NOTES AND ABSTRACTS. 



405 



can be readily pulled up. It is probable that roots suffer first. The base of 

 the bulb shows a mass of fluffy white fungus spawn or mycelium, and this dis- 

 tinguishes it at once from all other onion diseases. In advanced stages of the 

 disease, the fluffiness disappears and is replaced by a closely fitting weft, in 

 which numerous dark bodies, the sclerotia, are developed. These bodies are 

 left in the soil when plants rot, and are the cause of reinfection another season. 

 Both autumn-sown and spring-sown onions are attacked, and the disease is 

 most in evidence from June to early August. By August attacked plants have 

 been mostly killed, and few fresh infections take place after. 



The disease is not carried by the seed, but appears to be transferred by 

 infected soil being conveyed on roots of onion plants and on infected plants 

 sold for transplanting. No remedies can be suggested, but efforts should be 

 made to avoid infection and to keep onions off infected ground, which, however, 

 carries infection for some years. All common varieties seem subject to attack, 

 but shallots and leeks are markedly resistant, although not immune. Diseased 

 plants should be removed and burnt as soon as seen. — G. C. G. 



Onion Thrips, Control of the. By F. H. Chittenden (U.S.A. Dep. Agr., 

 Farm. Ball. 1007, January 1919 ; 11 figs.). — The Onion Thrips (Thrips tabaci 

 Lindeman), a minute prolific insect which causes damage to the United 

 States onion crop to the extent of at least $250,000 annually. This thrips also 

 preys upon cabbage, cucumber, and many other garden and truck crops. It also 

 breeds upon a large variety of weeds. Clean farming and proper crop rotation 

 help to control the pest. Spraying with nicotine sulphate has proved very 

 effective treatment: — Nicotine sulphate (40 per cent.), f pint; soap (dissolved), 

 4 or more pounds; water, 50 gallons. — V. G. J. 



Orchard Irrigation. By J. H. Fertier (U.S. A. Dep. Agr., Farm. Bull. 882, 

 pp. 1-40; 39 figs.).— S. E. W. 



Pea and Bean Weevils. By E. A. Back and A. B. Ducket (U.S.A. Dep. 

 Agr., Farm. Bull. 983, Sept. 1918 ; 24 figs.). — These insects not only destroy 

 much of the nation's food in the form of leguminous crops, but are responsible 

 for a curtailment in the acreage planted to these crops. They never attack 

 corn or wheat. There are no satisfactory remedies that can be applied to kill 

 weevil grubs in growing crops, the only thing is to harvest the crops as soon 

 as possible after maturity, and the seeds should be thrashed out and treated by 

 fumigation, heat, or cold storage, in order to kill the weevils in them before 

 they mature. — V. G. J. 



Peach Leaf-curl (Exoascus deformans). By W. Laidlaw and C. C. 

 Brittlebank (Jour. Agr. Vict. Aug. 1918, pp. 479-484)/ — Trials over several 

 years were made on an orchard badly subject to this disease ; the follow- 

 ing mixtures were used : Bordeaux, 6-4-40 ; copper soda, 6-8-40 ; lime sulphur, 

 1 in 9 ; and acetate of copper (verdigris), 3 lb. to 40 gallons of water ; all mixtures 

 were carefully prepared and tested ; the testing is important, as acid mixtures 

 are liable to burn and russet the fruit. Verdigris and copper soda made the 

 foliage quite free from curl ; though the results obtained with acetate of copper 

 were excellent, the high price of the material compelled its abandonment. Bor- 

 deaux mixture did not give quite such good results as the two previous sprays, 

 and lime sulphur, though it cleaned all lichens from the trees, was not a success 

 as far as the leaf -curl was concerned. In continuing the experiments, as copper 

 soda gave better results than Bordeaux, for the last three seasons it was used 

 exclusively. The right time to apply the spray is just before or when the 

 earliest buds are showing pink. The mixture used with complete success was 

 copper soda, 6-8-40. — C. H. H. 



Pear Blight (Bull. State Comm. Hort., California, vii. 10, October 1918). — 

 Among other items contained in this bulletin is a paper by F. C. Reimer entitled 

 " A New Disinfectant for Pear Blight." Experiments described show that 10 

 per cent, strength formaldehyde is the best disinfectant to apply to cut surfaces 

 and tools to prevent the spread of Pear Blight (Bacillus amylovorus). — V. G. J. 



Pear-growing in Victoria — History and Evolution of the Pear. By E. 



Wallis (Jour. Agr. Vict. Feb. 1919, pp. 76-86). — Resistance of pear to 

 adverse conditions, bad drainage, drought, smoke which would kill apple. A 

 pear that is cross-pollinated is generally larger at the basal end than one 

 which is the result of self-pollination. Pears borne on young, vigorous, or 

 heavily-pruned trees are apt to be coarse, and deviate from true shape of the 

 variety. — C. H. H. 



