ROBBING'S FRUIT GROWERS' GUIDE 



65 



waste and the trees remain in a dry condition. This 

 condition is only apt to occur on the hillside lands where 

 the fall is quite heavy. 



On the lighter sediment lands it is not necessary to 

 let the water run so long; in fact, some of these lands 

 will become sufficiently wet by allowing the water to 

 run only a few hours. Only on extremely sandy lands 

 is it advisable to flood citrus orchards. Ordinarily no 

 irrigation is required during the winter months, although 

 in some seasons it is necessary to irrigate up to 

 December. 



The length of time required for the land to dry 

 sufficiently for cultivation after an irrigation depends 

 largely on the nature of the soil and weather conditions. 

 A light, sandy soil will be dry enough to cultivate within 

 thirty-six hours after the water is taken off, but the 

 heavier soils require several days of sunshine before 

 they can be properly cultivated. The soil should be 

 dry enough so that it pulverizes or falls apart as it is 

 turned up by the cultivator. If it is inclined to stick 

 together and turn up in solid masses it should be left to 

 dry another day or two. In some of the heavier soils 

 where the drying process is very slow, it is oftentimes 

 best to fill in the furrows with a harrow as soon as the 

 surface shows signs of baking or crusting; then follow 

 with cultivator a day or two later. This prevents the 

 surface from getting too dry while that below is getting 

 sufficiently so to cultivate properly, thus obviating the 

 soil breaking up in large clods. Outside of the benefit 

 of turning over and aerating the soil, the main benefit 

 of cultivation is the forming of a mulch of finely pul- 

 verized soil, which keeps the subsoil from drying out. 

 Unless the cultivation is done so as to properly pulverize 

 the top soil a large part of the benefit of cultivation is 



A three-year-old Orange tree rather one sided. This irregular 

 development must be corrected. 



The same Orange tree pruned. The branch extending so far 

 beyond the tree was cut back, while those branches having 

 an upward tendency were shortened in. This method of 

 pruning will cause a tree to round out uniformly. 



lost, as loose, cloddy soil will dry out almost as fast as 

 though uncultivated. The deeper and finer the top 

 soil is stirred the less water the tree will require. I 

 strongly recommend the thorough cultivation of citrus 

 trees to a depth of from four to six inches where it is 

 possible, and not less than four times between each irri- 

 gation. It is at times impossible to cultivate more than 

 two or four inches deep the first time after an irrigation 

 without turning up mud, but by setting the cultivator 

 a little deeper each time a greater depth can be attained. 

 It is not best to do all the cultivating at once, as it 

 should be distributed over the interval between the 

 irrigations, for in this way it helps to conserve the mois- 

 ture in the subsoil, thus preventing the tree from 

 suffering. 



FERTILIZERS AND FERTILIZATION 



It is best to begin the study of soil fertility early, as 

 it is far better to feed the soil before it is exhausted. 

 How best this can be done is a question that has been 

 puzzling our best orchardists for a number of years, and 

 it will, no doubt, continue to do so for years to come, as 

 there are so many different soil conditions to contend 

 with that it is impossible to lay down any rule that will 

 apply in all cases. 



It is a well-known fact that nitrogen, phosphoric acid 

 and potash are the three chemicals required in the soil 

 to produce and sustain plant life, and chemists have 

 figured out just how much of each of these are required 

 for the different plants and tree's, and how much the 

 different crops will take from the soil; yet when it comes 

 to analyzing the soil it will be found that most of the 

 soil contains a sufficient amount of all these ingredients 



