226 FUNDAMENTALS OF FRUIT PRODUCTION 



phosphorus we have but httle evidence of an indirect benefit to the trees 

 through any increased growth of the intercultures resulting from the use 

 of potash-carrjang fertihzers. 



Sulphur. — Too httle evidence on the use of sulphur-carrying fertilizers 

 in the orchard is available to warrant an extended discussion of the differ- 

 ent forms in which it may be applied. Evidently many different forms 

 are eligible, for it has resulted in increased yields of certain orchard inter- 

 cultures when used in the form of both potassium sulphate and calcium 

 sulphate (gypsum) and increased grape yields have been reported from 

 the use of both gypsum and flowers of sulphur. ^^ Indeed it has been 

 noted that alfalfa and certain other legumes have been greatly benefited 

 from the sulphur contained in the lime-sulphur spray, which had 

 dripped from sprayed trees or had drifted to the ground in the process 

 of spraying. 



Lime. — Though calcium is one of the elements essential for the growth 

 of plants, the point has been made that there are but few soils to which 

 its application in fertilizers is desirable for the purpose of supplying the 

 tree directlj'^ with additional amounts and though there are indirect ways 

 in which it may frequently benefit orchard trees, there are indirect ways 

 in which it may also injure them. The data that have been presented 

 make it clear, furthermore, that the same plant may be either benefited 

 or injured by liming, according to the condition of the soil. That there 

 are marked differences between species — and even varieties of the same 

 species — in their tolerance of lime or their tolerance of the soil basicity 

 with which it is likely to be associated or in their response to lime applica- 

 tions, should be emphasized. The results of work at the Rhode Island 

 Experiment Station may be cited. Those results have been summarized 

 as follows: "According to experiments made by the Rhode Island Agri- 

 cultural Experiment Station on acid soils in that State, the plants tested 

 may be classified with regard to their behavior toward lime as follows: 

 Plants benefited by liming: . . . alfalfa, clover (red, white, crimson 

 and alsike) . . . oats, timothy, Kentucky bluegrass, Canada pea, 

 Cuthbert raspberry, gooseberry, currant (white Dutch), Orange quince, 

 cherry, Burbank Japan plum, American linden . . . plants but little 

 benefited by liming . . . rye, . . . Rhode Island bent, and redtop; 

 plants slightly injured by liming . . . Concord grape, peach, apple, 

 and pear; plants distinctly injured by liming . . . velvet bean, . . . 

 blackberry, black-cap raspberry, cranberry, Norway spruce, and Amer- 

 ican white birch. Other plants said to be injured are the chestnut, 

 azalea, and rhododendron." ^^^ 



Another point that may be mentioned in connection with the appli- 

 cation of lime is that there is little occasion to use it in the fruit plantation 

 for flocculation purposes. Soils with a texture so impervious that the 

 flocculating effects of lime are needed to promote drainage and aeration 



