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resembled those of yellow patch, they were present during all of the months when they would not normally be expected to show and never appeared over the winter when this disease would be most likely to appear. In addition, fungal diseases are heavily affected by local environmental conditions and it seemed very unusual to me that any fungal disease should appear at the same time and with equal severity across all greens on any affected course. With fungal diseases, you often find one or two areas on a course that are heavily affected and others with minor symptoms and, usually, some areas that are


unaffected due to aspect, air movement or light intensity, for example. A similar development of symptoms across an entire course is extremely unusual for fungal disease - so for me, this was quite intriguing. In addition, the symptoms never really changed during the year from how they initially appeared. With fungal disease problems, you tend to see a development of the symptoms and a progression with regard to severity either within the initially affected area or away from the initial outbreak in to previously unaffected turf. However the most intriguing piece of information relating to this problem was that of fungicide use. No fungicide, applied either as a single dose at label rate or higher, or as a tank mix, had any effect on reducing the symptoms on any of the courses where the


symptoms had been seen. The only product applications that appeared to have any effect on reducing symptom severity were foliar feeds. It had been noticed that for about a week after foliar fertiliser applications, the yellowing of the plants was reduced. With no foliar damage apart from the general yellowing of the leaf and no evidence of any foliar fungal pathogen, I was fairly sure that there must be some problem in the roots that was the primary cause of the symptoms. In April 2001, the


symptoms started to reappear on previously affected courses and my analysis of numerous core samples from several sites all showed the same results. There was no R. cerealis and never any evidence of fungal disease in the roots of the affected plants but ALL plants were heavily colonised by a root-knot nematode, Meloidogyne sp. The nematode was confirmed for us as Meloidogyne by a


nematologist in the UK but the exact species could only be confirmed by a root-knot nematode expert in The Netherlands and he recorded our find as a new species of Meloidogyne. It is now formally recorded as Meloidogyne minor. Following the


identification of these nematodes as the likely cause of the symptoms, Headland Amenity Limited commissioned independent research which confirmed beyond doubt that


Meloidogyne minor was the actual cause of the damage seen on the affected golf courses. Since M. minor directly enters the turfgrass root, causes direct and detrimental effects on the structure and function of the roots and produces symptoms that can be used to characterise the infection, this root-knot nematode can legitimately be classed as a new disease of cool-season turf.


TO date, we have seen the development of this nematode disease on putting greens from 6 to 12 months following establishment of the creeping bentgrass and on all American creeping bentgrasses cultivars used in the UK and Ireland. The good news is that although the symptoms return annually on affected greens, it would appear that after a period of approximately 5 years, the severity of the damage begins to decline. The reason for this is possibly due to the increased competition that develops as the rootzones mature and eventually the population of this nematode is brought in to balance with the overall rootzone ecology. Although M. minor has been recorded as a new species of root-


knot nematode, we believe that it is a native species that could be found in grassed areas across the UK and Ireland. It is quite likely that the use of non- native turfgrasses as monocultures on the putting greens, provided a new host with possibly reduced resistance to this particular invertebrate pest allowing rapid colonisation without competition in the new rootzone material. It may be of interest to know that Meloidogyne sp. have also been seen the roots on winter games pitches. Although the species is thought to be different, the yellowing symptoms that come with the root colonisation are remarkably similar. Currently, there are no pesticides available for use in amenity areas that can be used to manage this nematode. The severity of the symptoms can be reduced through regular foliar feeding and the impact of the nematode can be lessened by trying to maintain and encourage root development. We have identified and confirmed a new disease of close-mown fine turf but there is still a vast amount of information that we need to obtain about this new nematode species if effective and lasting management of the symptoms is to be achieved. Plant parasitic nematodes are generally unlikely to kill the turfgrass plant but their colonisation of the turfgrass roots will cause noticeable and detrimental symptoms on the sward and are likely to encourage increased severity of any subsequent fungal disease problems that occur, regardless of grass type. Be aware of their potential and the possibility that nematodes could be colonising the areas that you manage.


Shurtleff, M C & Averre III, C W. 2000. Diagnosing Plant Diseases Caused by Nematodes. APS Press, Minnesota. 187pp.


Dr. Kate Entwistle, The Turf Disease Centre, Waverley Cottage, Sherfield Road, Bramley, Hampshire RG26 5AG. UK Tel: 01256 880246 Email: Kate@theturfdiseasecentre.co.uk


RIBWORT


PLANTAIN Plantago lanceolata


Form / Appearance: Forms a rosette of elongated ribbed leaves with flower spikes. Plants can grow up to 300mm in height (if left uncut).


Roots: Roots are fibrous and shallow.


Flowers: The flower is formed on a spike, flowers June-October.


Leaves: The leaves are long and narrow, smooth, and dark green. The petioles are often purplish. The leaf margins entire or wavy, and the veins are prominent and parallel.


Reproductive method: From Seed. The flower stalks bear densely packed greenish white flowers each of which will become a seedpod containing 10 to 20 seeds. When the seeds are mature, the seedpods splits releasing the seed to the ground. Seed germination occurs at or very near the soil surface. The seed will germinate when soil moisture is adequate and soil temperatures rise.


Habitat: The main growth period for ribwort plantain is from June through September. Plantains are a good indicator of compacted soils and can tolerate dry soil conditions. Plantains like alkaline soils.


Miscellaneous info: Plantains are used as medicinal remedies by herbalists, it can be used to heal sores, wounds and bruises. Taken as tea internally to treat eczema and skin disorders and is well known for its ability to soothe urinary tract infections and ease dry coughs. The plant is often known by other names: ribwort, narrowleaf, plantain,English plantain,lanceleaf plantain, and ribgrass.


Cultural Control: Ribwort plantain can be mechanically or physically removed. Care should be taken to assure that all roots are thoroughly removed. Close mowing prevents seed head formation and maintaining a dense sward will deter or prevent plantains from establishing. Good turf density is important as broadleaf plantain competes by shading other plant species with its rosette of leaves. Good soil fertility is essential, whilst maintaining a soil pH of 6.5 to 7. Regular aeration of the soil will help establish better grass growth and reduce the likelihood of compacted soils


Chemical Control: Apply selective broadleaf herbicides when plant growth is active. There are a number of products available for controlling broad leaf weeds in established turf. These chemicals are best used when the weeds are actively growing, usually between April-October.


• Tritox (Contains 178g/L (16.2%w/w) MCPA 54.g/L(4.9%w/w) mecoprop-p and 15g/L (1.4%w/w) dicamba and potassium salts. Scotts.


• Intrepid 2. (Contains 20.8g/L dicamba,166g/L dichlorprop-p ans 166.5g/L MCPA). Scotts.


• Greenor. (Contains: 40g/L fluroxypyr, 20g/L clopyralid and 200g/L MCPA). Rigby Taylor.


• Bastion T. (Contains: 72g/L fluroxypyr and 300g/L mecoprop-p ). Rigby Taylor.


• Dormone (Contains 465g/L2,4- D(38.1%w/w) as the diethanolamine salt). A herbicide which can be used near water. Bayer Environmental Science.


• Supertox 30 (Contains 95g/L (8.8%w/w) mecoprop-p and 93.5g/L(8.7%w/w) as the diethanolamine salts). Bayer Environmental Science.


These herbicides are usually applied as a liquid using watering cans, knapsack sprayers and vehicle mounted sprayers. Ensure you follow manufacturer's directions, health & safety and product data sheets, and comply with COSHH regulations, when using these chemicals.


OF THE MONTH


WEED


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