Further field experiments on potato scab control in Western New York

Summary

All data have been obtained from experiments in a region characterized by soils of rather alkaline reaction, usually at least pH 6.0.

Formalin seed treatments have consistently given small reductions in potato scab when compared with the untreated check plots.

Mercurial seed treatments have given small but significant increases in scab over the checks and formalin treatments.

Mercurials added to the soil have, in all cases, increased scab.

In Western New York tuber defects are markedly decreased by the use of sulfate of ammonia in the fertilizer.

In limited trials tetrachloroethane and hexamethylenetetramine showed no promise of scab control.

Netted Gem possesses a rather high degree of resistance to serious injury by potato scab.

Slight differences in scab resistance apparently exist within the Smooth Rural group of varieties.

White Blossom Cobbler is considerably more resistant than is the Irish Cobbler variety.