Vol. X. No. 233. 



THE AGRICULTDKAL NEWS. 



Ill 



The prevalence of the Panama disease has called forth 

 various proclamations against the importation of banana 

 plants into the different islands. Jamaica led the way with 

 a proclamation prohibiting the importation of banana plants, 

 or implements used in banana cultivation, from all countries 

 of Central or South America and the Island of Trinidad. In 

 Barbados and the Windward Islands similar proclamations 

 have been issued, on the advice of the Imperial Commissioner 

 of Agriculture, with the difference that there is no prohibition 

 against the importation of tools, and that Tobago has been 

 added to the list of prohibited countries. The name of this 

 island does not appear on the proclamations in force in 

 Antigua and Dominica; though otherwise they are similar to 

 those in Barbados and the Windward Islands. It may 

 be noted further, that Mr. Ehrhorn, Entomologist to the 

 Board of Agriculture and Forestry, Hawaii, has advised the 

 Board not to permit the importation of the Bluefields 

 banana into that island at present, as is Shown by a letter 

 from him published in the Hawaiian Forester and Agricul- 

 turist, Vol. VIII, p. 31. 



Many of the above facts afford clear proof of the seri- 

 ousness with which the Panama disease is regarded, and 

 of the necessity of restricting it, as far as possible, to the 

 countries in which it is already present. 



THE GERMINATION OF HEVEA SEEDS 



It has been found that the seed of Hevea brasiliensis, 

 which has been imported from time to time for use in Grenada, 

 has shown very unsatisfactory germinating power, and in view 

 of the cost of the seed, it was considered expedient by 

 Mr. G. G. Auchinleck, B.Sc, Superintendent of Agriculture, to 

 make observations on seeds grown locally, for the purpose of 

 deciding as to what the low percentage of germination might 

 be due. The results of Mr. Auchinleck's investigations have 

 been presented by him in the form of a report, from which 

 the following information is taken. They show that experi- 

 ence in Grenada is confirmatory of that which has been 

 described already from other parts of the world. 



Mr. Auchinleck points out that the low germinating 

 power of imported '.-eed is obviously due to actual sterility of 

 the seeds, to their rapid deterioration after maturity, or to 

 both causes acting at once. For the purpose of obtaining 

 information in regard to the suggested deterioration, seeds 

 from capsules which had been opened just before dehiscence 

 took place Avere planted twenty-four hours after the fruits 

 had been plucked, a few being kept, however, for three days. 

 The number of seeds collected altogether was 975, and 160 

 of these were set aside as being too light. That there is 

 a great difference in weight between the heavy and light 

 seeds is shown by the fact that 100 of the former were found 

 to weigh 16 oz., while the weight of the same number of 

 light seeds was only 6 oz.: there was, however, no observable 

 difference in size between the two kinds. 



In the continuation of the experiment, all the light 

 seeds were planted in a bed. while of the heavy, eighty were 

 sown at stake and seventy-five in pots. None of the light 

 seeds germinated; of the heavy, nineteen of those at stake, 

 and thirteen in pots, gave sprouts. These results appear to 

 justify the rejection of light seeds when those of Hevea are 

 Ijeing selected for planting. 



Observations on the rapidity with which the seeds lose 

 weight, together with the consideration that from two weeks 

 to several months are rec]uired for germination, led to the 



supposition that the rate at which heavy seeds become lighter 

 in the soil might result in a serious diminution of their power 

 to germinate, before the young plant has had time to pierce 

 the hard seed coat. This led to the following experiment, 

 undertaken to find how quickly heavy Hevea seeds may lose 

 weight. 



For the i)urpose, ten heavy seeds were packed in 

 thoroughly dried charcoal, in a Hask; while ten others were 

 placed in a flask open to the air. Each lot was taken 

 periodically from its flask, at the same time, and weighed, 

 with the following results: — 



Day of weighing. Seeds in air, 

 grams. 



Lst 48-8 



.5th 48-5 



9th 47 



1.5th 45-5 • 



20th 44-4 



25th 430 



30th 41-8 . 



42nd 39 



49th 38 



54th 37-5 



Seeds in charcoal, 

 grams. 

 490 

 43-5 

 40-5 

 38-7 

 38-0 

 37-5 

 37-2 

 37-0 

 37-0 

 370 



Calculation of the results shows that in two weeks the 

 seeds kept in air had lost 6 per cent, of their weight, and those 

 in dried charcoal 20 per cent., the latter being about the 

 extreme limit of desiccation; the light .seeds took fifty days 

 to reach this. 



Further observations, made for the purpose of ascertain- 

 ing the cause of the decrea.se in weight, gave negative indi- 

 cations that this is due to the lo.ss of water; and it is thought 

 that it takes place on account of the presence of a definite 

 ferment in the seed. 



The fact that the trials were commenced late in the 

 bearing season make it impossible to ascertain if the poor 

 germinating power is the indirect result of some imperfection 

 in the flower, or irregularity in fertilization. It was noted, 

 however, that the embryos of all the seeds examined appeared 

 to be normal, and there was the interesting observation that, 

 out of about 320 capsules, all were triiocular and three-seeded, 

 except two, which possessed four loculi and four seeds. The 

 seeds in the abnormal capsules were subjected to a germina- 

 tion test, and three out of the eight gave sprouts. Attention 

 is drawn to the faint possibility that a tendency toward 

 irregularity in the floral organs of Hevea brasiliensis is indi- 

 cated, with the con.sequent production of a low germinatin,g 

 power in the seed that is eventually borne. The improba- 

 bility of the correctness of such a suggestion i.s, however, 

 pointed out. 



The final conclusions from the investigation are given as 

 follows: — 



(1) Seeds of Hevea. hrasiiiensix lose weight rapidly after 

 maturity, the loss being apparently due to desiccation. 



(2) The lo.ss of weight appears to coincide with loss of 

 germinating power. 



(3) Desiccation apparently takes place, in some instances, 

 even before dehiscence of the capsule. 



(4) Probably, without special precautions, Hevea seeds 

 will lose their germinating power within two or three weeks 

 after the ripening of the capsules. 



The matter of practical importance that can be deduced 

 from these results is that no Hevea seed should be sold until 

 it has been selected rigorously by weight, and there is the 

 additional indication that no unnecessary exposure, or loss of 

 time in planting, should be allowed after the seeds have 

 been received. 



