138 CALIFORNIA FRUITS I HOW TO GROW THEM 



There is less difference than formerly in the use of the harrow or 

 cultivator during the summer. Still some are content to use the culti- 

 vator only as a weed-killer, and after the weeds cease to grow and the 

 spring showers are over, the cultivator is laid aside and the land left 

 unstirred until the following winter. This, of course, refers to unirri- 

 gated ground, for wherever irrigation is practiced a cultivator must fol- 

 low, except on hillsides; where the surface is left undisturbed after the 

 irrigation furrows are made until the beginning of the dry season. 

 It is a fact, however, that even if no rain falls, the soil becomes com- 

 pacted to a certain degree, and the best way to imprison the greatest 

 possible amount of moisture below is to run the cultivator at intervals 

 all through the dry season. It should run shallow and only stir the sur- 

 face layer. The experience of the most successful growers is that fre- 

 quent stirring without, however, bringing new soil to the air, is the 

 best-paying practice. 



WHAT IS THOROUGH CULTIVATION 



As clean, thorough cultivation has been approved, it may be desir- 

 able to attempt to define the term. It can, however, only be approxi- 

 mately done, because of the great difference in individual views and 

 practices. Some indication of the operations which are contemplated 

 may be had in the following specifications upon which contracts have 

 been let for care of orchard : First, plowing away from the trees, fol- 

 lowed by harrowing; second, plowing toward the trees, followed by 

 harrowing; ten summer workings with cultivator; three working with 

 shallow cultivator or weed-cutter; five hand hoeings around the trees. 

 The contract intends the most complete and perfect working of the soil 

 and specifies the above merely that there may be no difference of opin- 

 ion between owner and contractor. 



In cases where the land is infected with morning-glory, weekly cut- 

 ting with sharp, flat teeth beneath the surface is stipulated for in some 

 cases, and this seems about the only way to cope with this formidable 

 trespasser. 



CULTIVATION FOR WEED KILLING 



Cultivation for weed killing is a minor consideration in California, 

 because cultivation for moisture conservation effectually disposes of 

 most of them, and weeds do not start readily in the earth-mulch during 

 the dry season. There are, however, a few most persistent pests which 

 require heroic measures. Johnson grass and morning-glory are the 

 most prominent of these. The only successful treatment consists in 

 cutting constantly with a weed-cutter (a sharp horizontal knife), oper- 

 ated so as to pass under the whole surface and run so often that the 

 plant is never allowed to show a shoot on the surface. It is of no use 

 merely to cultivate or "weed-cut" as for other weeds. This spreads 

 the pest more and more ; but if the rising shoots are continually cut 

 under the surface, and never allowed to get the light, it will kill the 

 plant surely, but it may take two seasons to do it. Weed-cutting knives 



