Effect of Spray Components on Glyphosate Toxicity to Annual Grasses

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside

Field and greenhouse research was conducted during 1980 and 1981 to evaluate the effects of carrier volume, surfactant concentration, and treatment date on glyphosate [N- (phosphonomethyl)glycine] toxicity to annual-grass weeds and volunteer small grains. Glyphosate phytotoxicity increased as carrier volume was decreased from 190 to 24 L/ha. The presence of a surfactant in the spray solution did not influence grass control when glyphosate was applied in a carrier volume of 24 L/ha. When glyphosate was applied in 48 or 95 L/ha, the presence of surfactant resulted in better grass control than glyphosate without surfactant. When applied in 190 L/ha, glyphosate with 0.5% (v/v) surfactant gave better grass control than glyphosate alone or commercially formulated glyphosate. When glyphosate was applied to plants under water stress, little control was achieved regardless of plant growth stage. Glyphosate application to grass after head initiation also resulted in reduced control. Maximum weed control with glyphosate was attained when applications were made to seedlings growing actively because of adequate soil moisture and favorable temperatures.

1990 ◽  
Vol 4 (2) ◽  
pp. 291-293 ◽  
Author(s):  
Bill D. Brewster ◽  
Arnold P. Appleby

Imazamethabenz is a selective herbicide used to control wild oat in small grains. The effects of rate, volume of carrier, and surfactant concentration on the efficacy of this herbicide in controlling wild oat were studied in field experiments. As each of the variables increased, wild oat control increased; the greatest degree of wild oat growth inhibition occurred at the highest herbicide rate, highest volume of carrier, and highest surfactant concentration.


Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 277-282 ◽  
Author(s):  
M. S. Ahmadi ◽  
L. C. Haderlie ◽  
G. A. Wicks

Under greenhouse conditions, postemergence herbicide effectiveness was greater when barnyardgrass [Echinochloa crus-galli(L.) Beauv.] plants were 5-or 10-cm tall as compared to 15-or 20-cm tall. Absorption of14C-glyphosate [N-(phosphonomethyl)glycine] decreased from 58% of applied to 47% as plant height increased from 5 to 15 cm, and an additional reduction (to 32% of applied at 5 cm) occurred when terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] was added to glyphosate. Translocation of14C-glyphosate was reduced in older plants or when terbutryn was added to glyphosate. Water stress studies included soil moisture levels of 10, 20, 30, and 40% moisture (PW). Herbicide treatments were less effective at soil moisture levels below field capacity (30 PW). When soil moisture was 10 PW (-37 bar) absorption of14C-glyphosate was greatly reduced in plants treated at both 7.5-and 15-cm heights with or without terbutryn. At 10 PW only 15 to 20% of applied14C was absorbed whereas at 40 PW, absorption was over 45% and 62% with and without terbutryn, respectively. The addition of terbutryn to glyphosate resulted in decreased translocation for all soil moisture levels except the 20 PW treatment at the 15-cm height. Translocation of14C was greatly reduced for plants in soils at 10 PW for both herbicide treatments.


Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 895-900 ◽  
Author(s):  
S. R. Kendig ◽  
J. C. Rupe ◽  
H. D. Scott

The effects of irrigation and soil water stress on Macrophomina phaseolina microsclerotial (MS) densities in the soil and roots of soybean were studied in 1988, 1989, and 1990. Soybean cvs. Davis and Lloyd received irrigation until flowering (TAR2), after flowering (IAR2), full season (FSI), or not at all (NI). Soil water matric potentials at 15- and 30-cm depths were recorded throughout the growing season and used to schedule irrigation. Soil MS densities were determined at the beginning of each season. Root MS densities were determined periodically throughout the growing season. Microsclerotia were present in the roots of irrigated as well as nonirrigated soybean within 6 weeks after planting. By vegetative growth stage V13, these densities reached relatively stable levels in the NI and FSI treatments (2.23 to 2.35 and 1.35 to 1.63 log [microsclerotia per gram of dry root], respectively) through reproductive growth stage R6. After R6, irrigation was discontinued and root densities of microsclerotia increased in all treatments. Initiation (IAR2) or termination (TAR2) of irrigation at R2 resulted in significant changes in root MS densities, with densities reaching levels intermediate between those of FSI and NI treatments. Year to year differences in root colonization reflected differences in soil moisture due to rainfall. The rate of root colonization in response to soil moisture stress decreased with plant age. Root colonization was significantly greater in Davis than Lloyd at R5 and R8. This was reflected in a trend toward higher soil densities of M. phaseolina at planting in plots planted with Davis than in plots planted with Lloyd. Although no charcoal rot symptoms in the plant were observed in this study, these results indicated that water management can limit, but not prevent, colonization of soybean by M. phaseolina, that cultivars differ in colonization, and that these differences may affect soil densities of the fungus.


2015 ◽  
Vol 21 (2) ◽  
pp. 235 ◽  
Author(s):  
Rhuanito Soranz Ferrarezi ◽  
Marc W. Van Iersel ◽  
Roberto Testezlaf

The objectives of this work were to evaluate the effects of distinct moisture contents to trigger subirrigation on salvia photosynthesis and plant growth, and to verify the feasibility of subirrigation use in water stress imposition research in this crop. We evaluated two substrate volumetric water contents (VWC) as treatments (0.2 and 0.4 m3 m-3) to trigger subirrigation, with 4 replications. Each replication was composed of 10 plants. An automated semi-continuous multi-chamber crop CO2-exchange system was used, with capacitance soil moisture sensors for continuous moisture monitoring. Manual subirrigation with nutrient solution was performed when VWC dropped below the thresholds. In both treatments, the values of net photosynthesis, daily carbon gain and carbon use efficiency reduced over time, from 2 to 1.1 μmol s-1 from 2.2 to 1 μmol d-1 from 0.7 to 0.45 mol mol-1, respectively, in both soil moisture treatments. Total shoot dry mass (p=0.0129), shoot height in the tip of the highest flower (p<0.0001) and total leaf area (p=0.0007) were statistically higher at 0.4 m3 m-3 treatment. The subirrigation system was not efficient to impose water stress, due to excessive variation on VWC values after each irrigation event in both treatments. Higher soil moisture promoted positive plant growth responses in salvia cultivated by subirrigation.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 656c-656
Author(s):  
Bruce Lampinen ◽  
K. A. Shackel ◽  
S. Southwick ◽  
D. Goldhamer ◽  
B. Olson

During this three year study, irrigation water was withheld from trees in a commercial drip irrigated french prune orchard (Butte County, CA), during different periods within the double sigmoid fruit growth pattern (stage I - III), and postharvest. Tree water stress associated with early season water deprivation was minimal, due to the presence of stored soil moisture and low evaporative demands. For mid and late season water deprivation there was no fruit growth stage that was particularly sensitive to water stress, although severe and prolonged stress caused smaller fruit with lower quality. For the three year average, irrigation treatments caused no statistically significant effects on fruit set or drop relative to the control, however most of the stress treatments increased return bloom relative to the control, resulting in higher fruit loads and higher yields. These results suggest that moderate water stress may enhance economic prune productivity.


SIGMA TEKNIKA ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 81
Author(s):  
Muhammad Irsyam

ABSTRAK           Faktor yang menentukan kegagalan pertumbuhan suatu tanaman hampir dipengaruhi oleh teknik atau cara penyiraman tanaman yang salah. Hal ini disebabkan oleh teknik penyiraman yang dilakukan secara manual sehingga tidak semua tanaman mendapatkan asupan air yang merata untuk menghidari tanaman menjadi layu. Faktor lain yang menyebabkan kegagalan pertumbuhan tanaman adalah kelembaban tanah.          Oleh karena itu, untuk mengurangi permasalahan tersebut dirancanglah “Sistem Otomasi Penyiraman Tanaman Berbasis Telegram”. Adapun sistem ini meliputi penyiraman tanaman secara otomatis berdasarkan kadar kelembaban tanah dengan sistem pemberitahuan atau notifikasi yang akan dikirimkan kepada petani dengan menggunakan aplikasi smart phone Telegram.          Sistem ini telah mampu mengontrol penyiraman sesuai dengan kondisi yang diinginkan. Dengan adanya sistem otomasi penyiraman tanaman berbasis telegram maka dapat meningkatkan efesiensi dan efektivitas petani sehingga kualitas tanaman dapat terjaga dengan baik.Kata kunci -- Penyiraman Tanaman, Penyiraman Secara Otomatis, Telegram.ABSTRACT                Factors that determine the failure of a plant's growth of almost are influenced by incorrect cropping techniques or methods. This is caused by the technique of watering is done manually so that not all plants get a uniform water intake to avoid crops withered. Another factor that causes plant growth failure is soil moisture.          Therefore, to reduce the problem was designed "Telegram Based Water Planting Automation System". The system includes automatic watering of plants based on moisture level of the soil with a notification or notification system that will be sent to farmers using Telegram smart phone applications.          This system has been able to control the watering according to the desired conditions. With the telegraph-based plant watering plant automation system can improve the efficiency and effectiveness of farmers so that the quality of the plant can be maintained properly. Keywords -- Watering Plants, Watering Automatically, Telegram.  


1988 ◽  
Vol 80 (4) ◽  
pp. 586-591 ◽  
Author(s):  
W. B. Hallmark ◽  
C. J. DeMooy ◽  
H. F. Mooris ◽  
John Pesek ◽  
K. P. Shao ◽  
...  

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 375-379 ◽  
Author(s):  
Thomas J. Peters ◽  
Russell S. Moomaw ◽  
Alex R. Martin

The control of three summer annual grass weeds with herbicides during establishment of forage grasses was studied near Concord and Mead, NE, in 1984, 1985, and 1986. Three cool-season forage grasses, intermediate wheatgrass, tall fescue, and smooth bromegrass, and two warm-season grasses, big bluestem and switchgrass, were included. The control of three major summer annual grasses, green foxtail, barnyardgrass, and large crabgrass, was excellent with fenoxaprop at 0.22 kg ai/ha. Slight to moderate injury to cool-season forage grasses and severe injury to warm-season grasses were evident. Sethoxydim at 0.22 kg ai/ha and haloxyfop at 0.11 kg ai/ha controlled green foxtail and large crabgrass, but not barnyardgrass. Sulfometuron-treated big bluestem and switchgrass plots had the best forage stand frequencies and yields and, at the rate used, sulfometuron satisfactorily controlled green foxtail but only marginally controlled barnyardgrass and large crabgrass.


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