314 GARDET^ 



stems and needles. In severe infections the 

 tops turn yellow and the needles fall from 

 the stems. Toward the end of the season 

 the black or Winter stage develops. To 

 control this disease, obtain rust-resistant 

 strains. 



ASTER 



Leaf rust (Coleosporium Sonchi-arvensis) . 

 May be recognized by the orange-colored 

 pustules or sori which develop chiefly on the 

 under side of the leaves. Spray with Bor- 

 deaux mixture, before the rust appears. 



BEAN 



Anthracnose (Colletotrichium linde- 

 muthianum) , a very serious fungous disease. 

 It is distinguished by the circular and 

 sunken black spots on both the pods and 

 seed which may at certain times contain 

 pink, gelatinous pustules on their surfaces. 

 Ths leaf veins on the underside of the 

 leaves and the stems also may be affected. 

 The disease is carried over Winter on the 

 seed, hence, use clean seed obtained by 

 selecting pods free from these spots . Spray- . 

 ing with Bordeaux (5-5-50) will also reduce 

 the amount of disease . Resistant strains of 

 some varieties like Red Kidney are now tc 

 be obtained. 



Blight (Bacterium phaseoU). A bac- 

 terial disease. Shows at first as large 

 brownish areas on the leaves with yellowish 

 water-soaked margins. Later these spots 

 become darker in color and dry. The pods 

 also develop water-soaked spots which are 

 circular or irregular in shape often with red 

 margins, and not sunken as in the case of 

 anthracnose. As with anthracnose the 

 seed which becomes infected from the pod 

 carries the organism over the Winter. No 

 satisfactory method of control is known 

 except the use of disease-free seed. Resis- 

 tant varieties have not yet been developed . 



BEET 



Leaf spot {Cercospora beticola). Very 

 common fungous disease. Appears first as 

 round brownish spots with red to purplish 

 borders. Later, after the spots enlarge, 

 they become ashen and papery in the center , 

 which finally drops out and leaves holes in 

 the leaf. When severe, these spots may 

 coalesce and destroy the entire leaf. Burn 

 the diseased leaves. Spray with Bordeaux 

 mixture (5-5-50) when the plants are about 

 six weeks old. Make later sprayings about 

 10 days apart. 



Root rot (Phoma betae). Causes a black 

 dry rot on stored roots. Small, pimple-like 

 structures are formed on the surface of the 

 diseased area. Also large circular spots are 

 produced on the leaves. Spray with Bor- 

 deaux mixture and remove all diseased 

 leaves before placing the Beets in storage. 



Scab (Actinomyces chromagenus) . Known 

 by the circular scabs with raised margins 

 and depressed centers which form on the 

 roots. Same as scab on Potatoes, which see. 

 Do not grow Beets if Potato scab is known 

 to be present in the soil, or where Beets 



GUIDE 



have been previously affected with this 

 disease. 



BLACKBERRY 

 Anthracnose. See Raspberry. 



Leaf spot (Septoria Rubi). Spots appear 

 on the leaves first as small whitish or brown- 

 ish areas. When very numerous on a leaf, 

 they may cause it to dry up. Spray with 

 Bordeaux mixture. 



Orange rust. See Raspberry. 



CABBAGE 



Black leg (Phoma lingam). Affects the 

 leaves, stems and roots. The leaves are 

 spotted, but not seriously injured. The 

 chief injury is caused by a rotting of the 

 stem and root which turn black; the leaves 

 then wilt and the plant dies. Disinfect the 

 seed as for black rot. 



Black rot (Bacterium campes tre) ■ Affects 

 also Cauliflower, Kale, Rape, Kohl-Rabi, 

 Brussels Sprouts, Radish, Turnip and other 

 members of the Mustard family. The 

 leaves show at the edges large dead areas, 

 in which the veins are black. The entire 

 leaf soon yellows and falls from the plant. 

 The blackening of the veins, easily seen on 

 holding a diseased leaf up to the light, is 

 diagnostic of this disease. On splitting a 

 diseased stalk, a blackening of the sap tubes 

 is apparent. The bacteria live over in the 

 soil and on the seed. Soak the seed 15 

 minutes in corrosive sublimate solution 4 

 ounces to 30 gallons of water, then dry in 

 the shade. 



Club root (Plasmodiophora brassicae). 

 A serious disease caused by a^slime mould, 

 which produces enormous swellings of both 

 the main and lateral roots. These swellings 

 or clubs are irregular and unsightly in 

 appearance. In hot, dry weather, wilting 

 of the tops of affected plants frequently 

 occurs. The organism lives in the soil. 

 Practice crop rotation, set healthy plants, 

 apply 2 to 3 tons of lime per acre to infested 

 soil at least one year before planting again 

 to Cabbage. 



Yellows (Fusarium conglutinans) . Its 

 appearance is much the same as that of 

 black rot, but the darkening of the veins 

 begins at the base of the stem and works 

 outward, while in black rot it does just the 

 opposite, starting at the edge of the leaf 

 and working toward the base. Use seed of a 

 resistant variety. 



CARNATION 

 Fusarium Stem rot (Fusarium sp.}. 

 Affects the stem causing a dry rot near the 

 base. A slow dying of the top takes place. 

 Change the location of plants each year, and 

 in the greenhouse use fresh or sterilized soil. 

 Avoid overwatering . 



Leaf spot (Septoria Dianthi). Shows 

 small circular grayish spots on the leaves 

 and stem. Spray about once a week with 

 blue vitriol (copper sulfate) 1 pound to 20 

 gallons of water. 



