More vigilance, regional cooperation needed to check emerging plant health threats

Fall armyworm feeding on sorghum in Niger. Photo: ICRISAT

Locusts, Fall armyworm, wheat blast, banana Fusarium wilt Tropical Race 4 and UG99 – a virulent strain of wheat stem rust, are some of the emerging crop health threats that require to be addressed efficiently to safeguard food security. This was emphasized by representatives of germplasm health units in CGIAR and its partner organizations during a week-long series of webinars to observe this year’s Phytosanitary Awareness Week.

The importance of robust phytosanitary measures was made apparent through demonstrations of the large exchange of material (both import and export) across the world during the Asia webinar on 10 November. Moderated by Dr Rajan Sharma, Head of ICRISAT’s Plant Quarantine Unit, it focused on phytosanitary implications of global exchange of crop germplasm and emerging crop pests and pathogens in Asia.

“Minor pests and diseases are becoming important due to climate change,” said Dr Safaa Kumari, Head of ICARDA’s Seed Health Lab, while listing some challenges to germplasm movement. ICARDA exchanged 115,898 accessions of wheat, barley, chickpea and lentil last
year alone.

Enumerating seed-borne pests in wheat, barley and legumes that can be tackled effectively with quarantine, Dr Kumari said seed-borne pests may result in germination loss, reduced seed size, discoloration and shriveling besides spread of pathogen to new areas. She explained that management of seed-borne pests can be done through a multi-pronged approach of seed health testing, control during crop production, chemical control and through phytosanitary measures like quarantine to prevent and control spread.

Dr Rola El Amil, Plant Pathologist at the Lebanese Agricultural Research Institute, said the institute’s Plant Protection Department is monitoring emerging diseases like bacterial brown rot and ring rot in potato, the Plum Pox virus and Xylella fastidiosa among others. She also informed that Tuta absoluta has been a major pest in tomato and efforts underway to control them include identification of new peptides that can prove effective in glasshouses.

In the recent past, the weed Solanum elangnifolium was observed in the region but eradicated after it was spotted, Dr Amil mentioned.

Speaking about phytosanitary measures at ICRISAT in India, Dr Sharma emphasized that healthy seed is essential for healthy crop. The identification of new fungicides for seed treatment is an important activity underway at ICRISAT, he explained. ICRISAT PQU has so far facilitated export of 1.34 million seed samples of its mandate crops and small millets to 174 countries while over 190,000 seed samples were imported from 96 countries. He highlighted the close collaboration and support from NPPO for the exchange of germplasm.

“New molecules have to be investigated as continued use of existing molecules comes with a risk of development of fungicide resistance. We test efficacy of new fungicides and we could find two fungicides, a combination of Carbendazim plus Mancozeb, and Tebuconazole plus Trifloxystrobin, very effective in sorghum and pearl millet for seed treatment,” he said.

Dr Sharma also informed that novel pest detection and diagnostic protocols are being explored across CGIAR’s germplasm health units including use of non-invasive techniques like Videometer seed analyzer for detection of seed-borne pathogens, and use of nucleic acid-based detection.

Dr K Anitha, Head of National Bureau of Plant Genetic Resources (NBPGR) Regional Station in Hyderabad, India, cited FAO while stating that up to 40% crop losses are attributable to pests and diseases.

Referring to recent interceptions in India, Dr Anitha mentioned that samples have to be thoroughly checked before being shipped. Dr Anitha also outlined a future strategy that includes upgrading standards within India, suitable check points while conserving germplasm in genebanks to tackle species admixture, closer coordination between government and exporters and need for standards for manufacturers, production units, monitoring of contaminants as well as additives.

Dr Gururaj Guddappa Kulkarni, Director Bio-Innovation and Global Head of Research Infrastructure and Compliance at IRRI, detailed activities of IRRI’s Seed Health Unit and mentioned opportunities for the unit in use of advanced pathogen detection techniques like PCR and ELISA.

He also informed that some of the next steps for germplasm health units across the world are strengthening monitoring of new pests and pathogens, enhancing testing methods, increasing sample testing and working more closely with NPPO in addition to coordinating and making uniform procedures across NPPOs in a region.

Ms Ellaine Tandang, Assistant Division Chief, National Plant Quarantine Services Division (NPQSD), Philippines, spoke about the importance of capacity building and increasing mass awareness of plant health and its importance for food security. The division has organized runs that involved students, government officials and police personnel, and a plant health summit last year and early this year, she informed.

Some of the other challenges pointed out during the webinar are the banning of some of the pesticides by the government which are used for salvaging of import/export material and issuance of non-compliance notices to exporting countries without scientific evidence as in the case of detection of non-pathogenic endophytes like growth promoting organisms.

The takeaway recommendations from the webinar was a call for bi-annual updates to national pests lists, regional coordination among the NPPOs, and the need to identify suitable alternatives to methyl bromide fumigation and other likely to be banned chemicals for seed treatment.

The global webinar series, “Phytosanitary Safety for Prevention of Transboundary Spread of Pests and Pathogens,” was organized by during 9-13 November by CGIAR Germplasm Health Units (GHUs) in collaboration with FAO, International Plant Protection Convention (IPPC), Crop Trust, National Plant Protection Organizations (NPPOs) and others. The UN has marked 2020 as the International Year of Plant Health.