Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
ALTERATION OF APICAL DOMINANCE IN SOYBEANS (GLYCINE MAX (L.) MERR.) WITH FOLIAR APPLICATIONS OF BENZOIC ACID DERIVATIVES OR TERMINAL BUD REMOVAL AND THE EFFECTS OF SALICYLIC, ACETYLSALICYLIC AND THIOSALICYLIC ACIDS ON NITRATE REDUCTION IN SOYBEAN LEAVES
Abstract
The terminal bud of soybean plants was killed or its immediate growth inhibited when plants were sprayed at the second trifoliate stage with formulations of salicylic acid, acetylsalicylic acid, salicylamide, benzoic acid or 2,4-dihydroxybenzoic acid (3000-6000 ppm). Apical dominance was eliminated or reduced, promoting the growth of axillary buds. Foliar sprays of these chemicals or terminal bud removal at the second trifoliate stage altered growth and yield parameters in field experiments with Amsoy and Clark soybeans, grown in 76 cm rows at 260,000 plants per hectare, in 1980. Treatments caused significant reductions in plant height, increased trifoliate leaf and stem number per plant, decreased weight per trifoliate leaf and altered dry matter partitioning between the vegetative and reproductive components, significantly increasing seed to stem and shelled pod to stem ratios. Removal of the terminal bud significantly increased pod number, seed number and seed weight per hectare. A 4500 ppm salicylamide and a 3000 ppm acetylsalicylic acid formulation significantly increased pod number per hectare with Clark and seed number per hectare with Amsoy, respectively. Leaf discs cut from soybean trifoliates were floated under dark, aerobic conditions on buffered solutions, pH 4.0 to 7.0, with or without 1 mM salicyclic acid, acetylsalicyclic acid or thiosalicylic acid. Positive nitrate fluxes from the leaf discs into solution were induced by low solution pH (4.0, 5.0) or by the chemicals tested. Rates of nitrate flux decreased from pH 4.0 to 7.0 for all treatments. Positive nitrite fluxes from the leaf discs were induced by the chemicals tested with little or no nitrite flux with the buffer controls. Maximum rates of induced nitrite flux occurred at pH 6.0. At each pH, nitrite flux was positively and significantly correlated to nitrate flux. At pH 6.0, the regression of nitrite + nitrate or nitrite flux on the log of the salicylic acid concentration (70 uM to 7 mM) was found to be positive and significant. Nitrite accumulated, gaseous NO(,2) and NO were emitted and ATP levels were reduced in intact leaves treated with salicylic acid or with salicylic acid with ametryn incubated under aerobic conditions in darkness or light, respectively.
Subject Area
Botany
Recommended Citation
DAVIS, MICHAEL PETER, "ALTERATION OF APICAL DOMINANCE IN SOYBEANS (GLYCINE MAX (L.) MERR.) WITH FOLIAR APPLICATIONS OF BENZOIC ACID DERIVATIVES OR TERMINAL BUD REMOVAL AND THE EFFECTS OF SALICYLIC, ACETYLSALICYLIC AND THIOSALICYLIC ACIDS ON NITRATE REDUCTION IN SOYBEAN LEAVES" (1982). ETD collection for University of Nebraska-Lincoln. AAI8217522.
https://digitalcommons.unl.edu/dissertations/AAI8217522