October, 1913. 



THE CANADIAN HORTICULTUEIST 



247 



Squash and pumpkin should be gath- 

 ered before frost, cut with a small piece 

 of vine attached. Handle them as care- 

 fully as you would eggs, as the slightest 

 bruise will soon spoil them. Store in 

 a sunny dry place where frost can be 

 kept out. Later store in a dark, dry 

 place, with the temperature as near forty 

 degrees as possible. 



HOW TO TREAT TOMATOES 



Just before frost, pick the best of 

 the unripened tomatoes and place them 

 on some clean straw in a cold frame or 

 greenhouse. Others may be put on 

 straw in the cellar. In this way you 

 may prolong your supply of tomatoes 

 until nearly Christmas. 



Put a few plants of parsley in a pot 

 or box and place them in the kitchen 

 window for use during the winter 

 months. Clean up the rhubarb and as- 

 paragus beds and put on a good dress- 

 ing of coarse stable manure. If you 

 have a greenhouse, and would like to 

 utilize some of the space under the 

 benches, lift a few roots of rhubarb for 

 forcing. Tender young stalks of it are 



^ sure to be appreciated in mid-winter. 

 In lifting, dig round the four sides with 

 a spade, being careful not to damage 



i the crowns. Turn the root upside down 

 and let it lie on the ground to freeze 

 well. Then place them under the bench 

 where you intend to force them. Work 

 soil well round and between the roots, so 

 that the crowns are just peeping out ; 

 water thoroughly. Spray them occa- 

 sionally with lukewarm water until the 

 growth has started, and maintain as 

 even a temperature as possible. 



Potato 



Prof. E. M. 



POTATO scab should not be con- 

 fused with the potato canker or 

 wart disease, sometimes called the 

 black scab. This latter disease is es- 

 tablished in Newfoundland but is not 

 found in Canada so far as we are aware 

 of. 



The roughened, scabby, pitted surface 

 of potato tubers affected with scab is too 

 well known to require description. It 

 is probable that no other potato disease 

 has a wider distribution. In addition 

 to being disseminated throughout this 

 country, it occurs in various parts of 

 Europe, South Africa and New Zealand. 

 In all probability scab occurs wherever 

 potatoes are grown. In addition to the 

 potato, turnips, carrots and beets may 

 be attacked. 



Many practical growers are of the 

 opinion that lime, ashes, chipdirt, and 

 other substances, cause the disease. 

 The nature of the fertilizer used, the 

 alkalinity of the soil may and do influ- 

 ence the amount of scab present on a 

 given crop, but such agencies are in- 

 capable of producing life. 



The cause of potato scab is a para- 

 sitic plant, to which the name of Oos- 

 pora Scabies has been given. This plant 

 is as dependent on certain conditions 

 for its rapid development as the potato 

 or root crop upon which it grows ; but 

 cannot grow in a soil unless seed of the 

 fungus has first been deposited there. 

 The old idea of spontaneous generation 

 has long been exploded. We have grown 



An Attraclire Exhibit at tht Exhibition o{ the Sherbraoke, Qne., Agricaltnral Soc'ety 



This exhibit was arranged by the Olta Agricultural College, La Trappe, Que. It included a few 

 boxea of apples that bad been grown in the proTincial demonstration ojcijards. 



Scab 



Straight 



beyond the thought that chipxlirt can give 

 rise to life ! Experiments have shown 

 repeatedly that scab does not develop on 

 new land unless it is affected from some 

 outside agency. If clean seed potatoes 

 are used on clean land, a clean crop is 

 sure to result. All or nearly all of the 

 infection of new areas may be traced to 

 diseased seed. 



SOURCES OF INFECTION 



When the soil once becomes infected 

 there are two possible sources of infec- 

 tion in future crops, viz., the seed and 

 the soil itself. It follows then that some 

 soils may give scabby potatoes even 

 when clean seed is used. 



Scab thrives best on an alkaline soil. 

 Dr. Wheeler, who has made an exten- 

 sive study of the disease, summarizes 

 his conclusions as follows: "The mater- 

 ials which favor scab and which are at 

 times applied to land are : Stable man- 

 ure, wood ashes, lime, magnesia and 

 soda-ash. The materials which do not 

 tend to make the scab worse, and which 

 may tend to decrease it, are : Most com- 

 mercial fertilizers, sea-weed, potash 

 salts, land plaster, common salt and 

 ammonium sulphate." 



As has been pointed out, potato scab 

 does best on an alkaline soil, that is to 

 say it makes its most vigorous growth 

 there. Unfortunately, potatoes also do 

 best on a like soil ; but potatoes are not 

 so susceptible to soil conditions as the 

 fungus. It is quite possible to grow 

 pdtatoes on a soil slightly acid without 

 materially affecting the yield, and at the 

 same time discourage the growth of the 

 parasite. 



SULPHITE MAT BE USED 



Sulphur applied to the soil gradually 

 oxidizes with the consequent production 

 of acid. Sulphur has been used on some 

 soils with much success, especially on 

 soils naturally neutral or only slightly 

 alkaline. The process is expensive and 

 hardly praqtical on large areas. 



Similar acid soil conditions may be 

 obtained by turning under some green 

 crop, such as buckwheat. In the break- 

 ing down of this green manure, acid is 

 formed often quite sufficient for the pur- 

 pose. This system would produce best 

 results on a neutral or slightly alkaline 

 .soil, and would not l>e entirely successful 

 on a soil strongly alkaline, as the de- 

 caying crop would not produce acid 

 enough to leave an excess in the soil. 

 By making choice of fertilizers which 

 do not encourage scab, by proper rota- 

 tion and by turning under a green crop, 

 a badly affected field is often cleared in 

 a few years. Without such treatment, 

 the fungus would remain active in the 

 soil, without the presence of a suscepti- 

 ble crop for indefinite periods. 



