Kicking Kikuyu back to Kaikohe
Pennisetum clandestinum, otherwise known as Kikuyu grass, is a vigorous tropical plant that grows rapidly in warm to hot, humid conditions to form a dense mat that stifles growth of other grasses and harbours insects. It survives droughts and frosts, and grows on sand, bare clay and other places where most grasses would not.
It is endemic in Northland where there are two schools of thought amongst farmers work hard to get rid of it or at least knock it back so that other species will grow, or learn to manage it as stock fodder.
Kikuyu is the politician of the pasture looks good, promises the earth but doesnt deliver and in fact just makes things worse, a real pain in the grass. If not checked can soon take over smothering anything in its path. The only way to deal with it is to cut it down to size frequently or vote it out altogether. Thats essentially what Northland farmers try to do with varying degrees of success.
Stolon moments
Kikuyu grows fastest from December to February with its stolons lengthening by up to 2.5cm per day. Such rapid growth might, in theory, be valuable in hot seasons when other grasses do not perform as well. However, only in early summer does its nutritional value come anywhere near a normal ryegrass/clover sward. By March its quality is way down and stock grazing it lose condition. In winter it does not grow at all. While frosts may cause it to die back, its underground rhizomes survive to re-grow in spring.
Halving of production on poorly managed kikuyu-dominant farms is not uncommon. Wayne Andrewes, LIC Farmwise consultant based in Kerikeri, quotes the case of a Northland dairy unit that could manage only 370kgMS/ha initially, and was able to increase to 750kg only after mulching the whole farm and drilling annuals in April at a cost of $350/ha.
But thats not the worst of it kikuyu kills! Kikuyu toxicity is a condition of unknown cause that kills cattle within 48 hours. More common is kikuyu impaction in which cattle trying to ingest enough energy to survive eat large quantities of indigestible stolons. Their stomachs swell and they become very skinny, and can die.
But wait, theres more, and you dont get a set of steak knives. The kikuyu mat shelters undesirables such as crickets, army worm and black beetles, and retains moisture so that the soil becomes wetter.
Why on earth would you want it? asks Andrewes.
The problem is that many farmers dont realise they have got it its not named clandestinum for nothing. It surreptitiously creeps along roadsides and invades pastures, and by the time farmers realise theyve got it eradication is almost out of the question.
Kikuyu seems to have spread from Northland down both coasts and can be seen in parts of the Bay of Plenty, the Waikato, and Taranaki. Federated Farmers in the Waikato has recently sponsored meetings to raise farmer awareness, and is trying to get local bodies to take an interest in control. They claim that they have more than enough pests to deal with, but given that kikuyu is probably being spread by roadside mowers it could be argued they have some responsibility.
Spread
One Waikato farmer mowed the church lawns and brought the clippings back home and put them on his compost heap. Kikuyu sprouted up within weeks and now he has a problem. Other farmers are concerned about hay, silage and drainage contractors bringing stolons and seed onto their properties. Stock spreading stolons with their hooves generally doesnt happen, but they do spread seed if they graze seeding kikuyu.
Kikuyu seeds around November in Northland, but there are sterile strains and it is not known if the plants in the Waikato actually form seed. If they dont, it will be much easier to eradicate. If they do, it will be a problem because seed lasts for at least seven years in the soil.
Identification
At the seedling stage its very difficult to tell kikuyu from ryegrass. However, once the stolons start to elongate in December it is easier to pick.
Eradication
Make a paddock location plan for kikuyu for the whole farm including tanker track, races, dairy effluent ponds drains, fence lines especially boundary fences, and lawns.
Spot spray small areas and individual plants when they are actively growing. Use label rates of Roundup Transorb or Glyphosate. Andrewes says that high rates result in a better kill and longer residual period and bares the soil longer. Mark the plants or spots with a solid marker such as a Waratah standard, otherwise when you go back you may not be able to locate the exact spot.
Go back to the same spots and spray any re-growth after six weeks.
Farmers who have large areas of kikuyu should use a cropping programme based on a double spray (spring and autumn) using Roundup Transorb or Glyphosate at label rates. Turnips in spring, permanent pasture in autumn. Diligent follow-up spot spraying is essential to prevent re-growth.
Cropping large areas is generally a temporary measure experience in Northland and one farm in the Waikato shows that within three years kikuyu will become dominant again.
Other control measures
Spray plants and mark the spot whenever you see them. However, avoid plant stress periods, eg drought or frost. Herbicide will not translocate past me underground nodes when kikuyu is stressed.
Introduce a quarantine area for stock movement from other land, eg. coming back from coastal grazing or other land that may have kikuyu on it. Always land stock in the same paddocks and graze them there for a week or two. This will help concentrate any brought in seed in one area where it can be sprayed out, rather than randomly across the farm.
Do not buy in kikuyu hay or baleage etc
Get contractors - graders, bulldozers, rotary hoes, drain diggers, etc to clean their gear before coming onto your property.
It is endemic in Northland where there are two schools of thought amongst farmers work hard to get rid of it or at least knock it back so that other species will grow, or learn to manage it as stock fodder.
Kikuyu is the politician of the pasture looks good, promises the earth but doesnt deliver and in fact just makes things worse, a real pain in the grass. If not checked can soon take over smothering anything in its path. The only way to deal with it is to cut it down to size frequently or vote it out altogether. Thats essentially what Northland farmers try to do with varying degrees of success.
Stolon moments
Kikuyu grows fastest from December to February with its stolons lengthening by up to 2.5cm per day. Such rapid growth might, in theory, be valuable in hot seasons when other grasses do not perform as well. However, only in early summer does its nutritional value come anywhere near a normal ryegrass/clover sward. By March its quality is way down and stock grazing it lose condition. In winter it does not grow at all. While frosts may cause it to die back, its underground rhizomes survive to re-grow in spring.
Halving of production on poorly managed kikuyu-dominant farms is not uncommon. Wayne Andrewes, LIC Farmwise consultant based in Kerikeri, quotes the case of a Northland dairy unit that could manage only 370kgMS/ha initially, and was able to increase to 750kg only after mulching the whole farm and drilling annuals in April at a cost of $350/ha.
But thats not the worst of it kikuyu kills! Kikuyu toxicity is a condition of unknown cause that kills cattle within 48 hours. More common is kikuyu impaction in which cattle trying to ingest enough energy to survive eat large quantities of indigestible stolons. Their stomachs swell and they become very skinny, and can die.
But wait, theres more, and you dont get a set of steak knives. The kikuyu mat shelters undesirables such as crickets, army worm and black beetles, and retains moisture so that the soil becomes wetter.
Why on earth would you want it? asks Andrewes.
The problem is that many farmers dont realise they have got it its not named clandestinum for nothing. It surreptitiously creeps along roadsides and invades pastures, and by the time farmers realise theyve got it eradication is almost out of the question.
Kikuyu seems to have spread from Northland down both coasts and can be seen in parts of the Bay of Plenty, the Waikato, and Taranaki. Federated Farmers in the Waikato has recently sponsored meetings to raise farmer awareness, and is trying to get local bodies to take an interest in control. They claim that they have more than enough pests to deal with, but given that kikuyu is probably being spread by roadside mowers it could be argued they have some responsibility.
Spread
One Waikato farmer mowed the church lawns and brought the clippings back home and put them on his compost heap. Kikuyu sprouted up within weeks and now he has a problem. Other farmers are concerned about hay, silage and drainage contractors bringing stolons and seed onto their properties. Stock spreading stolons with their hooves generally doesnt happen, but they do spread seed if they graze seeding kikuyu.
Kikuyu seeds around November in Northland, but there are sterile strains and it is not known if the plants in the Waikato actually form seed. If they dont, it will be much easier to eradicate. If they do, it will be a problem because seed lasts for at least seven years in the soil.
Identification
At the seedling stage its very difficult to tell kikuyu from ryegrass. However, once the stolons start to elongate in December it is easier to pick.
Eradication
Make a paddock location plan for kikuyu for the whole farm including tanker track, races, dairy effluent ponds drains, fence lines especially boundary fences, and lawns.
Spot spray small areas and individual plants when they are actively growing. Use label rates of Roundup Transorb or Glyphosate. Andrewes says that high rates result in a better kill and longer residual period and bares the soil longer. Mark the plants or spots with a solid marker such as a Waratah standard, otherwise when you go back you may not be able to locate the exact spot.
Go back to the same spots and spray any re-growth after six weeks.
Farmers who have large areas of kikuyu should use a cropping programme based on a double spray (spring and autumn) using Roundup Transorb or Glyphosate at label rates. Turnips in spring, permanent pasture in autumn. Diligent follow-up spot spraying is essential to prevent re-growth.
Cropping large areas is generally a temporary measure experience in Northland and one farm in the Waikato shows that within three years kikuyu will become dominant again.
Other control measures
Spray plants and mark the spot whenever you see them. However, avoid plant stress periods, eg drought or frost. Herbicide will not translocate past me underground nodes when kikuyu is stressed.
Introduce a quarantine area for stock movement from other land, eg. coming back from coastal grazing or other land that may have kikuyu on it. Always land stock in the same paddocks and graze them there for a week or two. This will help concentrate any brought in seed in one area where it can be sprayed out, rather than randomly across the farm.
Do not buy in kikuyu hay or baleage etc
Get contractors - graders, bulldozers, rotary hoes, drain diggers, etc to clean their gear before coming onto your property.