1921.] 



Hor-" Mould " and its Control. 



special dose given to the lowermost leaves. One good early 

 sulphuring frequently prevents a bad outbreak of " mould " 

 later in the season, and should never be omitted.* If 

 mould " has been noticed in the garden in the previous 

 season, the knapsack sulphuring should be given once a fort- 

 night until the lower leaves have been " stripped " off. Where 

 a bad outbreak of " mould " has occurred during the previous 

 season in the garden, or where the thoroughly bad practice has 

 been followed of leaving <f mouldy " hops unpicked, applica- 

 tions of sulphur with the knapsack pump, starting at the 

 beginning of May, should be given regularly at intervals of 

 a fortnight until the bines are high enough for the horse- 

 sulphurator to be used. The number of applications necess;u v 

 later in the season must of course depend on the extent and 

 character of the outbreaks of " mould," on the weather con- 

 ditions, and on the amount of " bine " in the garden. It 

 dangerous to tolerate patches of white " mould " at any 

 time in a garden, as under certain weather conditions favour- 

 able for its propagation the mildew T spreads with great 

 rapidity and if this coincides with the period when the hop- 

 plant is in " burr " or just in hop, irreparable damage may 

 be done. Up to the time the " burr " appears any white 

 " mould " in the garden should be promptly dealt with by 

 sulphuring. It is the practice of many of the most successful 

 hop-growers to sulphur the hops when in burr, not only as 

 a preventive of " mould " but in the belief that the sulphur 

 acts in some beneficial way, causing the " burr " to set into 

 hops quickly. Generally speaking, no further sulphuring is 

 necessary; should, however, " red mould " appear, applications 

 of sulphur must be given until the hops are approaching 

 ripeness. 



[n sulphuring with the horse-machine it is considered a 

 good practice — since the sulphur is so light that it drifts in 



* A striking instance of the efficacy of early sulphuring may lie mentioned 

 here. At the East Mailing Research Station, in Kent, a new variety of hop, " The 

 Foundling" (see this Journal, Vol. XXII, p. 136 (1915) ) has been grown, amongsl 

 others, in the Hop Variety Trials. " The Foundling" has proved to he so specially 

 susceptible to "mould" that nearly all the growers who have been testing H have 

 abandoned its cultivation. The treatment of the hops at Bast Mailing for the 

 years 1918-20 has been as follows : 1918 % 5 applications of sulphur, viz.. knapsack, 

 end of May, early June, July 21 : horse-sulphurator, Aug. 1<>. Aug. 17: 191B % 

 3 applications, viz., knapsack, early June ; horse-sulphurator. .Inly 24, Aug. 16 : 

 1020. 2 applications, viz., horse-sulphurator. July 16, second week in August. In 

 1918 and 1919 there was no trouble with "mould." Mr. .1. Amos* Manage? 

 Recorder, writes : "In 1920 the early sulphuring was omitted, which I must admit 

 was a mistake, for I noticed that the hops were more ' mouldy 1 than in the two 

 previous years, as was also the case in 1917 when DO early sulphuring was done. 

 I shall make a point of having the early sulphuring done annually in future."' 



