#Phytophthora on tomatoes professional#

Late blight can be considered one of the plant diseases affected by climate change. Diversity in the range of tomato types does restrict the progression of blight which can sweep very quickly through a single type crop. Working with vertical support structures, even string to walls, and combining tomatoes with other climbers for protection can be surprisingly successful and see good crops of mixed tomatoes. Varieties that fail in one spot one year can produce quite successfully in another area the following year. Using good heirloom varieties of tomato, mixing varieties and grouping them in clusters to individual areas in the garden can produce quite interesting results in understanding the progression of the disease. In this respect growing tomatoes in containers has some advantages over soil beds. Tomatoes planted in containers can benefit from reduced soil moisture content and when positioned by walls are offered some protection from weather while still enjoying open air flow. However, a balance is required to regulate light access and allow air movement. For example, tomatoes planted under a tree canopy in one part of a garden will grow quite successfully while others elsewhere in the garden are affected by blight. While staking and framing tomatoes up from the ground is normal, combining beans, cucumbers and other climbers which are not affected by blight, and which produce additional leaf cover, does provide some umbrella protection to tomatoes. Avoiding leaf litter around the base of plants helps to remove infection habitat. Ensuring air flow in and around plants and keeping the soil bed surface dry prevents excess moisture accumulating on plants. A well drained and well fed active growing bed ensures plants are strong and healthy. Strategies for addressing late blight start with the soil.

Lesions on tomato fruit are often followed by soft rot and disintegration. The blight produce dark brown, firm lesions on tomato fruits which enlarge and destroy the entire fruit. The entire plant can be destroyed in a few days after the first lesions are observed. Late blight on tomatoes is identified by black/brown lesions that appear on leaves and stems which expand rapidly – matter of days – across the plant. In particular, when the heavy downpour follows a period of hot clammy weather and results in a cool sharp chill in the 24 hours following, this is very indicative of the blight’s arrival. It is noticeable by the heavy volume of the downfall after a prolonged period of dry weather. Late blight comes with a particular downfall of rain which occurs at the end of summer around August/September each year.

They are also called “water moulds” because they thrive and produce spores under humid, moist conditions and cause infection only when excess moisture is present on the plants. It belongs to a group of organisms called “protists” which are commonly referred to as “fungi”. Phytophthora infestans is not strictly a fungus or a bacterium or a virus. However, working between varieties of tomato, combining these with complimentary other species, beans and cucumbers, and providing the right structured growing environment can result in losses some years being reduced to below 10%.

Doing so in a heavily shaded garden with limited exposure and an inclination towards dampness is not ideal. Growing tomatoes outdoor in a Brussels summer can be difficult. Some varieties of heirloom tomato have a natural resistance to blight which when combined with developed soil treatments and alternative planting procedures, can produce quite successful results.

#Phytophthora on tomatoes professional#

While many professional gardeners now reserve tomato growing for the greenhouse under glass, some organic producers and those interested in the natural resilience of heirloom varieties have continued to persevere with outdoor growing. Late blight was the fungus that caused the Irish Potato famine. It is especially virulent if the weather is unusually cool and wet. Late blight, as it is known, is caused by the Phytophthora infestans fungus and affects both tomatoes and potatoes. In recent years increasing numbers of professional gardeners have come to insist that the fungus is bred by heavy rain fall, mixed with humidity and certain soil conditions. Others say that a lack of lime in the soil is the problem. Some researchers say that soil which is nutrient-deficient provides the ideal breeding ground for blight. There are several competing arguments on what causes the disease. Put simply, blight is a fungal infection. Learning about this disease is a must for tomato growers. Each year, just as the tomato plants reach maturity and the main fruit has set, the tomato blight arrives and the plants begin to die. People who grow tomatoes all know about tomato blight.