Orchards countrywide face decimation by a fly-borne virus

8 April, 2009 - Bhutan’s most important cash crop, orange, officials say, is in danger of being wiped out as an industry because of the combination of a rapidly spreading virus, neglect by orchard owners, and poor implementation of plans by dzongkhag authorities.

Clear evidence is to be found in the decline in yield from 41 kg per tree in 2006 to 36 kg per tree in 2007. The virus, called Huanglongbing, has already wiped out 70 percent of orange orchards in Punakha. Other places like Wangduephodrang, Mongar, Zhemgang and Sarpang were also badly hit.

One of the key orange growing dzongkhags, Chukha, has seen an entire orange region being decimated in its main orange growing area of Baikuenza in Bongo gewog. “The forest used to produce around 200 to 300 truckloads per year but, right now, it’s hardly 10 to 15 trucks,” said Dr Sangay of the national plant protection centre (NPCC). He said that viruses could be present in more places.

The virus has already devastated orange production in Thailand and other countries. It is transmitted by a small fly, psyllid, which lives on leaves and transmits the virus while sucking the new leaf, which eventually kills the whole tree.

An agriculture ministry circular says: “Huanglongbing could devastate the whole citrus industry in the country, if appropriate measures are not taken soon.”

Another major threat comes from neglected and abandoned orchards. A letter from the agriculture ministry states that these orchards, because of their infestation with pests, constitute a menace to the citrus industry in the country. These orchards are being neglected either due to absentee landlords or negligent by farmers. There are 507.38 acres of abandoned or illegal orchards in the country.

“The problem is that, even if most orchard owners spray and follow good practices, the viruses can still reside and spread from these neglected orchards,” said the deputy chief of the horticultural division, Dorjee.

Another major problem is the non-adherence to earlier executive orders to rehabilitate the citrus industry by local governments. The orders had asked for the formation of citrus core groups in managing orchards at the village or community level. “Most dzongkhags, except Tsirang and Dagana, haven’t implemented the executive orders, so there’s now a proliferation of citrus pests and diseases leading to low productivity and declining citrus orchards,” said Dorjee.

The agriculture ministry is so concerned by these developments that it has issued a special ordinance to deal with the above issues to save the citrus industry in Bhutan.

According to the ordinance, an orchard investigative team would be created by the dzongkhag administration to control orchard pests. This team will investigate all pest complaints or incidents and give 30 days to farmers to control it. The team could then take other measures to control the pests, including removing the trees if the farmer cannot control it.

An absentee landlord or farmer’s orchards will be subject to pest control methods of the team. The team shall have the right of entry and can impose fines between Nu 5,000 to Nu 50,000 on anyone who violates the provisions of the ordinance.

The agriculture ministry is also proposing that illegal orchards without ownership or those on government land should be given to landless farmers for better management, the use the international practice of uprooting neglected or abandoned orchards as the best means to eliminate the pests.

The NPCC has also come up with an action plan of training and capacity development, quarantine of plants, insect proof nursery and replantation in virus-hit areas.

Except for Paro, Thimphu, Gasa and Bumthang, orange grows in all dzongkhags and is the primary cash crop for most orchard owners. In 2007, about 72,071 metric tonnes of oranges were produced.