68 PEACH LEAF CURL*. ITS NATURE AND TREATMENT. 



thousand dollars, having been largely lost in 1893. After a brief 

 correspondence Mr. Ditzler kindh^ offered to allow the Department to 

 select from the orchards of Lovell peaches a block of several hundred 

 trees of exceptionally uniform and vigorous growth and especially 

 suited to the purposes of the experiments planned, and no finer or 

 more uniform block of trees has ever been seen by the writer than 

 that eventually selected and assigned to this experimental work. It 

 consisted of nearly 600 trees at the southwest corner of a 40-acre block 

 of Lovells, and was nearly level. The soil was sandy loam — deep, 

 rich, and almost uniform in quality. The trees had been set in 

 orchard less than five years, were 25 feet apart each way, and had 

 grown so vigorously that before pruning the branches met between 

 the rows in many cases, thus presenting tops of exceptional size for 

 trees so young. 



The- experiments planned included a rectangular block of the orchard, 

 20 trees wide from east to west by 29 trees long from north to south. 

 The tract selected was 500 feet east and west by 725 feet north and 

 south, or nearly 8i acres in extent. At the south of these Lovells is 

 an almond orchard of the same age; at the west a young apple orchard. 

 Through the center of the experiment tract, extending from south 

 to north, Avas planned a driveway, thus dividing the trees into two long 

 rectangular blocks, each block being 10 trees wide from east to west, 

 and 29 trees long from north to south. Each cross row of 10 trees was 

 numbered. The south 10 trees, forming the south east-and-west row 

 on the east side of the driveway, was designated 1; the second row 

 from the south, 2; the third row, 3; etc., the north row on the east 

 of the driveway being row 29. On the west of the driveway the 

 south row was 30, the second row 31, etc., the north row being 58. 

 This arrangement gave 580 trees, divided into 58 rows of 10 trees 

 each, one-half of these, rows 1 to 29, being east of the driveway and 

 the other half, rows 30 to 58, west of the same. This arrangement 

 may he fixed more clearly in the mind by the diagram on page 69. 



This diagram, in addition to showing the arrangement of the rows, 

 as already described, is planned to represent and distinguish the 

 ■ rows which were to be treated with sprays from those which were to 

 be left untreated as check or control trees in each experiment. The 

 trees of the rows to be treated are represented by a star (*) and the 

 trees to be left uusprayed are shown by a circle (°). with the exceptions 

 to be noted. It may thus ))e seen that each row of 10 trees intended 

 for treatment has at its side 10 untreated trees as a check or control 

 row. With the exception of rows 29 and 58 each control row serves 

 for comparison with two sprayed rows, one on either side. This 

 method of contrasting each control row with a sprayed row on either 

 side admitted of the planning of 38 experiments in the block of 58 

 rows, each experiment comprising 20 trees— 10 sprayed and 10 

 unsprayed, in two. immediately adjoining and parallel rows. 



