Rijk Zwaan's solution against powdery mildew
Rijk Zwaan's Lt Defense varieties provide protection against powdery mildew (Leveillula taurica or Lt) in sweet and hot pepper cultivation.
Lt in susceptible varieties
Leveillula taurica (Lt) is a fungus that can only grow on living plant tissue. Spores form on the underside of the leaves and are carried by the air, whether in greenhouses or outdoors. If the spores land on other leaves, they germinate. Lt is difficult to detect at an early stage, which is why it is so easy for the disease to spread unnoticed.
Initially, small light green spots appear on the top side of the leaf. They gradually grow bigger and turn yellow. Eventually, the leaf tissue turns brown and dies. The mycelium grows inside the leaf and forms spores on the underside.
Trials reveal clear differences
Lt Defense pepper varieties are less susceptible to the effects of powdery mildew than standard varieties. Trials have shown that Lt Defense varieties slow down the growth and development of mildew. This not only delays damage to the crop, but also gives growers more time to react to any damage. In the resistant varieties, the production and fruit quality remain stable.
Why growers choose Lt Defense
Leveillula taurica is difficult to detect at an early stage, which is why it is so easy for the disease to spread unnoticed in sweet pepper and hot pepper crops. Growers who choose varieties with an Lt resistance can reduce their use of crop protection agents. The crop is healthier and more productive. There are also lower amounts of residue on the fruits, which is important to retailers. Moreover, using less sulphur is better for the plastic materials in the greenhouse. As a result, Lt Defense gives growers greater peace of mind throughout the crop cycle.
Minimising the risk of spread
It is very important to get each crop cycle off to a hygienic start by destroying all the old plant material. Because the spores can survive for approximately seven days, it is advisable to leave the greenhouse empty for two weeks.