Latest news with #StevenKildea
Agriland
31-07-2025
- Health
- Agriland
Combatting potato blight fungicide resistance key focus for researchers
The continuing work of Teagasc scientists to successfully confront the challenge of potato blight has been highlighted. This work is taking place against the backdrop of the fast-evolving blight populations that now impact on Irish potato crops. Details of this research input are contained in the recently published Teagasc Research Impact Highlights in 2024. In late autumn 2023, a single sample of Phytophthora infestans with resistance to the carboxylic acid amide group of fungicides was detected in Ireland. Currently, the control of potato late blight caused by P. infestans is almost exclusively reliant on the application of fungicides. This highlights the immediate and significant threat the detection of this strain posed to the Irish potato industry. To prevent such devastating impacts, it is essential to be able to rapidly detect this strain, devise control strategies to prevent its spread, and effectively communicate this to the industry. The Teagasc report outlined how a coordinated approach was taken between crops researchers and specialists to develop detection tools, and devise and disseminate field control strategies. To detect resistance, the team developed a digital droplet polymerase chain reaction (PCR) capable of detecting P. infestans and associated fungicide resistance in a variety of matrices including potato leaves, FTA preservation cards, and spore samples. This allowed for the rapid and extremely sensitive detection of resistance. In parallel, control strategies were devised which ensured both the mixing and alternation of fungicides at each application, guaranteeing field control whilst limiting potential selection for the resistant strain. These strategies were communicated to the industry throughout the season via dedicated workshops, crop walks, and a trials tour. Whilst the strain was again detected in 2024, its impact on late blight control has been contained. Potato growers attending a recent Teagasc farm walk in Co. Meath were told that the threat of blight remains very real. And this despite a continuing spell of dry weather, during which humidity levels remains very low. Testing carried out last year confirmed that 36A2 was the main strain of blight circulating in Ireland at that time, a strain that is not strongly associated with mutations that bring about resistance to specific fungicide chemistries. But according to Teagasc plant disease specialist, Dr. Steven Kildea, potato growers should not be lulled into any form of false security. He explained: 'Last year's survey work tells us one fundamental thing: 36A2 is a very active form of blight. It has imposed itself relative to other blight strains known to be in Ireland. 'This means that A36 has the potential to create serious damage within Irish potato crops if farmers do not take the required preventative steps.' As was the case last year, Teagasc agronomists have compiled a comprehensive blight spraying programme for 2025.
Agriland
01-06-2025
- Health
- Agriland
Growers discuss control of potato blight in Ireland
Irish growers fully recognise the need to secure effective blight control within their crops at all times. But some firmly believe they are not operating on a level playing field. The recent Teagasc farm walk hosted in Co. Meath provided those in attendance with an opportunity to air their views on this subject. Some claimed that potatoes grown in gardens and allotments, where fungicides are not used, represent a potent blight threat to commercial farmers. In tandem with this, the view was expressed that the non-commercial production of potato crops should be banned by the government. Organically produced potato crops were also cited as potent blight threats for the commercial potato sector. Blight control These were lines of thought that prompted a debate on how best the Irish potato sector can best protect itself against the fast-evolving threat of blight. Teagasc plant disease specialist, Dr. Steven Kildea, foresaw a future within which Integrated pest management (IPP) techniques would rise to the fore. He said: 'But in the here and now, we have to ensure that the fungicide chemistries available to the potato sector are used to best effect. 'Such an approach should also ensure the optimal longevity of these products.' Breeding new potato varieties with inherently higher resistance to fungal attack was flagged as part of the potato sector's response to blight. According to Dr. Kildea: 'But this is not a long-term, silver bullet. There is no doubt that fungal strains will evolve to counter the blight resistant properties of new potato varieties that we can breed. 'What we are looking at is a continuing battle – the grower versus the various blight strains that impact on Ireland.' Chatting at the Teagasc potato farm walk, (l-r): Daniel Williams and Rory Young, both from Lobinstown in Co. Meath The Teagasc representative also confirmed the value of the blight warnings issued by Met Éireann. 'However, these should be considered with evidence on the ground secured by growers actively walking their crops on a regular basis. 'For example, heavy dews can create conditions that are conducive to blight even during periods of dry weather.' But it wasn't all bad news emanating from the farm walk. The event was used as a platform to confirm the availability of a new blight fungicide, Privest from BASF, which has ametoctradin as a core active ingredient. Launched in the UK last year, Privest is a fungicide for use on a preventative basis and in the early stages of foliar late blight. It has been specified for use at the early season/rapid canopy stage within the 2025 Teagasc blight programme. BASF has indicated that there is sufficient Privest in Ireland to meet farmer demand at the present time. However, a number of growers at the Co. Meath farm walk indicated they could not source supplies of the product at all.
Agriland
31-05-2025
- Health
- Agriland
Specialists call on farmers to monitor for blight in Ireland
Potato growers attending a recent Teagasc farm walk in Co. Meath were told that monitoring for blight in Ireland must become a priority. Recent years have seen multiple mutations taking hold within Europe's blight populations, resulting in the development of resistance to numerous blight fungicide chemistries. Currently, the levels of blight population testing in Ireland is low relative to that taking place in the UK and across mainland Europe. Teagasc plant disease specialist, Dr. Steven Kildea, commented: 'We need real time information on how blight populations are changing in Ireland. And the input of growers is critically important in making this happen.' Monitoring for blight on-farm Potato farmers can make suspected blight samples available to the agriculture and food development authority in one of two ways. One is to physically put impacted leaves into an air-tight plastic bag and send them to Teagasc's Oak Park Crops Research Centre in Co. Carlow. The other option is the use of Fast Technology for Analysis (FTA) cards. These have been given out to growers by Teagasc staff at recent potato events. They allow growers to leave a sample of the blight-causing organism on the card. The cards are then submitted to Oak Park for analysis. According to Dr. Kildea, real-time monitoring of blight populations is the only way that Irish potato growers can hope to keep on top of a disease that still has the potential to create havoc within Ireland's potato sector. Fungicide availability is one issue when it comes to controlling blight. Using the chemicals effectively is the other challenge confronting growers. So, ensuring that sprayers are fit for for purpose when used to apply blight fungicides is critically important. The core objective is to ensure that crops are fully treated every time the sprayer goes into a field of potatoes. Spraying potato crops requires total attention to detail This means ensuring that all of the crops are sprayed with the correct rate of fungicide. Growers should avoid misses, overlaps, double applications, and low application rates. Put another way, growers should only sow what they can spray effectively. Global positioning satellite (GPS) systems can be used to deliver accurate boom overlaps. Where headlands are concerned, accurate sprayer on-offs are vital. In addition, GPS switching needs to be set up correctly. Distance from the boom, solenoid switching speed, and tractor forward speed all impact on this. Corners should be reversed into, and curves in fields can also impact on application rates, especially with wider booms.
Agriland
30-05-2025
- Health
- Agriland
Threat of fungicide resistance within Irish blight populations remains
Potato growers attending a Teagasc farm walk in Co. Meath earlier this week were told that the threat of blight remains very real. And this despite the recent spell dry weather, during which humidity levels remains very low. Testing carried out last year confirmed that 36A2 was the main strain of blight circulating in Ireland at that time. This strain not strongly associated with mutations that bring about resistance to specific fungicide chemistries. But according to Teagasc plant disease specialist, Dr. Steven Kildea, this should not lull potato growers into false sense of security. He explained: 'Last year's survey work tells us one fundamental thing – 36A2 is a very active form of blight. It has imposed itself relative to other blight strains known to be in Ireland. 'This means that A36 has the potential to create serious damage within Irish potato crops if farmers do not take the required preventative steps.' As was the case last year, Teagasc agronomists have compiled a 14-step blight spraying programme for 2025. It comprises a total of 14 applications, nominally a week apart. Each application contains a mix of fungicide chemistries. Blight prevention Dr. Kildea said: 'The doubling down on fungicide chemistries is important. This means that one active molecule is not tacking the blight threat on its own. 'So it's an approach that ensures the chemistries that are currently available can be retained for as long as possible into the future.' 'And all products must be included at their respective full rates. This is critically important if optimal efficacy is to be secured.' To all intents and purposes the Teagasc blight programme, as currently constituted, takes potato growers up to the end of July. This may be tweaked slightly if drier weather kicks in during the early season and canopy establishment phases. Potato crops are fast approaching full canopy in Co. Meath Beyond that though, it is a case of work-in-progress. Teagasc agronomist Shay Phelan takes up that story 'Growers must act to ensure that steps are taken to prevent blight from impacting on their potato crops at all times,' Phelan said. 'There are no longer any curative products available on the market. 'Late season control measures will be particularly problematic this year. Reglone is no longer available to burn back tops. 'This means that it will take longer than would previously have been the case to get crops through to final harvest,' the Teagasc agronomist stated.
