PLANT DISEASES

Gisborne Herald, Volume LXVI, Issue 20031, 1 September 1939, Page 3

PLANT DISEASES

EFFECTIVE RESEARCH WHITE BUTTERFLY A summary of the work of the plant diseases division of the Department of Scientific and Industrial Research in combating plant diseases, with several illustrations of how it accomplished its results, was given to the Auckland Rotary Club oy Mr. J. D. Atkinson, of the_ stair of the research station at Owairaka. “We are steadily importing new diseases into the Dominion, ’ Mr. Atkinson said. “In the last two years we have, imported no fewer than nine, and unfortunately most or them are serious. In these days we have stopped the import of many things, but not of plant diseases.

Mr. Atkinson went on to say that the most efficient inspection in t'nc world would not stop this, and in* stanced the case of the white butterfly, which, it was believed, had been introduced from cabbages that had been thrown overboard from a steamer at New Plymouth. Mr. Atkinson described the work of the division to identify and then eradicate the cirrus canker .that had been discovered in the Dominion in 1937. In America it was generally thought necessary to cut out all the citrus trees whether affected or not, within a radius of about a mile, but Dr. G. I-I. Cunningham decided to take a chance and simply have all the .first-year wood and the leaves cut off. This had ruined the crop for two years, but it had proved very effective. Of the-trees so treated only about a quarter of 1 per cent had been reinfected, and they were removed. Had that disease become established it would have meant the end of the citrus industry in this country.