1917] HOBTICULTUEE. 41 



the thin upland soils of central, eastern, and southern Ohio are seriously defi- 

 cient in nitrogen, and that the application of readily available nitrogen in such 

 cases surprisingly transforms the starving, unproductive orchards into those 

 that are vigorous, productive, and profitable. There has been little evidence of 

 additional benefit derived when acid phosphate and muriate of potash as sources 

 of phosphorus and potassium have been combined with nitrate of soda, so far 

 as tree growth or yield and appearance or texture of fruit are concerned. 



Nitrate of soda has given more favorable results than slower-acting organic 

 sources of nitrogen. The results of 4-year tests of fertilizers with a straw 

 mulch as compared with double-rate fertilization without a mulch of straw 

 have shown the heavier fertilization without mulching material to be most 

 advantageous. This result is attributed chiefly to the beneficial results of 

 nitrate of soda, which has encouraged the natural substitution of grasses and 

 clovers in place of an almost worthless soil covering of weeds and poverty 

 gra.ss. These grasses and clovers cut and used as a mulch have yielded better 

 returns than the straw mulch. 



Although acid phosphate has been of little direct fertilizing value to the 

 orchard, the experiments show that applications of acid pho.sphate u.sed either 

 alone or in combination with muriate of potash have caused the small scattering 

 clover plants to increase noticeably in size and gradually take possession of the 

 soil. After the clover had attainofl its maximum development, disappeared, and 

 left in connection with the decaying roots a liberal store of available nitrogen, 

 the better grasses began to come in. With the supply of nitrogen from the 

 clover a marked improvement in wood growth, foliage development, and dis- 

 position to produce fruit was observed among the apple trees. 



Relative to the practical application of this method of providing nitrogen by 

 means of acid phosphate, the author points out that it is too slow for practical 

 use where prompt results in fruit production are desired. It is suggested, how- 

 ever, that the use of nitrate of soda with acid phosphate in such a way as not 

 to stimulate the production of the various grasses to the extent that the clover 

 will be crowded or smothered out may prove to be the most economical method 

 of renovating these hill soils. Experimental tests of such a combination have 

 shown that where nitrate of soda at a rate of not above 200 lbs. in combination 

 with 200 lbs. and upward of acid phosphate is applied evenly over the orchard, 

 very nearly as good results are obtained from nitrate as where it is applied in 

 a circle under the outer extremities of the branches, without counterbalancing 

 the beneficial effects of the phosphate in clover encouragement. 



A test of cultivation versus the grass-mulch method of culture was conducted 

 for two years, with financial results slightly in favor of the grass-mulch method 

 of culture. 



Variation of internal structure of apple varieties, E. J. Kbaus {Oregon Sta. 

 Bui. 135 {WIG), pp. S-42, figs. 164). — In connection with apple studies con- 

 ducted at the station (E. S. R., 29, p. 541; 32, p. 855) considerable variation 

 was found to exist in the internal structure of different varieties of apples. 

 The author has undertaken a much more extended study of internal fruit struc- 

 ture. The present bulletin outlines the nature of this investigation, and contains 

 a number of plates showing variations in internal structures of a number of 

 different varieties of apples and pears. The more important differences are 

 briefly noted, but no conclusions are drawn nor interpretations made of the data 

 at this time. 



Effect of pi-uning' peach trees at different heights previous to planting in 

 the orchard. M. A. Blake {New Jersey Sfas. Bui. 293 {1916), pp. 3-SO, figs. 

 H)- — This bulletin reports the results of growth studies with peach trees pruned 

 at various lieights at the time of planting. Trees calipering J, J, |, i, and % in. 



