Pakistan is a God gifted country. It has vast diversity in its soil and climate, which is suitable for the production of fruit, vegetables, flowers and other crops. Many different types of fruits of high value are produced in the country. Citrus is the largest group of fruits being produced in the country. It has high potential of export and to fulfill the needs of the country. The origin of citrus is southeastern Asia, including from Eastern Arabian to Philippine and from Himalayas to south of Indonesia. Citrus fruits are famous in the world due to its distinct flavor and therapeutic values. These are rich source of vitamin C and minerals like calcium, phosphorus and iron. Its juice is very pleasurable, tasty and soothing. It also used as fresh and for the production of many products and by products. Frozen concentrated orange juice is of great demand in the world market due to its flavor and taste.
Citrus is at the top among all the fruits for its production and trade. It is grown in more than fifty-two countries of the world. Its world wild production is 108 million. Brazil is the largest producer of citrus world wild followed by USA, China and Mexico. Pakistan has prominent position among citrus producing countries. Pakistan is among top 13 citrus producing countries. In the country area of 185 thousand hectares in under citrus cultivation with the annual production of 1.67 million tones. Major citrus growing areas of the country are districts of Sargodha, Mandi Bahauddin, Faisalabad, Toba Tek Singh and Sahiwal. It is also grown in grown in other districts of Punjab, Singh and NWFP. Sargodha district and its accessories are main sites of citrus industry of Pakistan. There 200 fruit pack houses and three juice extraction units used fro export of citrus fruit and juice.
We have favorable agro climatic conditions, more area for production, cheap labor, more water for irrigation but in our country per hectare yield is less than other leading countries of the world and has negligible share of 1.90% in world export of citrus fruit. Major reason of low production of citrus industry are attack of diseases and insects, alternate bearing, unavailability of disease free planting material, lack of technical knowledge in farmers, lack of infrastructure and improper post harvest handling. Diseases, pest and post harvest losses are major factors which hinder the production and export of citrus. About 60 years ago there were no citrus disease but no 30 economically important viruses and virus like diseases has been recognized world wild. Citrus decline is a major disorder, which is the result of wrong agronomic practices, improper nursery management and diseases caused by different pathogens. These diseases are common in nursery and also in orchards and also transmitted by grafting. Citrus tristeza closterovirus (CTV) is a major virus disease. During attack of this disease initially branches and leaves become dry. Then after sometime whole plant will dry.
Gummosis is a serious disease of citrus prevailing through out the world. In Pakistan it is present in many orchards. It is caused by Phytophthora species which the roots of nursery and adult plants. In nursery it caused foot rot, Root rot, fibrous root rot and causes 20% loss to the plants. Its symptoms are shown on leaves, stem and fruits but main symptom is gum formation on the stem of affected plants. Roots become fibrous, leaves show nutritional deficiencies. Water socked lesions are formed at the base of leaves and then spread on whole plant. Another important citrus disease is citrus canker. This is cause by bacterium Xanthomonas axonopodis Pv. Citri occurred all over the citrus growing areas. Young plants are more attacked than matures ones. When disease is sever, defoliation, die back and fruit drop occur and fruits of infected plants are unmarketable. Different insects like Citrus psylla, Citrus leaf miner, Citrus white fly, Citrus red scale and Citrus mealy bug attack on citrus crop, decreases its production and quality. This inferior quality citrus crop cannot be exported because importing countries are imposing strict regulations to save their country from different insects and diseases. If we became successful in controlling these insects and diseases attack then we can earn lot of profit from our citrus crop. Different methods used to protect our citrus crop from different pest and diseases are ( i)Use of sterile and pathogen free soil for nursery.(ii)Use of resistant rootstock if possible.(iii) Obtaining the healthy nursery plants for planting.(iv) Removal citrus hedges because these act as reservoirs for pest build up. (v) Maintain proper spacing between plants for proper management practices. (vi) Pruning and destruction of infested plant portions.(vii) Removal of weeds like cactus, gardenia etc from the nursery.(viii)Use of sticky and slippery bands to control insects.(ix)Use of pheromone traps for insects. (x) Use of natural enemies like lady beetle, lacewing and syrphid flies that feed on insects.
Chemicals like Dimethoate, Imidacloperd, Bifenthrin, Amidaclopard, Curacron, Strepotmycine, Terrazole can be used to control different insects and diseases. But the use of chemicals should be avoided because excessive use of chemicals leaves chemical residues in the fruits. Such fruits are rejected at international level because residues of chemicals cause bad effect on health. According to an estimate 30-40% of our fruits and vegetables have pesticide residues and about 17% are unable to eat due to high marginal residual limit. Therefore our focus should be on integrated control of these different barriers of production. Citrus industry experience substantial post harvest losses due to careless and improper handling during its harvesting, storage, transportation and marketing, which causes bruises and different injuries to fruits, results in various disorders and fruit decay during storage and marketing system. Our farmers do not give more attention on the harvesting and post harvest handling due to which large amount of our precious produce wasted. Manual harvesting is most common method for harvest of citrus fruit world wild. Plucking is also used in all types of citrus fruits except mandarins, which are to be picked by clipping. During harvesting fruits should not be drop on the ground because it causes injuries and disease attack. After harvest fruits should be placed in bags and not on the ground. Transportation should be done in refrigerated vans. Proper handling and cool chain transportation is very important because about 40% of products are wasted due to improper post harvest handling.Proper management for diseases, pests and post harvest handling are most primal steps to boost citrus industry. Some suggestion are (i) Scientific knowledge should be dissemination through all possible means to educate the farmers.(ii)Promotion breeding programme to generate some CVs. of high quality and of local importance. (iii) Provision of capital facilities to small growers. (iv)Training of farmers for pre and post harvest handling. (v) Establishment of cool chain infrastructure.(vi) Establishing a well-developed and strong market of international levels.