APPENDIX TABLE III VALUES OF THE CRITERION DIFFERENCE FOR DETERMINING -E. DIFFERENCE SIGNIFICANCE OF DIFFERENCES IN ANNUAL MEANS, 1911-19. 1911 1912 1913 1914 1915 1916 1917 1918 1919 1911 .71 4.61 .19 1.53 .47 .44 1.73 1.98 4.06 .89 1.46 2.61 3.65 .80 .34 1.89 2.76 .89 1.46 1.18 2.54 1.98 1.58 2.96 3.90 .47 1.38 6.52 1917 .44 .38 5.08 .34 2.61 1.18 1918 1.73 1.09 2.62 1.89 3.65 2.54 1.58 1919 1.98 .57 7.69 2.76 .80 1.98 2.96 3.90| This table was constructed to facilitate the interpretation of differences in mean annual egg production. For each of the pairs of years listed, the difference between the means was found, its probable error calculated by the usual method, and the difference then divided by its probable error. The quotient (E Diff) (Diff.) for each pair of years has been entered at the intersection of their columns. Thus the difference in mean production between 1911 and 1912 is .71 times its probable error; between 1911 and 1913 the difference is equal to 4.61 times its probable error, etc. SPACING OF POTATO by B. A. BROWN The question of the best spacing of potato hills is an open one among growers and station workers. Naturally the answer to such a question depends on several variable conditions uch as: Variety grown. Size of seed pieces. 1. 3. 4. 5. Amount and distribution of the precipitation during the growing season. Natural fertility and water holding capacity of the soil. 6. Kind and amounts of "plant food" added. 7. Value of land and acreage available. 8. Disposition of the crop; as seed or table stock. The large amount of literature, bearing on this question, will not be reviewed here. Much of the previous work deals with the size of seed pieces. Also many of the experiments were conducted under conditions, varying widely from those existing in Connecticut and different varieties were used in most cases from those planted in the trials reported in this bulletin. During 1921, 1922, and 1923 this station conducted such tests as space and time have permitted, in order to obtain some data, which might aid in deciding the distance to allow between hills, when the rows are three feet apart, and the crop is grown for table stock. It was not possible to increase the scope of the tests by varying the distance between rows or the size of the seed pieces. Therefore, the common practices were followed in regard to these points, viz., the rows were three feet apart and the seed pieces averaged about one ounce. Three varieties, namely, Irish Cobbler, Green Mountain. and Russet Rurals have been planted at from three to five different rates each year. In 1921 and 1922, the planting was done with a two man planter, which had been calibrated and set to drop at the desired distances, while in 1923 the seed pieces were dropped and covered by hand. In all years the fertilizer (4-8-4 @ 1875 pounds per acre) was applied with the potato planter. The plots were single rows, 103.7 feet long, duplicated in 1923 only. The tests were located on the station fam. The soil there is well drained and is classified as Gloucester fine sandy loam. Culture and spraying were adequate to keep the plots free of weeds and the vines in a healthy condition. The digging has been done by hand and the grading with a machine. The results with the different varieties will be considered separately. TABLE I-EFFECT OF DISTANCE BETWEEN HILLS ON THE YIELDS AND SIZES OF IRISH COBBLER POTATOES. |