The rains, sometimes violent, of these last days should not be taken lightly. If the return of the humidity gives force to the flowers and vegetables from the garden, especially after this week of high heat, be aware that it also benefits… diseases, the most feared being unquestionably the mildew.
Under this generic term, derived from the English mildew, hides a slew of pseudo-fungi: Phytophtora infestans attacks tomatoes and potatoes, while Plasmopara viticola is, as its name indicates, to the vine, to mention only the most common. The spores of these micro-organisms, which have the ability to keep in the ground year to year on crop residue, germinate in the presence of water as soon as the temperature reaches 20°C. We are… In a few days brown spots appear on the leaves and on the stems, letting them believe, wrongly, that the plants are thirsty. Useless, of course, on the water: the mass is said because there is no curative remedy against this scourge.
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The nettle fertiliser is above all a makes bio-stimulating. Picasa/Patryssia – Fotolia
The unfortunate gardener who is caught will, death in the soul, cut off diseased branches and dispose of, with them, all the beautiful tomatoes still green that they wore. In taking early enough, we can expect to see the feet start and grow new but without warranty, and subject to the back-the season is sufficiently warm and dry. As for the potatoes, it is necessary to pull dare-dare, if it remains even, because the parasite also destroys the tubers!
To avoid such mishap, the only weapon is prevention. In the immediate future, a treatment based on copper before (count at least 6 h to ensure that the product is not washed away), and after the slightest rain. This metallic element contained in the famous bordeaux mixture, blocking in effect the germination of the cursed spores. By renewing the operation in 3 to 4 weeks, depending on the weather, you can protect the new leaves that will appear in the course of the development of the plant, and so on until mid-October. Do not release the guard, as rains of late summer can still provoke attacks carabinées!
so much for the emergency. But there is also a way to reduce the risk by adopting upstream measures prophylactic as the rotation (to wait 3 to 4 years before planting a sensitive crop in the same place), the choice of tolerant varieties and the spacing of the plants (50 cm minimum in the row and 1 m between two rows for the tomatoes). Vegetation that is too dense, promotes the retention of moisture after a rain, and therefore, as we have seen, the conditions favorable to the hatching of the parasite. It should be, for the same reason, watering tomatoes, and eggplants at the foot (the jet is prohibited because of the splash…) and only in the morning so the water dries quickly on the surface. The mulch and the size of the lower leaves are also recommended to minimize contact with the ground, the great reservoir of spores.
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Apple reached moniliose. 168737285/Christine Kuchem – stock.adobe.com
alternatives to the bouille bordelaise are put forward for the past few years. This is particularly the case with the nettle fertiliser, and baking soda that can be purchased now in the trade. It is important to know that the first does not, contrary to popular opinion, no fungicidal action, but rather act as a bio-stimulant by increasing the capacity of resistance to diseases. As for the second, it would prevent the germination of spores by altering the pH on the leaf surface. However, apart from the return of experience of some gardeners, no official test has come, for the moment, certify the effectiveness of baking soda against mildew, because the latter, classified as “basic substance” (in the same way that vinegar or salt), which is marketed without passing through the authorisation procedure for the placing on the market. Caution, therefore.
the Second major disease to declare itself as soon as it is hot and humid, powdery mildew affects mainly the rose bushes, vines, and cucurbits, but for the latter a little later in the season. Sulphur, applied at 8-10 day intervals during periods of risk, is the preventive remedy to use without fault, to preserve flowers and crops.
in The orchard, the moniliose, which is manifested by brown spots covered with white spots arranged in concentric circles on the fruit, is the wound of the summer. Apple, pear, peach, apricot-the list of potential victims is long. Highly contagious, the fungus can be spread by simple contact of one fruit to another, hence the importance of practicing a good clarification. Again, the fight is essentially preventive application of bordeaux mixture when the weather is wet and especially pick-up and destruction in the winter of mummified fruit that remain attached to the tree and contaminate the next crop.