SUBMEKSION OF VINEYARDS. 205 



CHAPTER III. 



IST. MOST FAVOR ABLE TIME FOR SUBMERGING VINEYARDS. 

 Faucon* noticed that phylloxera is very sensitive to the 

 action of water during the most active period of its life, from 

 the 15th of April to the 15th of October, and sometimes later. 

 During winter, on the contrary, when the insect is hiber- 

 nating, it does not suffer much from the action of water ; 

 therefore, if it were only necessary to take into account the 

 efficacy of this treatment against phylloxera it should be 

 done during the summer ; but we must also take into account 

 the life of the vine and its culture, which would suffer from 

 a long submersion during the summer, and would become 

 unworkable at certain times when it is most necessary. 

 During the winter, on the contrary, water does not injure 

 the plant, and the field work being stopped the vines can be 

 inundated without inconvenience. Water can be used with- 

 out danger directly the canes are completely liynified, and 

 the sooner it is applied after that time the better. Most of 

 our southern varieties ripen their wood towards the 1st of 

 November.! Grenache, Alicante, and Carignane, however, 

 are generally not sufficiently lignified by that time, and sub- 

 mersion must be done later on for vineyards in which they 

 are planted. Frequent failures resulted from not taking 

 this fact into consideration with regard to Grenache. 



2ND. DURATION OF SUBMERSION. 

 It varies according to climate, nature of soil, and seasons. 



(A.) Influence of climate. Experience has proved that in 

 our northern districts the duration of submersion may be 

 reduced to 25 or 30 days, while it must last 35 to 40 days 

 in the Herault and Gard (south of France). This fact is 

 explained by the poor multiplication of phylloxera in 

 cold climates, which enables a relatively large quantity 

 of insects to be left living without much detriment 

 resulting. Altitude has probably a similar influence, and in 

 high lands of the southern regions the duration of sub- 

 mersion may be reduced. 



* Louis Fau con, Gutrison des Vigne* phyllox4res Insti-uctions pratiques sur le proctde 

 de la submersion, Montpellier, 1874. [Trans.] 

 t End of May in Victoria. 



