28 



guaranteed to fall as occasion required that quantity would or should 

 prove sufficient. We have not so far been able to make the arrange- 

 ment, and so must find water some other way. 



Perhaps a few words may not be out of place here with regard to 

 the so-called dry systeni of culture as applied to the citrus family. 

 Briefly no such thing is possible. Water is an absolute necessity and 

 must be applied. In order to afford an approximate idea of the 

 quantity needed we will take thirty inches as a coastal and forty inches 

 for the interior districts as a minimum. If the question is examined 

 from a common-sense standpoint the absurdity of "dry" citrus 

 growing is at once apparent. 



An orange orchard in full bearing produces an enormous quantity 

 of fruit, the constituent ports of which are chiefly water. Evaporation 

 is extremely rapid iii South Africa and is answerable even under the 

 best possible conditions of tilth for the loss of a large amount of soil 

 moisture daily. When to these factors is added the third and most 

 important, that of " transpiration," it must be recognized that a large 

 supply of water ?nust be supplied in order to render these functions 

 callable of satisfactory fulfilment. It must be remembered that citrus 

 are evergreen trees, that their need for water does not, like deciduous 

 trees, comparatively cease with the fall of the leaf, but continuous 

 for three hundred and sixty-five days each year. When one bears in 

 mind that a sunflower plant with a leaf surface of 5616 square inches 

 transpires one and a half pints of water daily, it is more easily realized 

 that the moisture requirements of an orange tree are far greater than 

 is generally supposed. 



]]"hen to Irrigate. 



Having shown 1he necessity for the application of water, it may 

 l.e well to state first when, and afterwards how, to irrigate.. The trees 

 require water at the time of blossoming in order to enable them to set 

 a full cro|) of fruit, and from that time onwards until, the crop is 

 harvested water is required at intervals. It is not possibleto state any 

 exact period, because soils and their requirements differ so extensiyely, 

 but the leaves must not be allowed to show any signals of distress 

 such as curling up or wilting. As the orange takes about nine months 

 to mature from the time of blossoming it will be seen that irrigation 

 must be spread over this period. It was formerly customary to cease 

 the application of water as the orange commenced to turn yellow, the 

 idea being tliat by continued irrigation the carrying qualities of the 

 fruit boc;nne impaired. Experiments have shown and practice has 

 established the fact tliat oranges may be w-atered up to within a couple 

 of weeks of long distance sliipment with benefit to the contents of the 

 fruit and ^^itliout impairing its carrying qualities. 



There are many ways of irrigating citrus trees. Here are a couple 

 of different methods of ho^sv not to do it. Don't let the water run over 

 the land every eight days or whenever it is your turn to use the furrow 

 and then let it sink in until next water day comes along; that is just 

 feeding the stm, also getting the roots of the tree into bad habits; 

 they come lo the surface for moisture instead of going v/here roots 

 ought to go, deep down in the soil to seek it. Should a dry spell occur 

 and no water be available then these surface-fed roots drv out and the 



