While citrus is a major fruit crop of Pakistan, with a large share in exports of horticultural produce - the annual production of citrus in Pakistan was about 2.5 million tons in 2018 - at this point in time, yield losses of about 22% for kinnows, 25–40% for sweet oranges, 15% for grapefruits, 10% for sweet limes, and 2% for lemons are reported.
A big share of export quality fruit rejected annually due to the presence of signs of citrus greening disease on fruit. This means there is a need to control this disease to a reasonable level. There are also many diseases in the citrus crop which badly affect the fruit quality and its aesthetic look which made it unacceptable in the local and international markets.
Huanglongbing (HLB) considered as a bacterial disease assumed to be Originate from China in 1890 as “Yellow shoot disease”. The disease has symptoms on all over the plants and can be detected from leaves, shoot, chemical properties and fruits.
The Asiatic form is prevalent in Pakistan, which is a threat for the citrus industry of Pakistan.
HLB was first reported from China at the end of 19th century as “Yellow shoot disease”. In America first reported in 2004 in the state of Sao Paulo. In Africa the disease was first reported in 1937. This disease leads to a great loss in yield of citrus in different citrus growing states of worlds like Florida and Sao Paulo. At present there are more than 50 countries in Asia, Africa and America affected. The citrus export of Pakistan could be devastatingly affected due to this disease outbreak.