Winter Meeting. 397 



amounts used by the trees on account of the small fruit crop and the 

 very sparse growth they make in such an unfavorable season. 



Thus should we expect following a very dry season an extra- 

 ordinary season of growth, and if by any treatment in that dry season 

 we can without permanent injury to the trees induce them to set a good 

 fruit crop the following year, it is very likely to prove exceedingly 

 favorable for the development of this fruit. Not only are the condi- 

 tions likely to be favorable for the development of a fine crop of fruit 

 following a dry year, from the standpoint of an abundance of plant 

 food to mature a maximum crop, but from the standpoint of a diminu- 

 tion of insect pests and a reduction of the prevalence of fungous dis- 

 eases. 



In the ordinary season it is necessary for orchardists to put forth 

 some effort in order to unlock the plant food contained in this soil. 

 The conditions most favorable for the'unlocking of this food and render- 

 ing it available are the presence of air, carrying as it does free oxygen, 

 and carrying also carbonic acid gas, which is indirectly a very powerful 

 solvent. Thus the systematic aeration of the soil favors its breaking 

 down and increases the ratio of available plant food. This aeration may 

 1)- acomplished in two important ways: One, by systematic tillage, 

 another by keeping up the supply of vegetable matter. Humus or vege- 

 table matters keeps the soil open and porous, so that the air may circu- 

 late freely, and in addition, through the decaying of organic matter, 

 liberates a large quantity of carbonic acid gas, which we have just 

 learned is efifective in unlocking plant food. Humus also assists in main- 

 taining a more uniform water content in the soil, preventing it from 

 becoming water-logged for long periods after a rain and preventing it 

 from drying out to that point where very little or no chemical changes 

 occur. 



In soils deficient in humus this dry condition occurs as a rule in 

 midsummer, when the temperature and other conditions are naturally 

 most favorable to the breaking down of the soil, and at the same time 

 when the trees are carrying the maximum of fruit and when they 

 stand in greatest need of a copious supply of moisture and plant food. 

 xAnd even if the trees are not carrying fruit, they need food at this time 

 of ihe year to mature the growth they have started in the spring and to 

 fill out and perfect the fruit buds they have formed, in order that both 

 wood and buds may be in good condition for the succeeding winter. 



