The Gentle Touch

Pest and disease control are possibly top of the list of priorities for horticultural nurseries and plant growers. Maintaining the health and quality of stock throughout the production operation is key to business success, so there’s no doubt that reliable, easy-to-use, broad-spectrum solutions to these problems are very appealing to growers.

Guernsey grower Channel Island Plants is using a Scotts control, Intercept 70WG, to protect against a wide range of pests which threaten plants in the very mild climate – and keeping plants in immaculate condition as a result. Intercept is a highly systemic, curative and protectant pesticide which guards against whitefly, sciarid fly, aphids and vine weevil, and is the only broad-spectrum pesticide for container-grown ornamentals. It’s easy to use and granules quickly disperse in water to produce a solution for use in compost drench for seedlings, cuttings and established plants.

The grower produces a wide range of plants which provide cuttings for UK growers. These varieties include Surfinia®, Verbena tapien®, Verbena temari®, Million Bells®, Senetti®, Petunia, Diascia and Nemesia. Currently, 17 million cuttings are produced from 150,000 stock plants on two sites, in four acres of modern glasshouses. With this scale of operation, a simple and reliable solution to plant health is paramount to the success of the business.

Production director Judy Scott explains how they use Intercept as part of their pest control programme. “Insect damage at any stage reduces the vigour, and therefore the productivity of the plants,” she explains. “It’s imperative that the stock plants are in peak health when the first cuttings are taken, and this needs to be maintained throughout the production time for maximum cutting yields.

“We always apply drenches of Intercept to ensure pest protection is available at the time of maximum pest pressure,” Judy adds. “The first drench is applied when the tissue-cultured plants are newly potted and a second applied when the plants are potted into the stock plants container. This gives the plants maximum protection against sciarid fly, white fly and aphid. It also protects against vine weevil, but thankfully this isn’t a specific problem with the species we grow. 

“Intercept is very reliable and broad spectrum, which is an essential confidence factor. When the plants have produced all the cuttings we can sell in a season, they are still in perfect condition. Also, we are saving money by using just one, easy-to-use pesticide to give us all the protection we need.”

Another grower in the island, Guernsey Clematis, is using Intercept as part of an IPM (Integrated Plant Management) programme at its two 1.8-hectare sites. Their IPM system employs a combination of chemical pest treatments and biologicals (‘good’ pests) to control undesirable pests. 

Guernsey Clematis is one of the world's leading clematis producers. Owned by world renowned clematis expert Raymond Evison OBE, the company specialises in young plant production with particular focus on the new Evison/Poulsen introductions. This includes the recent Boulevard TM Patio range which formed the centre of Mr. Evison’s gold medal winning stand at this year’s RHS Chelsea show.

Clematis production begins with cuttings taken from mother stock, which are then put into cold storage before they are prepared and struck into the cutting medium. After rooting, the young plants are potted. Some 20,000 cuttings can be prepared in a day with each one going through four separate processes – so no risks are taken with plant health.

“At the optimum time, all plants are treated with Intercept,” says operations manager Paul Ingroueille. “We use it as a root drench via the recycle system, to ensure the clematis plants are given maximum protection against damage from both root and aerial pests. We have to be very careful in our selection of chemicals to ensure we don’t kill off the biologicals. This is why we use Intercept – it allows us to maintain that balance and it works very well with our IPM programme. Also, it only needs one application each season for complete protection, so convenience is another important factor for us.”

For complete disease control, Guernsey Clematis dips all cuttings in Scotts Octave fungicide before they are inserted into the growing medium. Octave is a broad-spectrum fungicide which is gentle on plants, but tough on a wide range of foliar and root diseases. It can be used without crop damage on hardy, woody and soft ornamentals. It also gives a reduction of the disease affecting the rooting of cuttings caused by a complex of common pathogens.

“Octave is a gentle fungicide with a broad spectrum of control,” adds Paul. “This minimises the risk of disease affecting the cutting chances of optimum rooting.”

Although plants for UK and European markets are shipped in plugs or pots, the nursery exports to over 18 countries and plants destined for foreign shores need to go through additional processes to ensure they meet strict hygiene requirements. “Exported plants have to be totally clean of growing media, foliage and pathogens,” explains Paul. “Octave is used as part of our pre-shipment procedures to ensure that bare-rooted plants are fully protected
from disease infection.

“Both these Scotts controls have allowed us to achieve the quality we – and our customers – demand. They us give long-lasting, reliable protection, but are gentle enough not to endanger desirable biologicals, and we can keep treatments as
un-aggressive as possible.” 

Channel Island Plants and Guernsey Clematis are both supplied with their Scotts control products by the local Guernsey distributor, Stan Brouard Ltd.