VIRUS IN WHEAT

Press, Volume CI, Issue 29994, 1 December 1962, Page 7

VIRUS IN WHEAT

Survey From Air Wheat crops which were sprayed to control the spread of aphides carrying yellow dwarf virus are already showing marked signs of benefit. Dr. H C. Smith, plant pathologist of the Plant Diseases Division of the Department of Scientific and Industrial Research, Lincoln, said this week.

With Mr L G. Copp, senior plant breeder of the Crop Research Divison, Dr. Smith made an aerial survey of crops in the Loburn, Amberley, and Waikari areas on Thursday morning. At Loburn, where half a paddock had been sprayed in June and the rest of the crop left untreated there was an outstanding difference to be seen from the air, he said. At Waikari most of the crops seen which were known to have been sprayed were looking very well. There were very small patches of virus resulting from the original aphis infestation but Ulis had been stopped from spreading by the spraying.

Dr. Smith said that there were odd crops which appeared to be fairly severely affected with virus and which were obviously unsprayed. Photographs were taken during the flight with colour film and with black and white film using an orange filter which accentuated the colour difference between the yellowed leaves and the healthy plants. The flight was made to see if signs of virus attack could be noted from the air at this stage, which was much earlier than previous flights, and the photographs will be compared with ones from a flight made shortly before harvest to see if the darkened patches where the heads of the virus-affected wheat have blackened as the crop ripens, correlate with the present patches of yellowing. A ground survey will also be made later.