Experiments on cutting potato tubers

Abstract

1. Field experiments on the use of cut ware setts with the potato varieties Arran Banner, King Edward and Majestic have shown that with proper handling no loss in plant establishment need result. When the cut setts are planted at the same distances as whole setts, there is liable to be a reduction in the yield per acre because of the lower yield per plant, but the actual rate of increase may be increased considerably by cutting because of the larger number of plants obtainable.2. No benefit has been found from the practice of dusting the cut surfaces of tubers of Majestic with slag, lime or ashes, while adverse effects resulted from the use of a fungicide and alum.3. The exposure of cut setts to drying conditions lowers their resistance to attacks by micro-organisms, and encourages the breakdown of the tuber flesh by bacteria of the carotovorum group.4. In general, the use of certain fungicides, either directly on the cut surface, or as a means of moistening sack coverings, is not to be recommended because of the adverse effects of the fungicide on the natural resistance of the live tissue of the tuber flesh.

Development of mould on the cut surfaces of potato tubers

“…It had already been determined that plant establishment was affected if cut tubers were left uncovered for a long period or their surfaces treated with copper sulphate (Bell et al 1942). It was of interest, therefore, to determine the reaction of whole, bruised and cut tubers to treatment with 2£ % copper sulphate and the effect on subsequent growth and yields.…”

“…As there was considerable divergence of opinion on the best methods of handling cut potato setts to ensure their successful use by the grower, a cooperative investigation was made and the results communicated (Bell, Gilson & Dillon Weston, 1942). Since then some aspects of this work have been reinvestigated, particularly as they apply to the treatment of cut tubers with certain disinfectants.…”

“…Since then some aspects of this work have been reinvestigated, particularly as they apply to the treatment of cut tubers with certain disinfectants. It has previously been stated (Bell et al 1942) that 'at first sight it would appear obvious that it is an elementary axiom of plant hygiene, founded on Pasteurian principle and Listerian practice, that a wounded surface should be disinfected and subsequently protected, so that pathogenic organisms are killed and their entrance to the wound prevented. This is a broad generalization which might overlook two important factors, namely, the inherent healing properties of the tissue itself and the chemical nature of the disinfectant concerned'.…”

“…This is a broad generalization which might overlook two important factors, namely, the inherent healing properties of the tissue itself and the chemical nature of the disinfectant concerned'. Evidence has already been given (Bell et al 1942) 'that the freshly exposed flesh of the potato tuber is strongly resistant to attacks by micro-organisms, and that this resistance can be destroyed either by exposing the cut tubers to conditions causing rapid evaporation from the cut surface, or by the use of certain disinfectants and fungicides'. On this latter aspect evidence has already been presented (Dillon Weston & Taylor, 1943) that when the cut surfaces of potato tubers were dipped momentarily in a 2 J % solution of copper sulphate (or certain other salts), Penicilliwn developed abundantly on these cut surfaces if they were kept under moist conditions, but that similar untreated surfaces were uncontaminated by this or any other fungus.…”