318 Agricultur. — Horticultur. — Forstbotanik. 



Howard, Albert, H o p E x p e r i m e n t s. 1 904. (Bulletin No. 1 . 

 1904—05. South-Eastern Agriciiltural College, Wye, Kent. 

 23 pp. With 8 plates.) 



The biilletin deals with a number of topics oi practical interest to 

 hop growers. 



1. Observations on the „gr o w in g- o u t" of the hop. Nor- 

 mally the hop plant is monoecious, and female inflorescences kept nn- 

 fertilized were found to form smail, green and unripe hops which com- 

 pared unfavourably with the v/eil grown, golden yellow and ripe hops 

 produced by artificialiy pollinated inflorescences of the same plants. The 

 non-pollinated hops were also more subject to fnngiis attacks than the 

 seed-hops. Fertilization apparently stimulated growth, hastened ripening, 

 improved the colour, and also increased the mould-rcsisting powers of 

 the hop. Observations in the field showed no well grown-out hops 

 without seeds. The observations and experiments point to the conclusion 

 that linder kentish condilions the growth of seed-hops^ rather than seed- 

 less hops^ should be aimed at. On the other band male plants occupy 

 Space, apparently unprofitable, and the relative values of seed and seed- 

 less hops requires investigation. Evidence is brought together from 

 kentish and american hop growers in favour of retaining a certain number 

 of male plants in the hop gardens, whilst german cultivators apparently 

 hold the contrary view. Lines of future work are indicated. 



2. Mould experiments. The results of experiments with Bor- 

 deaux mixture, sulphur, and natural enemies are recorded. 



3. Production of new varieties by cross-fertilization. 

 Of the many varieties now cultivated in Kent only tv/o are known to 

 have arisen from seed. The method employed of crossing hops is de- 

 scribed and seeds have been obtained for cultiveaation next season. 



4. A weak point in the Butcher System of trainin g. The 

 System is illustrated by a diagram, and it is pointed out that it tends at 

 certain points to harbour two important hop pests. Suggestions are 

 offered to overcome this and arguments brought forward for and against 

 the proposed changes. 



5 Hop drying temperatures. An apparatus in use for some 

 years for recording the temperature in the kiln is figured, and shown 

 to be lacking in sensitiveness. An alternative method is described and 

 comparative results with the two species of apparatus given in tabular and 

 graphic form. 



6. Manurial and Cultivation Experiments. Results with 

 various manures etc. at different centres, are recorded. 



W. G. Freeman. 



KiNDT, Ludwig, Die Cultur desKakaobaumes und seine 

 Schädlinge. (Hamburg, Verlag von C. Boysen, 1904. 

 157 pp. Mit 61 Einzelbildern und 35 Textfiguren. 157 pp. 

 Mit einem Geleitworte von Prof. Dr. Wohltmann.) 



Das Buch zerfällt in zwei Abtheilungen und ist, wie der Verf., der 

 22 Jahre auf Reisen und als Pflanzer in Central-Amerika, Ecuador, 

 Trinidad, Venezuela, Ostindien Erfahrungen gesammelt hat, aus 

 der Praxis heraus geschrieben und soll ein Leitfaden sein für den jungen 

 Pflanzer in den Tropenländern. 



Die erste Abtheilung behandelt in ausführlicher Form die Cultur 

 und Ernte und giebt hierüber ein klares Bild, so dass der Pflanzer in der 

 That vieles finden wird, was er mit Nutzen verwerthen dürfte. Bei der 

 Anführung der zum Anbau zu empfehlenden Kakaosorten gelangen zwei 

 Sorten zur näheren Besprechung, nämlich „Crioko" und „Forastero". 

 Es wäre auch noch die berühmte „Arriba"-Sorte von Ecuador zu be- 

 rücksichtigen. Sehr eingehend werden dann die Schattenpflanzen be- 

 sprochen, welche nicht vernachlässigt werden dürfen, da der Kakaobaum 

 ein Waldbaum (in Ecuador heute noch mehrfach Beständebildnei) ist 



