Disinfection of Seed Potatoes.

Horowhenua Chronicle, 12 September 1910, Page 4

Disinfection of Seed Potatoes.

FORMALIN

1. As a safeguard against- the introdiuotion of disease through the .use of seed potatoes that arc not visibly affected, but which may bo suspected to outwardly harboui disease-producing spores or germs, the following treatment is recoilmended Wash the tubers, if very dirty. Then immerse them for 1-f to 2 hours (if not sprouted, the time may bo safely extended) in a mixture of formalin (40 per cent) and water containing 1 pint (oi about lib) of the former to 2-1 gallons (6 kerosene tiufulls) of the latter. This mixture should be fr&shJy prepared, since the active principle on which its efficacy is dependent is a volatile one. As long a.s it possesses its characteristic odour, it is an efficient mixture. but, of course, rapidly deteriorates through use. It is convenient, in carrying out this process, _to _s-vr\;vnd the tubers in the disinfecting f! iid contained in a gunny big, i similar receptacle made >!' s .:nc ipmi fabric. After renin ;1, tl.o-v she :M bo spread o'ti to (Ivy, and then cut and planted without delav.

COIMIOSIVE SUBLIMATE. 2. 11 potato scab lie present on the "seed," and it is not convenient to substitute clean tubers, a ]i on It'll y crop may be grown from this scab-affected "seed," providing that the ground intended foi planting is not already contaminated, by treating it ivith a solution of corrosive sublimate. This should he prepared by dissolving 2:1 oz of the chemical named in about 2 gallons of hot water, and after an interval of 10 to 12 hours diluting with 12 gallons of water. The potatoes to be planted are simply immersed in the solution for an hour and a half, then spread out to dry, and planted in tfhe usual manner. A large barrel offers a convenient receptacle for the solution, and metal ones should not be used, since they are liable to be coirroded by it. It must, 'however, be borne in mind that corrosive sublimate is extremely prisonous to animal life, and must, therefore, be used with the greatest care. Both it and its solution nil J s £ " e kept out of the way olf and conspicuously la.bellod. Special receptacles should be employed for the treatment, and ror it only. _ And all tulbers treated' as described should be planted. Unly, therefore, under exceptional circumstances should the formalin steeping fluid be replaced by this one.

After tiro potatoes have been planted ana thus growth ensured, the crop must be sprayed with Bordeaux mixture or other efficacious niWKicide as a preventive treatment ■against the occurrence of blisjhit (l bytophithora infestans) or leaf spot (Madnosporiuim sola.ni), arsenate of lead or arsenite of soda being incorporated with the fungoid2 1 mixture to protect the foliage T attacks. Arsenate of i f , 10 form «l<i) may be substituted for the airsenite of lead. In the case of the "summer crop early planting is re<x>mmetided, and for the "winter ciW' the reverse-advice that has referonce exclusively tto the seasonal appearance of the "potato MWfefc "