February 2012 – Coping with Snow on the Green

ALTHOUGH many areas around the country have escaped any snow so far this winter, we may not be out of the woods by any means, so be prepared!

If we do get a blanket of snow, then one hopes you have spiked the green as much as possible since the end of last season to make certain you get the benefit during the summer months from any melting snow.

COPING WITH FUNGI ATTACKS

AS indicated in the December issue, disease on the green provides the biggest headache for greenkeepers, and that’s why it is imperative that aeration is carried out as much as possible during the close season.

Lack of maintenance in terms of scarifying to remove dead, dying, decaying and diseased materials and lack of aeration will contribute to the spread of fungi as this grass debris is all natural food for the fungi to feed on.

When the pore spaces in between the soil become filled with this waxy material and become impermeable to water resulting in the possibility of poor quality turf is it essential to aerate.

Spiking allows air into the surface and in turn water can get through the soil to the lower levels to assist the recovery of the turf. This is why regular maintenance operations are so important in turf culture.

Fungi can either have spores below ground in the case of ophiobolus, above ground (basal leaf), fusarium or in upper plants (red threads – corticium fuciforme).

FUSARIUM ATTACKS MAINLY ANNUAL MEADOW GRASS

A good example of fungi on the soil surface is annual meadow grass because it has thick, fleshy roots that have difficulty penetrating soil, but far easier into thatch and as soon as conditions are unfavourable for this annual its mechanism is that it produces a few seeds, scatters them, and the parent plant slowly dies out.

Warm temperatures (42F-45F – 5C-7C) in moist, muggy conditions is when fusarium is likely to be triggered off. It attacks the basal leaves of the annual meadow grass and shows a discolouring of a brown moist circular ring shapes. As the disease spreads it forms much larger patches of this sickly brown phenomenon.

On close inspection you will see that it is the very outside of the leaf that has been affected first and died off. In turn, if the damp, muggy conditions persist them the diseases takes a much stronger hold and could encompass the whole of the annual meadow grass plants.

It has often been noticed that the very crown of the grass stays greener for a much longer period and if we do have a further change in the weather then this starts to grow and partially recover, but the rest of the plant adds to the thatch in the turf and can be severely disfigured.

The practical way of dealing with fusarium attacks is to carry out regular, thorough scarifying, particularly in the Autumn, to clean out the debris using several passes with the scarifier set lightly into the turf, but not touching the soil, and changing direction frequently. Daily dew removal to raise the temperature at soil level is also vital.

A fungus that attacks above ground level is red thread and this gives two indications, first being that there is a lack of nitrogen that would have kept the leaf greener for a lot longer. Most leaves have a period of life around thirty days depending on its management.

Secondly, when this disease appears it shows that the fungi is working to eventually get in down from the tip of the diseased leaf and into the plant leaf structure to get the sugars and starches it needs. The fungi when active is like a series of little stick insects trying to build up like scaffolding to reach the tip of the leaf.

With good management this should never be a real problem because we can see from the practical point that a) if we keep a balanced feed ensuring that the plant has sufficient food at the right time to keep the disease at bay and b) with regular brushing to remove the dew each morning these red structures will get knocked down to earth and need to rebuild themselves up again by which time we may have had a change of temperature.