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ANNUAL REPORT 1920 AND 1921 



and keeping down pests. This system requires less labor than any other but 

 is quite expensive to install ; portable standards sixteen feet high cost about sixteen 

 dollars each in addition to the cost of piping the orchard and the necessary hose 

 connections. 



In any system, the proper amount of water for the best results is dependent 

 upon several conditions, one of which is the geographical location. Certain parts 

 of San Diego, Orange, Los Angeles, Ventura and Santa Barbara Counties 

 bordering on the shores of the ocean obtain a great deal of moisture from the 

 heavy fogs ; furthermore, the average temperature in these sections is considerably 

 lower than in some of the interior valleys, such as San Bernardino and Riverside 

 Counties. Using the same method of cultivation for both the interior and coast 

 regions, it is natural that less actual irrigation is required along the coast than 

 further inland. 



The second, and perhaps the most important factor to be taken into con- 

 sideration, is the local condition ; as to the lay of the land, and as to the texture of 

 the soil; whether heavy, medium or sandy. An orchard with the soil in good 

 physical condition and correctly cultivated can be properly maintained with 

 much less water than would be required in the same orchard when cultivated 

 poorly or not at all. Poor physical condition of the soil can be improved a 

 great deal by planting a good cover crop to be turned under, or by applying 

 stable manure or other fertilizer containing a large amount of humus. Sometimes 

 a heavy soil requires but one of these methods whereas a light seindy soil may 

 require both cover crop and manure. 



Taking into consideration the geographical location, local conditions and 

 physical properties of the soil, as well as weather conditions, the irrigations 

 during the season should be three to five weeks apart. In the more exposed 

 sections, the young growth may be seriously damaged by early frost, if the trees 

 are over irrigated in the fall months. 



Deep cultivation is the best means of preserving the moisture in the ground 

 between irrigations. Cultivate as soon after irrigating as possible, before the 

 soil gets too hard; repeat if possible once more before the next irrigation, discing 

 or cultivating to a depth of six inches. 



For the back yard trees it is practical to make a large basin, leaving twelve 

 to eighteen inches of soil around the base of the trunk to prevent the collection of 

 most of the water at this place. The ditch should be about four feet wide all 

 the way around the tree with a six inch excavation, placing the soil around the 

 outside of the basin so as to increase its capacity. The deepest part of the basin 

 should be around the outside in order to spread the seepage out as far as possible, 

 as the roots have a tendency to follow the moisture. The excavated portion of 

 the basin should be filled with strawy manure; all kinds of old leaves can be 

 used as well as peat or any other compost material which does not get hard after 

 the water recedes. During the irrigating season the basin should be filled about 

 every two weeks; however, if hardpan is present as a subsoil, care must be 

 taken not to over water, as sour soil will be the result. On the other hand, light 

 sandy or gravel soil cannot be over watered, unless underlaid by a heavier soil 

 such as clay or hardpan. It is advisable for any grower to have a soil auger 

 by means of which the moisture contents of the soil can be learned and the 

 necessity for application of water be gauged. 



