African Black Beetle
21. Two of the worst lawn pests
Lawn Armyworm (Spodoptera maurita) are a major pest during Summer and Autumn, causing severe damage to turfgrass surfaces where they attack leaves, stems and seedheads. Infestations in turf gradually extend outwards from gardens or higher cut turf areas as these plants are used as egg laying sites. Severe damage is predominantly caused by the later instar stages and as populations increase, the larger armyworms tend to move in groups into unaffected turfgrass areas, hence the name ‘Armyworm’. Armyworms characteristically have stripes or triangular patterns along their smooth body, differing from that of the sod webworms.
Armyworms are the larvae of moths of the family Noctuidae. The female moth may lay more than 1000 eggs, sporadically in clusters within 4 to 10 days, pending on temperature. The newly hatched armyworms stay together feeding on the same plant until it is devoured. The larvae are usually most active in the evening or at night, except in overcast weather conditions. During the day they hide under the safety of the lower grass leaves.
An Armyworm will undergo 6 to 9 instar stages before it is fully developed. This will take 21- 35 days and at a mature instar stage the insect will reach 3-4 cm in length. When fully fed the Armyworm will work its way into the soil profile where it pupates. 10-14 days later the moths emerge. There may be 2 or 3 generations of Armyworm during the Summer and Autumn period.
There are several options for lawn Armyworm control. Chlorpyrifos 500, Bistar, and Lepidex are useful options in controlling these pests. For most effective control, application should be made late in the afternoon.
African Black beetle
African Black Beetle (Heteronychus arator) is a scarab species causing most damage to turfgrass in September to February. The adult female beetle can lay up to 80 eggs that hatch in 2-5 weeks, depending on temperature. The larvae develop through 3 stages, each stage deeper in the soil profile feeding on grass roots. The adult provides little damage to turfgrass.
The first instar stage larvae feed on decaying matter near the soil surface. However as they go through they feed exclusively on grass roots. The fully grown larvae (3rd Instar) are about 25mm long, creamy white in colour, curled up with 3 pairs of legs. They cause extensive damage when present in high numbers.
When the larvae are fully grown they build an oval chamber, empty the hind gut and become a pre-pupae. After about a week the pre-pupae develop into pupae. The pupae develop into adult beetles after 1-3 months and emerge after rain or irrigation.
Weather patterns affect the number of ABB and can affect the potential for turf damage. After 2 successive dry Spring and Summer periods, the number of black beetles can reach plague proportions in the second year. During plague seasons on warm, humid nights in spring the beetles emerge and swarm to find new feeding and breeding sites. At these times green succulent intensively maintained turf is attractive to beetles as they search for lush food. The beetles are sometimes attracted to lights.
Application of pesticides is best carried out at the first sign of activity in September/October.
Meridian, Merit, Chlorpyrifos 500, Pennside will provide control of larvae. Baythroid and Chlorpyrifos will effectively control adults.
For further information, please contact Nuturf on 1800 631 008.
22. Maintenance of wetlands –A quick guide
Soon after a wetland is planted, water level control is critical, otherwise the plants could die from too much water, or for that matter from dryness. Even for long term maintenance, by fluctuating the water levels of wetlands, algae, weed invasion and other problems can be reduced. Make sure that water levels are monitored and controlled, keeping a particular eye out after large storm events, or long dry period. After planting, monitor and control algae problems, and ensure birds and other wild life do not pull out the wetland plants. Prevent erosion by strategically placing measures to slow water flow on slopes leading down to the waters edge, whilst off course planting plants in these areas is usually the best action. Replace any dead plants with new ones, and ensure the water is kept clear and not murky, while the wetland plants establish. Using a flocculant like Gypsum can settle the suspended fine sediment. Never let the wetland plants dry out. Remove or kill any non desirable plants or weeds throughout the first year after the wetland has been planted. The best way to do this is by using Round Up Bioactive to spot spray or wick wipe the undesirable plants. Natural wetlands survive and perform with no intervention from man. If the wetland has been constructed correctly, then after about a year, if the wetland is fully established, it should generally be able to look after itself, provided weeds are not a problem. Unfortunately with weed pressures of our modern cities, weed control is generally ongoing. Water weeds such as alligator weed can be a major problem, and if these weeds get into a constructed wetland system, it is necessary to undertake adequate weed control measures. By using emerging species (Baumea, Schoenoplectus etc) harvesting is generally not necessary. Many wetlands which contain emergent plants such as Phragmities that die back each year are harvested for visual reasons, and some believe it is necessary for nutrient stripping reasons, but this is neither proven nor disproven yet. If floating plants are used to soak nutrients, then annual harvesting is essential.
23. Reducing maintenance by using the correct mulch
Not all mulches reduce maintenance. Some actually help weeds germinate, stop water getting to the soil, and even create disease. Mulches should be sold in two categories; soil conditioner and ground cover mulch. Well composted soil conditioner is excellent for improving the conditions of the soil, providing better water penetration, less disease, and better growing conditions for plants. Soil conditioner has lots of composted fines. On the other hand, ground cover mulch should be pieces of mulch no smaller than 10mm in size, and definitely no fines. Ground cover mulch needs to provide lots of airflow to the base of the plant, which reduces the chance of disease. Unfortunately, too often landscapers, and maintenance people cover planting beds with mulch that is better suited to soil conditioning, or worse they use soil conditioner mulch that has not even been composted properly and as a result simply end up spreading disease. Good ground cover mulch with no fines will allow water and air to penetrate, stop weed seeds from germinating, keep moisture in the ground, and generally keep a garden looking great. The right mulch reduces maintenance costs, on the other hand a poor mulch with lots of fines will often repel water, germinate weed seeds, stop airflow to the base of the plant, promote disease, kill plants, and cause nitrogen draw down. So instead of reducing maintenance, a poor mulch will increase watering requirements, increase weeding costs, increase disease control work, cause more planting of new plants to replace dead ones, and increase fertilizer requirements. A good mulch is great, but it is better to use no mulch than use a poor mulch or the wrong mulch.
Remember; ground cover mulch should never have fines.
24. Localised Dry Patch in turf – causes, effects and treatment
Surfactant use on low cut turf situations, such as golf greens, is an integral part of turf management. As the turf is in a high stress, low cut situation, the appearance of dry patch can appear quickly and have a very negative impact on turf’s visual appearance.The appearance of dry patch will occur in areas where the soil is particularly hydrophobic. Hydrophobic soils result when organic matter builds up on soil particles making them difficult to wet, or water repellent. The build up of organic matter particularly occurs in the warmer months when soil microbial activity is at its highest level throughout the year.
A wetting Agent consists of surfactant molecules which attach to the soil particle and allow water to wet-up the soil particle, through the interaction of positive and negative charges.
Nuturf Pty Ltd can provide products which are a preventative approach to dry patch appearance, and differ in their longevity, or a curative approach.
I would like to thank Alexandra McCorquodale (Nuturf Pty Ltd – National Business Manager Wetting Agents) for this information and you can contact Nuturf on 1800 631 008 for more information.
25. Wetting agents for broad acre turf situations
Broad-acre surfactant use is easy and effective through an injection unit, which injects Wetting Agent into the irrigation system, distributing it over the irrigated area. By placing a foot on the sprinkler head, it will foam up, giving final evidence that the Wetting Agent has injected into the irrigation system.Dispatch is a cost effective penetrant used at the low rates of 2-4 L/Ha. Its primary function is to penetrate water quickly through the thatch layer and down to the root zone, limiting the amount of water loss through evaporation or run-off. This efficient use of water can save up to 50% in water and energy costs, and is backed by Aquatrols money back performance guarantee.
Studies undertaken in the United States show that Dispatch keeps water in the soil where it is needed, resulting in better turf quality and uniformity. Increased Nitrogen retention is a side benefit of its use. As Dispatch has widespread tank mix flexibility, soil applied fertilisers and chemicals will also be more uniformly distributed through the root zone, giving a more uniform response to fertilisers and other applied chemicals.
For more information on Dispatch, contact Globe Australia on 02 8713 5555.
26. Wick wiping weeds in lawns
Sometimes weeds in lawns can not be sprayed by selective herbicides, so you are left with either spot spraying them, which can leave dead spots, or hand weeding, which is simply a lot of work. Another alternative is to use a wick wiper. This can be a simple hand held wand that is filled with Glyphosate, or it can be more elaborate push devices, or even tractor or quad bike drawn implements. The hand device is simple to use, simply wipe the unwanted weed with the device, making sure you only touch the weed. If the wiper drips, you can ad a little starch, and this thickens the mixture, reducing leakage. I generally suggest using half Glyphosate and half water in these devices. The larger walk behind and tractor towed devices need more thought before using them. They are designed to take out faster growing weeds, that plague slower growing turf areas. For example, I have used these devices successfully to take out Summer grass, Sorgum, and even Kikuyu out of slower growing Buffalo lawns. I simply let the weed grasses grow taller than the desirable turf, which can take anywhere from one week to several weeks, and I then set the wiper at the right height so that it is touching the weeds and not the lawn, and I start wiping. I usually go over it at least twice with the second pass being at 90 or 180 degrees to the first depending on the weed, and then repeat the process a week or two latter to make sure I get all the weeds. I then do one last spot weed to get the ones I missed. I have cleaned up areas that a larger than 20000 square metres by using this method and that was with the manually pushed device.
27. Using growth regulators to reduce plant trimming
There is a product called Condense, which used to be called Bonzi. It is registered for ornamentals grown in containers, so I suggest reading the label to see if you can use it for your application and for your plant type. I find it terrific at keeping hedges of things like Camellias looking tight and compact in large pots, or large trough like containers. It also reduces the amount of trimming these plants require. It furthermore works on many other plant types. Please read the Label. This product once sprayed on the plant has the effect of reducing its speed of growth, and basically making the plants more dense. Once the target plant has been sprayed it will greatly reduce the trimming required, and if sprayed when the plant is half grown it will basically give you a dwarf looking plant. Eventually the plant will generally grow out of this shape. Make sure you follow the instructions on the label, as there are some important aspects to its application.It is a shame that more work has not been done on chemicals like this for general hedge plants in Gardens. Currently the label will not allow this product to be used in gardens. It would be great if a company would do the research and apply for products like this, to have on its label, allowing its use in gardens, and particularly on hedges that respond to this chemical or similar chemicals. It costs a lot of money to continually trim hedges, and to keep them looking tidy. To have a chemical that kept hedges and other plants tidy in a garden, with far less trimming, would be great for the landscape maintenance industry. Unfortunately, our small Australian market, and our tough labelling laws often make it unviable for companies to get label approval for the landscape industry. They tend to concentrate on the agricultural side of things.
28. Replanting in diseased or problem areas
Every garden maintenance organization experiences it. Dead plants! What do you do when areas of plants die of disease? Obviously the first thing to do is find out what the problem is, and treat it. However this still leaves you with a problem. What to do with the bare area. Unless it is absolutely essential it is better not to put back the same plant, as the same disease may kill it again. Hopefully you know what the disease is, if you don’t have it diagnosed. (See Tip 30). Then try to find plants that are very resistant, or immune to the problem. For example, if it is Phytothera use Little Jess or Breeze, which are strappy leaf Dianella caeruleas that don’t appear to suffer from this disease. If you have trees that have suffered from Armillaria, maybe you could use Acacias or something else that is less prone.Sometimes the plants have died because they have been planted incorrectly, or have been put in the wrong soil type. Again it is important to fix this problem. For example, many plants have problems when there crown is buried, so this time make sure the crown is above the mulch or soil level. It s hard to change the soil type, so here it may be necessary to change the plant. Maybe the soil has hydrophobia, so by using a wetting agent you may fix the problem. If it is too dry for the plants, try adding a good coarse grade mulch with no fines, or plant tougher more drought tolerant plants. There are many problems that can occur in a garden, so when plants die, find the problem, and either fix the problem, or plant different types of plants.
29. Diagnosing problems in plants and turf
Often you can diagnose problems in turf and plants yourself, however sometimes the problems can stump you. There is no need to be embarrassed about that. Everyone gets stumped at some time. When this happens, for most of us it is time to get expert advice. It is much better to know the real reason for the problem than to bury your head in the sand. It may cost to get testing done, but it will generally save far more money than letting plants or turf die. So for this expert advice, where do we go? For turf there are quite a few places you can go, but I find Nuturf provides an exellent diagnostic service. Phone 1800 631 008 Nationally. They have dedicated people that help with problems like turf disease and pests, soil and other problems. Another company that I find first rate is Elders Ltd. The great thing about this company is that they do plants, crops and turf. They are national, and they actually use specialists in each scientific area to do the testing. They conduct tests for pests, disease, water, soil, nutrition and more. Simply contact you local Elders store, and they will help you with this service. If you prefer dealing with government departments, the agricultural departments in each state do a great job. Try asking for plant health diagnostic services. You can usually find these departments quickly by looking on the internet.All these services can not only usually diagnose the problem, but they can generally help you with possible solutions. For example, I recently had problems with some plants dying of Phytopthera, which I did suspect, but by sending in samples of the plants, it was confirmed. I also decided to send in samples of the mulch, and what was found was that the mulch was harbouring the Phytopthera. This helped me realise that mulch with fines is a great place for diseases such as this to prosper. I now only use ground cover mulch that has good airflow. (Larger particles and no fines).
30. Maintenance and weed control in Native Grasses
Native grasses have been used extensively for Mass Planting. Grasses such as Kangaroo and Tussock grass, some Wallaby grass and more.
The entire areas should be covered in grasses to create a robust sward capable of shading out weeds. Each year in Spring the site should be inspected and new plants should be planted into gaps. Certain varieties, are better at shading out weeds, and are less likely to require replanting. Eg; Poa and Themeda.
In general, initial fertilizing is enough. On sites where ongoing maintenance is possible, slow release fertilizer used annually will produce much better looking plants. In areas where ongoing maintenance is not possible, fertilizer can benefit weeds more than the native plants, so follow up fertilizer is not recommended.
If you want a site to look ornamental, yearly trimming of native grasses is required. For revegetation sites this is not required, unless maintenance for fire control is needed. Some native grass like plants do not usually require regular trimming to look good, e.g. Lomandra Longifolia Katrinus and Tanika, Dianella Little Rev etc, but these are not really grasses. For ornamental sites use a sharp knife or brush cutter. Trim close to the base. (50mm to 100mm from ground). Avoid trimming C3 (Cool Season) grasses in summer or hot months, and avoid trimming C4 (Warm Season) grasses in winter or cold months or in dry summers. For revegetation sites, yearly trimming can be done with a brush cutter, or a slasher. If a slasher is used, rake off the clippings, do not leave them sitting on the grass. Slash at 100mm high. A good time to slash is early Spring or early Autumn. Try to pick a time when the new native grass seed crop is not destroyed.
For large commercial plantings, it is better not to irrigate or fertilise. If you do, do it sparingly, as these inputs will help weeds. Inspect entire site each week and remove all large emergent weeds especially those with seed heads or in flower. Spend remaining time removing all weeds from within a zone. 4 hours per week per 1000 m² should be sufficient. Leave small weeds hidden beneath the foliage until they are big enough to pull or wick wipe with herbicide. Many of these small weeds will die out anyway. Weed control means seed control. Don’t use mist sprayers to spot weed, as these leave “bare holes” throughout the landscape. For spot weeding it is better to use a wick wiper, or hand weed. For many plant types, Ronstar could be used. This pre-emergent will stop weeds for 2 months. Do not use on cool season grasses C3 e.g. Poas, Danthonia. Use Ronstar as per label only. Bromoxinyl + MCPA can be used on some types of Native Grasses, which will help remove broad leaf weeds. Please read the label thoroughly. For garden areas, the use of appropriate mulch will help reduce weeds. In garden situations, more money is available for weed control, so hand weeding methods are more viable.