Friday, June 5, 2009
Broccoli and Aphids
This query arrived without the pictures first so I imagined sooty mould, as it turns out I wasn’t far wrong. This Broccoli crop is supporting a healthy community of Aphids. Have a look at the image below, you can see a thick grey mass tucked snugly up beneath the Broccoli floret. Hundreds of them These little beasts are having a lovely time sucking the goodness out of the plant, so much so that the floret opposite is maturing unevenly. The sap sucking is also what causes the leaves to curl.
Aphids are insects that suck sap. They love soft, quick growing plants like fruit trees and roses in spring. Yum, juicy. There are lots of Aphid species, each one targeting a different plant type and their colour often reflects the plant they enjoy feasting on most. Some are yellow, some a beautiful green and these ones have adopted a grey to camouflage them amongst Broccoli.
Aphids infest plants quickly. Blink and the stems of your favourite plant are suddenly thickly coated in little fat bodies. They are also relatively easily disposed of with systemic chemicals such as Confidor. Aphids are a pest that we scout for regularly and spray only when we find them.
Liz and many other gardeners want a solution to the aphid problem that doesn’t involve chemicals. The most common suggestion is to hose them off, but you might find this option even more anti social under current circumstances.
Their bodies are so soft they can be manually squashed, but with an infestation like this one squashing will be both messy and time consuming.
Soft chemical options are Clensel and white oil. Clensel, a soap solution and white oil just clog up the insect’s ability to breath. Have a look at the Clensel link; there are all sorts of ‘alternative’ pesticides.
The ‘ideal’ solution is Bugs for Bugs. (I use inverted commas because we are all aware of the problems associated with the importation of Cane Toads as a biological control agent). The only problem is, I am note sure that predatory bugs are available in retail packages. If you know anything about packaged lacewings or ladybirds please let me know.