IRRIGATION OF THE GAEDEK. 187 



One drawback to the culture of tomatoes under 

 irrigation is a disease known scientifically as oedema, 

 which is a swelling of certain parts of the plant, brought 

 about by an excess of water stretching the cell 

 walls, making them very thin and the cells very 

 large. The excess of water may be so great that the 

 cell walls break down, and that part of the plant 

 dying, exerts an injurious influence in adjacent parts. 

 In an ordinary rainy season the irrigation of the 

 tomato plant should be a secondary consideration. In 

 ordinary moist land a good wetting just after trans- 

 planting and again in ten days, with subsequent culti- 

 vation, are usually quite sufficient. Too much water 

 is a bad thing for tomatoes. Peppers require exactly 

 the same methods. 



Cucumbers. For this crop a warm location is 

 best. All vines that belong to the Cucurbita family 

 must not be irrigated much while the plants are small, or 

 serious damage may be done to the crop. The ground 

 should be laid off by running shallow furrows about five 

 feet apart. It is best to irrigate the ground before the 

 seed is planted, if there seems to be a deficiency of mois- 

 ture^ rather than to apply water after the seed ia sown ; 

 and unless the soil is naturally a dry one it will not re- 

 quire any more water until the second or rough leaf is 

 formed, when another light watering will be necessary. 

 Thib will push the plants along a great deal faster than 

 if the ground is kept very wet. When the plants begin 

 to run and set fruit an irrigation should be given every 

 ten days or two weeks. While fruit is forming the irri- 

 gating can hardly be overdone. The water must never 

 run so as to come in direct contact with the plants, or 

 the ground will bake around the stems, and may possibly 

 injure the plants by stopping up the pores and excluding 

 the air. Cultivation is not in good form after the vines 

 begin to interlock. 



