SCIENTIST GIVES ADVICE TO GARDENERS

Chronicle (Levin), 13 May 1947, Page 2

SCIENTIST GIVES ADVICE TO GARDENERS

^ IMPORTANCE OF HEALTH OF SOIL Mr. H. Jacks, of the Plant Diseases Division of the Department of Scientific and Industrial Research (Auckland) addressed members of the Otaki Commercial Gardcners' Society last wetk. Mr. B. V. Cooksley, Dominion president of Commercial Gardeners, and Mr. D. Taylor, of the Department of Agriculture, were also present. Mr. E." T. Bartosh, . president of the Otaki Society, was in the chair. Mr. Jacks prefaced his address with a special appeal to those who still had much of their gardeninglife before them. "The future," he said, "will need the aid of science. If they meet science half-way, science will meet them half-way. The agricultural ofiicer is the mouthpiece of science." In horticultural problems of the past, a great deal of thought had been given to the plants, but not much to the soil. The health of the soil was all important and depended on the balanced presence and action of organ- ' 1 iM"Soni^* Jjittilcf8 tSrga'fffefris were one twenty-four thousandth of an inch in size. Unbalanced soil was sick infected" soil brought about by failure to rotate the crops, by growing the same crop each season. Corrections were sterilisation or disinfection of the soil, and correct feeding with artificial fertiliser. Comparing sterilisation with disinfection, Mr. Jacks explained that sterilisation meant killing everything, whereas disinfection was the killing only of those organisms not wanted in the -soil. This • could be done by heat or by chemical treatment. Heating might be by baking of by steaming at a temperature between -18'0 and 200 degrees Fahrenheit for at least ten minutes. It had to be noted that a temperature of 230 degrees would kill everything. He gave the details and compared the merits of the grid, the spike and the tray systems of heating. The soil had to be prepared, to a good tilth before treatment, which altered the texture of the soil. . 'Steam treatment should be repeated every second year. His suggestion was steaming one year and cliemical treatment the next. For disinfection by chemicals, formalin was a good fungicide and D.D. by-products were useful as an insecticide but of no vvalue as a fungicide. "As yet," said Mr. Jacks, "there % no ideal chemical for the purpo.e, but science, by a mixture cf chemicals, is sure to find the ,answer for the future." v The speaker then dealt with chloropicrin, popularly knowh as tear gas. This he termed an "honest gas." It was a good fungicide, a good insecticide, and a good weed' killer. To be effective, the soil had to be over 50 degrees, Fahrenheit. It could not be used on cold or overdamp soil. He exhibited a sample "gun" instrument used for injecting the gas to- the soil. It was used at £pecified spaces covering h& radius of discharge from the pruni, of the inserted gun. This aroused much. interest. • • Mr. Jacks referred to diseasee and pests affecting tomato - and -other plants, with some advice as" to the extent to which they could be controlled. In a brief sunnh&.iy of soil management he stressed the value of proper judicious liming. The speaker was foilowed throughout with keen attenfion, and afterwards answered nuuier-; ous queries on problems submitted by questioners. ■ At the conclusion he was accorded a very hearty vote : >f thanks. In acknowledging -thi.?, Mr. Jacks statcd -that he and the ofRcers of his division were ready at. all times to assist growers with scientific information when asked for..