Mimeo. HO-7
RESULTS OF POTATO VARIETY-TIME OF PLANTING TRIALS
IN 1945
N. Kent Ellis, Department of Horticulture, and R. W. Samson, Department of Botany and Plant Pathology, -Purdue University Agricultural Experiment Station, Lafayette, Indiana.
Seven potato variety-time of planting trials were carried out on mineral soils in 1945 with cooperators in Delaware County, in east central Indiana, Tippecanoe County in west central Indiana, and in Dearborn, Clark, Floyd, Jackson and Venderburg Counties in southern Indiana. An eighth trial was carried out under more carefully controlled experimental conditions on the Northern Indiana Muck Soils Experimental Farm in St. Joseph County. The 4 -varieties, Irish Cobbler, Katahdin, Sebago and Sequoia were included in all trials.
It was intended that these. varieties be planted at times considered early, medium and late for each trial -and locality. This was to determine the best time of planting for most satisfactory yields of marketable potatoes of the individual varieties, and to determine if the time of planting influenced the severity of scab development in mineral soils as it does -in muck soil. l/\
Seasonal soil and weather conditions interfered somewhat with the desired timing of the plantings on the mineral soils. However, satisfactory first plantings' were made in April or May and second plantings in June in five, of ..the, trials.. A complete and satisfactory series of 4 plantings, at 14-day intervals, was made in the Muck Farm trial.
The., results, .from the, 2 .planting, .dates .in $ of the trials on. mineral soils and of the 4 plantings in the trial on muck soil are reported in some detail. - Third plantings Were made in 3 of the trials on mineral soil but the results were effected by poor stand and were not sufficiently satisfactory to warrant their inclusion in the general report. In the 2 other trials on mineral soil, single plantings of the 4 varieties above and in one of the trials, Chippewa, Russet Rural and Rural New Yorker were included. The yields from these third plantings and of the other 2 mineral soil trials are reported in the tabulations of each individual trial in the Appendix (page 5). 
3./. The earliest feasible plantings of Irish Cobbler and Katahdin in previous trials on the Northern Indiana Muck Soils Experimental Farm have resulted in the highest total yields and highest yields of potatoes sufficiently free of scab to be marketable.
See:	Samson, R. W. and N. Kent Ellis,-Influence of time of planting
of potatoes in Indiana Muck Soil on yield and scab development.
Amer. Pot. Jour. 20(12):301-308. 1943.