IPM Innovation Lab Trip Reports Country Visited: Cambodia Dates of Travel: August 2-28, 206. Travelers Names and Affiliations: Jonathan D. Eisenback, Professor and Paulo Vieira, NIFA-Postdoc (Dept. Plant Pathology, Virginia Tech) Purpose of Trip: Conduct a survey of nematodes on vegetables, perform a survey of nematodes on rice, and present a workshop on Introduction to Nematology. Sites Visited: Phnom Penh and Siem Reap Description of Activities/Observations: August 2: Eisenback and Vieira traveled from the U.S.A. to Cambodia August : Eisenback and Vieira arrived in Phnom Penh August 4: Met with ide staff (Seng Kim and colleagues) and discussed the purpose of this trip and the program for the field visits and the workshop August 5: The team traveled to Siem Reap and collected supplies and equipment for the survey of vegetables Vieira and Eisenback inspecting root of cassava with a Cambodia farmer anxiously watching and later Vieira presents an informal workshop around the dinner table. August 6-7: We visited the IDE office in Siem Reap and met with CADF project manager Khong Sophoan and discussed project activities. We visited several fields of sweet melon, cucumber, eggplant, tomato, corn, wax gourd, cassava, yardlong bean and
banana, and collected several samples (soil and plants) from each field. We observed no symptoms of nematodes on the roots. Reniform nematode female, Rotylenchulus sp., first report for Cambodia, and Eisenback collecting a soil sample from tomato. August 8-2: We Returned to Phnom Penh and visited the Royal University of Agriculture and processed all of the samples by hand sieving and sugar floatation/centrifugation (number of samples and results are shown below). The roots and remaining soil was processed in modified Baermann trays. We met with the instructor of entomology that was trained with a Masters in nematology and discussed the state of nematology in Cambodia. We also met with other plant pathologists. We found several nematodes that are new to Cambodia and we preserved specimens for PCR (on-going analyses) and photographed several of them. We also selected material to be used for the workshop on nematology. Lance, Hoplolaimus sp., and ring nematode, Mesocriconema sp., from banana, first reports for Cambodia.
August 22-2: We traveled to southern Cambodia and visited several rice fields with another government-sponsored crew that were surveying for insects and rodents. We collected several samples for processing and looked for symptoms of nematode activity. Rice root nematode, Hirschmanniella mucronata, male and female from rice. August 24-26: Eisenback and Vieira returned to Phnom Penh and began processing the samples collected in the rice fields and to prepare for the workshop on nematology Eisenback and Vieira presenting a workshop on plant nematology August 26: We presented the workshop to about 24 participants on plant nematology. Topics covered included nematode morphology, body plan, global importance, life cycle and how they cause disease. A laboratory demonstrated the techniques that are useful
for the extraction of nematodes from the soil and plant material. Preparation of nematodes for light microscopy. August 28-29: Eisenback and Vieira return safely to the U.S.A. Training Activities Conducted: Training Location Male Female Training on Diagnosis of Nematode RUA 2 2 Diseases in Vegetable Crops and Rice Suggestions, Recommendations, and/or Follow-up Items: Based on our field visits and discussions with plant pathologists at RUA, we believe that nematode diseases are major constraints to rice production. There is one trained nematologist at the RUA, but he is assigned to teach and research insect diseases. We propose that emphasis be given to further evaluation of nematodes on rice and we estimate that the rice root nematode (Hirschmanniella mucronata) is causing a 20-0 percent loss. Conducting a demonstration plot where nematodes are properly managed, alongside a plot that is untreated would be extremely beneficial to show the effect that this nematode has on rice production. For potential visits to Cambodia, we would recommend the local staff to collect soil samples from infected fields, and sent them to RUA for processing. This will allow us to process a high number of samples, and from additional fields. Summary Recommendations: Follow up on molecular characterization of nematode samples collected to identify genus and species. Should advise farmers on nematode disease management. IPM components could include the following: o reduce pesticide usage to proper levels to restore soil health o increase organic matter in the soil o utilize resistant varieties o using appropriate crop density o reduce weed populations and minimize alternate weed hosts o crop rotation o perform a demonstration plot in rice to determine the loss caused by rice root nematode o in rice, utilize adequate weed control to minimize their impact
List of Contacts Made: Name Kim Hian SENG An Moyngech Khong Sophan Bun Saborn Koi Khun Title/Organization Project Coordinator, IPM and Agronomy Adviser ide Cambodia IPM IL research assistant CADF, ide Siem Reap Project Manager, CADF ide Siem Reap Horticulture Value Chain Advisor Lecturer and Researcher- RUA Contact Info (address, phone, email) CAMBODIA AGRIBUSINESS DEVELOPMENT FACILITY, ide Cambodia Tel. +855-89-678-6 Email: skimhian@ideglobal.org CADF, ide Siem Reap Tel. 855.6.80.777 Email: moyngech@ideglobal.org CADF, ide Siem Reap Tel. 855.6.80.777 Email: ksophoan@ideglobal.org CHAIN Cambodia Horticulture Advancing Income and Nutrition Project. Phnom Pen Tel. 855.2.994.562 Royal University of Agriculture (RUA) Phnom Penh Fields are marked with the star symbol in the map.
Nematode Survey on Vegetables: D a y S a m p l e Province Crop Nematodes Notes N E Siem Reap Cucumber 2 Siem Reap Cucumber Banteay Meanchey Tomato 4 Banteay Meanchey Pepper 5 Banteay Meanchey Tomato? Aporcelaimidae 27' 52." 0 4' 5.9" Rotylenchus?, Aphelenchida, More nematodes, Cephalobidae, Thylenchorynchus few mites Aporcelaimidae 26' 0." 02 59' 46.0" Aporcelaimidae 25' 5." 02 59' 24.4" Rotylenchulus, Rotylenchus?, Cephalobidae 26' 0." 02 59' 46.0" 2 A Oddar Meanchey Bean after Sweet melon Aporcelaimidae 4 7' 0.4" 04 ' 54.2" 2 B Oddar Meanchey Cassava Mesocriconema 2 Small galls in C Oddar Meanchey Corn after sweet melon Aporcelaimidae roots? Roots look very reduced 2 D Oddar Meanchey Corn after sweet melon Aporcelaimidae 2 E Oddar Meanchey Corn after pumpkin Aporcelaimidae 2 2 A Oddar Meanchey Sweet melon Aporcelaimidae 4 7' 9.4" 04 ' 2.8" 2 2 B Oddar Meanchey Sweet melon Mesocriconema 2 A Oddar Meanchey Honey dew Aporcelaimidae 4 9' 28.4" 04 6' 4.7" 2 B Oddar Meanchey Honey dew Cephalobidae, Aporcelaimidae 2 C Oddar Meanchey Honey dew melon Cephalobidae, Aporcelaimidae A Oddar Meanchey Eggplant Aporcelaimidae 4 8' 4.6" 04 6' 50.5" B Oddar Meanchey Tomato after cantaloupe Aporcelaimidae C Oddar Meanchey Corn Aporcelaimidae A good number of D Oddar Meanchey Pumpkin Free living, mononchids, tylenchids nematodes E Oddar Meanchey Corn Free living F Oddar Meanchey no label Very few free-living A Siem Reap Cucumber Galls in roots 2'.8" 04 ' 46.6" B Siem Reap Cucumber Very few free-living C Siem Reap Cucumber Very few free-living
2 A Siem Reap Cucumber 2 B Siem Reap Cucumber Free-living, Mesocriconema, Tylenchorhynchus Galls in grass? 2' 45.5" 04 ' 7.5" Free-living, Mesocriconema, Tylenchorhynchus A Siem Reap Bean Free living 2' 26.7" 04 4' 52.7" B Siem Reap Bean Free living Good number of 4 A Siem Reap Banana Tylenchorhynchus, Meloidogyne, Pratylenchus, Mesocriconema, Hoplolaimus Tylenchorhynchus and other nematodes 6' 46.2" 04 7' 47.2" 4 B Siem Reap Egg plant Free-living 4 C Siem Reap Egg plant Total number of processed samples: 2 Notes: Coordinates indicate the field area were samples were collected. Fields are marked with the symbol star in the map. Mesocriconema, Tylenchorhynchus, free-living Survey on rice: Day Sample Province Crop Nematodes Notes N E A_Soil Takeo Rice H. mucronata, free-living, Mesocriconema 8' 48." 04 55'.7" B_Soil Takeo Rice Tylenchorhynchus, Aphelenchoides, Tylenchus 8'.4" 04 55'.9" C_Stem Takeo Rice 2 A_Soil Takeo Rice H. mucronata, Aporcelaimidae, Tylenchorhynchus 0 55' 54.7" 04 5' 26." 2 B_Soil Takeo Rice H. mucronata, free-living 2 Rice 2 2_Stem Takeo Rice H. mucronata, free-living 0 56' 8.9" 04 5' 50.7" 2 2A_Soil Takeo Rice H. mucronata, Tylenchorhynchus, Tylenchus, Ditylenchus? 2 2B_Soil Takeo Rice H. mucronata, Tylenchorhynchus 2 2C_Soil Takeo Rice H. mucronata, Tylenchorhynchus, Aphelenchoides 2 2D_Soil Takeo Rice H. mucronata, Tylenchorhynchus, Aphelenchoides 2 2E_Soil Takeo Rice H. mucronata, Tylenchorhynchus, Aphelenchoides 2 2F_Soil Takeo Rice H. mucronata, Tylenchorhynchus, Aphelenchoides Total number of processed samples: 2 Notes: Coordinates indicate the field area were samples were collected. Fields are marked with the symbol star in the map.