This document summarizes a study on the occurrence, severity assessment, and management of citrus greening disease in Kavrepalanchok, Nepal. The study aims to identify mandarin varieties affected by citrus greening using an iodine-based test and provide awareness to farmers on the disease and its management. The methodology involves collecting samples from symptomatic trees, conducting the iodine test, assessing disease severity, and testing pesticide treatments in trials. A work schedule and budget are also presented with activities and costs outlined.

1. OCCURRENCE, SEVERITY ASSESSMENT AND
MANAGEMENT OF CITRUS GREENING IN
KAVREPALANCHOK
Presentation by:
Sanjok Timalsina (425)

2. LITERATURE REVIEW
MATERIALS AND METHODOLOGY
INTRODUCTION
01
02
03
04 WORK SCHEDULE-BUDGET

3. INTRODUCTION
01
• Citrus(Rutaceae) is one of the world's major fruit,
grown widely all over the world; China largest prod
• Major fruit crop grown in Nepal occupying 28.19% fruit
area. Main type is Mandarin with approx. 64% citrus
and 68% of citrus production
• Citrus greening disease; CGD(huanglongbing;HLB) or yellow
dragon disease caused by Candidatus liberibacter sp.
Vectored by citrus psyllid
• Present in Asian, African and American form; graft transm

4. Statement of problem:
• Productivity lag; 9.74ton/ha world but 8.79ton/ha as of
• All the citrus cultivars are susceptible to citrus gree
lead to decrease in production after 5-8 years of pl
• Prevalence study and severity of citrus greening have n
conducted in different citrus growing pockets of Nep
Rationale of study
• As an important fruit supply energy and nutrients, high
• Effective and long term elimination of citrus greening
prevalence and severity assessments

5. Objectives
Broad objectives
• Identification of Mandarin with HLB using Iodine – bas
test in Kavrepalanchok, Nepal
Specific objectives
• Provide analytical service to citrus nurseryman and gr
• Awareness raising to the farmers on harmful consequenc
HLB disease and its management
• Mapping of regimes with the result obtained

6. 2009/10 2010/11 2011/12 2012/13 2013/14 2014/15 2015/16 2016/17 2017/18 2018/19
Area(ha) 33,898 35,576 37,565 36,975 38,988 39,035 40,554 46,328 44,424 46,412
Production(Mt) 259,191 263,710 240,793 216,188 224,357 222,789 218,447 26,759 245,176 271,908
Yield(Mt/ha) 11.3 11.2 10 9.1 8.8 8.8 8.8 9 9.4 9.5
33,898 35,576 37,565 36,975 38,988 39,035 40,554
46,328 44,424 46,412
259,191
263,710
240,793
216,188
224,357 222,789 218,447
26,759
245,176
271,908
11.3 11.2 10 9.1 8.8 8.8 8.8 9 9.4 9.5
0
50,000
100,000
150,000
200,000
250,000
300,000
Citrus Fruits Production Over The Last Ten Years
Area(ha)
Production(Mt)
Yield(Mt/ha)

7. History of citrus greening
Huanglongbing (HLB) is thought to have originated in Asia an
was first described in the early 1900s.
The first detection of HLB in the United States occurred in
As of 2009, 33 countries have reported HLB infection in thei
Since it was first recognized in Nepal - near Pokhara - in 1
the disease has spread all over.
It is projected that virtually all the mandarin hubs in Nepa
infected in 10 to 15 years

8. Hardened and curled
outward
Blotchy yellow leaf mottle
Decline, stunting,
premature flowering,
defoliation, root decay
Fail to ripen, remain
prominent green, bitter
and salty flavor
Leaves
Trees
Fruits
SYMPTOMS
Citrus greening symptoms

9. Iodine test for Indexing CGD
• Biological indexing and PCR
test are reliable but expensive
• Rapid and cost effective; field
diagnostic iodine test
• HLB infected leaves had 6X
starch deposition; starch
reacts with iodine
• Grey to black stain; >90%
agreement to PCR results.
• Starch iodine reaction in HLB infected leaves is used in
scratch test for rapid detection

10. Management of citrus greening:
• Planting certified clean planting
materials
• Effective control of psyllid vectors
• Early detection; removal of infected
trees, twigs
• Following plant quarantine measures
• Penicillin and streptomycin(PS)
treatments
• Genetic control methods and varieties

11. Materials and methodology:
Site selection:
Panauti municipality
Sample collection
ees expressing strong symptoms
Iodine based starch test
scratch method
Citrus greening scale
0-no greening symptoms
1:upto 25% 2:26-50%
3:51-75% 4:>75%
Pesticides trial:
13 treatments with control;:
3 replications

12. Code Chemical compounds Solvent
CON Water -
PEN 10 Penicillin G potassium
10ppm
water
VA10 Vallidoxylamine A 10 ppm water
ZS10 Zhongshengmycin 10ppm water
KSM10 Kasugamycin
hydrochloride 10ppm
water
PEN100 Penicillin G potassium
100ppm
water
VA100 Vallidoxylamine A 100
ppm
water
ZS100 Zhongshengmycin 100ppm water
KSM100 Kasugamycin
hydrochloride 100ppm
water
PEN100
0
Penicillin G potassium
1000ppm
water
VA1000 Vallidoxylamine A 1000 water
Design of experiment:
Graft-based evaluation assay
To identify the effectiveness of a chemical
against Las and its phytotoxicity to
citrus, antibiotics are evaluated using the
previously published graft-based
chemotherapy
HLB-affected budsticks are sampled from
severely HLB-affected plants
The budsticks are individually soaked in
antibiotic solutions as listed besides.
Each antibiotic-soaked budstick was cut
into 2-buds scions and grafted onto an
individual two-year-old healthy rootstocks
and wrapped with plastic
All experimental plants are grown at
25°C±2°C under shade in an insect-proof

13. Activities Shrawan Bhadra Ashoj Kartik Mangshir
Preliminary site visit
Review of literature
Prevalence study
and Management
trial
Data entry
Data analysis
Report writing
Draft Submission
Feedback and
correction
Presentation
Submission of final
report and
manuscript
Work Schedule Bu
Estimation S.N. Particulars Amount
1) Preliminary visit 2,000
2) Materials:
Iodine
Sandpaper
Plastic bag
Distilled water
Pesticides
1,500
500
500
1,000
7000
3) Stationary 2,000
4) Data analysis 2,000
5) Report Writing 1,000
6) Final presentation 2,000
7) Publication 4,000
8) Transportation 5,000
9) Miscellaneous 5,000
Sub-total 33,000
10) Contingency 3,300
11) Overhead 1,650
Total 37,950

14. THANK
YOU FOR
ATTENTION