Mixing it on the GOLF COURSE


Dave Saltman discusses the significance of grass seed mixture formulation with Barenbrug’s Jayne Leyland


TURF is a society of many plants in which there is always competition and co-operation. Have you ever considered why grass seed mixtures are formulated as they are? Current UK industry performance trials are carried out at the Sports Turf Research Institute (STRI) in accordance with the protocol of the British Society of Plant Breeders (BSPB), the results of which are published each year in the form of the Turfgrass Seed Booklet.


The trials assess a limited number of individual cultivar characteristics, offering a good indication of the potential performance of each specific cultivar for a particular application or characteristic. However, there are many characteristics which are not assessed in these trials and Barenbrug consider it their responsibility, as breeders, to combine these results with in- depth knowledge of their own cultivars to formulate mixtures. In the UK, cultivars are rarely used as a monoculture. They are more commonly used either in blends of one species or in mixtures of different species. Furthermore, these are often used for overseeding into an established sward which already contains several different species, rather than for new sowings. Mixtures and blends offer great benefits by combining a range of desirable characteristics which can enhance the health, aesthetics and performance of the sward. Grass species – and cultivars within species – have different germination and establishment capabilities at varying soil temperatures and sowing depths. Maintenance practices and environmental impact also


influences the species composition of the sward. This is why Barenbrug has initiated a comprehensive and evolutionary mixture trials programme at Research Stations, golf courses and sports grounds throughout Europe. This is further supported by independent trials at the STRI in the UK.


The primary objective of the


trials programme is to assess and evaluate mixture performance to ensure they offer the best possible solutions using their highly rated cultivars and innovative new species.


Mixture Formulation for golf greens


Many Greenkeepers still choose a mixture of fescues and bents for overseeding golf greens. This may be because the original greens were sown out with that particular specification, or it’s perhaps difficult to apply bent grasses as a single species because the Greenkeeper’s current equipment cannot be calibrated to apply very small bentgrass seed at low rates – the fescue seeds in the mixture merely acting as a ‘carrier’. An 80/20 fescue bent mixture actually contains about 50 per cent each of fescues and bents by volume, so consider which species you are able to establish in your particular greens so you do not potentially waste half your bag of seed before you start! Even if you are fortunate enough to be in a position where you are able to manage and maintain a balance of fescues and bents in your greens, think about the optimum maintenance requirements for the individual species. Consider also that fescues


have superior wear tolerance to bents in drought conditions, and


vice versa. Also remember the closer the mowing height the greater the stress! Fescue/bent mixtures are


formulated for construction, rather than renovation. Depending on your maintenance regimes – and rainfall – one species will dominate over the other in the sward, so to keep a balance you may decide to overseed with fescues and bents separately. The additional benefit of this is you can adjust your timing and sowing depths for optimum establishment of each species. If you are trying to manage predominantly fescue/bent greens, you will know that the most vulnerable time is during winter play. Why combine slender creeping red fescue (Festuca rubra trichophylla syn. litoralis) with Chewings fescue (Festuca rubra commutata) in a blend? Slender creeping red fescue has better colour during summer, autumn and early winter. It also has excellent salt tolerance and a rhizomatous growth habit. Chewings fescue has better colour during late winter and spring, has poor salt tolerance and a tufted growth habit. Combining the two sub-species provides better colour for longer. Fescue seeds are much larger than bentgrass seeds and for optimum germination should be sown 4-6mm deep into the rootzone, below the thatch layer. If you are on a parkland


course with push-up greens that stay waterlogged for long periods during the winter, it is extremely difficult, if not impossible, to establish fescue in the sward. Fescue seed and seedlings cannot survive cold, wet soils. You can, however, dramatically improve the winter and early spring performance of


your greens by overseeding with bentgrass, particularly if you regularly mow at heights below 5mm.


Poa spp. greens can and do present and play extremely well in the summer under normal maintenance inputs. The problems are in the autumn, winter and early spring when – unless you have the budget for preventative spraying – Poa is extremely susceptible to fatal diseases such as anthracnose and fusarium, resulting in poorly presented, uneven putting surfaces. You can achieve success


when overseeding with bentgrass and it is possible within a few years to convert predominantly Poa greens into predominantly bentgrass greens, with all the benefits this brings. For whatever reasons (usually lack of equipment and enforced maintenance windows), the main causes of poor results when overseeding with bent are surface sowing on top of thatch, sowing when the soil temperatures are too cold, or inadequate irrigation during the germination and early establishment period. When choosing a bentgrass mixture, remember, you really do get what you pay for. Overseeding is an investment and whilst mixtures containing Highland bent (Agrostis castellana) are much cheaper than 100 per cent Agrostis capillaris mixtures consider this - Highland bent has poor shoot density, poor disease resistance, poor summer colour, poor wear tolerance and is broader leafed than cultivars of capillaris bent, often looking like a weed grass when mown at winter mowing heights.


Bentgrass seeds are extremely small and should be


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76