Nepali citrus is a Rs 2,470 million (€20 mln) per year industry. Cultivation of citrus fruits has been the income provider for people living in the mid-hills for ages. In Nepal, among all the citrus fruits, mandarin types of citrus occupy about 64% - 68% of the total citrus growing area and production, respectively, according to recent statistics on agriculture.
Now, the Nepali citrus industry is grappling with the most serious threat in history: a bacterial disease with no cure has infected most of the citrus growing hubs and is yet to receive any national attention. The world’s most destructive citrus disease, ‘citrus greening’, is threatening the groves of Nepal. The disease originated more than a century ago in southern China, where it is named ‘Huanglongbing’ (HLB), or ‘yellow shoot disease’, after its typical symptom. Since it was first recognised in Nepal in 1968, the disease has spread all over.
The disease entered the country because of the weak quarantine regulations. It is projected that virtually all the mandarin hubs in Nepal will be infected in 10 to 15 years, posing an incurable threat to citrus enterprises. The form in Nepal is caused by a bacterium, Candidatus liberibacter asiaticus, transmitted by an insect, Asian citrus psyllid, which thrives on young citrus leaves.
HLB has progressed from an “acute to chronic disease” throughout the nation and has caused the Nepali citrus industry increasing loss to the grower in terms of revenue. It has mostly squeezed the Nepali orange crop. Sweet oranges, mandarin and mandarin hybrids are most susceptible to the disease. The disease has wreaked havoc to the citrus business in Nepal, leading to a massive economic hit and has eliminated many related jobs.
In order to offset the citrus losses, quite a number of growers are venturing into different crops. Anxiety can be clearly observed in the orange growers of the mid-hills, following the noticeable sharp decline seen in the productivity from 12 metric tons a hectare to 8 metric tons in six years. Nepal has not been able to meet the citrus fruit demand and relies on imported oranges to satisfy internal demand.
According to thehimalayantimes.com, there is still no permanent solution to fighting citrus greening, but researchers and growers are trying various methods, and large sums of money are being spent for this. Globally, the methods used to control the disease – spraying to kill the psyllids and removing the infected trees – have proved inadequate. Replanting young vigorous trees have also been not effective because of the attack by the psyllids.