"NL: "Biology is our first choice on principle"

Duponchelia fovealis can have an incredibly harmful effect on a range of crops. The predatory soil mite Macrocheles robustulus (Macro-Mite) is an effective beneficial, but Capsanem has also proven to be efficient. Dutch grower Nolina, for example, has reduced the use of chemical crop protection by ninety per cent in the cultivation of their potted roses with this nematode product of Koppert.

Nolina exports its potted roses as far as Vladivostok in Russia. This company run by brothers Steven and Marcel de Lange is almost the largest producer of potted roses in the Netherlands, and one of the market leaders in terms of quality. Their products are being delivered exclusively to high-end retail chains across Europe. However, even in the furthest eastern regions of Russia their potted roses can be bought.

Potted roses are just one of the crops produced by this 20h hectare business (of which nine hectares are glass greenhouses) in Woubrugge, the Netherlands. Other crops include garden roses, Agapanthus, Clematis, Wisteria, and rose cuttings for fellow producers.

Potted roses have a cultivation period of twelve to fifteen weeks from potted cuttings to the end product. Duponchelia fovealis lays its eggs in the cuttings. The larvae that emerge eat away at the stems and young leaves with harmful consequences for the growth of the plant and cause eventual plant loss.

Efficient protection
"We first tried to combat Duponchelia with Macro-Mite," says crop manager Peter Verhoogt. "However, we were too late, as the eggs were already in the crop which is temporarily covered with plastic. This means that we were too late to effectively use Macro-mite."

Nola met with consultant Tom Konijn from distributor Horticoop and decided to use Capsanem - the entomopathogenic nematode Steinernema carpocapsae. "Immediately after potting the cuttings, we used our automated system to spray Capsanem on the pots," explains Verhoogt. "The conditions under the plastic are sufficiently moist for the nematode to flourish and it can live for up to ten days. This is enough time to tackle the first Duponchelia larvae. As the plant continues to grow, it becomes a less suitable environment for Duponchelia and the infestation level drops. We have created an efficient and comprehensive system of protection with Capsanem. The damage caused by Duponchelia is minimal now."

Ninety per cent reduction
Verhoogt estimates that the application of Capsanem in the cultivation of potted roses has reduced the use of chemical crop protection by ninety per cent, a benefit supported by the positive side-effects of the product. "The nematodes also attack Scatellas (shore flies), Sciaras (fungus gnats), and thrips." Nolina is forced to use corrective measures during a few isolated cases, especially after a sudden rise in temperature. "Duponchelia then develops so incredibly quickly in these circumstances that the biological beneficials are unable to keep up. In such cases, we use a biological product based on Bacillus thuringiensis if possible."

Biology: always the first choice
Nolina has welcomed the success in combating Duponchelia. This company aims to control pests without the use of chemical products. Beneficials are used against spider mites, thrips, and whiteflies and have reduced the use of chemical products by sixty per cent when measured across all crops.

"A zero-tolerance policy towards pests and chemical residues is key," states Verhoogt. "Biology is our first choice on principle."

For more information:
Koppert Biological Systems
info@koppert.com
www.koppert.com