Results of spraying and dusting potatoes for late blight
Four copper and four organic fungicides were tested against late blight of potato in Prince Edward Island during 1948 under severe epiphytotic conditions.
Phygon XL gave outstanding control of late blight on the foliage, and in this respect it was followed closely by Parzate. The four copper fungicides, Bordeaux (4-2-40), Bordow, C. O. C. S. Niatox, and Deecop, controlled the disease in the order listed, and were more effective than Dithane. Fungicide 629 gave almost no control.
It was evident that Phygon XL delayed the maturity of the plants.
All plots treated with fungicides except those treated with Fungicide 629 gave yields significantly higher than the check plots at the 5 per cent level. The yield resulting from the use of C.O.C.S. Niatox was significantly higher than the check plot at the 1 per cent level.
Three copper fungicides were applied in both dust and spray form.
Spraying was superior to dusting with regard to both yield and disease control.
KeywordsLate Blight Copper Sulphate Bordeaux Mixture Vine Killer Check Plot
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