U.K. Acharya1, S. Karki2, K.P. Paudyal3 and R. Pakka4
1Senior scientist & 4Scientist, Nepal Agriculture Research Council, NCRP, Dhankuta
2Joint secretary,MoALD,Government of Nepal
3Principal scientist, NARC
Corresponding address:umeshach@gmail.com
Abstract
Huanglongbing or Citrus greening, caused by Candidatus Liberobactor asiaticus (CLas) vectored by Asian Citrus Psylla(ACP),is reported in early 1960’s in Nepal when citrus saplings were introduced from Saharanpur, India to Pokhara valley Presently, out of 44 citrus growing districts,28 have confirmed greening positive result causing loss of hectares of productive mandarin groves across the country due to the disease We tried to adapt three strategies to control HLB:produce and distribute healthy saplings; eradicate diseased trees; and deter the vector of HLB(Diaphorina citri) using chemical measure with epic failure due to pooor legislation and implementation strategies. There are new technological advances made elsewhere such as use of tolerant scion cultivars like sugar belle and tolerant root stocks can be tested and adapted in Nepal with necessary modifications. Testing new chemicals like Zinkicides and Homobrassinolides against Huanglongbing and use of acetic acid as sex hormone to monitor ACP activities are suggested.Further cultivation of citrus under protective screens (CUPS) for sapling,mother stock and commercial fruit production with seedless varieties is other alternatives.Some of the expensive technologies need to be tested for economic feasibility.The most important approach would be quality planting material distribution from certified nurseries under strict quarantine system.Plant protection and quarantine units across the border of states need to be strengthened to look after interstate transportation of citrus planting materials.
Keywords:bactericides, citrus psylla, decline, HLB, citrus greening, sex-hormone