The GREEN HORSE - sustainable horsekeeping

In the June/July 2005 issue of The Green Horse you will find the following articles:

Talking Point and Information Exchange
Tractor Safety
Cotton Bush by Nicola Field
Wild Horse Update
Too Much Grass - managing the property.
Hay Itch Mite
Spiders - Friend or Foe? by Liz Tollarzo
Growing Equine Herbs - Clivers by Fiona Adams
Deeds, Steeds and Weeds
Planning a Property - Again!! by Chris Ferreira and Tracey Bell


You can read the Cotton Bush, Wild Horse Update and Hay Mite articles below

Cotton Bush

by Nicola Field

The next time you see a Wanderer Butterfly (Danaus plexippus) fluttering around your property, treat it kindly. It’s doing a good job combating infestations of Cotton Bush, which is the preferred food of the butterfly in its caterpillar stage. Unfortunately, it takes more than the butterfly’s efforts to control this weed.

A native of North Africa, Cotton Bush comes in several varieties: Balloon Cotton Bush (Gomphocarpus physocarpus), which has ball-shaped seed pods without a tapering point, and Broad-Leaf Cotton Bush (Gomphocarpus cancellatus) whose pods have no spines. The Narrow Leaf Cotton Bush (Gomphocarpus fruticosus) variety is the main culprit (though Cottonbush does hybridise) and the weed is currently found in southern West Australia and right along the east coast from Brisbane to Adelaide. It is often seen on road verges and vacant blocks of land, however, it is also associated with untended horse paddocks, where owners may be absent or do not use appropriate management methods. Once established, it can be difficult to remove and can prevent useful pasture plants from growing.

Cotton Bush is a relatively non-descript perennial shrub, about two metres in height with narrow, dull green leaves and small white flowers. It is the plant’s seed pod however, that makes identification easy. Appearing in early summer, the bright green fruit pod is an inflated oval about 4 to 7 cm long, covered in long, soft spikes. Once mature, the seeds emerge from the pod’s tapered base. Each tiny seed ends in a tuft of white silky hairs about 3cm long, from which the plant derives its name. Once they burst, these seed pods are easily blown about on the wind, spreading the seed far and wide.

Cotton Bush is poisonous to stock, though they will rarely eat it. The Wanderer Butterfly on the other hand, relishes the plant, and landowners can – and do - cultivate the insect for help in controlling the weed. Chemical methods of elimination though are a faster means of eradication – especially if infestations are large.

Cotton Bush should be slashed, and the cuttings burnt, in winter. The plant spreads chiefly by seed, so poisoning with a herbicide is best done in spring, when the plant is growing, but before the seed pods appear sometime in December. Glyphosate can be applied in the ratio of 1:100, but the West Australia Department of Agriculture recommends the use of Roundup Bioactive if the weed is growing in wet areas or along a water course.

As with all weeds, consistent follow up treatment of the area is a must to ensure any new growth is removed.


WILD HORSE UPDATE

After a series of holdups, the project to rescue wild horses of heritage value in the Western Australian outback has begun. Local drought caused problems with the initial plans to capture the horses, as drying up of waterholes made fencing these unfeasible. Instead, an aerial muster was used to drive the horses into hessian covered ‘wings’, leading to yards, assisted by a cavalcade of vehicles and motorbikes on the ground.

Many local station people assisted in the capture, without whom organisers Sheila Greenwell and Paul Wynne-Houchin say the capture could not have happened. Their knowledge of the terrain and geography of the area, coupled with many man-hours lugging metal yards in extreme conditions (temperatures ranged from 43 to 46 degrees celsius!) and additional vehicles for muster, were invaluable. Surprisingly, the level of panic was minimal and the horses, who came into the yards in small mobs, settled very quickly.

Most of the eleven captured were mares and foals, as the younger colts could well outstrip the ground crew given the rough terrain. One such group of striking blacks with silver manes and tails split in all directions just as they were heading to the yards, and so were unable to be captured. However, a further trip will be scheduled as soon as possible to bring them in. Loading the horses on to the truck was yet another experience - with a steep loading ramp horses made it on in many ways - frontwards, backwards (one mare constantly kicked so was reversed on) and some with the help of rump ropes!

Taken to a nearby station, the horses were able to eat, drink and rest for six days prior to the journey south. Long but uneventful, there was only one overnight stop along the way. It is interesting to note that the horses loaded back onto the truck in 5 minutes with very little human intervention. The horses then had six weeks at the Watsons farm in Margaret River, eating continuously and absorbing the new sights and sounds with great interest. The gentling process has begun, and they are now being quietly moved around the paddocks to desensitise them to human contact - although by the response so far, these intelligent creatures may just teach the humans more than we can teach them! Their training will begin in earnest in late May when the Watsons’ Horses and Horsemen Academy run their wild horse course. An open day is scheduled for May 28th.

Hay Itch Mite

If you ever been confronted with an angry mass of red wealts with a central blister after handling hay or grain, you may have been in contact with a mite known as hay itch mite. A common grain pest, hay itch mites are not usually seen because they are the size of specks of dust. The mites are related to ticks and spiders and have eight legs rather than the six that insects have.

Mites thrive under warm, moist conditions and can multiply 500 times in a month, with a life cycle of two to four weeks in favourable conditions. They are more common in the higher humidity of coastal regions than in drier inland areas, however haysheds that are exposed to rain-bearing winds in warmer conditions also offer ideal conditions for the mites. Because of their rapid growth, they usually reach peak numbers during late summer.

Mites feed on soft bodied insect larvae, present in many hays, grains and grain products, their host pests are such as the pea weevil, saw-toothed grain beetle and the Angmounis grain moth. The mite bite injects a venom and causes an allergic reaction in most humans, accompanied by severe itching. The resulting welts are extremely itchy, and can cause the sufferer to scratch themselves red raw, often preventing sleep at night.

Hay itch mites rarely appear to affect horses, however their bites are extremely uncomfortable when inflicted upon humans. The most common type of contact tends to be when handling affected hay, the heat and sweat causing even further itching. Areas particularly affected are the covered areas of the body - mostly stomach, chest, arms and inside leg.

It is important when handling affected produce that protective gear is used, and a personal insect repellent such as Aerogard or Rid is applied to wrists, ankles, neck and waist.

Mites do not breed on mammals, so limiting exposure to affected produce will help conditions to subside, however treatment is essential, as scarring from the scratching can be quite severe and may even lead to dermatitis and secondary infection. Calamine lotion, Savcol, lavender oil or any calming type of cream will help, but consulting a doctor is your best bet, as sufferers may need some heavy duty prescription drugs to get rid of the irritation quickly and help start the healing process. Cortisone type creams and lotions are very effective as is the lotion Benzemul, which is usually prescribed for scabies, or Ascabol lotion. This needs to be applied all over the entire body every day for several days until the welts disappear.

Strict hygiene practices in and around grain or produce storage and handling areas are essential for control, as mites are tolerant of all chemical control measures available for treatment of grain and grain products, therefore reliance on chemical control alone will not work! Remove and destroy unwanted, infested produce by burning or burying.

Fumigation may even be necessary. Mite eggs can survive fumigation, so correct advice on how best to fumigate is essential. See your local Dept. of Agriculture or Primary Industries for advice pertaining to your area. Fumigate any produce kept, clean up and destroy hay wastage, grain dust and grain residues at least weekly and clean all storage and handling equipment before handling new, uninfested produce. Walls and floors of stables and sheds can be sprayed with an insecticide such as Alfacron, but surfaces that come into contact with the hay, grain or produce should not be sprayed with this.

If you do find feed that is affected, it is important to tell your feed supplier so he can check his stores and notify growers to keep the pest in check.