30 [ CITRUS FRUITS 



general weakness, owing to which the fruit is easily 

 dropped off when it has reached the size of a pea or of a 

 hazelnut The shedding of green fruit generally com- 

 mences in May, but goes on more or less until the first 

 days of August, and by that time an orange-grove which 

 was most promising in May or June may have retained 

 few fruits in the beginning of August, when no further 

 danger is apprehended. Trimming is best done from the 

 beginning of June to the middle of July. Small twigs 

 are cut with the secateur and larger ones with the 

 pruning knife. Thick branches are sawn off or cut with 

 the pruning axe, or with chisel and mallet ; the surface 

 is then levelled with the pruning knife, and besmeared 

 with tar, or with a mixture of tar, wax, and clay, to keep 

 it cool and favour cicatrisation, the process of healing 

 being greatly aided by cutting in a slanting direction 

 from below upwards towards the branch retained, thus 

 leaving no stump to perpetuate the wound. This atten- 

 tion is particularly insisted upon when cutting off the 

 stump of the stem, which is reserved on budded plants 

 in order to secure to it the tender shoot to give it a 

 straight upward direction and to protect it from injury. 



Old trees which have become partly sterile, are 

 sometimes rejuvenated by being headed off, all the main 

 branches being lopped off at an equal distance from the 

 trunk. This operation is best done in February or March 

 and the strong shoots which are soon formed are allowed 

 to ripen until September, when the superfluous twigs are 

 removed and those retained are trimmed to shape. In 

 about two years the tree forms a new crown of healthy 

 foliage and enters into a new period of productiveness. 

 As a rule the lemon and the mandarin dislike heavy 

 pruning, and the seedless or navel oranges are found to 

 have their productiveness markedly impaired if they are 

 not allowed to retain a dense crown of foliage. At any 

 rate, large wounds should be carefully avoided, as they 

 heal slowly or do not heal at all, and are usually the 



