• During cultivation

As soon as the first symptoms due to Alternaria tomatophila are observed during cultivation, the plants must be treated as quickly as possible with one of the fungicides * authorized (applied alone or in combination) ( e-phy ). Applications should be repeated after heavy rains and sprinkler irrigation. Note that these promote the spread of the disease, so they must be carried out during the day , at a period that will allow the plants to dry out and not stay too long wet.

It is also advisable to avoid any stress to the plants, and to ensure them a balanced manure , in particular in nitrogen.

As far as possible, as much plant debris as possible (leaves, stems and in particular fruits) should be removed during and at the end of cultivation, and destroyed. Some authors advise burying them deeply.

• Next crop

During the next crop and if the nursery takes place in the same place as the previous year, disinfection of the soil or preventive applications fungicide will be carried out. Healthy seeds should be used. In case of doubt, the uncoated seeds can be treated with hot water, with chlorothalonil, iprodione ...

Of crop rotation long enough, on the order of 3 to 4 years, involving small grains, corn ... will be considered in heavily affected plots. Weeds that can serve as intermediate hosts should be eliminated.

De plus, on avoid de mettre en place une culture nearby for parcelles de tomate déjà affectees or other cultures sensibles comme la pomme de terre, the aubergine ... Les fumures déséquilibrées favoriseraient the alternariose, en particulier les Excès ou les nitrogen deficiency. Those well supplied with potassium would have the opposite effect, as would calcium intakes.

In some countries, disinfecting the floor of the boards with steam or with a fumigant is recommended.

The quality of the plants will be checked before their establishment. It is also recommended to arrange the plantations at a density which allows good aeration of the vegetation, good wiping after rains or sprinkling irrigations, and to produce rather vigorous plants. Avoid planting in hydromorphic soils. It will be better to irrigate the plants by drip rather than by sprinkling. Tomato plants should as far as possible be trained or grown on grids so that the leaves and fruits remain away from the ground; a mulching of the latter contribute to the same effect by providing a mechanical barrier. The equipment for the trellis should be disinfected between each culture.

Fungicide treatments should be applied preventively with the active ingredients mentioned above. It should be noted that there are several decision support systems developed in order to better determine the periods of fungicide applications , to improve their effectiveness and to reduce their number. These prediction models, now well known, are NJ-Fast, CU-Fast, and more particularly Tom-Cast. The interest of these tools is no longer to be demonstrated in the context of the reasoned protection of the tomato.

It should be added that the baking soda sprayed on the tomato would reduce the germination of conidia A. tomatophila and would have some effectiveness in controlling early blight. Other unconventional products have also been tested with varying degrees of success in order to induce resistance in tomatoes, in particular to early blight. In the same vein, various plant extracts, vegetable oils ( Acacia concinna , Bassia latifolia [= Madhuca longifolia var. Latifolia '], garlic, Azadirachta indica …) would limit the development of this mycosis.

Several antagonists potential have been reported in the literature: bacteria ( Pseudomonas fluorescens , Bacillus spp., Etc.) such as fungi ( Trichoderma polysporum , Chaetomium globosum, etc.); however, their performance does not seem important in a natural epidemic situation.

Sources of resistance have been found in several wild species , in particular Lycopersicon hirsutum and L. pimpinellifolium . They have been used in breeding programs and have made it possible to obtain lines and cultivars with partial polygenic resistance to Alternaria and also having a rather late maturity. No variety currently marketed in France has this capability.

Lower sensitivity of the stem and crown to early blight has been reported in other wild species without being effectively exploited. Let us add that in certain cultural contexts in India, a certain number of tomato varieties ('Ace', 'Flora-Dade'…) have been shown to be less susceptible to this disease.


* Chemical control : As the number of pesticides available for a given use is constantly changing, we advise you to always confirm your choice by consulting the e-phy site of the Ministry of Agriculture and Fisheries which is an online catalog of plant protection products and their uses, fertilizers and growing media approved in France. This also applies to all biological products based on microorganisms or natural substances.