Delhi Defense Cucumber

The Tomato Leaf Curl New Delhi virus (ToLCNDV or ‘New Delhi’ virus) has been a serious problem for many cucurbit growers, especially in the Mediterranean region, for numerous years. Due to its high infection pressure and rapid spread, this disease poses a severe threat to cucumber crops. Our new solution, called ‘Delhi Defense’, minimises the risk of infection since cucumber varieties with ‘Delhi Defense’ show good resistance against the New Delhi virus.

"The variety has a very good production, high fruit quality and a very strong resistance package."

- Juan Jose Rodriguez, Spanish cucumber grower

Spread of the disease

In greenhouses and fields, white flies are the source of spread within and between crops and very efficient in transmission. A single white fly can acquire the virus only after a short period of feeding of 15 to 60 minutes and will subsequently be able to transmit the virus for some weeks or even its entire life. The combination of a broad host range of plants, that are susceptible for the New Delhi virus and the dispersal by the, often abundant present, white flies makes this disease a very serious danger for cucumbers.

Symptoms of ToLCNDV

Compared to other crops, the symptoms of this virus in cucumber are relatively mild, but still very serious. In squash and melon, the virus causes severe leaf curling and stunting, thus completely halting the development of the plant. In cucumber, the plants continue to grow but they lose a lot of their productivity. Symptoms in cucumber are best described as yellow mosaic, later turning into severe patchy yellowing with moderate leaf curling in the apical leaves.

Trials show great differences

Trials in greenhouses with high infection levels of the ‘New Delhi’ virus have demonstrated that the resistant varieties stay healthier, whereas the susceptible varieties in the same greenhouse show both clear infection and production loss.

Firstly, fewer infections occur in ‘Delhi Defense’ cucumber varieties and secondly, if infection does occur, the symptoms and effects of the disease are limited. The ‘Delhi Defense’ varieties are part of Rijk Zwaan’s ‘Blueleaf’ line of varieties that have stronger natural resistances against diseases and pests. This combination offers the best of both worlds.

Practical benefits

Our ‘Delhi Defense’ cucumber varieties offer significant benefits for growers, compared with the regular susceptible varieties. The advantages include:

  • Higher production
  • Better fruit quality
  • Limited symptoms and disease effects in case of infection
  • The varieties are part of the ‘Blueleaf’ line

Minimize the risk of spreading

The introduction of resistant cucumber varieties is offering protection, but it remains important to minimize the risks of an infection. To have a healthy crop we advise you to:

  • opt for a Delhi Defense variety
  • keep the number of white flies as low as possible
  • keep a close eye on symptom development in other host plants like squash or melon.

With the practical benefits of Delhi Defense, Rijk Zwaan fulfills its promise to offer growers a peace of mind.