TOBACCO MOSAIC

Nelson Evening Mail, Volume 79, 12 January 1944, Page 2

TOBACCO MOSAIC

INTERESTING EXPERIMENTS WORK AT RIWAKA RESEARCH STATION One of the most interesting experiments at the Tobacco Research Station, Riwaka, this season is again that which demonstrates the ease with which tobacco mosaic can be spread from infected to healthy plants by any one of the many handlings that the plants receive while being set out in the field. In this experiment all the plants came from the one bed which was apparently free from mosaic. In the first plot the girl pulling had first deliberately handled a mosaic infected plant, but all other operations were carried out by workers with clean hands. Next to this is a plot where the girl laying out had first had a diseased plant in her hands. Then comes a plot where the planter was known to have been pi*eviously handling mosaic-infected plants. In all these cases the percentage of mosaic is high. INFECTION FROM MANUFACTURED LEAF Perhaps one of the most interesting cases is that where the planter, before he commenced work, rolled four cigarettes frr-i manufactured tobacco. In this : nee the amount of mosaic was also high, demonstrating that the mosaic virus can survive through the high temperature of the drying proAdjacent to these experimental areas are control plots where the usual precautions of washing the hands at regu--1 a intervals during the work were observed. These plots show up clean in marked contrast to those already mentioned. To demonstrate the effect of washing the hands one puller had her hands veil contaminated by handling diseased plants. Before commencing pulling she thoroughly washed her hands in running water, and the freedom from mosaic of the plot set out from these plants demonstrates the effectiveness of this sigrple precaution.