GREEN KEEPING

Timaru Herald, Volume CXXXVII, Issue 19667, 8 December 1933, Page 5

GREEN KEEPING

REPORT ON RESEARCH MANURES AND WEED CONTROL The first annual report of the New Zealand Greens Research Committee contains advice useful, not only to the professional green keeper, but also to owners of private tennis courts and lawns. Research is carried out on a part of the Hokowhitu Golf Club's course at Palmerston North. The area of approximately one and a quarter acres was sown down during the fourth week in March, 1932, and regular applications of manures were made monthly and every three months. Before the preparation of the seed bed, water reticulation was installed so that the whole of the area could be conveniently watered, and as the summer opened extremely dry, this was necessary from the middle of December to the end of March. “The year must be regarded primarily as a period of establishment of the turf,” states the report, “and apart from the elaborate manural trials, little concerted effort has been made for control of weeds and worms, nor has it been deemed advisable to put into operation methods for mechanical treatment of turfs such as raking, spikrolling, etc. Such operations may be injurious to the turf until establishment of the grass and a good underground root and tiller system have been effected. In the case of seed mixtures and strains of species sown little comparative w r ork other than observations on early and rapid establishing species is of much value the first year of sowing down, and this is particularly true of the slower establishing species and strains of these. In the case of manurial applications some time for accumulative effects of treatments to show themselves on botanical composition and on the soil itself must necessarily elapse before reliable data are secured.

Watering and Manuring. “Before the end of Decsember the whole area began to dry up and growth on all the plots, irrespective of seed mixtures, manures, or treatments, was checked. On the application of water each treatment assumed its former significance. Watering of greens by mechanical sprinklers is essential if manurial and other aids to turf improvement are to give their maximum results. “Manures for greens,” continues the report, “may be classed as toxic, those which cause leaf burn when applied at the rates of from one to two cw*t an acre, and non-toxic fertilisers. The toxic application has the double effect of controlling weeds and providing plant food, though this may be accompanied by danger to the health of the grass sward. The non-toxic manures provide a healthy grass sward irrespective of weed or clover control. The balancing of manurial dressings to reduce a minimum permament grass injury and also to control weeds and clover is a work for the future. Alternate applications of toxic and non-toxic fertilisers, or the balancing up of toxic manures in large quantities, and control of weeds and clovers by poisonous sprays of plant polslons that are selective in their action, are the lines for future development. "It seems certain that sulphate of ammonia alone or in large excess in the manurial mixture is detrimental to the grass. There are four ways in which the deleterious after-effects of this manure may be reduced: (1) By periodic applications of lime; (2) by intimate mixing or by chemical combination with minerals such as phosphates: (3) by the inclusion of iron in the top dressing; and (4) by liberal use of composts. Seed Mixtures. “A mixture of brown top and Chewings fescue has definitely given the best results to date and the inclusion of other species in the mixture at present does not seem to be warranted,” the report adds. “As far as rapid and strong early competitors in the mixture, such as ryegrass and crested dogstail, are concerned, these have definitely shown to be inimical to the establishment and well-being of the finer-leaved grasses. As far as the slower establishing species in the mixtures are concerned, it is yet too early to give any information regarding these. Soil fertility, condition of the seed-bed, weather conditions, even spreading of seed and depredations <.f birds, all must be taken into account when recommending quantities to sow and heavy applications rather than light should be the rule. The relative position also that brown top and Chewings fescue will take in the sward depends largely on the standard of soil fertility. The general thesis at present is that too high manuring plus watering will favour brown top at the expense of the Chewings and low manuring plus dry conditions will favour Chewings fescue at the expense of the brown top. Mechanical Treatments. “The plots sown out in sterilised soil were the quickest to establish, and these plots have given the densest turf of any on the area. The seedling death-rate was very slight., and the growth for some months after establishment was exceedingly healthy. The soil was sterilised only once, but this did not effectively kill all seed, particularly in the case of the 'hard' seeds of suckling clover. "No treatments other than rolling have been started to date, it being considered advisable to let the turf become well established before mechanical treatments of the sward began. Rolling was carried out on a portion of the section set aside for this purpose

starting at an early date. Too early rolling, i.e., before the young seedlings reached one inch in height, was detrimental. The foliage was bruised and turned yellow in colour. Upwards cf eight rollings were given during the first three months to some plots—other plots received seven, six, five, four, three, two. and one rollings, respectively. Apart from the early damage to the young turf no differences could be observed. Certainly no good resulted o the general health of the sward by the rolling. Worms, Weeds and Clovers. "Specific experiments, other than those incorporated in the use of toxic manures, have not been prosecuted to j an extended scale during the year, as j it was thought advisable to allow a j full year for the grass to become well j established before weed and clover | control measures were adopted," the report concludes. "Some preliminary ; work with arsenic pentoxide and am-

monium thiocyanate has been carried out. and it would appear as though arsenic pentoxide is tire better spray to use for the general weed control work in hand. "Worms are now appearing troublesome, and extensive control measures will soon need to be adopted. Some preliminary trials were conducted, copper sulphate being the basis of the work. The most significant feature emanating from these was that the quantity of liquid applied plays a more important part than the strength of the solution, provided always that the solution is of a strength sufficiently

strong to bring the worms to tHe surface. A solution made by dissolving one pound of copper sulphate in 100 gallons of water was sufficiently strong to kill the worms, but with a solution so dilute it required no less than one gallon of liquid to the square yard to effect this. This treatment had no detrimental effect on the grass.”