Insect Pest Control
It is not often that I get excited about some gardening aspect these days but this week I am very much so. It all started off recently when the local community newspaper published an article on insect pests which I had written. Along with the article they placed a picture of a garden with a raised crop cover spread over the vegetables growing. I saw the picture and did not take any further notice. Then the phone started ringing with local gardeners asking what was the cover and where could they obtain some. I had come across various crop covers in the past mainly used by commercial growers in limited situations. It can work out very expensive to cover a hectare of land with a raised cover. I also have noted that the new dreaded pest called the potato/tomato psyllid has big populations currently causing havoc with late crops of potatoes and ruining tomato plants.
Even down in Southland gardeners are not lifting the good yields of potatoes that they are accustomed to because of the psyllids. (They are luckier down there as the psyllid population take longer to get going so they get some reasonable size potatoes, which set earlier and then the smaller ones that were affected because they set later). You can spray Neem Tree Oil regularly and apply Neem Tree Granules to the soil to reduce the damage but with each female laying 500 eggs it is a battle.
Wouldn’t it be nice if they developed a force field that you could put around your vegetable garden and it kept out all pests including insects, cats, birds and anything else that might harm our crops.
Well a crop cover might not be as good but it would do the same sort of job. So I went in search of suitable crop covers and found two that would work well. The first of these is an Insect Mesh that is 4 metres wide and whatever length required.
It is clear, 45gsm and gives a 15% shade factor. Rain will pass through but most insects, cats, birds would not. Ideal for larger insect pests such as white butterfly, moths, beetles down to about adult aphids. The gaps of the mesh would unfortunately allow some small insects such as psyllids to get through; though it could act as a deterrent. Nice price being about $5.00 a cut metre. (also ideal for whitebait nets).
The other one is a special Quarantine mesh, white, 125gsm 3.3 metres wide, 50 x 25 mesh with a 25% shade factor. This is the type that is used when quarantine situations are required in regards to imported plants, under which they are grown till they have met MAF requirements.
I don’t think a very small insect like the psyllid would be able to get through this small gauge net.
They are more expensive of course at around about $17.00 a cut metre, 3.3 metres wide.
Also these mesh products are fairly new in New Zealand and have mainly been used by commercial operators especially over entrances to glasshouses and tunnel houses. I see a great potential for home gardeners to use them for crop protection. For instance I am going to test the Quarantine one by planting a late crop of potatoes in one of my raised gardens. I will plant the seed potatoes deep using Neem Tree Granules and then cover the area completely with the Quarantine mesh. It will be raised about a metre above the soil to give ample room for the potatoes to grow and held in place so wind, rain and watering will not be a problem.
I think I will be able to achieve a late crop without having to spray Neem Oil for the psyllids.
You may like to try either covering yourselves and as far as I am aware they are not available in Garden Centres only by mail order. (Contact me for details) There are various ways you can make supports for the meshes, for small applications loops of no 8 wire, next would be plastic conduit pipe into larger hoops before having to build a structure out of wood or other materials.
Excellent for using over raised gardens.
The Insect mesh would be ideal at this time of the year for gardeners that are planting brassicas for their winter crops. Keeping the white butter fly off the plants along with grey aphids, moths, pesky birds and cats that like to dig up young seedlings.
The shelter offered by the mesh should also enhance the growth of the crops as well.
Given due care the meshes should last for many a season, so a good investment.
Problems ring me at 0800 466464 (Palmerston North 3570606)
Dear Wally. I have ignored my brassica plants and now they are covered in the grey eggs of white butterflies. Is it too late for me to save them.
It really depends on what brassicas you are growing, get them treated asap and they should be ok unless they have been eaten.