So far, 2006 has been a highly stressful year for grass - and for groundsmen and greenkeepers too! For most of the country spring was late and unseasonably cold, resulting in very slow spring recovery. There was frost in May and, unusually, sand rootzone temperatures in the south east of the UK struggled to reach 80 0C. For most parts of Scotland there was little growth until June. From this we went straight into drought and heat stress from early June onwards.
Because of the continued stress,Poa annua seeded heavily for an extended period, leading to an extraordinary amount of Poa germination in existing swards.
Unfortunately this has exacerbated the impact of the drought/heat stress, particularly for those who do not have the resources to maintain this type of sward.
The prolonged spell of hot,dry weather has been a painful experience for many, particularly those who are under pressure to present a green sward whatever the conditions. But, on the positive side, it has presented an excellent, and for some, ongawaited opportunity to introduce more desirable species and cultivars, or to begin complete species exchange programmes.
Whatever your situation, the important thing now is to plan and prepare for what nature may have next in store.
Species selection for drought
Different species of grasses have different physiological features that enable them to survive and recover from drought. Characteristics such as deep rooting capability, aggressive rhizome production for recovery, high root density, waxy leaf coating and slower translocation are essential attributes that enable individual species to survive.
No one knows if we willexperience a repeat of 2006 summer conditions next year, but what we can do is prepare.
Combining drought tolerant species - each with its own individual characteristics for specific applications - with traditional species in mixtures offers real solutions.
Cultivars of traditional species, for example perennial ryegrass (Lolium perenne), exhibit variable tolerance to drought and heat stress so, with careful cultivar selection, you can achieve improved tolerance from this species for heavy duty sports applications. Sometimes it is a question of degrees of improvements over time, especially for golf courses.
For example, changing from cultivars with high water demand (e.g. creeping bent tees and fairways) to a combination of drought/heat tolerant perennial ryegrass (Lolium perenne) and using these cultivars together with drought tolerant fescue mixtures containing hard fescue (Festuca ovina duriuscula) can help you reduce water requirements without compromising on playing quality.
For golf greens,some cultivars of bent grass (Agrostis capillaris) have superior drought tolerance without the loss of winter quality e.g. BarKing.
Drought tolerance without compromise ALTHOUGH choosing the most drought tolerant cultivars from traditional species will undoubtedly help, now is perhaps the right time to consider one or more of several different species which offer superior drought tolerance, all with very different characteristics.
RTF Rhizomatous Tall Fescue (Festuca arundinacea) is a remarkable species which, through its amazing rooting depth capability, can tolerate both drought and waterlogging (nature may restore the balance in 2006 with a wet winter). RTF increases this capability by producing underground stems (rhizomes), offering unrivalled recovery and tensile strength, plus the added benefit of incredibly fast establishment when laid as turf, which could be critical in terms of water conservation. Its wear tolerance is similar to perennial ryegrass once established.
Crested hairgrass (Koeleria macrantha) thrives under minimal water and nitrogen regimes and produces very little thatch. It is in fact the ultimate sustainable grass; low maintenance inputs with high aesthetic quality. It has been successfully utilised with slender creeping red fescue where the irrigation source is treated effluent water.
Hard fescue (Festuca ovina duriuscula) is little known or used in comparison with red fescues (Festuca rubra spp.) but it has superior drought tolerance.
It is extremely fine-leaved with high shoot density and has outstanding survival capabilities in both heat/drought and cold/drought stress.
Furthermore, it has excellent natural shade tolerance. It is a species which has been overlooked, but new cultivars with improved characteristics means hard fescue should become very important for the future of fine turf as the potential for water restrictions increases.
What is extremely important for the future is the recovery capability of these new species from the effects of drought to offer you a more persistent, sustainable sward with reliable performance characteristics in place of the high demand cycle of Poa regeneration.
Water quality A FEW turf managers, including sports fields, golf courses and turf producers, have had to resort to salt water sources (20,000 parts per million) to keep their turf alive. Again, there are species and cultivars which are better adapted to salt tolerance.
Cultivars of traditional species, such as Barlennium perennial ryegrass and Barcrown slender creeping red fescue, have this salt tolerant characteristic, as do innovative species such as RTF and crested hairgrass. It is possible this type of water source (borehole, tidal river, treated effluent) may become a necessary part of future irrigation programmes.
Winter uncertainties We don't know what next summer will bring, or what's in store for us this winter. It could be mild and very wet (nature has to balance out somewhere) or we could experience a very cold spell in spring (more like continental Europe), particularly on the eastern side of the UK.
A general recent trend over the past few years has been for warmer temperatures later into the autumn and early winter, but staying cooler later into spring.
Fertiliser programmes will need adjusting to suit this seasonal growth change and disease pressure will become more of an issue. While coping with the drought issue has been the priority this summer, we mustn't forget that we suffer from other, equally damaging environmental pressures such as waterlogging, shade, disease, cool temperature growth etc.
This is why it is increasingly important that Barenbrug's extensive breeding and research programmes on every continent work together to help you respond to the challenges of climatical and environmental change.
Forward planning THE summer drought and associated water restrictions underlined the urgent requirement for increased use
of drought tolerant grasses in amenity applications. But let's not forget winter 2005 and late spring 2006, which was a sharp reminder that grasses suffer drought stress in cold temperatures as well as in heat.
Now is the time to prepare for whatever the coming winter may hold and for the possibility of further water restrictions and escalating costs in 2007. Think of the financial implications; no playing surface equals lost revenue if your competitors
are better placed to provide.
Investment now in carefully selecting your autumn 2006 and spring 2007 renovation mixtures will be rewarded. Any grass once established, however drought tolerant, still requires water for successful germination and establishment; timing of overseeding and sowing at the recommended depth will help you control water requirement at this critical time. You will never have a greater need or a greater opportunity than at this present time so seize the moment and help make life just that little bit less stressful!
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Pictures: Top Left, Will brown golf courses like this become more common?
Middle right : Salt tolerance - chewings fescue (left)and slender creeping red fescue (right). Saline solution 30,000ppm applied for
Bottom Left : Grasses suffer drought stress in cold temperatures too.