A series of four studies were conducted in Colombia, South America,
in the field and the greenhouse to determine the effect of plant
competition and mulching on carbohydrate and photosynthate distribution
and nitrogen fixation in beans (Phaseolus vulgaris L.).
Mulching beans (determinant growth habit) with rice hulls in the
lowland...
In view of the stimulant effects of gibberellic acid on plant
growth, and its interesting modifications of various metabolic products,
it was decided to determine whether this growth regulator
would induce a favorable effect on total alkaloid production, especially
on the antineoplastic alkaloids, of Catharanthus roseus (L.) G. Don
(Vinca...
An investigation was undertaken to determine whether
potassium is indeed necessary for the in vivo synthesis of a
specific protein. The effects of univalent cations on the
inductive formation of nitrate reductase and on the level of
activity of representative non-adaptive enzyme are presented.
Cultures of Neurospora crassa were grown...
Cytokinins are plant hormones regulating cell division and differentiation.
Most developmental events from germination, vegetative morphogenesis to seed
and fruit set are influenced by cytokinins. t,ns-Zeatin is the major natural
occurring cytokinin. Its isomer, cis-zeatin, and its derivatives are usually present in
low quantities and have traditionally been considered as...
Further development of an environmental grid for interpreting plant distribution and growth took place this last year as an attempt to solve problems associated with spatial diversity in ecosystems. Special emphasis was placed on developing more universal integrated indexes to environment,
ones that might permit wide extrapolation throughout the range...
Blue spruce (Picea pungens) and Engelmann spruce (Picea engelmannii) experience varying levels of spruce beetle (Dendroctonus rufipennis (Kirby)) colonization, yet the underlying differences and mechanisms resulting in lower colonization for blue spruce are not known. Both spruce species have important roles in subalpine ecosystems where examining changes in mortality, distribution,...
To understand the effect of human-induced stresses on forests, there is a need for a method to separate effects of imposed stress from effects of natural climate stress. I developed an approach to predict forest response to climate stress using as indicators stable carbon isotopes in tree foliage and growth-rings....
