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Variation in the Male Hop, Humulus Lupulus L.

Published online by Cambridge University Press:  27 March 2009

H. Wormald
H. Wormald
Affiliation:
(Research Department, South-Eastern Agricultural College, Wye.)
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Extract

The hop plant Humulus lupulus L. is best known in Britain from its cultivated forms grown for use in the brewing industry. Those varieties which are grown on a commercial scale in this country all conform to the general description of Humulus lupulus L. and the presumption is that they are all variations (directly, or indirectly through other varieties) from the female form of the original wild hop. Since the plant is dioecious it follows that any one of these varieties was in all probability derived primarily from one ♀ plant which arose either as a mutation or as a hybrid and has subsequently been propagated vegetatively by cuttings or “sets,” i.e. the variety is represented by a number of plants comprising a clone; such a variety is not necessarily provided with a corresponding male form possessing all the vegetative characters of that particular ♀ variety.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 7 , Issue 2 , September 1915 , pp. 175 - 196
Copyright
Copyright © Cambridge University Press 1915

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References

page 175 note 1 The word “clone” was first used by Webber in 1903 and has been adopted by Dr Johs. Schmidt, Director of the Carlsberg Laboratory, Copenhagen. In his recent paper “On the Aroma of Hops” (Comptes-rendus des travaux du Laboratoire de Carlsberg, llme Vol. 1915) Dr Schmidt, in discussing the use of the word “clone,” writes (loc. cit. footnote, p. 153): “I would suggest that the word be adopted into the terminology relating to hops, where such a term is actually needed. A hop-clone would thus be all those plants derived from the same seedling by vegetative propagation, a clone-plant being any single plant belonging to the clone.”

page 175 note 2 Agricultural Botany, 4th Ed. 1910, p. 345.

page 176 note 1 The Journal of the South-Eastern Agric. College, No. 17, pp. 364–391.

page 176 note 2 I.e. Somatic Parthenogenesis of Winkler or Parthenapogamy of Prof. Farmer.

page 176 note 3 The Journal of the South-Eastern Agric. College, No. 21, p. 425.

page 176 note 4 When the stigmas of the ♀ flowers are receptive they project from between the bracts and bracteoles of the strobiloid inflorescence which develops into the “hop” of commerce, and the plant is “in burr.“

page 176 note 5 Owing to an attack of “nettle-head” disease only eleven of these were fully available for the season 1914, since two of the three hills in one case and one hill each in two others had to be “grubbed” during the winter 1913–14.

page 177 note 1 Loc. cit. 4th Edit. 1910, p. 346.

page 177 note 2 Journal of Genetics, Vol. III. No. 3, 02. 1914.Google Scholar Footnote on p. 195.

page 177 note 3 A description of this system of training hops is to be found in an article on “Hop Cultivation” by MrAmos, A. in the Journal of the Board of Agriculture, 02. 1910, Vol. XVI with figures on p. 891.Google Scholar

page 178 note 1 The “breast-wire” or middle wire of the Butcher System is about 4 feet 6 inches from the ground.

page 178 note 2 Or rather bracts, since the laterals (inflorescences) grow in their axils.

page 179 note 1 The numbers in brackets refer to hills obtained by planting cuttings from the hill bearing the number in front of the bracket.

page 180 note 1 Occasionally a bine with nine ridges and bearing a whorl of three leaves at each node is met with.

page 181 note 1 Vigour in a seedling is probably often due to the stimulus resulting from fertilization.

page 181 note 2 Unfortunately three of the hills succumbed to “nettle-head” disease and had be removed before observations were resumed in 1914.

page 183 note 1 Braungart, in Der Hopfen (München u. Leipzig, 1901), p. 170, writes: “Merkwürdig ist, dass man die Laubblätter des Hopfens eben wegen dieser Drüsen in Hopfennotjahren (getrocknet) sohon zur Verwendung in der Brauerei, besonders zur Herstellung geringer und Nachbiere, empfohlen hat.”

Prof. R. Bradley, of Cambridge University, in The Riches of a Hop-Garden Explained (London, 1729), wrote: “It often happens by haste, that the smaller leaves of the plant mingle with the hops. At the time of stripping these leaves are of good virtue, and were alone sold in Flanders, Anno 1566, for twenty-six shillings and eight pence a hundred, no one hop being mingled with them.”

page 185 note 1 I.e. the type in which a glass circle with scale is dropped into the eyepiece.

page 187 note 1 It should be noted that these terms are merely relative and no attempt has yet been made to reduce them to terms of size and frequency of the hairs.

page 188 note 1 Those laterals below the breast-wire are, together with the lower leaves, stripped off before “hop-washing” commences.

page 188 note 2 By first internode is here meant that between the first and second pairs of bracteoles. When the bracteoles were not truly opposite, but were more or less alternate, the node was taken as being midway between the two bracteoles representing an opposite pair.

page 188 note 3 Sooner or later along the lateral the bracteoles towards the distal end are represented merely by scales.

page 188 note 4 By the “stipular inflorescences” is meant those short laterals at the base of each main lateral and growing apparently in the axils of the stipules.

page 189 note 1 See page 178.

page 191 note 1 Afterwards it was found that these glands are figured in Braungart's Der Hopfen, p. 206.

page 192 note 1 Salmon, E. S. and Wonnald, H.: “Humulus Americanus Nuttall,” Journal of Botany, 05, 1915, pp. 132–135.Google Scholar

page 193 note 1 Vide p. 178 for definition of “Time of Flowering” as used in this paper.

page 195 note 1 See, however, Journ. of Bot. May, 1915, p. 135.

page 196 note 1 At Wye no seedling has been known to flower during its first season, although Dr Johs. Schmidt finds that at Copenhagen his seedlings frequently come into flower the first year (see Comptes-rendus des travaux du Laboratoire de Carlsberg, llme Vol. 1915, p. 170Google Scholar); even during the second season the plants do not attain to their full vigour and it is evident that certain characters at any rate are not constant at that age.