3S 
C.'akne — Broivii Bot of Citrus. 
SUMMARY. 
A serious fruit rot, leaf bli^'lit and twi^' fUebaek of citrus trees 
in Australia caused by Phiftoplithora JiiberraHs sp. nov. is here 
described. 
Tliis ]»atIiogeu is identical witli an undescribed species of Plii/to - 
pliflmra recently found by iNfoniz da iNiaia to be responsible for a 
citrus fruit rot in Portuo'al ainl probably in other iSrediterranean 
countries . 
ThyfopJiiJiura hibentaUs occui's in the States of Victoria, South 
Austi-alia. Western Australia and Queensland. It is active only in 
the cooler niontlis (May to October) under conditions of Iii^^Ii 
atnu')S])heric and soil humidity. 
Jt is characterised by the i)iesence of i)ersistent ])edicels on the 
conidia. The conidia measure 17 — 50 x JO — 28mmm.. -with an average 
ratio of length to l)readth of 2..‘>. Tlu> oospores measure 22 — 4o.(immm. 
The oj'tiniuui growth tem])e]‘ature is about 12^^ 0. 
"^t has ])een confused in the jiast "with Pytliiacysl is citrophthora 
Sm. l) Sm . , from wliicli it is separable on morphological and 
cultural characters . 
J^hyfophfhora hibrnialis is effectively controlled by spraying 
rvith Bordeaux or Burgundy Mixtures before the advent of the cool 
wet season . 
laTEKATrRE CiTEI). 
1. Ashl>y, S. F. Leaf-stalk Hot caused by Phyto]dithora para- 
sitica. West Indian Hull.. XVITT: 70 — 78. 1920. 
2. Ashby, S. K. Oospores in cultures of Phytophthora faberi. 
l\ew Bull. Misc. Inform., 287 — 262, 1922. 
8. Barrett, J. T. Pythiacystis related to Phytophthora. Phy- 
topath., 7; ibO — Idl. 1917. 
4. Bri^^tlebank, (t 0. The LeaOer, Alelbourne, ATctoria— 4th June, 
1921. 
o "'bnhr L. J. (fc Kulkarni, (1. B. 0(>lo<-asia Blight. Mem. 
Dept. Agric., India. Bot. Beries, V: 233—261. 1913. 
6. (‘arne, AV. A1 . Citrus Diseases. Brown Rot and Leaf Blight. 
Jnl. Agrie., W.Aust., 1 (2nd Serie-s) : 519 — 522, 1924. 
7. Carue, W. A1 . A Xew Disease of Citrus Trees. Fruit World 
of Australasia, XXV; 227, 1924. 
5. r'firne, W. A1 . Citrus Brown Rot. Jnl. Agrie., W.Aust. 2 
(2nd Weries) : 359, 1925. 
Clu'kayne, A. 11. & Clinningham, G. H. Lemon Brown-rot 
and its control. N. Zealand Jnl. Agile., XXII: 271 — 274, 
1921. 
9 . 
