Plant Growth Response to the Phytotoxin Viridiol Produced by the FungusGliocladium virens

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 683-687 ◽  
Author(s):  
Richard W. Jones ◽  
W. Thomas Lanini ◽  
Joseph G. Hancock
Keyword(s):  
Root Zone ◽  
Wide Spectrum ◽  
Soil Surface ◽  
Application Rate ◽  
Herbicidal Activity ◽  
Peat Moss ◽  
Application Rates ◽  
Gliocladium Virens ◽  
Root Necrosis ◽  
Shoot Weight

Gliocladium virens, when grown on peat moss amended with sucrose and ammonium nitrate and then applied to soil, resulted in root necrosis. Herbicidal activity was correlated with fungal production of the phytotoxin viridiol. Viridiol had a wide spectrum of activity; it was particularly effective against annual composite species but was less effective in monocot control. Emergence of most weeds was reduced >90% at application rates of 8.7% (of total volume) or less. Treated seedling dry weights were drastically reduced. Applications of 4.5% reduced root and shoot weight of redroot pigweed by 93 and 98%, respectively. Crops were affected at higher treatment levels; however, the toxicity was readily avoided by applying the mycoherbicide out of the root zone of the crop, instead applying it between the seed and the soil surface. Viridiol production, which confers herbicidal activity, was detected 3 days after incorporation of the fungus-peat mixture. Viridiol production peaked on days 5 and 6 at approximately 25 μg viridiol/100 ml soil, based upon an application rate of 11%, then declined to undetectable levels by the end of 2 weeks.

Chemical Weed Control in Tall Bearded Iris

Weed Science ◽  
1973 ◽  
Vol 21 (3) ◽  
pp. 258-260
Author(s):  
D. C. Milbocker
Keyword(s):  
Root Growth ◽  
Weed Control ◽  
Root Zone ◽  
Application Rates ◽  
Root Necrosis ◽  
Iris Germanica ◽  
Better Than

Fall-applied 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) satisfactorily controlled annual and biennial weeds in tall bearded iris (Iris germanica L.). Increased application rates improved control of semitolerant weeds. Trifluralin controlled grass weeds better than simazine. Simazine caused leaf tip and root necrosis, and trifluralin prevented root growth of iris plants when incorporated in the root zone at high rates of application.

scholarly journals Evaluating the Efficacy of Dazomet for the Control of Annual Bluegrass Seed Germination in Renovated Turf Surfaces

2018 ◽  
Vol 28 (1) ◽  
pp. 44-47
Author(s):  
Jacob S. Bravo ◽  
Thomas Okada Green ◽  
James R. Crum ◽  
John N. Rogers ◽  
Sasha Kravchenko ◽  
...  
Keyword(s):  
Soil Type ◽  
Block Design ◽  
Soil Layer ◽  
Soil Surface ◽  
Application Rate ◽  
Annual Bluegrass ◽  
Application Rates ◽  
Trial Treatment ◽  
Soil Preparation ◽  
Native Soils

The soil sterilant, dazomet, is the primary product in the turfgrass industry set to take the position of methyl bromide, which is no longer available for use on turfgrass. With turf surface renovations taking place throughout the country, the need for an effective soil sterilant is critical. This study focused on the ability of dazomet to inhibit germination of annual bluegrass (Poa annua) seeds when it is used as per the current, turf focused, label which decreased legal application rates across all surfaces. This study was a four-way factorial in a split-split plot design with whole plots in a randomized complete block design arrangement with three replications. The first factor, soil type, included two levels. Soil-type plots (60 × 95 ft) were either sand capped from topdressing over the native Capac loam or they were the native Capac loam. Sand topdressing was applied biweekly at a rate of 0.14 yard3/1000 ft2, April to September since 2011; accumulating a total of 1.5 inches of sand. Each of three replicated blocks consisted of two soil-type plots. The second factor was time trials, with two levels of starting times, June and August. Each soil-type plot was split into two subplots and the trials were assigned at random to subplots within each plot. The third factor, soil preparation, involved either removing the upper 1.5 inches of the sod/soil layer or spraying plots with glyphosate and then heavily cultivating them. This cultivation included a vertical-cut and a core cultivation with an aerator using 0.5-inch hollow tines at 2 × 2-inch spacing. The fourth factor, treatment regime, comprised 11 parameters that encompassed dazomet application rate, incorporation method, and the technique used to seal the soil surface. Dazomet treatments were applied with a shaker bottle, at rates that included 262, 421, 525, and 262 lb/acre applied twice at a 5-day interval. The treatments were incorporated into the soil either through 1 inch of irrigation, through four consecutive days of irrigation following this schedule: 1, 0.5, 0.25, 0.125 inch each day after application, respectively, or physically (P) with a rotary tiller set to 1.5 inches, the depth of the topdressing layer. All P incorporated plots were hand rolled following application, regardless of the tarping procedure. Water-incorporated plots were either sealed with a clear plastic 4-mil tarp or they were left unsealed. Researchers evaluated the level of germination control by counting individual annual bluegrass seedlings using a 1 × 1-ft grid. A significant interaction occurred between soil type and soil preparation as well as between soil type and treatment. A three-way interaction also occurred between trial, treatment and soil preparation. In general, tarped treatments showed better annual bluegrass control compared with nontarped treatments. Furthermore, sand topdressed soils showed lower numbers of annual bluegrass as compared with native soils. Finally, reduced annual bluegrass germination was found in plots that had the top 1.5 inches of material removed.

scholarly journals CORN GLUTEN MEAL: ALTERNATIVE WEED CONTROL FOR SQUASH

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 884e-884
Author(s):  
Charles L. Webber ◽  
James W. Shrefler
Keyword(s):  
Soil Surface ◽  
Application Rate ◽  
Vegetable Crops ◽  
Corn Gluten Meal ◽  
Plant Survival ◽  
Application Rates ◽  
Significant Difference ◽  
Corn Gluten ◽  
Direct Seeded ◽  
The Impact

Corn gluten meal (CGM) has been identified as a potential organic preemergence and preplant-incorporated herbicide. It is an environmentally friendly material that has demonstrated ability to decrease seedling development and plant survival by inhibiting root and shoot development. Unfortunately, CGM can also decrease the development and plant survival of direct-seeded vegetable crops. As a result, the use of CGM is not recommended in conjunction with direct-seeded vegetables. The development of equipment to apply CGM in banded configurations has created an opportunity to investigate whether banded CGM applications will provide significant crop safety for direct-seeded vegetables. The objective of this research was to determine the impact of banded CGM applications on squash plant survival and yields. A factorial field study was conducted during the summer of 2004 on 81-cm-wide raised beds at Lane, Okla., with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and non-incorporated), and three application rates (250, 500, and 750 g·m–2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on 18 Aug. The banded application created a 7.6-cm-wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 2.5 to 5.0 cm of the soil surface with a rolling cultivator or left undisturbed on the soil surface. `Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was not a significant difference between powdered and granulated CGM formulations or incorporating and non-incorporating the CGM for either squash plant survival or yields. CGM application rates made a significant difference for both squash survival and yields, when averaged across all other factors. As the CGM application rate increased, the plant survival and yields decreased. When averaged across all other factors, the banded application resulted in significantly greater crop safety (59% plant survival) and yields (228 cartons/ha) than the solid applications (25% plant survival and 118 cartons/ha). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in a banded application configuration. Additional research should further investigate the interaction of CGM application rates and the width of the CGM-free zone on crop safety for various vegetables.

Amelioration of subsurface acidity in sandy soils in low rainfall regions .1. Responses of wheat and lupins to surface-applied gypsum and lime

Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 835 ◽  
Author(s):  
CDA Mclay ◽  
GSP Ritchie ◽  
WM Porter
Keyword(s):  
Sandy Soils ◽  
Soil Surface ◽  
Field Trials ◽  
Application Rate ◽  
Growing Seasons ◽  
Application Rates ◽  
Lime Application ◽  
Water Holding ◽  
Different Sources ◽  
Gypsum Application

Amelioration of subsoil acidity using gypsum (CaSO4.2H2O) or lime (CaCO3) was studied on sandy textured soils with low water holding capacity in a low rainfall environment. Field trials were established in 1989 at two sites on yellow sandplain soils to investigate whether different rates, sources and combinations of gypsum and lime application could be used to increase wheat and lupin yields. Gypsum increased wheat yields by up to 45% in the first two growing seasons whereas lime increased wheat yields by up to only 15% in the second season. The highest yields were generally recorded when gypsum and lime were applied together. The response of wheat to the various treatments varied both regionally and temporally and it is suggested that the inherent soil solution composition affected the magnitude and rapidity of wheat responses to gypsum. The rate of gypsum application affected the longevity of the wheat responses, with a low application rate (1 t ha-1) increasing yields for only one season. No differences in wheat yields were recorded between different sources of gypsum or application rates higher than 3 t ha-1. In contrast to wheat, lupin yields were substantially lower on gypsum-treated plots. The yield decline did not appear to be related to any simple nutritional factor and the gypsum effect was generally minimized when lime was added with the gypsum. The results indicated that lower rates of gypsum than used in previous subsoil amelioration studies were suitable for increasing wheat yields on sandy soils in low rainfall environments, and that gypsum should not be used if lupins are to be grown within at least 2 years of its application to the soil surface.

NH3 volatilization, soil concentration and soil pH following subsurface banding of urea at increasing rates

2013 ◽  
Vol 93 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Philippe Rochette ◽  
Denis A. Angers ◽  
Martin H. Chantigny ◽  
Marc-Olivier Gasser ◽  
J. Douglas MacDonald ◽  
...  
Keyword(s):  
Soil Ph ◽  
Nonlinear Response ◽  
Ammonia Volatilization ◽  
Soil Surface ◽  
Application Rate ◽  
Wind Tunnels ◽  
Application Rates ◽  
Silty Loam ◽  
Loam Soil ◽  
Main Factor

Rochette, P., Angers, D. A., Chantigny, M. H., Gasser, M.-O., MacDonald, J. D., Pelster, D. E. and Bertrand, N. 2013. NH 3 volatilization, soil [Formula: see text] concentration and soil pH following subsurface banding of urea at increasing rates. Can. J. Soil Sci. 93: 261–268. Subsurface banding of urea can result in large ammonia (NH3) emissions following a local increase in soil ammonium ([Formula: see text]) concentration and pH. We conducted a field experiment to determine how application rates of subsurface banded urea impact NH3 volatilization. Urea was banded at a 5 cm depth to a silty loam soil (pH=5.5) at rates of 0, 6.1, 9.2, 13.3 and 15.3 g N m−1. Ammonia volatilization (wind tunnels), and soil [Formula: see text] concentration and pH (0–10 cm) were monitored for 25 d following urea application. Volatilization losses increased exponentially with urea application rate to 11.6% of applied N for the highest urea rate, indicating that as more urea N was added to the soil a larger fraction was lost as NH3. Cumulative NH3-N emissions were closely related (R 2≥0.85) to maximum increases in soil [Formula: see text] concentration and pH, and their combined influence likely contributed to the nonlinearity of the volatilization response to urea application rate. However, the rapid increase in NH3 losses when soil pH rose above 7 suggests that soil pH was the main factor explaining the nonlinear response of NH3 volatilization. When compared with previous studies, our results suggest that the response of NH3 volatilization losses to urea application rate in acidic soils are controlled by similar factors whether urea is broadcasted at the soil surface or subsurface banded.

scholarly journals Laboratory assessment of the influence of rice straw mulch size on soil loss

2019 ◽  
Vol 48 ◽  
pp. 11-18 ◽  
Author(s):  
João L. M. P. de Lima ◽  
Lara Santos ◽  
Babar Mujtaba ◽  
M. Isabel P. de Lima
Keyword(s):  
Rice Straw ◽  
Soil Loss ◽  
Crop Residues ◽  
High Surface ◽  
Soil Surface ◽  
Bare Soil ◽  
Application Rate ◽  
Laboratory Assessment ◽  
Straw Mulch ◽  
Application Rates

Abstract. Application of crop residues (mulch) over the soil surface is a common practice to control soil erosion and promote infiltration. This laboratory study aimed at investigating the effect of different rice straw mulch sizes on runoff and sediment transport. The experimental runs were conducted using a soil flume of adjustable slope and a rainfall simulator, considering bare soil and three different soil covers: 1, 2 and 5 t ha−1 application rates, for three sizes of rice straw mulch (10, 30 and 200 mm). The experimental results showed that for the same mulch application rate (by weight), the smaller mulch sizes (i.e. high surface coverage percentage) presented less soil loss. For example, 90 % soil loss reduction was achieved for smaller sizes of rice straw mulch and 80 % for the bigger size. The results of this study are an important contribution to the understanding of the soil loss process in small basins and to the definition of relevant soil conservation measures, at the plot/field scale.

Ammonia emissions from rough cattle slurry and from derived solid and liquid fractions applied to alfalfa pasture

2008 ◽  
Vol 48 (2) ◽  
pp. 198 ◽  
Author(s):  
P. Balsari ◽  
E. Dinuccio ◽  
E. Santoro ◽  
F. Gioelli
Keyword(s):  
Liquid Fraction ◽  
Soil Surface ◽  
Application Rate ◽  
Ammonia Emissions ◽  
Gaseous Emissions ◽  
Cattle Slurry ◽  
Air Velocity ◽  
Application Rates ◽  
Daily Sampling ◽  
Air Speed

A field trial was conducted to assess the emission of ammonia from rough cattle slurry and solid and liquid fractions (generated from its mechanical separation) applied to alfalfa pasture. Three materials (rough slurry, liquid fraction and solid fraction) were applied on alfalfa over two seasons (summer and autumn), with two application rates (40 and 70 kg N/ha) and with two air velocities (0–0.6 m/s) at the soil surface. Ammonia losses were measured either by a set of wind tunnels (adjusting the air velocity at 0.6 m/s) or by a funnel system, allowing measurements to be recorded at an air speed close to 0 m/s. Each trial lasted 5 days with daily sampling of the gaseous emissions. Trial results showed that the rough slurry substrate had the highest level of ammonia emissions, followed by the liquid and solid fractions. Up to 35% of the applied total Kjeldahl nitrogen was lost as ammonia from the rough slurry in 5 days in summer conditions and with an air velocity of 0.6 m/s. No effect due to the application rate was observed, however, a significant effect of the temperature and air velocity on ammonia emissions was measured. Ammonia emissions after the spreading of the rough slurry were up to 26% higher when compared with those generated after application of the two fractions (solid + liquid).

Herbicidal Activity of Fluazifop-Butyl, Haloxyfop-Methyl, and Sethoxydim in Soil

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 824-831 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside
Keyword(s):  
Sorghum Bicolor ◽  
Field Experiments ◽  
Root Zone ◽  
Seedling Survival ◽  
Soil Surface ◽  
Herbicidal Activity ◽  
Grass Species ◽  
Propanoic Acid ◽  
Forage Sorghum ◽  
Sorghum Seedling

Fluazifop-butyl {(±) butyl 2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, haloxyfop-methyl {methyl-2-[4-[[3-chloro-5-(trifluoromethyl-2-pyridinyl] oxy] phenoxy] propanoic acid}, and sethoxydim {2-[1-(ethoxyimino)-butyl]-5-[2-ethylthio)propyl-3-hydroxy-2-cyclohexen-1-one}exhibited soil herbicidal activity to annual grass species in greenhouse and field experiments. Control of forage sorghum [Sorghum bicolor(L.) Moench. ‘Rox Orange’] with all three herbicides was greater when seeds were planted at or near the soil surface than when planted 2, 4, or 6 cm deep. Imbibition of the herbicides by forage sorghum and soybean [Glycine max(L.) Merr.] seeds did not reduce germination at concentrations of 10-3M or lower, but forage sorghum seedling survival and vigor were reduced by herbicide concentrations as low as 10-7M. Fluazifop-butyl, haloxyfop-methyl, and sethoxydim were more phytotoxic when applied to the root zone than the shoot zone. Haloxyfop-methyl exhibited the longest soil residual control in the field followed by fluazifop-butyl and sethoxydim. Haloxyfop-methyl and fluazifop-butyl controlled simulated shattercane [Sorghum bicolor(L.) Moench. ♯3SORVU] in soybeans with preemergence and early postemergence applications, whereas control from similar applications of sethoxydim was limited and variable.

scholarly journals Mobility, Degradation, and Uptake of Indaziflam under Greenhouse Conditions

HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1216-1221
Author(s):  
Amir M. González-Delgado ◽  
Manoj K. Shukla
Keyword(s):  
Retention Time ◽  
Preferential Flow ◽  
Sandy Loam ◽  
Soil Surface ◽  
Growing Season ◽  
Application Rate ◽  
Homogeneous Porous Media ◽  
Application Rates ◽  
Loam Soil ◽  
Irrigation Volume

The objectives of this study were to evaluate the leaching, degradation, uptake, and mass balance of indaziflam, as well as its potential to produce phytotoxicity effects on young pecan trees. Pecan trees were planted in pots with homogeneous porous media (sandy loam soil), preferential flow channels open to the soil surface, and shallow tillage at the soil surface. Pots were treated with indaziflam at two application rates of 25 and 50 g a.i./ha in 2014 and 2015. Each pecan tree was irrigated with 7 L of water every 2 weeks during the growing season. An irrigation volume of 2 L was used to maximize indaziflam retention time in the soil from Dec. 2015 until the end of the trees’ dormant stage. In 2014, leachate samples were collected after each irrigation for quantifying indaziflam mobility. Soil samples were collected at depths of 0 to 12 and 12 to 24 cm after 45, 90, and 135 days of indaziflam application, and leaf samples were collected at the end of the growing season to quantify mobility and uptake. Indaziflam was detected in leachate samples, and the leaf indaziflam content increased with increasing application rate. Indaziflam and its breakdown products were detected at both sampling depths. Mass recovery and half-life values for indaziflam in the soil ranged from 38% to 68% and 63 to 99 days, respectively. No phytotoxicity effects were observed from increasing application rate and retention time of indaziflam in the soil. Most of the applied indaziflam was retained in the soil at shallow depth.

scholarly journals Supraoptimal Root-zone Temperature Influences the Medium Solution and Growth of `Helleri' Holly

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1020-1025 ◽  
Author(s):  
Ronald F. Walden ◽  
Robert D. Wright
Keyword(s):  
Root Zone ◽  
Application Rate ◽  
Pine Bark ◽  
Solution Ph ◽  
N Application ◽  
Root Zone Temperature ◽  
Application Rates ◽  
N Application Rate ◽  
Rate Effects ◽  
Zone Temperature

Rooted cuttings of Ilex crenata Thunb. `Helleri' were grown for 12 weeks in pine bark with two root-zone temperature treatments (unheated or heated to 40C for 6 hours·day–1), two rates of limestone addition (0 or 6 kg·m–3), and three weekly N application rates (200, 400, or 600 mg·liter–1 as urea ammonium nitrate) in a factorial combination. Decreases in shoot and root dry weights due to root-zone heating (69% and 75%, respectively) or limestone addition (41% and 42%, respectively) were not influenced by N application rate. Effects of root-zone heating on medium solution characteristics, which differed in response to limestone addition, were similar for all N application levels. In unlimed pine bark at 400 mg N/liter, the pH and the NH4-N: NO3-N ratio were higher in the heated medium (5.5 and 1.15, respectively) than in the unheated medium (3.9 and 0.64, respectively) after 80 days, suggesting that 6 hours of daily exposure to 40C inhibited nitrification. The higher medium solution pH due to root-zone heating resulted in lower medium solution and shoot tissue Mn concentrations.

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