Relieve stressed city trees with Trichoderma

Sitting under a tree on a hot summer’s day is something wonderful! No parasol or awning can compete with this natural shade provider. This is not just because each tree reduces the ambient temperature, but also because of the soothing rustling effect of leaves and the wonderful atmosphere created by these green giants.

Perhaps we also feel naturally comfortable under trees because they filter dust and particles from the air with their leaves or needles. The rain washes the atmospheric impurities into the soil, leaving the air purified. For these reasons, we are happy and grateful for every park, urban garden and street tree that collectively form our urban forests.

However, because trees are forced to become city dwellers, this also means our trees are under considerable stress. Trunks and roots are routinely damaged during construction work. The spreading of road salt in winter can have detrimental effects on trees, while even dog walking can damage trees with urine and feces.

A lack of space for tree crowns and roots stresses trees. Root growth is restricted by cramped tree pits that hinder oxygen and water supply. In addition, highly compacted soils common in urban environments and often caused by concrete and paving stones, is not conducive to sound tree health.

Humans need the trees

Large tree crowns intercept water, thereby acting as huge water reservoirs reducing the peak discharge. Some rainwater evaporates while roots absorb much of the remainder while leaves slowly release part of the intercepted water to the ground over time.

All green plants use photosynthesis to grow. They store CO²trunk, branches and leaves and release vital oxygen as a by-product with the help of light energy. An average tree of 20 m produces enough oxygen to support approximately five people per day. In cities with their characteristic high-rise buildings, however, a lack of light is inevitable. This makes CO² filtering more difficult.

Although trees regulate climate, global warming is very hard on them. The last two very dry summers have, among other things, contributed to weakening the green lungs of our cities. At higher temperatures, trees evaporate more water. However, because the surface surrounding the tree is impervious to water, less water available to support growth and cellular function. Decay fungi and parasites can take advantage of a weakened tree, which in turn can reduce mechanical stability resulting in stem or branch failure. For safety reasons, trees must therefore be felled on a more regular basis. These prospects are welcoming for people for reside in and use the city on a daily basis.

New plantings are expensive and labour-intensive during the  first years of establishment due to the need for programmed irrigation and carefully managed pruning. For this reason, new tree species are being tested to better adapt to a city’s demands. However,  it takes years to verify if trees have successfully established and with the desired traits to resist stress.  Considering how slowly trees grow, and, it makes sense to take precautionary measures and protect them early on.

BioControl Agent Avengelus

For this reason, we recommend the use of our BioControl agent Avengelus with Trichoderma atrobrunneum even for new plantings. The formulation supports trees during planting stress and helps them to establish roots by producing and passing on auxins. It also facilitates the absorption of nutrients. Trees are strengthened against pests by the activation of defensive substances such as jasmonic and salicylic acid. When soil-borne harmful fungi are present, enzymes of Trichoderma dissolve their cell walls, using the cell content as food.

Avengelus supports newly transplanted and replacement plantings during the early years of establishment in many ways. Our products can also improve the vitality and resistance of already stressed, mature trees.