“BLADDER PLUM.”

Wairarapa Daily Times, 20 October 1930, Page 4

“BLADDER PLUM.”

LOCAL ORCHARDS ATTACKED. SPRAYS RECOMMENDED. Last week a Masterton resident brought in a sample of a diseased plum tree bud to the "Daily Times” Office. He stated that a number of trees in Masterton orchards were attacked w T ith the disease this season. In order to obtain some information on the subject, the sample was sent to Mr J. W. Whelan, Orchard Instructor of the Department of Agriculture.

Writing from Palmerston North Mr Whelan says: "The bud in question is badly attacked by a fungus disease commonly called "Bladder-plum” (Tapliriua pruni). Bladder-plum infects leaves, fruits, flowers and shoots of the plum, but is most noticeable on the fruits about three weeks after blossoming. These become greatly enlarged and after a time fall to the ground. These enlarged fruits are at first somewhat globose, eventually becoming greatly elongated and more or less curved and twisted. They are spongy in texture, and w r hen cut open are seen to be quite hollow, the stone and ovule not being developed. They change in colour from green to white at first somewhat smoothly, then they soon become much wrinkled. Finally they turn brown and die.

"The organism over-winters by means of hibernating mycelium in the shoots or by spores lodged in budscales and bark crevices. The disease is only partially controlled by spraying, so this treatment should be supplemented by cutting out of infected branches. The following spray programme is recommended: —(1) When buds begin to swell: Lime sulphur 1-10, or Bordeaux mixture 8-6-40; (2) when buds are standing out in cluster: limesulphur 1-35 but not open; (3) as the last blossoms are falling: Lime sulphur 1-125; (4) subsequent applications: lime-sulphur 1-125 at intervals of 18 to 21 days throughout the growing season; (5) when leaves are falling: Bordeaux mixture 8-6-40.

"I will be glad to supply further information if required,” says Mr Whelan in his letter.