TECTONA 



721 



Actually on bare ground teak seed becomes buried naturally in a remarkably 

 short space of time. Rain is the chief agent in burying the fruits, but white 

 ants frequently devour the outer felty covering, leaving the inner hard nut 

 intact, and these insects no doubt assist in burying them. In experimental 

 plots at Dehra Dun a quantity of fruits scattered on bare ground in February 

 had almost all become buried before the end of July : on grass-covered ground 

 they remained for the most part on the surface uncovered, but here germination 

 was moderately successful owing to the protection from the sun which the 

 grass afforded during the process. The beneficial effects of loose soil are due 

 in part to the fact that it facilitates the burjdng of the fruits. A covering of 

 half an inch or less is quite sufficient, seed buried deeper germinating more 

 tardily. 



(iv) Combinations of factors. An experiment which I carried out at 

 Tharrawaddy, Burma, in 1904, throws some light on certain combinations of 

 factors influencing the germination of teak. Eight adjacent plots were marked 

 out in the open, exposed to the full effect of the sun's heat and light. In each 

 plot 100 teak seeds, not treated in any way, were sown. In six of the plots, 

 which may be termed A, sowing was carried out on April 13, that is, before 

 the first showers, and in the remaining two plots, which may be termed B, 

 sowing was carried out on June 23, that is, after the monsoon had w^ell set in. 

 The method of preparation of the plots and the results of the germination 

 were as follows : 



Tectona grandis : results of germination experiments, Tharrawaddy. 



Method of preparation of soil and sowing of seed. 



A. Sowing carried out on April 13. 



Soil not prepared Seed so\\ii broadcast 



Percentage of seeds 



which germinated up 



to date. 



burnt ; about 3 in. 

 r of leaves 



not burnt ; spar- 

 Y covered with dry 

 t grass at time of 

 ing 



Soil loosened with hoe 

 Soil not prepared 



Soil loosened mth hoe 



and not covered (1) 

 / Seed sown broadcast 

 ' and not covered (2) 

 I Seed sown broadcast 

 * and lightly covered (3) 

 Seed sown broadcast 

 and not covered (4) 

 [ Seed sown broadcast 

 I and not covered (5) 

 1 Seed sown broadcast 

 I and lightly covered (6) 



June 

 18. 



26 

 32 



67 



19 

 42 



June 

 24. 



27 



43 



75 



8 



21 

 42 



July 

 17. 



28 

 47 

 81 

 11 

 25 

 44 



B. Sowing carried out on June 23. 



/ Seed sown broadcast 

 and not covered (7) 



Soil not prepared 



Seed placed in shallow 

 holes and lightly 

 covered (8) 



Xo germination took 

 place throughout the 

 rains : even had it 

 done so the j'oung 

 plants would have had 

 a harder struggle 

 against weeds than 

 those in plots A. 



Although a single experiment of this kind cannot be regarded as con- 

 clusive, yet it confirms results obtained in other experiments, and indicates ; 

 (1) that germination is greatly stimulated if the seed lies exposed to the sun 

 from before the commencement of the early shoAvers preceding the monsoon, 



2307.2 c c 



