent of the total fruit production.
Guava can grow from sea level to an altitude of about 5,000ft (1,515m). It grows best with the annual rainfall below 40 inches (1,016mm) restricted from June to September. The young plants are susceptible to drought and cold conditions.
Although the plant requires dry atmosphere at the time of flowering and fruiting, high temperature at the time of fruit development causes fruit to drop. Guava tree is very hard and can thrive in all types of soil from the alluvial to lateritic. However, it can be grown on heavier but well-drained soil. The best soils are deep, friable and well-drained.
The guava is generally propagated by seeds; root suckers, root-cutting, layering, and gootee. Propagation through budding has not been very successful. Tree-ripe fruits should be used for seed extraction.
The seed should be cleanly washed, dried in shade, mixed with wood ashes and stored in preferably closed containers in a cool place until sowing. Guava seeds retain their viability for a year, but it is better to sow them promptly.
Seeds taken from winter crop should be planted not later than the following monsoon. Seeds are sown broadcast, or in lines in flat, or preferably raised beds at the commencement of rains. Seeds germinate after three weeks but may take longer time under unfavourable conditions.
Planting of guava is usually done in June-July and October-November. The land is thoroughly ploughed. Pits of 60 X 60 X 60cm size are dug at a spacing of six to seven metres on either side.
The pits are filled with a mixture of tank slit, well-rotten compost or the FYM on top soil in equal proportion to which one kg of super phosphate is added at the commencement of monsoon. Layers taken from good pedigree trees should be planted to obtain good crop.
Space between plants is generally recommended at 20-25ft, while 25ft is considered the best space for commercial planting. The total number of fruits per plant and the number of fruits of different grades do not influence at early stage by plant density but high density planting adversely effects the quality.
To keep the guava plants healthy, vigorous and productive, it is necessary to assess the nutritional requirements of the plant. Growers are regularly using the FYM in guava orchards to maintain the fertility level. It has been observed that growers do not follow the recommendations of scientists in respect to its nutritional requirements.
The plant heavily depends on soil nutrients and removes nitrogen, phosphorus and potash from the soil in substantial amount. Mature trees may require as much as 112 pound of actual nitrogen per year.
Guava is a bushy tree. The lateral branches, up to a height of 2-3ft from the ground, should be pruned. Pruning needs to be done regularly at all stages of growth and development.
During early years the formative pruning is necessary to train the tree to attain an open-centred form in order to reduce the height and to have desired number of strong productive branches. Mature shoots are pruned regularly to reduce excessive vegetative growth and to encourage new shoots bearing flowers.
The plant population is found not to be systematic or regular in all types of guava orchard. Those who plant their orchard about 15 years ago planted 67 trees per acre in Sindh and 65 trees per acre in Punjab.
However, in recent years growers have realized the importance of plant's space and have decreased the number of trees to about 55 in Sindh and 52 in Punjab. Table. Major factors affecting production and technology adoption have been recognized based on a primary survey of guava producers, secondary sources and direct observation of the farms.
The major problems identified are old planting material, poor management practices, extensive fruit dressage and attack of insects and pests. This sector has a tremendous scope for future expansion of production and export performance.
This would be possible by screening the potential planting material as there is the potential to improve the production by up to 30-40 per cent with better management practices and adoption of scientific recommendations.
