The most prevalent diseases and pests are: Mosaic. (Nicotiana Virus I); Verticillium wilt (V. dahliae and V. albo-atrum); Black root rot (Thielaviopsis basicola); Leaf miner (Gnorimoschema operculella); and Cutworm (Heliothis armigera). A physiological effect causing bronzing of the leaf late in the season and, thought to be a form of chilling, can cause quite severe losses.

by Moore Grant Baumgart, B.SC., Horticultural Division, Department of Agriculture, Nelson.