IRISH BLIGHT.

Bush Advocate, Volume XXII, Issue 67, 21 March 1910, Page 7

IRISH BLIGHT.

The Department of Agriculture and Technical Instruction for Ireland, which should certainly know all about it, has this to say of Irish blight:— "By the term 'lrish blight' it is presumed that reference is made to the fungus Phytophthora infestans. This disease is usually referred to in the United Kingdom as ordinary potato "blight. The disease occurs to a greater or less extent in Ireland every year, and it causes most damage in seasons when warm, wet weather is continuous, in July and August, as such conditions favor the development of tlie disease. The foliage is then destroyed in the early stages of tubering, and the crop yield is greatly diminished. Once the disease appears on the leaves, repotedial measures are not usually successful. The main effort should be directed towards prevention. A system of spraying is now regarded as essential to the successful cultivation of the potato crop in Ireland. Two, and in wet seasons, three, sprayers are necessary. The Burgundy mixture. It consists of sulphate of copper and washing soda, made in the following proportions:— 21b sulphate of copper of 98 per cent, purity, 10 gallons clean water. The Bordeaux mixture (sulphate of copper and lime) is made in the following proportions : —2lb sulphate of copper 98 per cent, purity, lib unslaked lime of the best quality, 10 gallons water. The department recommends the use of washing soda in preference to lime for the following reasons: The spraying mixture adheres longer to the foliage of the plant, and is not so readily washed off by rain; the mixture can be more easily prepared; the nozzle of the machines are not so liable to become stopped with grit or refuse material. (If washing soda is used and the mixture carefully made, there should be no sediment.)