282 



The Supplement to the Tropical Agriculturist 



VITALITY OF RUBBE R SEEDS. 



[By F. G. Spring, Superintendent, 

 Government Plantations, F. M.S.] 



Seeds of Htvea. braziliensis do not retain their 

 vitality for a long period and the consequent 

 difficulty of forwarding them successfully to dis- 

 tant countries is well known. This year several 

 hundred thousand Para seeds from tapped trees 

 were packed in Venesta chests with charcoal 

 and forwarded to Trinidad. The results obtained 

 were far from satisfactory although the seeds 

 were most carefully selected and packed. 



There is no doubt that seeds picked imme- 

 diately on falling, and carefully packed, give the 

 best results. If they are allowed to lie on the 

 ground, or if badly packed, a smaller percentage 

 of germination will be obtained, It must be 

 borne in mind, however, that no matter how the 

 packing has been done, the vitality of Para 

 seeds cannot be retained for any length of time 

 if they are not gathered immediately. The seeds 

 must not be packed too many in a box, other- 

 wise fermentation starts and the whole mass 

 heats and loses its vitality ; the packing material 

 must be just sufficiently moist to prevent the 

 seeds from drying out and not moist enough to 

 encourage the growth of moul Is and bacteria. 

 For the same reason the packing must be fairly 

 tight and yet not quite air-tight. Small boxes 

 seem better than larger cases. 



Experiments have been carried out as men- 

 tioned iL a previous aiticle* at the suggestion 

 of the Director of Agriculture to compare the 

 germinating power of seeds from tapped and 

 untapped trees (Expt. 1.) and to see if by coa- 

 ting the surfaces of the seeds with various sub- 

 stances (f£xpt. 11.) the germinating power could 

 be retained for a longer per od. The tapped 

 and untapped trees selected for the experiments 

 are 12 ytats old; the first mentioned have been 

 tapped for the past two years, the seeds were 

 collected fresh each morning and treated as 

 mentioned in the following list. 



Experiment 1, 

 The Vitality of Seeds from Tapped and 

 Untapped Trees. 



All seeds were packed with burnt padi husk 

 in biscuit tins, each containing 200 seeds. The 

 tins wore wrapped in brown paper and sealed. 



Boxes Nos, 1, 2, 3, 4, 5 and 6 were kept 3, 5, 

 7, 8, 9, and 10 weeks respectively then opened, 

 and the seeds planted in well prepared nursery 

 beds. It will be seen from the tables that seeds 

 from untapped trees gave on an average 50 per 

 cent, higher germination than those from tapped 

 trees reckoned on the absolute percentage. In 

 each test the former showed from two to three 

 times as many germinations as the latter. 



A record of similar experiments is published 

 in the Circulars and Agricultural Journal of the 

 Boyal Botanic Gardens, Ceylon, Volume IV., 

 No. 11. May 1908. This circular states that 

 "seeds from tapped trees kept for five weeks did not 

 germina e but those kept for four weeks showed *8 per 

 cent, germination while seeds from untapped trees kept 

 for four weeks <!id not germinate and those kept for 

 three weeks showed on y 3 per cent, germination. Both in 

 percentage, germination, and time of germination the 

 seeds from tapped trees are better throughout." 



* Agricultural Bulletin of the Straits and Federated 

 Mala; Slates Vol. X. No. 11, p. 345, November, 1911. 



No information is given regarding the manner 

 in which the seeds were kept previous to plant- 

 ing. It will be seen that the Ceylon figures are 

 at variance with those obtained here, but it is 

 difficult to say why this should be. The Ceylon 

 Circular also states that seeds from tapped 

 trees are smaller, weigh less per 1,000 seeds than 

 those from untapped trees. This agrees with 

 the figures obtained here namely, seeds from 

 untapped tree3 were found to be on an average 

 10 7 per cent, heavier than those from tapped 

 trees of simil tr ages. The figures in Experiment 

 I. are of interest not only as regards the suitabil- 

 ity of exporting seeds from untapped trees but 

 they also tend to show the effect tapping has on 

 the vitality of the seed. Tapping lessens the 

 weight and size of the seeds, and according to 

 the present experiments reduces the germina- 

 ting power. 



It is evident that seeds which are to be ex- 

 ported are best selected from untapped trees. 



Experiments are to be conducted to com- 

 pare the growth of plants resulting from seeds 

 of tapped and untapped trees. 



TABLE I. --Percentage of Seed Germination obtained 

 from Tapped and Untapped Trees. 



No. of plants Percentage of 

 obtained. seeds 



C CO © 



as 

 S . 



Germination. 



CD 





■a 





•a 





s 





CD 



■6 



c 





Oi 



CO 



p. 



CO 



Pi 



a. 



d 



£3 



a. 



si 



c. 



cS 



a 



a 



(3 



a 



H 



£3 



H 



O 



67 



156 



S3 



78 



46 



133 



23 



66 



48 



100 



24 



50 



40 



167 



20 



83 



40 



164 



20 



82 



49 



165 



24 



82 



1 20 > 3 weeks 



2 2U0 5 do 



3 200 7 do 



4 200 8 do 



5 200 9 do 



6 200 10 do 



Experiment II. 

 the Preserving of Rubber Seeds from 

 Tapped Trees. 



The seeds in these experiments were collected 

 and packed in a similar way to those in the first 

 experiment but they were coated respectively 

 with bees wax, hard paraffin, and vaseline. The 

 beeswax and hard paraffin were melted and the 

 seeds dipped into their respective liquids, al- 

 lowed to solidify and then packed. Previous to 

 planting the seeds, the hard paraffin, beeswax, 

 and vaseline were removed. 



The percentage of germination of untreated 

 seeds from tapped trees can be seon by referring 

 to experiment I. On comparing this with the 

 seeds coated with beeswax it will be seen that 

 the latter showed an increased germination to 

 the extent of approximately 30 percent. The 

 seeds coated with hard paraffin gave better 

 results than untreated seeds from tapped trees 

 but not as good as those coated with beeswax. 



The seeds treated with vaseline did not germi- 

 nate. The coating of rubber seeds with any sub- 

 s' ance is undoubtedly an expensive treatment but 

 if seeds have to be sent to countries which take 

 from 1 J to 24 months to reach and seeds from un- 

 tapped trees cannot be obtained, then, £ think 

 that the extra percentage of germination result- 

 ing from seeds being coated with beeswax would 

 more than repay the extra expense entailed by 

 this system of treatment 



