520 



irrigation, and water standing round the trunk favour the disease ; 

 also sun scorch and late cold weather, which hurts the shoots. 



The disease is an obscure and serious one, and has not yet 

 been thoroughly investigated. Supposed to be produced by a 

 microscopic fungus (the coryneum Beijirinchi) which develops in the 

 vegetal cells and change into gum the cells which constitute the 

 pith, as well as those of the medullary rays, and sometimes also the 

 woody tissue. In mild cases, recovery has followed the cutting out 

 of the bark and gouging out the dark decayed wood underneath 

 with a half -moon chisel until the sound wood is reached, which is then 

 coated over with shellac paint or some other protective cover, pre- 

 ferably an antiseptic one, such as carbolic acid solution. Burn 

 all diseased bark. Affected trees are profuse bearers for a season or 

 two, and then generally die out. If a spot where the gum is oozing 

 out is cut out in diseased trees, a dark channel is seen under- 

 neath, extending generally from the root to the top of the tree, 

 following fibro vascular bundles of wood tissue ; this wood is some- 

 times dry (and so hard that no sap could flow through its vessels) or 

 rotten and decayed. In the majority of cases the best plan is to root 

 up and burn the tree. 



iMELANOSE must not be confused with the disease called Rust 

 or Madri. The numerous small madder-brown spots characteristic 

 of the disease have (says Dr. Cobb) a tendency to group themselves 

 in curved lines, which run together and form larger patches. Both 

 Madri (caused by a mite) and Melanose at times occur together on 

 the same orange. The leaves are attacked as well as the fruit. 



Remedies. As soon as the new crop has set, begin spraying 

 with Bordeaux Mixture of weak strength, and keep on spraying, if 

 necessary, every fortnight until the fruit is half grown. The addi- 

 tion of a little soap will cause the spray to wet the citrus leaves 

 better. Paint the trunk and limbs with a thin whitewash, or with 

 full strength Bordeaux Mixture. Apply to the ground under each 

 tree one pound of sulphate of iron in 25 gallons of water; also give 

 to the ground a dressing of three to four pounds of bonedust and 

 the same amount of kainit per tree, and avoid dry blood or organic 

 nitrogen fertilisers. Make sure that drainage is good. 



BLACK SPOT OF CITRUS FRUIT (Phoma citricarpa, McAlp.) 

 This disease, known also as anthracnose of citrus fruit, is on the 

 list of prohibited diseases, and fruit showing signs "of them are 

 destroyed at the ports of entry. 



For the information of growers, and also of the officers in charge 

 of the disinfection sheds at the ports of entry, I reproduce a plate 

 from Mr. D. McAlpine's Monograph of Fungus Diseases of Citrus 

 Trees in Australia, together with a summary of the description 

 which accompanies it. 



The disease, it is stated, has not been met with in Victoria, 

 but it is quite common on oranges, mandarines, and lemons sold in 

 Melbourne and suburbs, and imported from Sydney. 



