FOR many years now, many agronomists and advisory bodies (but not all of them) have insisted that the presence of annual meadow grass - Poa annua - in greens is indicative of a flawed maintenance programme. Consequently, remedial programmes, of a rather simplistic nature, have been proposed to eradicate greens of this undesirable grass. Most greens committees will have experience of these programmes.

So, the recent US Open at Congressional must have wrought confusion amongst such committees when the quilted appearance of the greens confirmed this prestigious tournament was being played on Poa annua greens. Was this not an absolute contradiction of the teachings of agronomists this side of the Atlantic?

Poa annua, annual meadow grass, is defined as a weed in golf greens simply because it never comprises, or forms part of, the original seed mix. Despite this, unless hand picked from newly sown greens, this grass rapidly invades the sward in the early years and can completely take over a green in four or five years. This is particularly the case if Fescues comprise the bulk of the original seed mix.

There are many varieties of Poa: some are very coarse and truly annual in nature, others are respectably fine leaved and have a perennial cycle.. With regular mowing and verti-cutting, the finer types are encouraged and the coarser types are eliminated. Some fescue and bent will continue to survive but the greens will be described as Poa greens.

But there are exceptions to the norm and new greens, sown to a monoculture of creeping bent, where individual Poa plants are removed by hand, or sprayed out in the States, can remain pure. This, however, is a daunting task that demands huge labour input and will only succeed if the programme of hand picking is rigidly adhered to on a regular basis. Is it all worthwhile?

In the early years when colonisation is ongoing, greens reverting to Poa have a mottled unattractive appearance and this often leads to concern amongst the membership. However, as the transaction progresses and the rougher grasses are eliminated, the greens appear homogenous from a botanical point of view and concern is erased. Members feel that Poa has been defeated when the opposite is, in actual fact, the case. Indeed, many of our longest established and most famous golf courses have greens that evolved as described. They have performed well over the years and committees have quite rightly decided to live with Poa greens rather than try to defeat the natural process of evolution.

The question arises. "Why is Poa annua considered to be the bete noir of putting greens?"

Meadow grass is prone to disease, mainly Fusarium patch and Anthracnose and is seen as a very good reason for not tolerating the grass. It is accepted that disease resistance is low but it is also suggested that proper course maintenance will reduce the incidence of these fungal diseases and that a proper spraying programme will eliminate them at no great expense.

Poa annum can lead to thatch accumulation and this demands very intensive aeration that impacts on putting surfaces to an unacceptable level. All grasses produce organic matter, none more so than creeping bent, so meadow grass is not alone in this. Indeed adequate amounts of organic matter are required if greens are to remain stable. The problems arise when soil conditions are not suited to the breakdown of this organic matter and thatch forms as a result. Therefore grass species is not the major consideration, soil conditions are.

Unlike any other grass, Poa seeds in May every year at very low heights and greens are unsightly for a few weeks. This is indeed true but putting quality does not deteriorate which must be the important factor to be considered. Furthermore, the ability of Poa to seed at these low heights should be seen in a positive light as this ensures self-propogation.

Probably the biggest problem associated with meadow grass is susceptibility to drought due to its shallow root systems Again, this contention does not stand up to scrutiny.

Irrigation systems must not be excluded from this debate, and it is difficult to fully understand the concern about drought when the mechanism to prevent drought can be activated by throwing a switch.

Finally, the opponents of Poa allude to thin swards in winter and uneven growth habits in summer. Experience suggests that Poa remains vigorous long after Fescues and Bents have entered their dorment phases and, consequently, Poa greens, once established, do not thin to the same extent.

Uneven growth is not a problem as we live in an age where greens are cut every day in order to satisfy all golfers.

To conclude, the opponents of Poa greens could be accused of ignoring all of the evidence that existing golf courses present and tending to concentrate instead on minor, but surmountable, problems associated with the grass. They refuse to accept that Poa annua has been a good friend to greenkeepers the world over and has produced some of the fastest and truest greens for championship golf. Where pragmatism prevails and performance is the criterium for judging greens, Poa annua is not considered a problem.

Therefore, the best advice would be that if greens are predominantly Poa, manage it, rather than fight it. It will not be starved out... it will not be controlled by a zero water campaign... it will survive such acts and continue to dominate as it has done for many years.