1916] HORTICULTURE. 39 



which were fair crop years, were larger ou tlie fertilized plats. The yields 

 for 1915 showed an increase consistent with the amount of fertilizer used. 



The experiment is to be continued for a number of years before definite con- 

 clusions are drawn. 



Field experiments in spraying apple orchards, B, S. Pickett et al. {llUiwis 

 Sta. Bui. 1S5 (1916), pp. /f'J-2I2, figs. 22). — This bulletin comprises reports on a 

 number of field experiments conducted in the leading orchard sections of Illi- 

 nois. The experiments were undertaken for the purpose of coordinating the 

 results of earlier investigations into general systems of spraying, the attempt 

 being made to evolve methods of practice which would be practical from a 

 commercial standpoint. The following work is reported: Spraying experiments 

 in 1910, 1911, and 1912 at Neoga, Cumberland County, by O. S. Watkins (pp. 

 58-103) ; spraying experiments in 1912 at Flora, Clay County, by W. A. Ruth 

 (pp. 104-117) ; spraying experiments in 1909 at Griggsville, Pike County, in 

 1910 and in 1911 at Centralia, Marion County, and in 1912 at Anna, Union 

 County, by L. E. Foglesong (pp. 118-155) ; spraying experiments in 1911 and 

 in 1912 at Griggsville, Pike County, by A. J. Gunderson (pp. 15G-186). The 

 results secured in each investigation are summarized. An introductory account 

 of the scope and methods of conducting the experiments (pp. 49-57), together 

 with a general sunnnary of the work as a whole, including recommendations 

 for spraying practice in Illinois apple orchards (pp. 187-212) are given by B. S. 

 Pickett. 



The experiments as a whole have shown the general effectiveness of applica- 

 tions of standard spray mixtures, including Bordeaux, lime-sulphur, and ar- 

 senate of lead in the control of fungi and insects of the apple. Both Bordeaux 

 and lime-sulphur properly used were excellent sprays for the apple. Bordeaux 

 gave greater efficiency as a fungicide but also showed serious tendencies to in- 

 jure fruit and foliage. Lime-sulphur exercised a fair degree of control of 

 fungi and caused little damage to fruit or foliage. Bordeaux is especially 

 recommended where fungus diseases are known to be serious and also for the 

 cluster bud spray since it seldom injures either fruit or foliage at this stage. 

 In orchards previously cared for the authors advise the use of lime-sulphur 

 for the spray which follows the fall of the petals find for the third summer 

 spray which follows from a week to ten days after the fall of the petals. 



Experiments were undertaken to determine whether Bordeaux injury can 

 be lessened or prevented by covering the first spray with a secondary spray of 

 Bordeaux or by maintaining over the Bordeaux a coating of lime throughout 

 the season. Some beneficial elfects were observed in certain of the experiments 

 but the work as a whole gave no marked results. 



Self-boiled lime-sulphur proved inferior to lime-sulphur made in the usual 

 way as a fungicide although it appeared to exert some stimulating or bene- 

 ficial effect on the health and vigor of the foliage. Owing to its worthlessness 

 in the control of apple scab it is not recommended as a successful spray for the 

 apple. The addition of copper sulphate to lime-sulphur did not add to its use- 

 fulness as a spray. In three of the experiments reported-on it resulted in more 

 or less severe injury to the fruit. An application of lime-sulphur made at the 

 strength used for San Jose scale applied while the trees were dormant was of 

 no value as a preventive of apple scab. Paris green proved less effective than 

 arsenate of lead when used in combination with standard fungicides for the 

 control of chewing insects, particularly the codling moth and the plum curculio, 

 and caused considerable foliage injury. 



Arsenate of lead alone possessed practically no fungicidal value and it is 

 recommended that it never be used except in combination with a fungicide. 

 43795°— No. 1—16 1 



