For iceberg lettuce growers, Nasonovia ribisnigri is a real headache, according to Martin Schrörs, Crop Specialist at Rijk Zwaan in Germany. “Last June, the aphid pressure became so intense that some growers had to destroy their lettuces. They have doubts about continuing with this crop next year due to the high risks and costs involved,” says Martin. “The two new Nr:0,1-resistant iceberg lettuce varieties are therefore a game-changer.”

Aphids peaked early 

Besides being an iceberg and Crunchy Cos Lettuce specialist at Rijk Zwaan, Martin is active as a sales rep for open field crops in North Rhine Westphalia. When he visited lettuce fields in mid-June, he even had aphids crawling on his arms. “The aphid peak usually occurs in September, but this year it came early. It affected almost every grower in this region – especially of iceberg lettuce crops, but also of other lettuce types,” Martin explains.  

Huge costs  

The crop specialist understands how concerning this issue is for growers. “When the aphid pressure is so high, they simply can’t supply their lettuces to retailers. Consumers won’t accept a lettuce crawling with aphids. Growers have no choice but to destroy their crop. By that time they have already incurred a lot of costs: for renting the land, planting the young plants and applying crop protection agents. Growers question whether they are willing to take such risks again next year,” Martin says, describing the extent of the uncertainty. 

Shortage of options 

Moreover, use of systemic insecticides containing the active ingredient spirotetramat will no longer be authorised in the European Union as of next year. “Without these insecticides, controlling lettuce aphids is a real challenge. 

Significant development 

In other words, growers have few options when faced with high aphid pressure. For Martin, it’s crystal clear that the new iceberg lettuce varieties with Nr:0,1-resistance are a very significant development for growers. “I don’t have to explain that to them at all – especially after a year with so many aphid problems. A resistant variety can mean the difference between yield and no yield. It’s a game-changer.”  

Resistance makes an impressive difference 

At the German Rijk Zwaan Trial station in Welver, Martin saw for himself how effective the new trait can be when the aphid pressure is high. “In the non-resistant variety we found a big amount of aphids per head, while in the resistant variety we only found the occasional aphid. That’s an impressive difference.” 

Pleasant surprise 

Martin wasn’t only impressed by the resistance in this and other trials, but also by the agronomic traits of the two new iceberg lettuce varieties, Happinas RZ and Friendlinas RZ: “Based on the blind evaluation we did in early summer  of both the new and existing material, the resistant varieties have a nice shape and meet our general quality standards. It was a pleasant surprise that they performed so well. The breeding team did a fantastic job.” 

Contributing to a healthy future 

The Crop Specialist is proud that Rijk Zwaan can really make a difference for growers in this way. “It’s upsetting to see them sometimes having to destroy entire fields of iceberg lettuces. As entrepreneurs, the uncertainty and risks weigh heavily on them,” he states. “I’m happy that our team can contribute to a healthy future – including for their businesses. I expect growers to be just as enthusiastic as I am.” 

Visit our Demo Days 

Come and see the new varieties with Nasonovia Defense for yourself! We warmly invite you to attend the Pfälzer Feldtag in Schifferstadt, Germany, on 11 September and the Kundentage Welver from 22 September to 2 October. Alternatively, we look forward to welcoming you to the Open Field Demo in Fijnaart, the Netherlands, from 15 September to 10 October.