THE CONTROL OF COMMON SCAB (ACTINOMYCES SCABIES (THAXT.) GÜSS.) OF THE POTATO BY TUBER DISINFECTION

Publisher Website
Google Scholar
Abstract
SUMMARY: This investigation deals with an attempt to determine the value of seed tuber disinfection as a method for controlling common scab (Actinomyces scabies (Thaxt.) Güss.) of the potato crop when tubers affected with the disease are used for planting. A résumé is given of previous work by other investigators dealing with the control of this disease. Under Northern Ireland conditions it has been found that a satisfactory control of the disease may be obtained by the disinfection of afEected seed tubers before planting providing that a sufficient interval has elapsed between the growing of successive potato crops in the same land. After a 6‐year interval, which is normal in Northern Ireland farm practice, satisfactory control was obtained in all cases, and it is suggested that a 4‐year interval would probably be sufficient to ensure satisfactory results. Although good control has been obtained after the lapse of shorter intervals, such is not always the case, and the method cannot be relied upon with certainty. No control was obtained where no interval elapsed between the taking of successive potato crops. Solutions of mercuric chloride, formaldehyde, copper sulphate, Burgundy mixture and proprietary organic mercury compounds employed in various ways were used in these experiments. The most satisfactory method for the farmer's use was found to consist of the instantaneous dipping of the tubers in solutions of proprietary organic mercurials. The results obtained indicate that in some cases the planting of very slightly afEected seed in land which has not carried potatoes for many years may result in a high incidence of the disease in the resultant crop. A slight depression in growth was sometimes observed to result from the planting of disinfected tubers, and this was particularly noticeable in the case of the variety Majestic. After a period of from 10 to 12 weeks it disappeared and the crop grew out normally. In some cases tuber disinfection stimulated the growth of the plants. Some of the results obtained suggest an increase in tuber yield due to disinfection of the seed tubers, but the experiments were not laid down in such a way as to permit a statistical analysis of the yields being made.

This publication has 6 references indexed in Scilit: