Abstract

                                In the State of Madras, the Nilgiris district enjoyв a cool, equable climate and is well suited for potato cultivation. No less than three crops are raised in a year. When there is demand in the market the ryots harvest their crop even before the haulms have dried up. With a view to find out the correct stage of harvest to secure maximuın yield, a study of the tuber development in four of the more important commercial varieties of potato that come up well in the Nilgiris was undertaken. The literature giving information on tuber development in potato is very seanty. Werner (1917) working at the North Dakota Station, U. S. A. found that tubers of the variety Green Mountain harvested in August 10, 20 and 30 and in September 8 and 11 showed a daily increase of 2.34 bushels during the last 3-day interval. The total yield secured in August 10 was 121 6 bushels per acre, as compared against 220 bushels secured in September 11. Kohler (1909) experimenting with the variety Early Ohios at the Minnesota University Farm, by digging tubers at 7-day intervals from July 31 to August 30 obtained a daily increase of marketable potatoes at the rate of 7-18 bushels per acre. The daily gain near the end of the period was lower as the foliage died.

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