Farm Notes.

Te Aroha News, Volume XXVII, Issue 43369, 8 September 1908, Page 4

Farm Notes.

SCAB IN POTATOES. CAUSE AND PREVENTION. The following notes are extracted from the summary of a report of a senes of trials and investigations made at the Maine Agricultural Station : The use of untreated seed, and the too common practice of reserving unsaleable, scabby tubers for planting, may result in a rapid increase bf potato, scab. Scab is caused by a minute parasitic fungus. Soil conditions, the application of lime, ashes, chip dirt, etc., may favour tl e development of scab, but are incapable of causing it. Crop infection on qld land may come fro n the soil, from the seed or from both. Cn new land the source is largely from undisinfected seed. Alkaline soils, the use of stable -manure, lime, ashes, and certain chemicals of an alkaline nature favour the fungus. Acid soils and certain other chemicals are unfavourable to it.

Beets, and the roots of a few other vegetables are attacked by the disease, but the fungus may persist in infected soil .for several years without the presence of known host plants. Badly infested soils should be devoted to such crops as grains, grasses, and clovers for as long time as possible. Fertilisers favourable to scab should be avoided, and “ souring ” the soil by green manuring is recommended. On clean soils only healthy, disinfected seed tubers should be used. Manure containing uncooked scabby potatoes, or refuse should be avoided, but no other precautions as to fertilisers . are necessary. Clean soil may be infected by means of tools, bags, baskets, etc., which have been in contact with infected land or tubers. Small amounts of seed are best disinfected by soaking : (a) Two hours in a solution of one-half pint formalin, to fifteen gallons of water, or (b) one and a-half hours in 2 -oz. of corrossive sublimate dissolved in fifteen gallons 01 water. For large quantities qf seed, formaldehyde gas, generated by the use of potassium permanganate, is the_ rftost practical disinfecting agent. Place seed fubers in bushel crates, or shallow slat-work bins in a clo-ed room. For each 1, 000 cubic feet of space spread 23 oz. of potassium permanganate evenly over the bottom of a large pan or pail in the cantreof the room. Pour over this three pints of formalin, leave room at once and allow it to remain tightly .closed for twenty - four to forty-eight hours.