CULTURAL METHODS IN ORCHARDS 173 



only one cultivation for the season will produce markedly 

 increased results as compared with sod. 



143. Yield of fruit. — As previously stated, the soil treat- 

 ment is larg(>ly responsible for the amount of bloom and 

 hence for the possibilities of a crop of fruit. Therefore, it 

 becomes of the first importance to study the cultural treat- 

 ments that are most likely to give a maximum crop, so 

 long as this is not inconsistent with the health and vigor of 

 the trees. 



A fundamental principle established by all the experi- 

 mental evidence at hand may be stated as follows: The 

 growth of the tree and yield of fruit proceed in the same di- 

 rection and are not antagonistic. This of course is within 

 reasonable limits, for a point may be reached when the 

 growth is so excessive as to suppress flower-bud fonnation. 

 An extreme of such a condition is reported from the tropics.^ 

 "Of our apple trees it is well known that in warm insular 

 climates they grow into magnificent foliage trees, but re- 

 main unproductive." 



In keeping with this principle, it may be said that the 

 above data on the growth of the trees applies with much 

 the same force to the yield. In regard to jneld no one sys- 

 tem is always best, but the one most suitable to the condi- 

 tions should be adopted. 



As seen above, the purposes of adopting a cultural sys- 

 tem are to conserve sufficient moisture for maximum re- 

 sults, to increase nitrification in the soil, and to set free plant- 

 food materials, as well as to control weed growth. This, 

 interpreted in terms of the plant, results in increased growth 

 and fruitfulness. 



144. Sod, tillage, and mulch for the apple. — The work 

 with the apple shows that, as a rule, the trees growing in sod 

 land are lower in yield and the fruit smaller but higher in 



' Sorauer, P. A Treatise on Physiology of Plants, p. 222. 



