Two Commofv Wilts of Vegetables 



Two diseases which often cause con- 

 siderable loss to the gardener are 

 the wilt (sometimes called black 

 rot) of cabbages and other members of 

 cruciferae family, such as cauliflower, 

 kale, brussels sprouts, and the wilts 

 attacking the cucurbits, as instanced in 

 cucumbers, pumpkins, melons and 

 squash. Both of these diseases are caus- 

 ed by bacterial organisms and in most 

 respects are somewhat similar. 



In cabbages, the characteristic symp- 

 tom of the disease is a yellowing of a 

 portion of the leaf. The most common 

 point of entrance for the bacteria is 

 through the water pores at the edge of 

 the leaf, especially through the drops of 

 water which may be seen on the edge of 

 the leaf in the early morning. From 

 these pores the bacteria make their way 

 through the veins, the mid ribs and the 

 stalk, feeding on the plant juices. The 

 tiny tubes which carry these plant juices 

 are technically known as the vascular 

 bundles. 



ACTION OF THE DISEASE 



From the vascular bundles the spread 

 of the disea.se is comparatively slow. The 

 yellowing of the leaves is niot caused so 

 much by the presence of the bacteria in 

 the tissues as by the stoppage of the sup- 

 ply of nourishment. It sometimes hap- 

 pens that the leaves become yellowish 

 because of drought. To determine the 

 exact cause of the wilting, if the stem or 

 mid rib of the leaf is cut across just be- 

 low the yellow portion, the vascular bun- 

 dles are found to be blackened, appear- 

 ing as black spots on the cross section, 

 then the disease may be safely said to be 

 caused by the bacteria. A few trials will 

 make even a novice expert in detecting 

 the cause of the trouble. 



The blackening of the leaves, from 

 which comes the name "black rot," is 

 not caused by the bacteria but by a 

 fungus which attacks the plant after it 

 has been weakened by the bacteria. 



From plant to plant the disease is 

 most commonly spread by caterpillars 

 and other biting insects ; also by the cul- 

 tivator. The bacteria have been known 

 to live in seed from an infected field for 

 eight or nine months. Infection also 

 takes place by handling diseased plants 

 and then healthy ones. To this end the 

 seed may be soaked for fifteen minutes 

 in a one to one thousand solution of cor- 

 rosive sublimate, a five jjer cent, solution 

 of formalin or a Ave per cent, solution 

 of carbolic acid. After handling diseased 

 plants the hands and implements used 

 should be washed in one of these solu- 

 tions. Young plants showing any signs 

 of the disease should not be planted. All 

 diseased plants should be gathered and 

 burned. Keep insects under control. 



Cucumbers grown in the greenhouse 



B. Blanchard, O. A. C, Guelph, Ont. 



the most susceptible of the cucurbit 

 family to attacks. A whole green- 

 house crop will sometimes be destroyed in 

 two or three weeks. The organisms en- 

 ter the vascular system of the leaves in 

 the same manner as in the cabbage, but 

 the disease spreads much more rapidly 

 through the leaf which becomes dry, dull 

 in color and droops. The presence of the 

 disease can be determined by making a 



cross section of the leaf stem or stalk 

 and scraping the end of the stalk. If the 

 plant is infected the plant juices will be 

 found to be slimy and stringy, instead of 

 watery. 



The most common means of infection 

 is by the cucumber beetle. These insects 

 therefore should be kept in check. Other 

 control measures are similar to those 

 mentioned for cabbage. 



Ho"w to Judge Potatoes 



By Prof. F. M. Straight, B. S. A. 



MOST of us farmers think that we 

 know a good potato when we 

 see it, and we do ; but not every- 

 one of us can pick out prize winners at 

 one of our exhibitions. In judging pota- 

 toes, fancy points are hardly considered. 

 They are examined from the standpoint 

 of utility. Quality and economy are the 

 points kept to the fore. Potatoes excel- 

 ling in these, win. Some external points, 

 apparently unimportant, are emphasized 

 only because they are indications of the 

 interior quality or economy when pre- 

 pared for the table. 



SIZE AND SHAPE 



Under the heading of external appear- 

 ance we consider the size. Very large 

 potatoes are as undesirable as very small. 

 Both are classified as unmarketable. Very 

 large potatoes must be cut when prepar- 

 ed for cooking. Even then they do not 

 cook evenly and never present a pleas- 

 ing appearance. Potatoes ranging from 

 eight to ten ounces in weight are right in 

 size. 



Markets demand potatoes slightly ob- 

 long in shape, but not drawn out as the 

 Black Kidney, once so popular. Again 

 there is a reason for this. The percent- 

 age of weight is much less with potatoes 

 of this shape than with others. Potatoes 

 with recessed ends with knobs or pro- 

 tuberances, and irregular in shape, are 

 annoying to the housewife, and far from 

 economical when prepared for the table. 



UNIFORMITY THE MAIN FEATURE 



Every judge corlsiders uniformity. A 

 plate of potatoes pleases no one if not 

 uniform. The same is true of a barrel. 

 A barrel of potatoes containing ten per 

 cent, "away off" in shape and size will 

 throw discredit on the whole package. 



In truth color amounts to nothing. A 

 red potato is as good as a white one, and 

 a black one as either. The demand on 

 the various markets changes with the 

 years. On most markets white potatoes 

 take the lead at present, but not because 

 they are really superior. The best far- 

 mers have learned that it never pays to 

 quarrel with a customer.- They produce 

 and sell what the market demands. They 

 agree with the voice of the market even 



270 



when its demands are not backed by rea- 

 son. 



EVIDENCES OF QUALITI 



Netting of the skin is one of the minor 

 external points which speaks of quality 

 within. By netting of the skin we mean 

 that russeted appearance, caused by the 

 rupturing of the outer skin in two or 

 more directions. When skin is smooth 

 and more or less transparent, the pota- 

 to is usually deficient in starch. It is 

 soggy. The amount of netting varies 

 with varieties, but with a given variety 

 the more russeting the better the quality. 



From the standpoint of the household- 

 er, if potatoes had no eyes so much the 

 better. That being impossible, selection 

 is made from tubers having a compara- 

 tively small number. For any purpose, 

 even that of the seedsman, a sufficient 

 number of eyes is always present. The 

 eyes are a nuisance. It is difficult to 

 breed deep eyes out of some varieties ; 

 but when best potatoes of any variety 

 are on exhibition, deep eyed specimens 

 are never among the prize winners. 



Freedom from blemish and disease 

 scarcely requires discussion. A jxitato 

 partially peeled is blemished, as it also is 

 if marred with the fork in digging. Scabs 

 and rots disqualify ; a scabby potato can 

 never win, or should never win, if it is 

 the only specimen displayed. The inter- 

 nal appearance counts practically for the 

 same as the external. We put the pre- 

 mium on white potatoes, without red or 

 blue streaks. A faint suspicion of blue 

 or yellow when freshly cut is objection- 

 able. 



TEXTUEE 



"Breaking as short as a pipe stem," is 

 an apt phrase when applied to texture in 

 the best potatoes. Sponginess and 

 coarseness are never associated with good 

 quality. If a very thin section is cut 

 across a potato and held to the light, 

 it will be readily seen that the section 

 readily divides itself into three parts : 

 these are the cortical layer next the skin, 

 an external and an internal medullary 

 area. Each one of these layers is unlike 

 the other in texture, owing to the fact 

 that different percentages of starch are 

 found present in each as here shown : 



