Light Intensity and the Absorption and Translocation of 2,4,5-T by Woody Plants

Weed Science ◽  
1969 ◽  
Vol 17 (3) ◽  
pp. 320-322 ◽  
Author(s):  
Homer A. Brady

Absorption of the isooctyl ester of (2,4,5-trichlorophenoxy)-acetic acid varied more than 20% in four woody species when incident light intensity was increased from 40 to 4,000 ft-c. Variations in translocation of the herbicide of 45 to 50% in post oak (Quercus stellataWangenh.) and water oak (Quercus nigraL.) accompanied changes in illumination. Light intensity did not affect translocation in longleaf pine (Pinus palustrisMill.) or American holly (Ilex opacaAit.)

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 270-275 ◽  
Author(s):  
C. J. Scifres ◽  
J. W. Stuth ◽  
R. W. Bovey

Aerial applications of 20% tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N-dimethylurea} pellets at 2.2 kg/ha (ai) in the spring effectively controlled post oak (Quercus stellataWangenh.), blackjack oak (Q. marilandicaMuenchh.), water oak (Q. nigraL.), yaupon (Ilex vomitoriaAit.), winged elm (Ulmus alataMichx.), downy hawthorn (Crataegus mollisScheele), gum bumelia [Bumelia lanuginosa(Michx.) Pers.], and willow baccharis (Baccharis salicinaTorr. & Gray) in the Post Oak Savannah of Texas. Tree huckleberry (Vaccinium arboreumMarsh.), black hickory (Carya texanaBuckl.), honeylocust (Gleditsia triachanthosL.) and cedar elm (Ulmus crassifoliaNutt.) were partially controlled by 2.2 kg/ha of tebuthiuron. Canopies of buckbrush (Symphoricarpos orbiculatusMoench), southern dewberry (Rubus trivialisMichx.), American beautyberry (Callicarpa americanaL.), and persimmon (Diospyros virginianaL.) were reduced for about two growing seasons after which the woody species recovered. American beautyberry appeared to increase in abundance by the third growing season after control of the other woody species. Honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], eastern redcedar (Juniperus virginianaL.), and Texas persimmon (Diospyros texanaScheele) were not controlled by tebuthiuron at 2.2 or 4.4 kg/ha, and saw greenbrier (Similax bona-noxL.) and peppervine [Ampelopsis arborea(L.) Koehne] apparently increased following application of tebuthiuron.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuying Yang ◽  
Zhiyan Chen ◽  
Xiangqian Lu ◽  
Xiaotao Hao ◽  
Wei Qin

AbstractThe organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole interaction at organic multiferroic interfaces, where overall ferroelectric polarization is tuned to present an organic magnetoelectric coupling. Moreover, the magnetoelectric coupling of the organic ferromagnetic/ferroelectric complex is tightly dependent on incident light intensity. Decreasing light intensity, the dominated interfacial interaction will switch from spin–dipole to dipole–dipole interaction, which leads to the magnetoelectric coefficient changing from positive to negative in organic multiferroic magnetoelectric complexes.


2021 ◽  
Author(s):  
Xiaoluo Bao ◽  
Xiaokun Wang ◽  
Xiangqing Li ◽  
Lixia Qin ◽  
Taiyang Zhang ◽  
...  

It is necessary for the commercialization of sunlight-driven H2 evolution to develop an efficient photocatalytic system whose energy utilization is independent on incident light intensity. Unfortunately, limited attention has been...


Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
Mohamed Ahres ◽  
Krisztián Gierczik ◽  
Ákos Boldizsár ◽  
Pavel Vítámvás ◽  
Gábor Galiba

It is established that, besides the cold, incident light also has a crucial role in the cold acclimation process. To elucidate the interaction between these two external hardening factors, barley plantlets were grown under different light conditions with low, normal, and high light intensities at 5 and 15 °C. The expression of the HvCBF14 gene and two well-characterized members of the C-repeat binding factor (CBF)-regulon HvCOR14b and HvDHN5 were studied. In general, the expression level of the studied genes was several fold higher at 5 °C than that at 15 °C independently of the applied light intensity or the spectra. The complementary far-red (FR) illumination induced the expression of HvCBF14 and also its target gene HvCOR14b at both temperatures. However, this supplementation did not affect significantly the expression of HvDHN5. To test the physiological effects of these changes in environmental conditions, freezing tests were also performed. In all the cases, we found that the reduced R:FR ratio increased the frost tolerance of barley at every incident light intensity. These results show that the combined effects of cold, light intensity, and the modification of the R:FR light ratio can greatly influence the gene expression pattern of the plants, which can result in increased plant frost tolerance.


1984 ◽  
Vol 21 (03) ◽  
pp. 464-478
Author(s):  
William J. Anderson

The response of the photographic grain to light is a non-deterministic process which is as yet not completely understood. This response, as measured by the photographic density, is usually taken to be a function of the product of incident light intensity and exposure time interval duration, but at extreme values of either of these two quantities, this is no longer true. This latter effect is called reciprocity-law failure. This paper discusses a probabilistic model, similar to a multiserver queue, for high-intensity reciprocity failure.


Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 358-362 ◽  
Author(s):  
R. E. Meyer ◽  
R. W. Bovey

Hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] was applied to honeylocust (Gleditsia triacanthosL.), honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], huisache [Acacia farnesiana(L.) Willd.], live oak (Quercus virginianaMill.), Macartney rose (Rosa bracteataWendl.), post oak (Quercus stellataWangenh.), saw greenbrier (Smilax bona-noxL.), whitebrush (Aloysia lycioidesCham.), and yaupon (Ilex vomitoriaAit.). Bromacil (5-bromo-3-sec-butyl-6-methyluracil) and tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} were used for comparison in some experiments. Hexazinone was required at the following rates to kill at least 75% of the following species: 1.1 kg/ha for live oak, 2.2 kg/ha for post oak, 4.5 kg/ha for huisache (at Bryan, Texas) and whitebrush, and 9 kg/ha for honeylocust. Hexazinone was ineffective at 9 kg/ha for control of honey mesquite, huisache (at Washington, Texas), Macartney rose, saw greenbrier, and yaupon. Tebuthiuron at 1.1 kg/ha killed 80% of the live oak, and as a subsurface spray at 4.5 kg/ha, killed huisache (at Washington, Texas). Bromacil was effective on huisache at 9 kg/ha.


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