scholarly journals Nematode Control from Shank- and Drip-applied Fumigant Alternatives to Methyl Bromide

HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1826-1832 ◽  
Author(s):  
Sally M. Schneider ◽  
Husein A. Ajwa ◽  
Thomas J. Trout ◽  
Suduan Gao

Field studies were conducted to evaluate potential alternatives to methyl bromide (MBr) for the control of plant parasitic nematodes in shallow-rooted, bedded cropping systems such as strawberry and in perennial nursery cropping systems in central California. Chloropicrin (Pic), 1,3-dichloropropene (1,3-D or Telone), combinations of 1,3-D + Pic, iodomethane (IM) + Pic, propargyl bromide (PBr), and metam sodium (MS) were compared with untreated controls and industry standard MBr/Pic treatments. Materials were applied by both shank-injection and drip-application, except MS and PBr, which were applied only by drip. The efficacy on citrus nematode (Tylenchulus semipenetrans Cobb) and/or root-knot nematode (Meloidogyne spp. Chitwood) control was investigated in three trials conducted on soils ranging from sandy loam to silty clay loam. All treatments controlled nematodes near the injection point (center of bed and moderate depths) comparable to MBr/Pic. Drip-applied Pic provided somewhat less control than MBr/Pic at the shoulder of the bed when delivered in 25 mm of water and MS provided no control at the bed shoulder. IM + Pic, both shank-injected and drip-applied, provided nematode control to a depth of 150 cm comparable to MBr/Pic. Telone EC applied to a dry field in 75 mm water did not control nematodes well at either 90- or 150-cm depths, whereas PBr controlled nematodes as effectively as MBr/Pic at the 90-cm depth, but not at the 150-cm depth. Propargyl bromide at 67 kg·ha−1 was effective at killing the nematodes up to 30 cm deep in a strawberry plant bed. The dosage exposure values (within 96 h after fumigation) observed for greater than 99% control of nematodes were much lower for PBr (≈1 mg·L−1·h) than those for 1,3-D + Pic (17 mg·L−1·h when applied at 61:35 1,3-D:Pic mass ratio), Pic alone (10 mg·L−1·h), and IM + Pic (19 mg·L−1·h when applied at 50:50 mass ratio). Drip application technology showed promise for effective alternatives to MBr/Pic. Consistent delivery of an effective dosage of a material throughout the target soil profile is necessary for consideration as an acceptable alternative to MBr for high-value crops.

1997 ◽  
Vol 77 (2) ◽  
pp. 145-152 ◽  
Author(s):  
A. F. MacKenzie ◽  
M. X. Fan ◽  
F. Cadrin

Nitrous oxide (N2O) produced from agricultural activities represents a threat to the ozone layer and economic losses. Rates and magnitudes of N2O emissions of cropping systems must be determined to establish corrective management procedures. In 1994, N2O emissions were determined with corn (ZeaMays L.) and corn-legume rotations. Continuous corn was studied on four soils, two from a long-term experiment, a Ste. Rosalie heavy clay (Humic Gleysol) and a Chicot sandy loam (Grey-Brown Podzol), at 0, 170, 285 or 400 kg N ha−1, and two from a corn rotation study, a Ste. Rosalie clay (Humic Gleysol) and an Ormstown silty clay loam (Humic Gleysol). Treatments included no-till (NT) and conventional tillage (CT), monoculture corn (CCCC), monoculture soybean; corn-soybean; and soybean-corn-alfalfa phased rotations. Nitrogen rates of 0, 90, or 180 kg N ha−1 for corn and 0, 20, or 40 kg N ha−1 for continuous soybean were used, and soybean/alfalfa following corn no fertilizer N. Rates of N2O emission were measured from closed chambers through the growing season. About 0.99 to 2.1% of N added was lost as N2O. Nitrous oxide emission increased with increased soil water content, NO3 concentration and fertilizer N rates. Emission of N2O was higher with NT than with CT, and with corn than with soybean or alfalfa. A corn system using CT, legumes in rotation and moderate fertilizer N would reduce N2O emission. Key words: Greenhouse gases, soil nitrate, tillage methods, water-filled pore space, denitrification, rotations


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Ruihuan She ◽  
Yongxiang Yu ◽  
Chaorong Ge ◽  
Huaiying Yao

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.


2000 ◽  
Vol 29 (4) ◽  
pp. 1322-1328 ◽  
Author(s):  
Sharon K. Papiernik ◽  
Jianying Gan ◽  
Scott R. Yates

1988 ◽  
Vol 110 (1) ◽  
pp. 119-140 ◽  
Author(s):  
G. N. Thorne ◽  
P. J. Welbank ◽  
F. V. Widdowson ◽  
A. Penny ◽  
A. D. Todd ◽  
...  

SummaryWinter wheat grown following potatoes on a sandy loam at Woburn in 1978–9, 1980–1 and 1981–2 was compared with that on a clay loam at Rothamsted in 1978–9 and 1980–1, and on a silty clay (alluvium) at Woburn in 1981–2. The cultivar was Hustler in the harvest years 1979 and 1981 and Avalon in 1982. On each soil in each year multifactorial experiments tested effects of combinations of six factors, each at two levels.The best 4-plot mean grain yield ranged from 89 to 11·1 t/ha during the 3 years; it was smaller on the sandy soil than on the clay soil in 1979, but larger on sand than on the clay in 1981 and 1982. Until anthesis the number of shoots, dry weight and N content of the wheat giving these best yields were less on sand than on clay. Unlike grain weight, straw weight was always less on sand.Sowing in mid-September instead of mid-October increased grain yield on clay in each year (by 0·4·0·7 t/ha) and increased yield on sand only in 1981 (by 1·6 t/ha). Early sowing always increased dry weight, leaf area, number of shoots and N uptake until May. The benefits were always greater on clay than on sand immediately before N fertilizer was applied in the spring and usually lessened later on both soils.Aldicarb as an autumn pesticide increased grain yield of early-sown wheat on both soils in 1981 by lessening infection with barley yellow dwarf virus. Aldicarb increased yield on clay in 1982; it also decreased the number of plant parasitic nematodes.Wheat on sand was more responsive to nitrogen in division, timing and amount than was wheat on clay. In 1979 yield of wheat on sand was increased by dividing spring N between March, April and May, instead of giving it all in April, and in 1982 by giving winter N early in February. In 1981 division and timing on sand interacted with sowing date. Yield of early-sown wheat given N late, i.e. in March, April and May, exceeded that given N early, i.e. in February, March and May, by 1·4 t/ha; single dressings given all in March or all in April also yielded less than the late divided dressing. Yield of later-sown wheat given all the N in April was at least 1·2 t/ha less than with all N given in March or with divided N. In all years treatments that increased yield usually also increased N uptake. Grain yield on clay was never affected by division or timing of spring N or by application of winter N. This was despite the fact that all treatments that involved a delay in the application of N depressed growth and N uptake in spring on both sand and clay. The mean advantage in N uptake following early application of spring N eventually reversed on both soils, so that uptake at maturity was greater from late than from early application. Increasing the amount of N given in spring from the estimated requirement for 9 t/ha grain yield to that for 12 t/ha increased yield in 1982, especially on sand. The larger amount of N always increased the number of ears but often decreased the number of grains per ear and the size of individual grains.Irrigation increased grain yield only on the sandy soil, by 1·1 t/ha in 1979 and by 07 t/ha in 1981 and 1982. The component responsible was dry weight per grain in 1979 and 1982, when soil moisture deficits reaching maximum values of 136 and 110 mm respectively in the 2 years developed after anthesis; the component responsible was number of ears/m2 in 1982 when the maximum deficit of 76 mm occurred earlier, in late May.


2009 ◽  
Vol 6 (6) ◽  
pp. 7247-7285 ◽  
Author(s):  
N. P. Peranginangin ◽  
B. K. Richards ◽  
T. S. Steenhuis

Abstract. Accurate soil water sampling is needed for monitoring of pesticide leaching through the vadose zone, especially in soils with significant preferential flowpaths. We assessed the effectiveness of wick and gravity pan lysimeters as well as ceramic cups (installed 45–60 cm deep) in strongly-structured silty clay loam (Hudson series) and weakly-structured fine sandy loam (Arkport series) soils. Simulated rainfall (10–14 cm in 4 d, approximately equal to a 10-yr, 24 h storm) was applied following concurrent application of agronomic rates (0.2 g m−2) of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) and 2,4-D (2,4-dichloro-phenoxy-acetic acid) immediately following application of a chloride tracer (22–44 g m−2). Preferential flow mechanisms were observed in both soils, with herbicide and tracer mobility greater than would be predicted by uniform flow. Preferential flow was more dominant in the Hudson soil, with earlier breakthroughs observed. Mean wick and gravity pan sampler percolate concentrations at 60 cm depth ranged from 96 to 223 μg L−1 for atrazine and 54 to 78 μg L−1 for 2,4-D at the Hudson site, and from 7 to 22 μg L−1 for atrazine and 0.5 to 2.8 μg L−1 for 2,4-D at the Arkport site. Gravity and wick pan lysimeters had comparably good collection efficiencies at elevated soil moisture levels, whereas wick pan samplers performed better at lower moisture contents. Cup samplers performed poorly with wide variations in collections and solute concentrations.


Plant Disease ◽  
2021 ◽  
Author(s):  
Caroline E. Land ◽  
Gary E. Vallad ◽  
Johan Desaeger ◽  
Edzard van Santen ◽  
Joseph Noling ◽  
...  

Fresh-market tomatoes are produced on a raised-bed, plasti-culture system that relies heavily on soil applied, pre-plant fumigants for the management of soil borne pathogens, nematodes and weeds. Since the transition from methyl bromide to alternative fumigants, growers have experienced a resurgence of several soil borne pests and pathogens, including root-knot nematode caused by Meloidogyne spp. and Fusarium wilt caused by Fusarium oxysporum f.sp. lycopersici Race 3 (FOL). This resurgence is attributed to the inability of the alternative fumigants to effectively disperse through the soil in the same manner as methyl bromide. Two supplemental fumigation strategies, the application of chloropicrin below bed edges (supplemental PIC) and broadcast, deep shank applications of 1,3-dichloropropene (deep shank 1,3-D), were evaluated in conjunction with standard raised-bed applications of Pic-Clor 60, Pic-Clor 80, and Pic 100 covered with either a virtually impermeable film (VIF) or totally impermeable film (TIF). Large plot replicated studies were conducted in two separate commercial tomato fields with a history of production losses caused by root-knot nematode and Fusarium wilt. Deep shank 1,3-D applications significantly reduced the recovery of root-knot and total parasitic nematodes across field sites prior to the preparation of raised beds. Both supplemental PIC and deep shank 1,3-D reduced root-knot galling and Fusarium wilt incidence; although, the latter supplemental treatment statistically had the greatest impact. Neither the fumigant applied within raised beds nor plastic film had a significant effect on root-knot galling or Fusarium wilt. Although both supplemental fumigation strategies had a significant effect on pest and disease pressure, neither statistically improved tomato yields based on small sub-plot harvests. Controlled lab experiments confirmed the fungicidal activity of 1,3-dichloropropene against FOL, with LD75, LD90, LD95, and LD99 corresponding to estimated field application rates of 56.1, 93.5, 121.6, 184.7 L/ha, respectively. Results demonstrate how fumigant placement can improve pest and disease control activity with current fumigant alternatives to methyl bromide; and further support the broader pesticidal activity of some chemical fumigants.


Weed Science ◽  
1994 ◽  
Vol 42 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Pau Y. Yen ◽  
William C. Koskinen ◽  
Edward E. Schweizer

Laboratory studies were conducted to determine the influence of degradation and sorption processes on the dissipation of alachlor in one Colorado soil (Kim clay loam) and three Minnesota soils (Port Byron silt loam, Webster silty clay loam, and Estherville sandy loam) as a function of soil depth. Persistence and movement of alachlor in an irrigated corn production system also were determined on the Kim soil. Laboratory degradation data fit first-order kinetics, and rate constants ranged from 0.0094 to 0.0251 d-1and varied with soil type and depth. For instance, in 60- to 75-cm-depth Kim soil, alachlor degraded at a slower rate (k = 0.011 d-1) than in surface soil samples (k = 0.022 d-1). Alachlor sorption to the four soils was moderate (Kf= 0.7 to 7.4; Kf,oc= 71 to 470) and concentration dependent (1/n < 1.0). Significant hysteretic desorption of alachlor from soils also was observed (1/n desorption < 1/n sorption). The combined effect of degradation and sorption processes has been used to classify a chemical's potential to leach to groundwater. Based on Kf,ocand dissipation half-life, alachlor would be classified as a “leacher” in Kim, Port Byron, and Estherville soils and classified as transitional between “leacher” and “nonleacher” in the Webster soil. The dissipation first-order rate constant (k) of alachlor in Kim soil in the field was 0.036 α 0.012 d-1. Dissipation was apparently not due to leaching since bromide applied at the same time remained in the top 15 cm during the first 28 d. It appears that laboratory-derived leaching indices may overestimate actual leaching and should be used with caution for predictive or regulatory purposes.


Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 688-691 ◽  
Author(s):  
Michael G. Patterson ◽  
Gale A. Buchanan ◽  
Robert H. Walker ◽  
Richard M. Patterson

Analysis of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] in soil solution after application of 0.5 or 1.0 ppmw revealed up to five-fold differences among three Alabama soils (Lucedale fine sandy loam, Decatur silty clay loam, and Sacul loam). Differences in fluometuron in soil solution were attributed to variable organic matter present and clay fractions. Fluometuron concentration in soil solution for each soil correlated well with control of four broadleaf weed species in a field experiment.


1992 ◽  
Vol 6 (3) ◽  
pp. 583-586 ◽  
Author(s):  
John S. Wilson ◽  
Chester L. Foy

The soil organic matter and/or humic matter fraction was highly correlated with the adsorption of ICIA-0051 herbicide onto five soils; clay content and other soil factors were less correlated. The Freundlich equation was used to describe the adsorption of ICIA-0051 by the various soils. Based on the K constants, the general order for adsorption for each soil was Hyde silty clay loam > Frederick silt loam > Davidson clay = Bojac sandy loam > Appling loamy sand. Across all soils, 25 to 50% of the amount adsorbed was removed by two desorptions. Appling, Bojac, and Davidson soils retained less herbicide after two desorptions than did Frederick and Hyde.


Soil Research ◽  
2012 ◽  
Vol 50 (1) ◽  
pp. 58 ◽  
Author(s):  
P. Jiao ◽  
D. Xu ◽  
S. Wang ◽  
Y. Wang ◽  
K. Liu ◽  
...  

Reducing nitrogen (N) loss from agricultural soils as surface runoff is essential to prevent surface water contamination. The objective of 3-year study, 2007–09, was to evaluate surface runoff and N loss from different cropping systems. There were four treatments, including one single-crop cropping system with winter wheat (Triticum aestivum L.) followed by summer fallow (wheat/fallow), and three double-cropping systems: winter wheat/corn (Zea mays L.), wheat/cotton (Gossypium hirsutum L.), and wheat/soybean (Glycine max L. Merrill). The wheat/fallow received no fertiliser in the summer fallow period. The four cropping systems were randomly assigned to 12 plots of 5 m by 2 m on a silty clay soil. Lower runoff was found in the three double-cropping systems than the wheat/fallow, with the lowest runoff from the wheat/soybean. The three double-cropping systems also substantially reduced losses of ammonium-N (NH4+-N), nitrate-N (NO3–-N), dissolved N (DN), and total N (TN) compared with the wheat/fallow. Among the three double-cropping systems, the highest losses of NO3–-N, DN, and TN were from the wheat/cotton, and the lowest losses were from the wheat/soybean. However, the wheat/soybean increased NO3–-N and DN concentrations compared with wheat/fallow. The losses in peak events accounted for >64% for NH4+-N, 58% for NO3–-N, and 41% for DN of the total losses occurring during the 3-year experimental period, suggesting that peak N-loss events should be focussed on for the control of N loss as surface runoff from agricultural fields.


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