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Dr Jhoana Opena
Dr

Jhoana Opena

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Overview

Background

Dr. Jhoana Opena, a seasoned researcher, joined The University of Queensland as a Postdoctoral Research Fellow in 2021. Dr. Opena has over 18 years of experience in research related to Integrated Pest Management (IPM) in vegetables and weed management within rice-based cropping systems across Australia, the Philippines, Cambodia, and Lao PDR. Previously, she worked as an Associate Scientist in the Weed Science group at the International Rice Research Institute and was appointed as an Adjunct Associate Professor at the University of the Philippines in Los Baños. She successfully completed her Doctor of Philosophy in Agriculture at Charles Sturt University in Wagga Wagga, Australia, in 2021. Currently, she is working on an ACIAR project entitled “Weed Management Techniques for Mechanized and Broadcast Lowland Crop Production Systems in Cambodia and Lao PDR.”

Availability

Dr Jhoana Opena is:
Available for supervision

Qualifications

  • Bachelor, University of the Philippines Los Baños
  • Masters (Coursework), University of the Philippines
  • Doctor of Philosophy, Charles Sturt University

Research interests

  • Weed management in rice and rice-based cropping systems

  • Weed ecology

  • Integrated weed management in direct seeded rice systems

  • Weed population dynamics

  • Allelopathy and its application for weed management

Research impacts

Through a five-year ACIAR program in Laos and Cambodia, our research co-designed and field-tested integrated weed management (IWM) for mechanised direct-seeded rice, working with partners across 14 villages. The packages (good seed, precise seeding, early water management, mechanical tools, mungbean intercropping, and judicious herbicides) reduced weed-seed contamination by ~90% (≈290 → ~30 seeds/kg) without reducing head-rice yield, improving grain quality and farm returns. Addressing baseline reliance on herbicides (≈43% of farmers in Laos; ~80% in Cambodia), we shifted practice toward safer, targeted use—including drone applications—while training 49 Master Trainers and delivering gender-responsive farmer training that increased women’s confidence in weed ID and safe handling. The work also informed draft national drone guidelines (Cambodia) and herbicide-use guidance (Laos), providing a scalable, gender-inclusive pathway to higher profitability, reduced chemical dependence, and more sustainable rice systems.

Works

Search Professor Jhoana Opena’s works on UQ eSpace

55 works between 2012 and 2025

1 - 20 of 55 works

2025

Conference Publication

Efficacy of pre- and post-emergence herbicides in direct-seeded rice in Lao PDR

Lovanxay, Douangsavanh, Xangsayasane, Phetmanyseng, Opena, Jhoana, Lemerle, Deirdre and Mitchell, Jaquie (2025). Efficacy of pre- and post-emergence herbicides in direct-seeded rice in Lao PDR. TropAg 2025 Conference, Brisbane, QLD, Australia, 11-13 November 2025.

Efficacy of pre- and post-emergence herbicides in direct-seeded rice in Lao PDR

2025

Conference Publication

Impact of integrated weed management on grain quality in direct-seeded rice in Lao PDR

Vongxayya, Khamtay, Opena, Jhoana, Xangsayasane, Phetmanyseng, Lemerle, Deirdre and Mitchell, Jaquie (2025). Impact of integrated weed management on grain quality in direct-seeded rice in Lao PDR. TropAg 2025 Conference, Brisbane, QLD, Australia, 11-13 November 2025.

Impact of integrated weed management on grain quality in direct-seeded rice in Lao PDR

2025

Conference Publication

Mungbean intercropping as a sustainable weed management strategy for direct seeded rice system in Lao PDR

Manivong, Phatsalakone, Opena, Jhoana, Xangsayasane, Phetmanyseng, Lemerle, Deirdre and Mitchell, Jaquie (2025). Mungbean intercropping as a sustainable weed management strategy for direct seeded rice system in Lao PDR. TropAg Conference 2025, Brisbane, QLD, Australia, 11-13 November 2025.

Mungbean intercropping as a sustainable weed management strategy for direct seeded rice system in Lao PDR

2025

Conference Publication

Farmers perceptions on the use of mungbean intercropping as alternative for sustainable weed management in direct seeded rice systems in Lao PDR

Bouahom, Bounthanom, Palaniappan, Gomathy, Opena, Jhoana and Mitchell, Jaquie (2025). Farmers perceptions on the use of mungbean intercropping as alternative for sustainable weed management in direct seeded rice systems in Lao PDR. TropAg 2025 Conference, Brisbane, QLD, Australia, 11 - 13 November 2025.

Farmers perceptions on the use of mungbean intercropping as alternative for sustainable weed management in direct seeded rice systems in Lao PDR

2025

Conference Publication

Breeding rice for climate resilience in Lao PDR

Homsengchanh, Laeh, Opena, Jhoana, Mitchell, Jaquie, Lemerle, Deirdre and Xangsayasane, Phetmanyseng (2025). Breeding rice for climate resilience in Lao PDR. TropAg 2025 Conference, Brisbane, QLD, Australia, 11 - 13 November 2025.

Breeding rice for climate resilience in Lao PDR

2025

Conference Publication

Sustainable weed management in mechanised direct seeded rice system: a 5-year Laos & Cambodia ACIAR project

Opena, Jhoana, Palaniappan, Gomathy, Banayo, Nino Paul Meynard, Sukmawijaya, Adhera, Bouahom, Bounthanom, Chea, Sareth, Manivong, Phatsalakone, Lovanxay, Douangsavanh, Vongxayya, Khamtay, Bunna, Som, Sinath, Pao, Xangsayasane, Phetmanyseng, Sathya, Khay, Abdul Aziz, Ammar, Vial, Leigh, Lemerle, Deirdre and Mitchell, Jaquie (2025). Sustainable weed management in mechanised direct seeded rice system: a 5-year Laos & Cambodia ACIAR project. TropAg 2025 Conference, Brisbane, QLD Australia, 11-13 November 2025.

Sustainable weed management in mechanised direct seeded rice system: a 5-year Laos & Cambodia ACIAR project

2025

Conference Publication

Integrating agronomic tools for effective weed management and enhanced rice productivity in Cambodia

Lim, Vanndy, Touch, Veasna, Srom, Sodany, Phoeun, Chetra, Sun, Chanketya, Opena, Jhoana and Mitchell, Jaquie (2025). Integrating agronomic tools for effective weed management and enhanced rice productivity in Cambodia. TropAg 2025 Conference, Brisbane, QLD, Australia, 11 - 13 November 2025.

Integrating agronomic tools for effective weed management and enhanced rice productivity in Cambodia

2025

Conference Publication

Enhancing weed competitiveness in direct-seeded rice for sustainable weed management in Cambodia

Thanak,Tho, Chourn, Orn, Opena, Jhoana and Mitchell, Jaquie (2025). Enhancing weed competitiveness in direct-seeded rice for sustainable weed management in Cambodia. TropAg 2025 Conference, Brisbane, QLD Australia, 11-13 November 2025.

Enhancing weed competitiveness in direct-seeded rice for sustainable weed management in Cambodia

2025

Conference Publication

Development and validation of a QuEChERS-LCMS/MS method for the determination of triazole pesticide residues in rice grains

Bunquin, Michelle Anne B., Daygon, Venea Dara, Opena, Jhoana and Mitchell, Jaquie (2025). Development and validation of a QuEChERS-LCMS/MS method for the determination of triazole pesticide residues in rice grains. Tropical Agriculture (TropAg) 2025, Bowen Hills, QLD Australia, 11-13 November 2025.

Development and validation of a QuEChERS-LCMS/MS method for the determination of triazole pesticide residues in rice grains

2025

Conference Publication

A pilot study on integrating traditional method and enzyme-based biosensor for predictive detection of triazole fungicide residues in rice

Bunquin, Michelle Anne B., Opena, Jhoana, Daygon, Venea Dara and Mitchell, Jaquie (2025). A pilot study on integrating traditional method and enzyme-based biosensor for predictive detection of triazole fungicide residues in rice. UQ-ARSA NextGen Ag Symposium 2025, St Lucia, QLD Australia, 7 November 2025.

A pilot study on integrating traditional method and enzyme-based biosensor for predictive detection of triazole fungicide residues in rice

2025

Conference Publication

Tasting and testing: identifying high-quality weed competitive genotypes across diverse Lao environments

Vongxayya, Khamtay, Opena, Jhoana, Xaiyatham, Nouy, Homsengchanh, Laeh, Xangsayasane, Phetmanyseng and Mitchell, Jaquie (2025). Tasting and testing: identifying high-quality weed competitive genotypes across diverse Lao environments. 75th Australasian Grain Science Conference, Brisbane, QLD Australia, 20-22 August 2025.

Tasting and testing: identifying high-quality weed competitive genotypes across diverse Lao environments

2025

Conference Publication

Translating systematic insights into application: validating conventional method to support emerging technologies for detecting triazole pesticide residues

Bunquin, Michelle Anne B., Daygon, Venea Dara, Opena, Jhoana and Mitchell, Jaquie (2025). Translating systematic insights into application: validating conventional method to support emerging technologies for detecting triazole pesticide residues. 75th Australasian Grain Science Conference, Brisbane, QLD, Australia, 20-22 August 2025.

Translating systematic insights into application: validating conventional method to support emerging technologies for detecting triazole pesticide residues

2025

Journal Article

Exploring alternative detection methods for azole-containing pesticide residue detection in food: a systematic review and future perspective

Bunquin, Michelle Anne B., Daygon, Venea Dara, Opena, Jhoana and Mitchell, Jaquie (2025). Exploring alternative detection methods for azole-containing pesticide residue detection in food: a systematic review and future perspective. Trends in Food Science and Technology, 161 105064, 105064-161. doi: 10.1016/j.tifs.2025.105064

Exploring alternative detection methods for azole-containing pesticide residue detection in food: a systematic review and future perspective

2025

Journal Article

Integrated weed seed impact mills for Southeast Asian Rice systems: could they aid sustainable weed management?

Vial, Leigh, Opeña, Jhoana and Mitchell, Jaquie (2025). Integrated weed seed impact mills for Southeast Asian Rice systems: could they aid sustainable weed management?. Agronomy, 15 (6) 1333, 1-15. doi: 10.3390/agronomy15061333

Integrated weed seed impact mills for Southeast Asian Rice systems: could they aid sustainable weed management?

2024

Other Outputs

Mutual benefits of partnerships between SE Asia and Australia for sustainable weed management

Lemerle, Deirdre, Mitchell, Jaquie, Molesworth, Anika, Opena, Jhoana, Palaniappan, Gomathy, Reade, Cathy and Wunderlich, Nicola (2024). Mutual benefits of partnerships between SE Asia and Australia for sustainable weed management.

Mutual benefits of partnerships between SE Asia and Australia for sustainable weed management

2024

Conference Publication

Phenotypic traits associated with weed competitiveness for aerobic rice production system in Australia

Opena, Jhoana, Eam, Sreynich, Vinarao, Ricky, Gong, Wenliu and Mitchell, Jaquie (2024). Phenotypic traits associated with weed competitiveness for aerobic rice production system in Australia. International Temperate Rice Conference 2024, New Orleans, LA United States, 5-8 June 2024.

Phenotypic traits associated with weed competitiveness for aerobic rice production system in Australia

2024

Conference Publication

Screening weed suppressive rice germplasm in Cambodia and Lao PDR

Opena, Jhoana, Homsengchanh, Laeh, Thanak, Tho, Orn, Chourn, Xangsayasane, Phetmanyseng and Mitchell, Jaquie (2024). Screening weed suppressive rice germplasm in Cambodia and Lao PDR. 23rd Australasian Weeds Conference, Brisbane, QLD Australia, 25-29 August 2024.

Screening weed suppressive rice germplasm in Cambodia and Lao PDR

2024

Conference Publication

Capabilities of hyperspectral spectroradiometer for differentiating rice and rice mimicry weeds on leaf-level measurement

Sukmawijaya, Adhera, Opena, Jhoana, Akber, Ali, Mitchell, Jaquie and Abdul Aziz, Ammar (2024). Capabilities of hyperspectral spectroradiometer for differentiating rice and rice mimicry weeds on leaf-level measurement. 23rd Australasian Weeds Conference, Brisbane, QLD Australia, 25-29 August 2024.

Capabilities of hyperspectral spectroradiometer for differentiating rice and rice mimicry weeds on leaf-level measurement

2023

Conference Publication

Herbicides in lowland rice farming: What's driving the farmer's choice in Lao PDR?

Bouahom, Bounthanom, Palaniappan, Gomathy, Opena, Jhoana and Mitchell, Jaquie (2023). Herbicides in lowland rice farming: What's driving the farmer's choice in Lao PDR?. 28th Asian Pacific Weed Science Society Conference (APWSS 2023), Phuket, Thailand, 26-29 November 2023. Weed Science Solutions for Global Food Security:

Herbicides in lowland rice farming: What's driving the farmer's choice in Lao PDR?

2023

Conference Publication

Empowering rice farmers in Laos through gender-inclusive integrated weed management training

Bounthanom, Bouahom, Gomathy, Palaniappan, Jhoana, Opena and Jaquie, Mitchell (2023). Empowering rice farmers in Laos through gender-inclusive integrated weed management training. International Rice Congress 2023, Manila, Philippines, 16-19 October 2023. doi: 10.5281/zenodo.10398315

Empowering rice farmers in Laos through gender-inclusive integrated weed management training

Supervision

Availability

Dr Jhoana Opena is:
Available for supervision

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Supervision history

Current supervision

Media

Enquiries

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