RESISTANT VINES; THEIR SELECTION, ADAPTATION, ETC. 11 



rooted out and burned on the spot, the ground around being covered lightly 

 with straw or brush, which is immediately burned, so as to destroy all 

 insects that may be on or near the surface of the soil, or on the roots 

 and trunks of the vines. Aside from this use of insecticides for pur- 

 poses of the eradication of the insect from a small spot, it is far too 

 expensive an operation to be relied on in this State, with any known 

 insecticide. 



While none have thus far been found that are economical, it is by no 

 means certain that the time will not come when we may have a cheap 

 and effective insecticide for our phylloxera-infected vineyards. But the 

 public is warned against trusting to seductive advertisements of those 

 who claim to have infallible remedies. The field has been so carefully 

 worked by the best chemists, entomologists, and practical vineyardists of 

 the world, that there is little probability of anything effective being dis- 

 covered very soon. But even though a very cheap insecticide be found, 

 it must not be forgotten that this must be applied annually, and no 

 matter how slight the expense, this annual treatment merely means a 

 diminished net revenue. Perhaps one of the commonest deceptions 

 practiced by the sellers of phylloxera remedies is the use of powerful 

 fertilizers mixed with some so-called insecticide. By this means it is 

 certain that the vine may be temporarily revived, but the revival is too 

 short-lived to be depended on for crops enough to pay for the treatment, 

 which amounts simply to a heavy fertilization. 



SUBMERSION. 



Much misconception has arisen concerning the utility of this opera- 

 tion. While it is perfectly true that, under certain special conditions, 

 it is effective and economical, yet the conditions under which submer- 

 sion is possible are so special that but few can avail themselves of this 

 means of combating the phylloxera. 



Nature of the Soil. In the first place, the vineyard must be perfectly 

 or almost level, and in easy communication with an abundant water- 

 supply. Then, the soil must be neither too porous nor too compact. 

 Again, the submersion must be continuous, and not interrupted, even 

 for an hour. Should the surface of the soil be exposed for an hour 

 at the end of forty days in a vineyard that requires a sixty-day sub- 

 mersion, the forty days of submersion do not count, but the whole 

 operation has to be begun as though there had never been a day of 

 submersion. We give below a table illustrating some of the special 

 conditions that have to be fulfilled in order to make this seemingly 

 simple operation possible and practically effective. This is dwelt upon 

 somewhat at length, as the Station is in receipt of numerous inquiries 

 on this subject from those who imagine that mere heavy irrigation will 

 be effective in checking the phylloxera. 



Depth and Duration. In all cases where the loss of water per day, 

 either on account of the permeability of the soil or the evaporation, or 

 both, amounts to more than 500 cubic yards per day on an acre, 

 submersion becomes impossible. 



