Transactions of RHASS Volume 1940 - Page 063
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| Year | 1940 |
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| OCR Text |
114 INSECT AND OTHER PEsTs OF .1939. infested kindly furnished an estimate of the losses which he incurred as a result of aphid attack. In all 66 acres of crops Were affected, and the average loss per acre amounted to about £19. In the table which follows it will be understood that oruciferous crops were attacked by the Mealy Cabbage Aphis and the Potato Aphis, the potato crop by the Potato Aphis, Whilst the beetroot crop was infested by the Bean Aphis. TABLE I. ESTIMATED LossEs or CRors DUE TO Arum INFESTATION IN A MARKET GARDEN NEAR EDINBURGH, 1939. ' Acreage. Loss per acre. Total loss. £ 150 300 300 200 112 75 25 100 £ Potato . . . . l 5 Beetroot . . . . l 5 Cauliflower 1 . . . 30 Savoys . . . . 20 Cabbage . . . . l 8 Broccoli 1 . . . . 25 White turnip 1 . . . 25 Lettuce . . . . 16 l H 0) cooccccc- ccccccccz:~ eoooooccs Control.—Methods of control of the Mealy Cabbage Aphis are given in Advisory Leaflet No. 269, Ministry of Agriculture and Fisheries. The recommendations made there apply equally to M. persicae on cruciferous crops. Among other things it is advised that— (1) Old Brussels sprouts, broccoli, and cabbage should be ploughed under not later than 15th May; otherwise the stalks should be gathered and piled in heaps Where they may be burnt or left to dry. This method aims at getting rid of overwintering aphids and eggs, and if generally adopted throughout an area subject to outbreaks would go far to solve the aphid problem. (2) All autumn-sown Brassicas should be examined before being planted out. If aphis is found the plants should be dipped in a nicotine wash—nicotine, 98 per cent, 3 oz. ; soft soap, 4 lb. ; water, 40 gallons. (3) Examine the new crop in June, and if infested dust with a 3 per cent nicotine powder at the rate of 40 or more lbs. per acre according to the size of the plants. The chief fault of the dusting method is that the powder does not reach the aphids attached to the under side of the ‘ Whole crop was destroyed. ' V INsEoT AND OTHER I’ESTS or 1.939. 11.; ' ‘ v '1 '- this is less the r es of the host plants.‘ llovuur, I _ I Psi? giggle dust than the machines used. 1n its apphcatloré. ralux same criticism applies equally to machmes for wet splllray . f 1L, ( I ests were made with an atomised pyret rum 1,] othians t 1 U , - Eggmgion which gave fairly good results. Elsewhere it has I ' 2 ve caused leaf-scorch. . been S&1dzf§):shiii the field M. parsicac is controlled by the l . n . I, . 01 I) f a combination spray conslsting of nlcotine , '. ‘ O . to 10 OZ” and Bordeaux mixture, 50 gallons. 1 ‘ 7 Two or three ten to fourtee weeks old. ' y ' tervals of treatments should be applied at in I 11 days, the first when the plants are five to SIX |
| Title | Transactions of RHASS Volume 1940 - Page 063 |
