Extra long-term effect against phytophthora needed

Phytophthora is in full swing, but due to the dry and warm summer you hardly noticed it in 2018. However, new more aggressive strains are advancing and they require a different approach. What is the best thing to do in these circumstances to keep your crop free of phytophthora for as long as possible?

Research by Wageningen University & Research (WUR) shows that 2 new strains have taken over. These strains (called Yellow 36 and Dark Green 37) are a lot more aggressive. They develop more easily and faster. In recent years, even in the dry summer, the proportion of these aggressive strains has increased sharply.

The basis of the prevention of phytophthora is preventive work. If an infection has occurred, this remains the motto. The curative agents have virtually no protective long-term effect. With the faster development of phytophthora, these products have to deal with the same problem: a shorter curative effect. A better solution is to extend the duration of action of the preventive fungicides, in order to be able to stick to a weekly spraying schedule.

Spray Interval
In order not to take unnecessary risks with the more aggressive strains, the maximum label dosage must be used for each fungicide (certainly under critical circumstances). The interval between 2 sprayings should be shortened (if possible). When the interval has to be shorter than 7 days, a problem often arises. This is because most products cannot be used with an interval shorter than 7 days. How can you, as a grower, stick to a weekly schedule as much as possible under these circumstances? The solution to this is Adigor.

What is Adigor?
Adigor is an adjuvant, a unique additive that ensures that the active substances are absorbed into the plant faster and better (and more). Adigor consists of an esterified rapeseed oil, in combination with emulsifiers. How this combination works is simply explained:

• The emulsifiers ensure optimum wetting and a spread of the spray liquid on the leaf.
• The esterified rapeseed oil allows the active ingredients to penetrate more quickly and easily into and through the wax layer of the plant.

The end result is the sum of both: more active substances in the plant, so a better and longer effect. In short: better use of the resources you inject. Of course, this especially applies to the agents that are included in the crop. With contact agents (for example mancozeb), which remain on the leaf and are not absorbed into the plant, Adigor only ensures a better distribution on the leaf.

Widely applicable
Adigor is gentle on the crop and can be used in various crops in combination with fungicides, but also with various insecticides or herbicides. The research of the previous 2 years has mainly focused on the prevention of phytophthora, given that there are major challenges in practice due to the emergence of the aggressive strains.

More fungicide in the plant, for better and longer protection, can be achieved by 2 simple measures:

• Always use the maximum dose of the fungicide.
• Add Adigor to the spray liquid.

Phytophthora under harsh conditions
The graph at the bottom of this article shows the results of a phytophthora trial in Lelystad. To substantiate the added value of Adigor (compared to a reference additive), the crop was wetted several times every day. This also to obtain an extremely heavy disease pressure.

The result is obvious: Revus has a good effect compared to unsprayed potatoes. However, under tough conditions, combined with the new aggressive strains, the weekly schedule is too long. The addition of Adigor does give a considerable improvement in the effect (also compared to the reference additive). In critical circumstances the spraying interval can be extended in practice and you can more easily stick to a weekly spraying schedule.

Security and benefit for you
Nothing is more expensive than phytophthora in your crop and when you have to intervene with heavy, expensive curative schedules. You should always avoid this. Adding Adigor under critical circumstances, which extends the long-term effect of your spraying, will not cost you any extra money per day.

In other words: a 7-day schedule with Adigor is at the same price level as a 5-day schedule with only a phytophthora drug without Adigor. Of course there is the advantage of less spraying, so less work and more security for you. A weekly schedule is also the most practical for your work planning.

In addition, research has shown that the optimal dose of Adigor in potatoes is 0,25%. Given the current more aggressive strains, our advice is: add 0,25% (0,5 liters per 200 liters of spray liquid) Adigor to, for example, Revus 0,6 liters per hectare.

This extends the duration of operation under critical circumstances and makes it easier to stick to the weekly schedule. Of course you can also use Adigor under normal circumstances for an extra long-lasting effect.

In short?
In summary: with the developments of the aggressive strains, always assume a maximum label dosage of the products to be used and add 0,25% Adigor. This gives you more certainty and more peace of mind in the spraying schedule.

Syngenta offers various solutions that help growers to responsibly optimize their business operations. See: www.syngenta.nl/stewardship† Use plant protection products safely. Read the label and product information before use.