Mildew is a generic term used to designate different maladies cryptogamiques also say fungal diseases. Since downy mildew is dreadful, it worries all gardeners because it attacks countless plant species, including tomatoes. If we do not react at the first signs, the vegetable garden and the ornamental garden can suffer seriously, infested by unicellular living organisms belonging to the group of Oomycètes. To save the plantations attacked by these famous protists, you might as well know at your fingertips the different solutions for treating tomato mildew, but let’s not get carried away: there is no no miracle cure for mildew. This is why we recommend playing the card of prevention because prevention is better than cure. Let’s do a check in.
Know how to identify tomato late blight at the first symptoms
You have to react very quickly to hope save your tomato plants affected by mildew because if the fruits are affected, they can no longer be eaten. This dreadful disease can therefore lead to an economic disaster when it affects field crops.
Signs raising fears of aerial blight (Phytophtora infestans) are the following :
- Wet spots on the leaflets,
- limbo necrosis,
- The pale green to brown discoloration of the affected tissues at the level of the aerial organs,
- A powdery, white film on the back of the leaves, strongly resembling down,
- Brownish spots on the front of the leaves,
- Brownish cankerous legions on petioles, stems, flower buds,
- The premature fall of the forming flowers,
- Marbling of brown color on the fruits which also take on a bumpy appearance,
- A whitish down on the tomatoes.
As soon as the climatic conditions are favorable to this fungal disease, it can spread to other tomato plants in a minimum of time. In any case, it should be noted the importance of never use seeds from diseased plants mildew.
Treating Tomatoes Affected by Late Blight Promptly
From the very first manifestations of the disease, it is advisable to proceed without delay to theelimination of all affected plants. In the aftermath, the application of a remedy is essential. The gardener can then opt for a chemical product or a natural solution.
Chemical treatment against mildew
When the infestation is very important, there is little other choice than to resort urgently to a fast-acting mildew fungicide treatment which may be based on mancozeb, copper, cymoxanil or even maneb. However, to respect the environment, avoid excessive use of synthetic chemicals (Strobilurins, Anilides).
Non-chemical mildew treatment
We have several natural treatments to be applied on tomato plants, the effectiveness of which is more or less satisfactory.
The Bordeaux mixture is widely used to eradicate this disease. It is an effective solution against all fungal diseases. It must of course be used with awareness because this type of product is never harmless to nature even if its use in organic farming is authorized.
Bordeaux mixture is a bluish mixture made up of limed’eau and of copper sulfate which must imperatively be dosed in accordance with the rules. You should also know that too frequent or intensive use of this fungicide of natural origin is not only polluting for soil and waterways, but also toxic for aquatic fauna, micro-organisms and earthworms that live in the soil, and its ingestion by humans is also toxic.
The copper wire
The process at the heart of the debates consists of threading a copper wire all along the main rod in order to cause a sap oxidation. Opinions differ on the effectiveness of copper wire against mildew. Everyone can therefore get their own idea by testing it on a few tomato plants.
Sodium bicarbonate and black soap against tomato mildew attacks
Many gardeners opt for this solution that they use in sprays. Be careful to respect the following dosage: 1 teaspoon of black soap and 1 teaspoon of sodium hydrogen carbonate per liter of water. This solution is no longer very effective if mildew has already wreaked havoc on the plantations. It is therefore rather at the start of the attack and, better still, in prevention that one resorts to this mixture.
Finally, we can try to act against tomato mildew with another natural curative solution. The expected results are not always achieved, especially with extracts of fennel, rosemary, thyme or lavender. But this can only be applied to a limited number of tomato plants.
Prevent tomato late blight
Ce scourge is absolutely awesome. He is also considered the tomatoes’ worst enemy because the whole crop can be ruined because of mildew. It is therefore better to do everything possible to prevent this cryptogamic disease from setting in because in the event of a serious infestation, the gardener is never sure of winning the battle. It should therefore be known that what favors mildew is 90% humidity or more and one temperature from 12 to 25°Cas during a stormy episode causing heavy summer rains.
On the other hand, when the temperatures are scorching and the drought persists, we no longer hear of mildew since its development ceases under such conditions. It is therefore preferable to cultivate Cherry tomatoes drought resistant as well as varieties and cultivars less susceptible to downy mildew than the others (Maestria, Iron Lady F1, Fantasio, etc.), but this is far from being the majority.
Prophylactic measures to prevent late blight
The gardener has every interest in applying prophylactic measures in parallel with an antifungal treatment if his plants are affected or in the prevention of tomato late blightto know :
- Opt for resistant varieties,
- Reduce the ambient humidity under the tunnels, the greenhouse and other shelters thanks to optimal ventilation because from 20°C condensation increases during the day,
- Plant your tomatoes in a sunny corner of the garden,
- Limit plant density,
- Amend the soil with organic manure, highly preferable to mineral manure, as it reduces the susceptibility of plants to mildew,
- Put a mulch at the foot of the tomato plants,
- Plant Chinese chives, corn and basil between the rows, tomato-friendly plants that could help fight mildew (all things considered),
- Avoid wetting the leaves of tomato plants when watering,
- Water frequently but without excess because the soil must not be soggy,
- Systematically empty saucers after watering potted tomatoes,
- Only mist foliage when absolutely necessary, and only if it can dry out before the end of the day.
- Stake your tomatoes,
- Systematically eliminate the parts showing signs of mildew attack and burn them,
- Disinfect cultivation shelters at the end of the harvest period,
- Immediately eliminate plant debris at the end of cultivation.
Finally, it is essential to opt, if possible, for the rotation des cultures. We recommend waiting at least three years before planting new tomato plants on the same plot. By applying all of these measures as a preventive measure, the gardener puts the odds on his side so as not to ruin his efforts because of tomato mildew.