CITRUS CULTURE IN HAWAII 



35 



lings growing in 8-inch containers. Emphasis has been placed 

 on the importance of drying citrus seeds only slightly between 

 the time of removal from the fruit and planting to prevent 

 "bench root" conditions. Experiments by the station showed 

 sour orange stock to be resistant to gummosis, and shaddock 

 stock to be unusually vigorous. If the stocks are planted rather 

 high in the tree hole so that eventually the crown roots will be 

 slightly exposed above the general surface of the ground, attacks 

 of gummosis will be rare. In irrigation it is highly important 

 that the soil should not be allowed to become waterlogged or 

 sour as such conditions are not only very favorable to the spread 

 of gummosis but may kill the trees. 



The pruning of citrus trees is most important during the 

 early training and formation of the crown branches supporting 

 the top. Severe pruning should be avoided as it will upset steady 

 growth much as does improper fertilizing. 



Cover crops should be grown in the orchard and turned under 

 once, or, in many cases, twice a year. Hawaiian soils are gener- 

 ally lacking in organic matter and when used for orchard pur- 

 poses should be enriched and given greater moisture-holding 

 capacity. The improved physical condition greatly aids the bene- 

 ficial action of bacteria. 



Citrus fruits can be successfully matured in individual bags 

 of paper or of cellophane. These should be placed over the fruit 

 4 or 5 weeks before it is mature enough to turn yellow. 



Both parasitic insects and strong juices of the rind usually 

 prevent fruitfly eggs from hatching or the young larvae from 

 developing on the fruit. Punctures made by adult flies in de- 

 positing the eggs invariably cause the fruit to fall in the early 

 stages of ripening. Fruit punctured by the fly is more subject 

 to decay, and consequently is unsuited for packing for shipment. 



