NOTES AND ABSTRACTS. 



421 



The causal organism is a small yellow bacillus closely related to, if not 

 identical with, Bacillus Laihyri, which causes a similar disease in the sweet pea. 

 It travels up the stem, in pith adjacent to the vascular bundles, and thence to 

 affected parts, including the fruit. In this way the seed is infected either by 

 direct infection, or by the organism being dried on the seed coat. The resist- 

 ance of the varieties differs, ' Kondine Red ' and ' Comet ' being more affected 

 than ' Ailsa Craig ; ' but susceptibility varies with manurial treatment, excessive 

 nitrogen and lack of potash lowering resistance, and increase of potash raising 



it- 

 Remedial measures depend on above facts, and suggestions made include 



(1) growing of more resistant varieties, (2) sterilisation of soil, (3) avoidance 



of excessive nitrogen and deficiency of potash, (4) care in pruning, and (5) care 



in cultivation. — G. C. G. 



Transpiration : Relative Transpiration of Coniferous and Broad-leaved Trees 

 in Autumn and Winter. By J. E. Weaver and A. Morgensen (Bot. Gaz. vol. 

 lxviii. No. 6, Dec. 1919, pp. 393-423 ; with 18 figs.). — The autumn transpiration 

 losses are practically the same for both deciduous and coniferous trees. Decrease 

 in transpiration rate in broad-leafed trees, due to leaf-fall, is gradual, and not 

 unlike the decrease shown by conifers at the corresponding season. During the 

 winter, the amount of water transpired from the defoliated stems of deciduous 

 trees is very much the same as from the evergreen conifers. " The winter 

 losses from conifers are only to as great as those of autumn." — R. J. L. 



Truffle-growing. By F. de Castella (Jour. Agr. Vict. Aug. 1918, pp. 496). 

 — Vines in the drier situations, where the yield of fruit is poor, are being 

 replaced by evergreen oaks. It is on the roots of this tree that this 

 valuable fungus lives as a parasite, forming the tubers, or truffles, which were 

 worth 135. per lb., though in years of plenty the price falls to about one-third of 

 this price. Small trees, 4 to 8 feet high, often bear a truffle on their roots of up 

 to 1 lb. in weight. Being underground, the tuber can only be located by the 

 keen sense of smell of pigs or dogs ; both animals are used for the purpose. 



C. H. H. 



Udo. By R. de Noter (Le Jard. vol. xxxiii. p. 361). — Udo (Aralia cordata, 

 A. edulis) is grown in large quantities in China and Japan, where it is a favourite 

 vegetable on account of its delicious flavour. The roots are planted in autumn 

 in trenches on a layer of manure covered with soil and the trench is half-filled 

 with good light soil. In January a top-dressing of well-rotted manure is applied 

 and the plants are earthed up. In March and April the earth is removed and 

 the large roots cut and gathered for use. Udo comes into full bearing in its 

 second year. — 5. E. W. 



Vanilla Fruits, Influence of Foreign Pollen on Development. By T. B. Mc- 

 Clelland {Jour. Agr. Res. xvi. pp. 245-252 ; March 1919; plates). — Two types of 

 vanilla pods are of economic importance in Porto Rico — those of V anilla plani- 

 folia and of ' Vanillon.' The former are the better, but the shorter thicker pods 

 of the latter type are the easier to deal with, since they do not split open if left 

 too long curing. The form of the fruits was found* to differ according as to 

 whether they were pollinated from flowers of the same form or of different forms, 

 and the author considers this to be the result of different lengths of pollen tube 

 being produced by the different forms, and consequently ovules in different 

 parts of the fruits being fertilized. — F. J. C. 



Vegetable Pests, Two Important. By W. H. Brittain (Coll. of Agr., Truro, 

 N.S., Cir. 26, Dec. 191 7, pp. 3-6 ; 2 plates). — Brief life histories are given 

 of the Potato Stem Borer, Gortyna, Hydroecia micacea Esp., and the Zebra Cater- 

 pillar, Ceramica picta Harr. The former insect attacks potato, corn, rhubarb, 

 sugar beet, docks, &c, by the larvae boring into the stems, causing wilting and 

 death. 



Control measures are (1) the eradication of all weeds, (2) Rotation of crops, 

 and (3) picking and destroying the larvae. The latter pest is very injurious 

 to turnip, potatos, beets, mangolds, beans, peas, &c, by stripping the plants 

 of their leaves. Remedies advised are (1) the handpicking of leaves with egg- 

 masses and young larvae attached, or (2) dusting the plants with arsenate of 

 lime or lead diluted with 8-10 parts of hydrated lime, and the larvae must be 

 treated when young. — G. F. W. 



