Wednesday, July 10, 2013

Pests and diseases on auriculas

Primula hirsuta infected with root aphids.
At this time of year root aphids can suddenly appear on the roots of your auriculas, they seem to thrive in warm dry conditions. They are not deadly but can severely weaken the auricula if not treated

The picture shows  a Primula Hirsuta infected with root aphids, these can occur when the plant is left too dry & more often when the plant has been neglected.
It is easily cured using a systematic insecticide such as  CALYPSO used as a spray or 'drench'. A 'drench' is a diluted solution of Calypso concentrate poured directly into the infected auriculas pot. DO NOT FORGET TO FOLLOW THE MAKERS INSTRUCTIONS CAREFULLY:
The same Primula hirsuta circa 6 weeks later.

Some times it takes two treatments to cure badly infected plants. Picture shows a Primula hirsuta circa 6 weeks after treatment, it is now free of root aphids. After treatment it is re-potted into a fresh pot & the old pot is destroyed.

I use CALYPSO (Tiakloprid) spray as a preventative measure against pests; I normally spray all my auriculas twice a year.

Other pests are caterpillars, slugs & snails, I find they cause very little damage & are easily removed by hand or can be sprayed with insecticide.

Botrytis is a fungal disease which starts as a white/grey mould on dead or dying leaves. This is normally the result of high humidity & poor ventilation in greenhouses or cold frames. Prevention is better than cure, keeping Greenhouses & cold frames open to increase ventilation, not over watering plants. The best way I have found to try & save the plant is to cut away all infected parts back to fresh growth and on the open areas of damage apply a dusting of ‘flowers of sulphur', this helps in preventing reinfection. Then hopefully new shoots start from the carrot.
Flowers of sulpher.
Root rot is caused by overwatering, the roots become brown and rotten and again prevention is better than cure. Do not overwater. Cut away all rotten roots, dust with 'flowers of sulpher' & re-pot in fresh soil.
I hope the above information helps you to keep your auriculas in good health.

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