Lt Defense offers protection against powdery mildew
Rijk Zwaan’s Lt Defense varieties protect against infection with powdery mildew (Leveillula taurica or Lt) in sweet pepper and hot pepper cultivation. This disease can be a big problem for growers. The resistance restricts the growth and development of the powdery mildew. Varieties with this resistance are an effective solution for growers. Lt Defense is part of Rijk Zwaan’s Defense label.
Interested in Lt Defense varieties?
Heleen van Rijn-Wassenaar
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.
Benefits of Lt Defense
- A healthier crop
- A higher yield
- Reduced need for crop protection agents
- Lower residue levels on fruits
- Less impact on plastic greenhouse materials thanks to reduced use of sulphur
Sweet pepper and hot pepper varieties with Lt Defense
Rijk Zwaan offers a growing number of sweet pepper and hot pepper varieties with Lt resistance. These varieties are indicated by the Lt Defense label. Lt Defense is available for Rijk Zwaan’s sweet pepper and hot pepper segments as follows:
- Hungarian Wax
- Med hot pepper
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.
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.