Healthy range of potato chemistry in the pipeline

With sales in excess of €85m last year, potatoes remain an important part of Ireland’s agricultural economy. Like all tillage crops, potato growers continue to have to learn how to grow the crop in an ever-changing plant protection product landscape. With the loss of many mainstay sprays over recent years, and with more to go, growers may take comfort in the knowledge that a healthy pipeline of new potato protection products exists.

Paul Goddard, BASF’s potato technical lead, recently briefed members of the industry about the new products the company has in development.

These include new products for blight control, weed control, wireworm reduction and aphid control using existing conventional chemistry and new chemistry.

Goddard also explained that BASF has a range of biologicals and biostimulant potato products in the pipeline to improve nutrient use and uptake and improve the plants’ defences against nematode attack. This article will run through what we know so far.

Enervin SC for late blight

Late blight (Phytophthora infestans) continues to be the most destructive potato disease facing Irish growers. As Dr Steven Kildea eluded to in this year’s Crop Protection magazine, reduced sensitivity to fluazinam has been confirmed here in Ireland. This will force a rethink on the use of the active here and increase the reliance on others. So new late blight fungicides are to be welcomed.

Enervin SC is a new late blight product, which will provide protection against the early stages of foliar late blight in potatoes. It is expected to be available for the 2022 season.

The QoSI active ingredient is Ametoctradin which is a unique mode of action. It works by interrupting the life cycle by inhibiting the formation and release of blight zoospores, thus providing protectant activity.

Enervin SC is a protectant spray, so it works best when applied in the early stages of foliar late blight. However, as the chemistry uses a single-site mode of action, it is vital that it is mixed with a robust rate of another product from a different chemical group.

“It’s not a product to be used on its own, it’s got a single-site mode of action which must not be left exposed,” Goddard explained.

Enervin SC provides good control against phenylamide-resistant strains of blight with no cross-resistance observed, Goddard continued.

The fungicide is cleared for use on seed and ware potatoes with a seven-day pre-harvest interval. It can be used up to four times per season at an application rate of 1.2 litres/ha in 200 to 400 litres/ha of water.

BAS 657 for late blight

The new BAS 657 fungicide, which is expected to receive registration in 2024, incorporates two unique modes of action.

BAS 657 is a combination of Enervin SC’s active ingredient, ametoctradin, along with potassium phosphonate.

The innovative “Syn-Tec” formulation means it is the first co-formulated potassium phosphate potato product to combine protectant activity with systematic and multisite activity.

“It gives great overall protection and fits very well early in the spray programme, freeing up slots for other actives later where they may be better targeted or when saving the strongest for when blight really gets going,” Goddard explained.

Potato growers continue to have to learn how to grow the crop in an ever-changing plant protection product landscape

For optimum performance and protection, BAS 657 is best applied from early rapid canopy to canopy complete at a rate of 3.2 l/ha.

Revysol for early blight

Early blight (alternaria) control hasn’t been a significant issue with many growers due to the availability of mancozeb. This is set to change however so new chemistry is welcome.

Revysol, first launched for use in cereals in 2020, has been developed to support early blight disease control and is expected to be available in 2023.

The isopropanol triazole is expected to give improved levels of disease control compared to existing azoles, even where populations of shifted sensitivity to the disease exist, according to Goddard.

Growers will be able to apply up to three applications from mid-July, at a minimum of seven-day intervals from formation of basal side shoots to senescence.

BASF trials with the fungicide delivered an average blight reduction of 91.2%, compared to difenoconazole (eg Narita), which delivered a 79.6% reduction.

BAS 700 tuber treatment

BAS 700 (fluxapyroxad) is a new tuber SDHI treatment product from BASF, which is likely to be available for 2023 planting.

It demonstrates strong control of rhizoctonia, silver scurf, black dot and has shown activity against dry rot and gangrene in the lab. It will be approved on all varieties of potato, seed and ware.

BAS 656 for weed control

With the loss of diquat, weed control in potatoes will involve ever-more complicated tank mixes. Expected to be approved in 2024, BAS 656 is a new pre-emergence herbicide, which contains the active dimethenamid-p and will offer a new mode of action for weed control in potatoes.

Its dual uptake mechanism enables the actives to be taken up by the plant’s roots and shoots, delivering better weed control and will be applied at rates of 1.2l/ha.

“Weed control will increasingly be about building a ‘team in the tank’ for the job. BAS656 will be a useful ‘team player’ to give effective weed control,” explains Goddard.

BAS 480 for wireworm control

BAS 480 BCI is a new biological product in development for the reduction of wireworm damage in potatoes. The product will have no harvest interval.

The liquid formulation contains a biological active, consisting of the Beauveria bassiana fungus which grows naturally in soils. Wireworms come into contact with the fungus, where a combination of anti-feeding, repellent and pathogenic effects occur. Few details are known about the product, including its expected launch date.

Axalion for aphid control

Axalion is a new aphicide, which is currently undergoing registration. We know little details of the product so far, other than it has a new mode of action and has no known cross-resistance issues.

Expected in 2026, it will control piercing and sucking pests such as aphids, whitefly and thrips but is compatible with beneficial insects, including pollinators.

Axalion will quickly stop insect pests from feeding, reducing nutrient loss for the plant and preventing the pests from transmitting diseases.

Three biostimulants, BAS913033, BUK99414 and BUK99415 are currently in development, each targeted at different stages in the potato life cycle, where their specific components can work their best at reducing biotic and abiotic stresses resulting in healthier plants and higher yields. BASF will be looking to trial these on farm in 2023.