CALIFORNIA AVOCADO ASSOCIATION 



65 



say that probably the limit of the steepness of the natural slope should not 

 exceed thirty per cent, except for a short distance. 



The so-called contours on which the trees are to be planted are in 

 reality terraces and should have a slope along their length of from one 

 to two and a half per cent, the greater the distance the water has to run, 

 the greater the fall. The ground should be laid out by some competent 

 person and if it is of any great extent, a surveyor's instrument is almost 

 indispensable. A reversible hillside plow should next be run along the line 

 of stakes set and, when a few furrows have been plowed, V shaped and 

 other grading tools will be called for to complete the work. It is wise to 

 make the terraces almost as wide as the lay of the land will permit, for 

 the cost (which may well be considered as part of the land) is less if the 

 work is done at one time and especially before there are any trees to 

 interfere. When the terraces are made the slope should be carefully tested 

 by running water and all inequalities remedied. If possible, a delay in 

 planting until after a winter's rains have settled the ground and brought 

 out the defects will be of advantage. Any neglect to attend to the per- 

 fecting of this slope will increase the expense of irrigation materially. 

 Roughly, the terraces may be made thirty feet apart. The lay of the 

 land will sometimes bring two terraces much nearer together or much 

 farther apart than this distance, but where they approach nearer than 

 twenty feet, one may be discontinued and when they draw apart as far 

 as — say fifty feet — a new terrace, short or long as the ground permits, 

 may be inserted. 



Water is preferably supplied from a large service pipe running along 

 the upper terrace and from this smaller pipes should cross the lower ter- 

 races at their highest point, where a tap should be provided. Under a 

 sixty foot pressure, a three quarter inch pipe should be sufficient for the 

 lines crossing the terraces. If these terraces are longer than three hundred 

 feet it will be necessary to have an additional up and down supply pipe 

 and tap. 



When the ground is considered ready for planting the trees should be 

 set out at a point on the terrace about where the original surface of the 

 ground lay, thus giving to- the growing roots the benefit of a larger supply 

 of well cultivated top soil. However, should the hillside be quite steep, 

 it is well to plant the young tree from six to fifteen inches inside the line 

 of the original surface. 



Concerning the important point as to how far apart on the terrace the 

 trees are to be planted, the principal consideration is whether the tree has 

 an erect, medium, or spreading habit. The extremes I should say would 

 be about fifteen feet for trees like the Lyon and fifty in the case of those 

 like the Taft. Some growers may choose to plant alternately different 

 kinds quite closely, with the intent of eventually eliminating the less de- 

 sirable. 



The proper irrigation seems to be by furrows. Where the terraces 

 are so wide that the water can be run both inside and outside the line of 

 trees, this plan may be resorted to, care being taken to raise the outer edge 

 of the terraces. Where the hillside is so steep that the terraces are neces- 

 sarily narrower, one or two furrows should be run inside the line of trees. 

 If the terraces have been carefully graded, the water may be regulated so 

 as to merely run slowly and only in such volume that on arriving at the 

 end of the terrace there will be no waste. 



