Embed Size (px)
DESCRIPTION
Presentation at the RTB Annual Review and Planning Meeting (Entebbe, Uganda, 29 Sep-3 Oct 2014)
Citation preview
A region-wide response to emerging cassava pests and diseases in SE Asia
Kris A.G. Wyckhuys
RTB Annual Review & Planning Meeting
30/09/2014
Outline
Antecedents SE Asian cassava Plant health situation
Invasive pests & emerging diseases Cassava mealybug complex Cassava witches broom
Ongoing initiatives Monitoring Capacity building Applied research Extension
Partnerships: cornerstone of success
Cassava in SE Asia
40,000,0008,000,000
X 4
Smallholder producers
Thailand Indonesia2-3 ha/farm 0.2-0.5 ha/farm
Cambodia Laos1-4 ha/farm 0.3-0.4 ha/farm
Cassava in SE Asia
Cassava in SE Asia
Invasive pests widen yield gap
Phenacoccus manihotiCassava mealybug
First record: 2009Eastern seaboard Thailand
Host range: 9 host plant spp.Cassava, soybean, citrus
Yield impact: up to 84% lossInitial impact: 20-40% loss (2010,
Thailand)
Paracoccus marginatusPapaya mealybug
First record: 2008 – Indonesia2010 – Cambodia, Thailand
Host range: 80 host plant spp.Cassava, papaya, sweetpotato
Cassava yield impact: 40% loss(2013, India)
Ferrisia virgataStriped mealybug
First record: 1942 – Thailand
Host range: 272 plant spp.Cassava, coffee, guava, cashew,
citrus
Cassava yield impact: 20-80%(Bellotti et al., 2013)
Pseudococcus jackbeardsleyiJackbeardsleyi mealybug
First record: 1987 – Thailand
Host range: 131 plant spp.Cassava, guava, mango, cacao
Cassava yield impact: unknown
P. manihoti impact forecasts
Hyman & Herrera, unpublished
P. manihoti direct economic impact
Country Total area affected (ha)
Average 2010 yield
(t/ha)
Country-level yield loss estimates (1000 t)
Worst case (84%)
Intermediate (30%)
Thailand 246,167 18.8 3,794 1,388
Indonesia 145,556 20.2 2,411 882
India 43,600 34.8 1,244 455
Vietnam 39,503 17.3 560 205
China 4,998 16.8 69 25
Cambodia 2,843 21.0 49 18
Lao PDR 1,322 25.1 27 9
Burma 1,321 13.5 15 5
CWB: an emerging curse on cassava
Cassava witches broom
Causal pathogen 16SrI phytoplasma Presumed insect transmission Spread through infected planting material
Symptoms Stunting Leaf proliferation Yellowing / discoloration
Yield impact Average 10-15% yield losses 25-30% reduction starch content / quality Plant death General crop loss
Monitoring
Monitoring efforts
Regional scouting Vietnam/Laos/Cambodia/Myanmar/Thailand 2014 dry season ~450 cassava fields
Simple survey protocol Standardized across countries/regions Quick screening
Mealybug species complex Cassava witches broom Other phytosanitary constraints
PCR-based confirmation CWB
Anticipated outcome Early detection > Rapid response Sustained monitoring > Safe areas
Pest monitoring - 2014
Phenacoccus manihoti Paracoccus marginatus Long-tailed mealybugs
Pest monitoring - 2014
Long-tailed species
P. manihoti P. marginatus
% CM-infested plants / field
78.2 ± 26.7 4.0 ± 4.9 68.2 ± 17.5
# mealybugs / plant
36.6 ± 27.8 8.4 ± 8.2 35.7 ± 19.1
Long-tailed species
P. manihoti P. marginatus
% CM-infested plants / field
24.5 ± 19.9 35.9 ± 29.4 39.6 ± 25.5
# mealybugs / plant
2.7 ± 1.6 13.7 ± 17.0 14.8 ± 31.3
Long-tailed species
P. manihoti P. marginatus
% CM-infested plants / field
49.5 ± 28.5 16.3 ± 14.3 26.7 ± 16.1
# mealybugs / plant
9.8 ± 10.7 24.8 ± 26.5 13.6 ± 17.9
CWB monitoring - 2014
CWB monitoring - 2014
KampheangPhet
Field-level estimate
Transect walks
% symptomatic plants
17.7 ± 17.5 6.00 ± 6.00
% fields infested
100 100
Quang Ngai
Field-level estimate
Transect walks
% symptomatic plants
43.9 ± 24.5 39.5 ± 26.1
% fields infested
90 90
Kracheh
Field-level estimate
Transect walks
% symptomatic plants
44.1 ± 20.9 56.2 ± 26.9
% fields infested
100 100
Capacity building
Capacity building
Morphology-based identification
Monitoring & symptom recognition
Expert workshop & awareness-raising
Extension officer training
Applied research
Applied research – mealybug complex
CATAS - Haikou, ChinaLaboratory research
Associational resistance to P. madeirensis ~ cassava companion
crops
PPRI – Tay Ninh, VietnamField research
Mealybug – parasitoid – hyperparasitoid food webs in cassava plots of differing size
HUAF – Hue, VietnamLaboratory research
Effect of plant nutrition on P. manihoti and Anagyrus lopezi
development and fitness
KU - Bangkok, ThailandField research
Effect of mealybuginfestation level and plant age on
cassava yield
RYFCRC- Rayong, ThailandLaboratory research
Compatibility of thiamethoxam stake dips with mealybug biological
control
Applied research - CWB
HARC – Dong Nai, VietnamLaboratory research
Evaluation of dry/wet heat treatments for CWB-infested cassava planting material
PPRI – Dong Nai, VietnamField research
Membrane feeding assays to identify potential insects vectors of
CWB phytoplasma
RYFCRC – Rayong, ThailandField research
Temporal fluctuations in species composition and abundance of plant- / leafhoppers in CWB-
infested fields
Roll-out & Extension
P. manihoti invasion of Indonesia
2010 production areas
Forecasted P. manihoti impact
2010 2014
Parasitoid introduction & release
Indonesia enlists wasps in war on crop killer (ABC News)
Wasp ‘SWAT’ team to the rescue of Indonesian cassava crop (Business Insider)
Parasitic wasps unleashed on insect pest (Inside Science)
Des guêpes face aux cochenilles pour sauver le manioc (Liberation)
Farmer-to-farmer video
Mealybug prevention & control Audience
Extension workers, farmers
Farmer-to-farmer educational video Curative / preventative tactics
Healthy planting material Field sanitation & stake treatments
Translated into 7 diff. languages
Distributed through ‘agricultural cinema’ – following ‘Going Public’ methodologies
Pest/disease research network
Monitoring PPD (Vietnam), PPC, NAFRI (Laos),
GDA (Cambodia), DoA (Thailand), IPB (Indonesia)
Research PPRI, IAS, HUAF (Vietnam), Kasetsart
University, AIT & DoA (Thailand)
Extension Farmer survey work: DoAE (Thailand),
RUA (Cambodia), NUoL & PPC (Laos) Extension: PPD (Vietnam), PPC (Laos),
GDA (Cambodia), DoAE(Thailand)
