The diseases and pests of the rubber tree . FiQ. 30.—^A ridged stem, x |. 198 THE RUBBER TREE menon is fairly simple. When the young tree was plantedout in the field it was, as usual, stumped. The stem thendied back to the next node, and the new leading shoot sprangfrom the bud at that node. But instead of growing straightup by the side of the dead stem, it coiled round the latterthree times. The cause of this coiling is revealed in the 1 .fBI ( ? ?9^^1 ::..:^i 1 \ f f. Fig. 31. Fig. 32. A twisted Hevea stem, x J. second photograph, where, stiU twined round the deadoriginal stem, is seen part
The diseases and pests of the rubber tree . FiQ. 30.—^A ridged stem, x |. 198 THE RUBBER TREE menon is fairly simple. When the young tree was plantedout in the field it was, as usual, stumped. The stem thendied back to the next node, and the new leading shoot sprangfrom the bud at that node. But instead of growing straightup by the side of the dead stem, it coiled round the latterthree times. The cause of this coiling is revealed in the 1 .fBI ( ? ?9^^1 ::..:^i 1 \ f f. Fig. 31. Fig. 32. A twisted Hevea stem, x J. second photograph, where, stiU twined round the deadoriginal stem, is seen part of some cLLmbing weed. Thisclimber grew up the stem of the young plant, and arrived atthe bud just as the latter started into growth ; and in twiningfurther round the dead part of the stem it carried the youngshoot round with it. When the two reached the top of thedead stem the Hevea shoot grew straight upwards, and the VI NON-PARASITIC DISEASES 199 climber then twisted itself round the green shoot; this isshown by the spiral groove on the upper part of the stem,which is caused by the pressure of the coils of the climberon the young stem as the latter expanded. It is mostprobable that the coils of the Hevea stem were at first wideapart, but they have come into contact owing to its subsequentthickening. If the tree had been allowed to grow the coilswould no doiibt have become fused into a solid mass. Scorched Trees In many cases trees have been scorched by leaf f
Size: 956px × 2614px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidcu3192400285, bookyear1921
