FIELD TRIALS IN AMURI COUNTY

Press, Volume LXXXIV, Issue 25609, 25 September 1948, Page 5

FIELD TRIALS IN AMURI COUNTY

Work Of Department Of Agriculture

WEED KILLING A FEATURE Field experiments being carried out by , the Department of .Agriculture were explained to Amuri County farmers at a field day recently. Time did not permit of the inspection of more than a few of more than 20 trials at present being carried out in the county, but keen interest was shown in all the experiments visited. The random block method of experimentation, where small plots, usually seven-drill coulters wide by two chains, are sown, was explained by Mr F. G. Spite, instructor in agriculture. Each variety or treatment is sown once in each block of plots. Six to eight of these blocks are sown in each trial, giving six to eight plots of each treatment a trial. These replicated trials obviate the effect of varying soil conditions which would otherwise affect comparisons. In cases such as cereal trials where harvesting is carried out, each plot is threshed and the produce weighed separately. The results are then statistically examined for significant differences. The first trial visited was at Balmoral, where new varieties of oats and barley are being grown for greenfeed in comparison with Algerian oats and a mixture of Italian ryegrass and broad red clover. Mr Spite said that although the trial was sown under extremely dry conditions, S 17 and Russet oats provided a good bulk of early grazing. Wong barley established evenly, but was backward in growth until after the first grazing in July. Since that time it has made good growth. The Italian ryegrass and broad red Clover plots are only now coming into high production, whereas if this mixture had been sown in a normal autumn and after a summer fallow, valuable grazing would have been obtained during the winter. The trial will later be harvested for grain and seed yield. After an inspection of a milling oat variety trial in the Balmoral district, the party went to Culverden where a hormone weed killer trial is being carried out on a crop of Cross 7 wheat. Mr J. F. Brown, of the department, who specialises in the use of hormones, outlined the history of hormone weed killers, since they were first used in 1945, and presented data collected from the 200 hormone trials laid down by departmental officers in Canterbury. Improved Spraying Methods Mr Brown said that until a year ago it was necessary to carry approximately 100 gallons of water to spray one acre, but to-day, with the aid of the new low volume nozzles which spray 1.2 gallons an acre, and the new highly concentrated 2-4 D materials, it was possible to spray 30 to 40 acres with a 50-gallon tank of the spray. Those in the party were able to compare plots sprayed with both the high and low volume nozzles attached* to the under, side of a mower-bar so that the actual cross surfaces of the weeds could be sprayed at the moment of cutting. It has been claimed that much better penetration may be obtained by this method. Similarly, spraying equipment has been mounted on a plough to spray the cut surfaces of roots while ploughing. The effect of the latter treatment was demonstrated on a Rotherham farm where onion rooted twitch has recently been treated with various weed killers. Most promising results are being obtained with Isopropyl-N--PFlnyl carbamate, a substance being us 11 experimentally for the control of twitches. Heavy concentrations of 24 D had also been applied on the Rotherham experiment. Some plots have been ploughed and some disced, while on others the materials were applied on the unbroken surface. Although the onion twitch is severely damaged in many of the plots it is still too early to.form any definite conclusions. Other experiments inspected in-

cluded topdressing on both flat land and hill country, surface sowing of clovers on hill country, wheat manorial trials and disposal of wheat stubble. In the last-named experiment an area had been divided into lands and the wheat straw burnt and ploughed in, on alternate blocks during the aiftumn of 1946. The paddock was’ then sown to wheat followed by blue lupins. This season wheat was again sown in May and thq. experimental area will be harvested to ascertain yield differences. The evidence, obtained from departmental trials has a wide application in Canterbury and the trials form an important link between the research worker and the farmer.