The new resistance creates an extra option in the battle against the blackcurrant-lettuce aphid Rijk Zwaan has introduced the first two iceberg lettuce varieties – Happinas RZ and Friendlinas RZ…

The new resistance creates an extra option in the battle against the blackcurrant-lettuce aphid

Rijk Zwaan has introduced the first two iceberg lettuce varieties – Happinas RZ and Friendlinas RZ – with a high resistance against biotypes 0 and 1 of the extremely troublesome blackcurrant-lettuce aphid Nasonovia ribisnigri (Nr:0,1). This innovation by the Dutch fruit and vegetable breeding company is a very significant development for lettuce growers and their customers, especially in Europe.

The new resistance creates an extra option in the battle against the blackcurrant-lettuce aphid. This is particularly important now that lettuce growers in the European Union (EU) will no longer be allowed to use systemic pesticides containing Spirotetramat as the active ingredient as of next season. “They are asking themselves how they can stay aphid-free,” explains Peter Sonneveld, Crop Coordinator at Rijk Zwaan. Growers face substantial risks because lettuces affected by the aphids are virtually impossible to sell.

Therefore, the new iceberg lettuce varieties – which are being marketed under the Nasonovia Defense™ label – have come at just the right time for growers, representing a significant step towards future-proof lettuce production. The high resistance has been proven in multiple field trials by Rijk Zwaan over the past year. When disease pressure was high, susceptible lettuce varieties became heavily infested by blackcurrant-lettuce aphids. In contrast, the researchers found hardly any aphids in the high-resistance varieties in the same field.

Moreover, the new iceberg lettuce varieties have positive agronomic traits. Trials at 20 growers’ facilities in north-western Europe showed that the varieties perform well in terms of head shape, base, weight and strength against tipburn. “We’re happy to share the details with growers,” says Peter Sonneveld. Rijk Zwaan expects to have sufficient seeds of both iceberg varieties available for the upcoming season.

Besides the iceberg lettuce varieties Happinas and Friendlinas, growers can expect to see varieties of other types of lettuce with the same resistance before too long. Johan Schut, Breeding Manager at Rijk Zwaan, explains: “Our team is busy crossing the resistance into other lettuce types for each market. Furthermore, our goal is to combine the Nr. 1 resistance with the complete package of resistances against Bremia races and against the soilborne fungus Fusarium.”