Control of Morningglories (Ipomoea spp.) in Sugarcane (Saccharum spp.)
Abstract Morningglories are summer annual or perennial dicots, and are troublesome weeds in sugarcane cultivated in northern India. If not controlled, they may compete with sugarcane, interfere in the harvest operation, and reduce yields. Managing morningglories in sugarcane continues to be a serious challenge for sugarcane growers. Field experiments were conducted during the 3-yr period from 2007 to 2009 to evaluate herbicides applied PRE and POST for control of morningglories in sugarcane. The herbicides applied PRE included diuron, metribuzin, and atrazine at 1.6, 1.4, and 1.0 kg ai ha−1, respectively, applied alone or followed by 2,4-D amine salt (0.58 or 1.16 kg ae ha−1) or 2,4-D sodium salt (0.8 or 1.6 kg ae ha−1) applied POST. Herbicides applied PRE controlled morningglories ≤ 87% at 15 d after treatment (DAT); however, control reduced to ≤ 56% at 90 DAT. Control improved when herbicides applied PRE were followed by POST application of 2,4-D amine or sodium salt. For example, diuron applied PRE followed by 2,4-D amine salt applied POST at any rate provided 100% control of morningglories at 15 and 30 DAT. At 90 d after POST application, control ranged from 68 to 82% with the PRE followed by POST herbicides, compared to 0% control when metribuzin or atrazine were applied PRE alone. The density and biomass of morningglories was also reduced to zero in treatments that included 2,4-D amine salt. The number of millable canes, cane height, and single cane weight was superior in PRE followed by POST herbicide treatments compared to herbicides applied PRE alone. Maximum cane yield was recorded for the treatments that included 2,4-D amine or sodium salt compared to only PRE treatments, and it was usually comparable with the nontreated weed-free control. It is concluded that a combination of PRE and POST herbicides were effective for control of morningglories; however, more research is required to evaluate other herbicides and their tank mix partners for control of morningglories in sugarcane. Nomenclature: Japanese morningglory, Ipomoea nil (L.) Roth.; obscure morningglory, Ipomoea obscura L. Ker Gawl.; sugarcane, Saccharum spp.
Efficacy and Economy of Weed Management Systems for Sicklepod (Senna obtusifolia) and Morningglory (Ipomoea spp.) Control in Soybean (Glycine max)
Field experiments were conducted in Tifton, Midville, and Athens, GA to determine economic net returns from PRE-broadcast, PRE-banded, POST, and POST-directed herbicide treatments and inter-row cultivation in conventional-tillage soybean. Metribuzin applied PRE-broadcast was more effective for sicklepod and morningglory control than PRE-banded. Soybean net returns were not significantly reduced in two of three years in plots treated with metribuzin applied PRE-banded compared with broadcast application. The addition of POST or POST-directed herbicides increased treatment net returns over PRE-broadcast and PRE-banded metribuzin two of the three years of the study. No significant soybean injury was observed.
ABSCISSION OF FLOWER BUD PEDICELS IN BEGONIA II. INTERACTION AND TIME SEQUENCE OF PLANT GROWTH REGULATING SUBSTANCES ON THE ABSCISSION WITH EXPLANTS
SUMMARY 
 
The influences of indoleacetic acid (IAA), abscisic acid (ABA), and ethylene on the abscission of Begonia pedicels were studied by estimating the periods of sensitivity to them and by analyzing their interactions. 
 
 
 
Except for the alternation of sensitivity to IAA and to ethylene, the hormones affect the abscission independently from one another.