Si 



THE GARDENERS' CHRONICLE. 



[February 10, 1912. 



to induce sturdy, short jointed growths also tend 

 to accentuate colour/' Checking action upon a 

 strong growing tree is likely to induce such 



growth as is described, win Teas stimulating 



action promotes long- jointed and sappy growth. 

 As to colouring having been helped by allowing 

 only one or two strong roots to go dowi. into a 

 chalk subsoil, mentioned by 11 r. Johns, tho ex 

 periment involved root-pruning, which, of course, 

 checked growth. 



The Fruit Grower's Tribulation. 



This is only another name for the most 

 detestable and yet most necessary operation car- 

 ried out on a fruit farm, that of spraying, which 

 entomologists and mycologists prescribe for us 

 in frequent doses with light hearts. Unfortu- 

 nately I found it necessary to incur the dreaded 

 penalty before the middle of January, as bull- 

 finches and probably other birds had begun to 

 attack the buds of Gret ngages, which they appear 

 to prefer to those of any other Plums. Monarch 

 buds stand next in favour with them, and these 

 they began to attack when the Greengage buds 

 had been rendered distasteful to them by spray 

 stuff I wished to defer spraying until the buds 

 had begun to swell on the chance of killing some 

 mother-queen aphides, but the birds would not 

 allow me to wait so loi , and therefore the 



tedious work has been going on as regularly as 

 the weather allowed since January 23. 



The spray stuff used is f tory-made lime- 

 sulphur, with a little sulphate of iron added, 

 partly because I think it adds to the adhesive 

 power of the other ingredients of the wash, and 

 partly because it may be expected to strengthen 

 their fungicidal action, brown rot being prevalent 

 in my oldest Plum orchard. The lime-sulphur 

 tests 31° on the Baume scale, equivalent to 

 1.2719 on the ordinary hydrometer scale, and 1 

 gallon of it is diluted with 12 gallons of water, 

 while sulphate of iron to the extent of 3 lb. to a 

 40 gallon tub is added after being dissolved in 

 hot water. 



Birds attack the fruit-bud- first, and later on, 

 when the leaf-buds begin to start ever so slightly, 

 these are eaten also. Chaffinches and tits help 

 the bullfinches in their destructive work, and 

 probably sparrows also. 



The Cost of Spraying. 



The labour of spraying trees of full size cost 

 about 12s. an acre, as the trees were thoroughly 

 drenched. The quantity of spray stuff used was 

 accordingly huge, quite as much being wasted 

 on the ground as was placed on the trees, and 

 the cost of this was fully 10s. an acre, making 

 22s. altogether. As rain followed the spraying 

 on three or four days before the stuff had time 

 to dry hard upon the trees, it is to be feared that 

 much of the work will have to be done over 



again 



Efficacy of Spraying. 



Birds have attacked a few trees slightly since 



they were sprayed, possibly where buds were not 

 covered with the spray-fluid. The damage done 

 when bird attack is not checked is very serious, 

 particularly on the outsides of Plum orchards, 

 close to the hedges. Probably the reason why 

 Greengages are poorer fruiters than other Plums 

 is that birds are particularly fond of their fruit- 

 buds. Monarehs, as a rule, fruit less thickly 

 than most other Plums, and this may possibly be 

 explained in like manner. 



To a great extent the injury done by birds is 

 permanent, many of the portions of shoots 

 stripped of buds being rendered permanently 

 bald. I am not certain that fruit-buds never 

 form again where they have been picked off. 

 Dormant leaf-buds do develop at the bases of 

 lost fruit-buds in some cases ; but whether these 

 ever develop into fruit-buds is uncertain to me. 



After a bad bird attack on Gooseberry bushes, 

 branches may be seen in the spring bare of leaves 

 except at the tips, or there may be a few also near 

 the bases of the shoots. No damage has yet been 

 done to Gooseberries, so far as I can see ; but it 

 may be expected when the buds begin to swell, 

 as birds are wry short of 1 >d this winter. 



Spraying for Big Buds. 



The experiments of the Board of Agriculture in 

 spraying Black Currant bushes for the bud 

 mite, referred to on p. 58 of the issue for January 

 27, like all other similar trials, failed to give a 

 substantial amount of benefit. The reduction of 

 the proportion of swollen to normal buds 

 from 66.7 to 45.5 per cent, is very much 

 less than can be attained by picking off 

 the affected buds where they are few every 

 year, and cutting off badly infested branches, 

 cutting also bushes covered to the ground 

 level or replacing them with fresh bushes. I 

 have pursued this plan for years, and have kept 

 the pest within quite moderate bounds. It seems 

 to me unreasonable to suppose that spraying three 

 times in six w r eeks can kill any considerable pro- 

 portion of the mites which are migrating daily 

 for about three months. Then there are the great 

 expense of spraying and the scorching of foliage 

 to take into account. 



Keeping Apples. 



The storing of Apples has not been a very pro- 

 fitable business this season. Some very fine fruits 

 of Lane's Prince Albert and Bramley's Seedling 

 kept till the middle of January, made only 5s. 6d. 

 a bushel, with 6d. for commission and a trifle for 

 rail carriage for a short distance to come off. 

 Some selected Apples, very large and perfect, 

 made up to 2s. per peck in chips, tastefully 

 packed. But the expense of the chips, wood wool, 

 extra time in packing, and extra rail carriage to a 

 distance take off nearly all the advantage, besides 

 which the firsts were rendered less valuable than 

 they would have been if no selected fruit had 

 been taken out. If left in, the whole, it may be 

 assumed, would not have made more than 6s. per 

 bushel, or 5s. 6d. after paying commission. The 

 markets were full of American and Canadian 

 Apples. There was a good deal of waste from 

 rotting, specks of rot showing on some of the 

 finest Apples, so that these could not be marketed 

 except at a low price. A Southern Grower. 



can be transmitted through the seed. YY 



3 



SWEET PEA DISEASE. 



(Concluded from page 53.) 



Our know ledge of the life history of Macrospo- 

 rangium solani, the fungus which Mr. Dyke has 

 shown to be responsible for Sweet Pea streak, is 

 by no means complete. A certain expert has 

 even gone so far as to say that the conidia could 

 not be seen with a 1-inch objective lens ! In 

 point of fact, when once the spores are developed 

 they may be seen with the naked eye in a 

 general way. 



The Sweet Pea Macrosporium conidia are prac* 

 tically identical with those of M. Tomato, 

 which latter is also recognised as being allied to 

 M. solani. The conidia are club-shaped, and in 

 this respect are not unlike those of Thielavia. In 

 the first plant I sent to Mr. Dyke, he could find 

 no trace of Thielavia, Fusarium, or Botrytis ; but 

 swarms of Macrosporium conidia were present, 

 varying in size and form, differing in this re- 

 spect from those of M. solani. Mr. Dyke is in- 

 clined to think that the " streak " variety of 

 -Macrosporium is M. sarcimeforme, which is 

 found in Clover ; however, to all intents and pur- 

 poses, it is identical with M. solani. 



Mr. Dyke points out that not all Sweet Peas 

 which show symptoms of yellowing foliage are 

 attacked by Macrosporium. Plants which die 

 suddenly without showing the brown streaks are 

 found to contain Fusarium, though this occur- 

 rence is not common. 



Having thus ascertained the nature and cause 

 of the disease which forms the subject of our 

 investigations, the next problem is to find a 

 cure; or, if this is too ambitious, at least we 

 may discover a preventive. 



The cause of the attacks of Macrosporium in 

 Tomatos is over-feeding with nitrogenous 

 manure, and it has been proved that the disease 



e may 



therefore safely conclude that b h these condi- 

 tions also apply to Sweet Pea disease. Sweet 

 Pea growers, knowing the forcing qualities of 

 nitrates, have used them freely, in conjunction 

 with heavy manuring, thus laying the plants 

 open to freqi nt attacks of disease. Potash 

 manures have been left severely alone by moit 

 growers, and yet the Rothamsted experiments 

 plainly show that, in the case of legumes, potash 

 is essential, tests on grass land having proved 

 that a complete fertiliser produced about 55 per 

 cent, of legumes amongst the herbage. When 

 potash was omitted, the percentage of legumes 

 was 22, and when only nitrogen was applied, 

 legumes totally disappeared. • 



Here, then, at any rate, is a basis on which 

 to work. Modern Sweet Pea growers will net, 

 I admit, be content to go back to the old st}le 

 of culture, omitting altogether the heavy manur- 

 ing without which giant stems and monster 

 flowers are impossible. The supply of nitrates 

 can, how T ever, be stopped, the manure alone con- 

 taining quite sufficient of this fertilising agent. 



There is another important item in the pre- 

 vention of disease, and that is firm soil. When 

 the trench system is adopted, and carried out 

 late in the year, the soil is apt not to sink back 

 quite tightly enough. When a Sweet Pea plot 

 is to be prepared, the whole ground should be 

 trenched (not merely the plant stations), and 

 the soil should be trodden down as tightly as 

 possible. That this method is good is borne out 

 by the fact that " streak " is almost unknown on 

 the Essex farms, where the ordinary ploughing 

 method is adopted. 



I come now to the third and last preventive 

 measure, which is that of spraying. In this con- 



- 



nection, the very greatest care must be taken, 

 and it will be necessary to experiment. Tomatos 

 and Potatos are sprayed with Bordeaux mixture 

 in order to prevent the attacks of Macrosporium 

 solani ; but this would not do for Sweet Peas, 

 partly because it would disfigure the plants, and 

 partly because the foliage is so constructed that 

 it throws off moisture, instead of allowing it to 

 spread over the surface. A quick-spreading, 

 non-staining fluid is therefore necessary; the 

 only one I know of which answers to this de- 

 scription is Evans' Aseptic Fluid. 



The above notes were written before the con- 

 ference reported in vol. 1, p. 445, when many 

 contradictory statements were made. Mr. Chitten- 

 den thought that Thielavia basicola was the actual 

 cause of streak, the disease securing a hold after 

 the plants have received a check. His tests with 

 plants growing on soil inoculated with Thielavia 

 and on soil not inoculated, resulted in the former 

 showing the disease after the plants had been 

 repeatedly over watered. As, however, the non- 

 inoculated soil was also over-watered, it follows 

 that the plants received the same amount of 

 check as the others, yet they remained healthy 

 and flowered themselves to death. If » check 

 can be caused by over-watering, the disease 

 should have stricken all the plants. The over- 

 watering theory is not proven, however, for 

 many growers at the conference stated that they 

 gave no water at all, yet the disease was rife. 

 One grower, after sterilising many tons of soil, 

 had disease in his plants as bad as ever. 



We are, therefore, compelled to accept the 

 Thielavia argument with some reserve, more so 

 because this fungus is usually considered to be a 

 saprophyte not a parasite. However, one man's 

 word is as good as another's until it is disproved, 

 and it behoves us to test the Macrosporiuin 

 theory to the full. Personally, I shall soak all 

 seed in a strong solution of permanganate of pot- 

 ash — one ounce to the quart. As the plants 

 grow they will receive occasional waterings of 

 permanganate— i ounce to the gallon. A 

 fortnight or so before planting out, the soil will 



