346 MISSOURI STATE HORTICULTUR. 



at intervals of three weeks, the last planting to be made about the 

 middle of July. This crop, if not wanted for snap beans, can be used 

 to good advantage for pickling. 



A small planting of strap-leaf turnips should be made as early as 

 possible in the season, and another on the ground where the early peas 

 were grown. A later planting can be made, as well as one of ruta- 

 bagas, where the early potatoes were grown. In any vacant places, if 

 such there are in the garden, a small patch of spinach should be culti- 

 vated, if for no other purpose than to turn under as a vegetable ma- 

 nure. It is of the greatest importance to make an early and late plant- 

 ing of tomatoes. For the first, put out strong, stocky plants ; for the 

 second, dror> a seed or two in each hill of early corn, and as soon as 

 the corn is done cut the stalks to the ground, and a splendid crop of 

 tomatoes will be secured, which will be very useful after the first has 

 ripened its best fruit?. — From American Garden. 



NATURE OP THE DISEASE. 



The potato rot is a contagious disease which often spreads from 

 plant to plant and field to field with great rapidity. The disease at- 

 tacks the tops as well as the tubers, and is due solely, or primarily at 

 least, to the presence of a minute parasitic fungus, phytophthora infes- 

 tans. The life history of this parasite was carefully investigated many 

 years since by De Bary and other botanists, and is now well known. 

 The destructive effects of the fungus are generally first observed upon 

 the tubers late in the fall, but the disease is present much earlier in the 

 season, and may be recognized on the tops by a certain characteristic 

 blotched, black or brown-spotted, dead appearance. A more critical 

 inspection of the diseased tops would show numerous small white 

 spots scattered over the leaves and stems. When highly magnified these 

 spots are found to be mioature forests of slender stems growing up out 

 of the surface of the leaves and stems of the potato. These tiny stems 

 commonly branch and swell out at the ends into ellipsoid or oval bod- 

 ies, known as summer spores. These little spores are produced by mil- 

 lions and are so small that a million could easily lie side by side on a 

 square inch without crowding. Whan ripe they separate from the 

 stem by a joint and fall. Under the influence of water the livings 

 jelly-like contents of the si)ore may push out a long, slender tube, ca- 

 pable of growing down directly into any part of the potato plant to 

 begin a new cycle of growth, or may separate into several distinct por- 

 tions (swarm spores) which, being endowed with life and motion, burst 

 through the wall of the mother spore, swim about actively for a few 



