558 FRUIT CULTURE IN FOREIG-N COUNTRIES. 



DISEASES. 



The development of disease in the orange trees is greatly contributed 

 to by atmospherical phenomena, various insects, and parasitical plants, 

 as also the neglect or limited knowledge of the cultivators.. 



The effects of cold, snow, humidity, dews, frosts, hail, wind, burning 

 rust, chlorosis or yellowing of the leaves, and withering are as follows: 



Cold. This commences by destroying the tender shoots of the trees, 

 followed by the drying up of the blossoms, after which takes place the 

 disorganization of the fruit and afterward that of the leaves, branches, 

 trunk, and finally roots ; crevices open in the branches, which bend 

 and turn black, the leaves wrinkle, roll up, and die ; the flowers become 

 blackened and disorganized ; the fruit loses its brilliancy, dissipates its 

 odorous principles, loses its juice, and becomes bitter, falls off the tree 

 and rots; or, if the cold has not been very intense, the fruit is half frozen 

 and remains on the tree till the following spring. 



Snow. This injures the trees both from cold and its weight. Should 

 the storm be heavy and the fall great, this bears down the branches and 

 in many cases breaks some. As regards the cold occasioned by it, this 

 does not always do harm, but when it does do so it is very frequently 

 confined to the young shoots. Should the weather be fine both before 

 and after a snow-storm, the cold water produced on thawing produces 

 its effects on the young branches, for which reason no time should be 

 lost in shaking all the snow off them before nightfall, for should it be 

 condensed on them the harm occasioned would be of much greater im- 

 portance. The system of placing heaps of damp straw at fixed dis- 

 tances between the trees, so that on setting said heaps on fire in order 

 to obtain a smoke between the sun's rays and the trees has produced a 

 magnificent result. If after snowing the weather continues threatening, 

 or there be heavy clouds floating about, neither the trees nor the fruit 

 will suffer any harm, although the thermometer might be below zero. s 



Humidity, dews, and frost. An excess of humidity in the atmosphere 

 during the fecundation of the blossom generally produces bad results, 

 especially in such places where the ventilation is limited, should the 

 temperature at night decline to any extent. Frost with an east wind 

 occasions a deal of harm, but should the wind be from the north it is 

 not so bad. Little that is economical can be availed of in l$,rge or- 

 chards, but in reduced ones the harm is lightened at small cost by avail- 

 ing of certain materials for shelter, of little value, which in certain dis- 

 tricts are plentiful. 



Sail. This causes a deal of damage to the fruit. Should the storm 

 be of short duration and the wounds occasioned by it be of slight pro. 

 fundity, these will soon heal up and everything continue well, but cer- 

 tain black stains will remain, which reduce the value of the fruit. 

 Should the storm be heavy, it completely destroys the orange, which 

 quickly enters into a state of putrefaction. 



Wind. This exercises its influence on the orange trees in two differ- 



