Herbicide Effectiveness, Soil Residues, and Phytotoxicity to Peach Trees

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 257-260 ◽  
Author(s):  
W. A. Skroch ◽  
T. J. Sheets ◽  
J. W. Smith
Keyword(s):  
Weed Control ◽  
Prunus Persica ◽  
Cynodon Dactylon ◽  
Soil Depth ◽  
Soil Layer ◽  
Soil Surface ◽  
The Third ◽  
Low Concentrations ◽  
Peach Trees ◽  
Annual Application

Dichlobenil (2,6-dichlorobenzonitrile), 3-tert-butyl-5-chloro-6-methyluracil (terbacil), and 3-tert-butyl-5-bromo-6-methyluracil (hereinafter referred to as DP-733) were applied annually for 3 years as soil surface or incorporated treatments for weed control in young peach (Prunus persica(L.) Batsch., var. Redhaven) trees. Average monthly ratings showed significant increases in bermudagrass (Cynodon dactylon(L.) Pers.) control with incorporation of all three herbicides. Treetrunk diameters in incorporated dichlobenil plots were greater than those in surface-applied dichlobenil plots. Incorporation in the soil reduced loss of dichlobenil, terbacil, and DP-733. The herbicides did not accumulate in the 0 to 15-cm soil layer. Low concentrations were detected in the 30 to 60-cm soil depth 1 year after the third annual application of 6.72 kg/ha of dichlobenil and 4.48 kg/ha of DP-733. Terbacil was not present in detectable amounts at 30 to 60 cm but was present in the 15 to 30-cm layer of 4.48 kg/ha plots.

scholarly journals The Soil Moisture during Dry Spells Model and Its Verification

Resources ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 85
Author(s):  
Małgorzata Biniak-Pieróg ◽  
Mieczysław Chalfen ◽  
Andrzej Żyromski ◽  
Andrzej Doroszewski ◽  
Tomasz Jóźwicki
Keyword(s):  
Soil Moisture ◽  
Least Squares Method ◽  
Soil Depth ◽  
Soil Layer ◽  
Atmospheric Precipitation ◽  
Soil Surface ◽  
Model Verification ◽  
Individual Measurement ◽  
Dry Spells ◽  
Dry Spell

The objective of this study was the development and verification of a model of soil moisture decrease during dry spells—SMDS. The analyses were based on diurnal information of the occurrence of atmospheric precipitation and diurnal values of soil moisture under a bare soil surface, covering the period of 2003–2019, from May until October. A decreasing exponential trend was used for the description of the rate of moisture decrease in six layers of the soil profile during dry spells. The least squares method was used to determine, for each dry spell and soil depth, the value of exponent α , which described the rate of soil moisture decrease. Data from the years 2003–2015 were used for the identification of parameter α of the model for each of the layers separately, while data from 2016–2019 were used for model verification. The mean relative error between moisture values measured in 2016–2019 and the calculated values was 3.8%, and accepted as sufficiently accurate. It was found that the error of model fitting decreased with soil layer depth, from 8.1% for the surface layer to 1.0% for the deepest layer, while increasing with the duration of the dry spell at the rate of 0.5%/day. The universality of the model was also confirmed by verification made with the use of the results of soil moisture measurements conducted in the years 2009–2019 at two other independent locations. However, it should be emphasized that in the case of the surface horizon of soil, for which the process of soil drying is a function of factors occurring in the atmosphere, the developed model may have limited application and the obtained results may be affected by greater errors. The adoption of calculated values of coefficient α as characteristic for the individual measurement depths allowed calculation of the predicted values of moisture as a function of the duration of a dry spell, relative to the initial moisture level adopted as 100%. The exponential form of the trend of soil moisture changes in time adopted for the analysis also allowed calculation of the duration of a hypothetical dry spell t, after which soil moisture at a given depth drops from the known initial moisture θ0 to the predicted moisture θ. This is an important finding from the perspective of land use.

Movement of Alachlor and Metribuzin from Controlled Release Formulations in a Sandy Soil

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 606-613 ◽  
Author(s):  
Gwen F. Fleming ◽  
Loyd M. Wax ◽  
F. William Simmons ◽  
Allan S. Felsot
Keyword(s):  
Controlled Release ◽  
Weed Control ◽  
Soil Depth ◽  
Soil Surface ◽  
Column Experiments ◽  
Limited Effect ◽  
Emulsifiable Concentrate ◽  
Growing Seasons ◽  
Primary Mechanism ◽  
Controlled Release Formulations

Field and column experiments were conducted to determine the effect of controlled release formulations on weed control and leaching of alachlor and metribuzin on a Plainfield sand. Controlled release formulations including two starch encapsulations of both herbicides and a microencapsulation of alachlor were compared to emulsifiable concentrate and dry flowable formulations of alachlor and metribuzin, respectively. Herbicide movement was measured in laboratory columns and in the field throughout two growing seasons to a soil depth of 91 cm. Soybean injury and weed control were monitored. No significant differences in herbicide movement between starch-encapsulated and emulsifiable concentrate formulations were observed in either field or column experiments. Microencapsulation resulted in the greatest retention of alachlor in the soil surface in field and columns. Compared to the dry flowable formulation, starch encapsulation did not affect metribuzin distribution in the field but reduced leaching in columns. Controlled release formulations did not result in significant differences in weed control and soybean injury compared to the emulsifiable concentrate alachlor and dry flowable metribuzin formulations. Starch encapsulations had a limited effect on alachlor and metribuzin movement. Degradation appeared to be the primary mechanism for herbicide dissipation while leaching losses were minor.

scholarly journals Pecan Shell Mulch Impact on ‘Loring’ Peach Tree Establishment and First Harvest

2009 ◽  
Vol 19 (4) ◽  
pp. 775-780 ◽  
Author(s):  
Eric T. Stafne ◽  
Charles T. Rohla ◽  
Becky L. Carroll
Keyword(s):  
Weed Control ◽  
Tree Mortality ◽  
Prunus Persica ◽  
Waste Product ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Research Station ◽  
Cross Sectional ◽  
Waste Products ◽  
Peach Trees

Pecan (Carya illinoinensis) shells are waste products that are occasionally used for mulch in ornamental landscape settings, yet most shell waste is left in piles near the shelling facility or discarded by other methods. If another use for this waste product could be developed, it may add income for pecan producers and provide peach (Prunus persica) growers with another option for weed control. A block of ‘Loring’ peach trees grafted onto ‘Halford’ rootstocks was planted at a spacing of 18 × 22 ft in Feb. 2005 at the Cimarron Valley Research Station near Perkins, OK, to determine the effect of pecan shell mulch on peach trees. Five treatments were imposed: no weed control except mowing (MOW), weed-free 6- × 6-ft area maintained with glyphosate herbicide (SPRAY), 6-ft × 6-ft × 2-inch deep mulch (TWO), 6-ft × 6-ft × 4-inch deep mulch (FOUR), and 6-ft × 6-ft × 6-inch deep mulch (SIX). Yields in 2008 were poorest in the MOW treatment (13.2 kg/tree and 93 fruit/tree). All other treatments did not differ. Soluble solids concentration as a measure of fruit quality and fruit weight was unaffected by treatment. Tree height, pruning weights, and trunk cross-sectional area were similar with the exception that MOW was lower for all three growth measurements beginning in 2007. Pecan mulch appears to have the potential to reduce soil pH. Foliar analysis for nitrogen (N), potassium (K), and zinc (Zn) showed treatment differences in 2006. No treatment differences were evident in 2007 and 2008 for K and Zn, but in 2008, FOUR had greater N than MOW. Tree mortality increased with pecan mulch depth. MOW, SPRAY, and TWO had little tree loss (0%–5%), whereas FOUR and SIX had 15% and 35% mortality, respectively. Tree mortality was attributed to record rains in 2007 coupled with longer soil moisture retention under the deeper mulch.

scholarly journals Effects of Topramezone and Bispyribac-sodium in Irrigation Water on Warm-season Turfgrasses

2017 ◽  
Vol 27 (5) ◽  
pp. 599-606
Author(s):  
William T. Haller ◽  
Lyn A. Gettys ◽  
Taizo Uchida
Keyword(s):  
Weed Control ◽  
Cynodon Dactylon ◽  
Southeastern United States ◽  
Warm Season ◽  
Hydrilla Verticillata ◽  
Paspalum Notatum ◽  
Aquatic Weed ◽  
Primary Target ◽  
Low Concentrations ◽  
Herbicide Concentration

Topramezone and bispyribac-sodium were registered for aquatic weed control in the last decade. A primary target for these products is fluridone-resistant hydrilla (Hydrilla verticillata), which is one of the most invasive submersed weeds in the southeastern United States. Both products have water use restrictions that prohibit irrigation of turfgrasses with treated waters until the herbicides have degraded to very low concentrations. The objective of these studies was to identify the concentrations of topramezone and bispyribac-sodium that are phytotoxic to turfgrasses that are commonly planted in Florida. Three species of turfgrass were irrigated twice weekly with 0.5 inch of treated water for 4 weeks (eight irrigations total). Cumulative EC10 values (the herbicide concentration that caused a 10% reduction in biomass compared with untreated control plants) after eight irrigations with water containing topramezone were 3.5, 4.3, and 17 ppb for ‘Palmetto’ st. augustinegrass (Stenotaphrum secundatum), ‘Pensacola’ bahiagrass (Paspalum notatum), and ‘Tifway 419’ hybrid bermudagrass (Cynodon dactylon × C. transvaalensis), respectively. Bispyribac-sodium was less toxic to all turfgrasses evaluated, with EC10 values of 56, 16, and >800 ppb for ‘Palmetto’ st. augustinegrass, ‘Pensacola’ bahiagrass, and ‘Tifway 419’ hybrid bermudagrass, respectively. These results support label instructions and highlight the need to comply with irrigation restrictions because the typical use concentrations for submersed weed control with topramezone and bispyribac-sodium are in the 20–40-ppb range.

scholarly journals Evaluation of Mechanical Control and Alternative Insecticides for Managing Squash Vine Borer on Summer Squash, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 167-167
Author(s):  
J. Boucher ◽  
G. Nixon
Keyword(s):  
Weed Control ◽  
Soil Surface ◽  
Mechanical Control ◽  
The Third ◽  
Summer Squash ◽  
Entire Plant ◽  
Direct Seeded ◽  
Plant Stem ◽  
Squash Vine Borer

Abstract ‘Multipik’ summer squash were direct seeded 28 Jun, in Storrs, Connecticut. Weed control consisted of the stale-seedbed technique, using paraquat as a preplant application, supplemented by hand and mechanical cultivation. Plots consisted of 12 plants in a single 24-ft long row, with 2-ft spacing between plants and 4 ft between rows. Four treatments were replicated four times in a RCBD. Two treatments involved application of Neemix or Ambush at weekly intervals on 12, 19, and 26 Jul and 2 Aug. The third treatment involved washing the entire plant stem above the soil surface with an ordinary face-cloth and a 0.5% solution of dish detergent (Sunlight, Lever Brother’s Co., NY, NY) on the above dates. The fourth was the unsprayed check. Insecticide applications were directed at the foliage and stems by spraying plots from the top and sides with a CO2 backpack sprayer at 50 psi with 40 gallons of water per acre. Fruit from five plants per plot were harvested, counted and weighed on 9, 12, 16 and 19 Aug. Five plants from each plot were dissected on 19 Aug and SVB larvae were counted. Data were analyzed using ANOVA (larval infestations) or GLM (yields) and Fisher’s LSD.

scholarly journals USE OF SIMAZINE AS A PREVENTATIVE WEED CONTROL HERBICIDE FOR BIRDSFOOT TREFOIL

1968 ◽  
Vol 48 (4) ◽  
pp. 393-399 ◽  
Author(s):  
J. E. Winch ◽  
G. W. Anderson ◽  
G. E. Jones
Keyword(s):  
Control System ◽  
Weed Control ◽  
Birdsfoot Trefoil ◽  
Leaf Stage ◽  
The Third ◽  
True Leaf ◽  
Initial Application ◽  
Original Application ◽  
Annual Application

Simazine at 0.8, 1.1, 1.6 and 2.2 kg/ha (active) was applied in October of each of three years to an established stand of Empire birdsfoot trefoil infested with grass. These rates were used alone and with an original application of each of 1.1 kg/ha paraquat and a mixture of 3.4 kg/ha dalapon + 1.1 kg/ha 2,4-DB (active). In addition, 1.1 kg/ha simazine (active) was applied in October to a new sowing of Empire birdsfoot trefoil. This rate was used alone and where each of 4.5 kg/ha dalapon, 1.1 kg/ha 2,4-DB or their mixture had been applied at the third true leaf stage of trefoil development earlier in the establishment year. The purpose of these trials was to determine the effect of simazine on the yield of birdsfoot trefoil and on the control of grass and broadleaf weeds. Simazine at 0.8, and 1.1 kg/ha applied in the fall of each year had no deleterious effects upon the yield of Empire trefoil. At the 1.6- and 2.2-kg/ha rate, a reduction in yield did occur after the second, but did not occur after the third, annual application of simazine.Although the grass proportion in old stands of trefoil was reduced to 10% or less by initial application of 1.1, 1.6 and 2.2 kg/ha of simazine, an increase up to the 30% level occurred after the second application at the 1.1- and 1.6-kg/ha rates. This grass proportion was maintained by a further application at these rates. Only the 2.2-kg/ha rate of simazine maintained the grass proportion below 10% of the yield. The original reduction in the proportion of grass was improved and subsequently maintained at a level of 25% or below where simazine was used at any rate in conjunction with an initial application of a mixture of dalapon and 2,4-DB. Combination of paraquat and simazine resulted in a trefoil stand reduction and low trefoil yields.A preventative weed control system using simazine is discussed. The program involves the initial use of a mixture of 3.4 kg dalapon and 1.1 kg 2,4-DB per hectare on new seedlings or on established stands. This is followed by an annual October application of 0.8 to 1.1 kg/ha (active) simazine.

Response of Peach Trees to Herbicide and Mechanical Weed Control

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 133-136 ◽  
Author(s):  
Jeff W. Daniell ◽  
W. S. Hardcastle
Keyword(s):  
Weed Control ◽  
Prunus Persica ◽  
Soil Types ◽  
Cultural System ◽  
Mechanical Methods ◽  
Peach Trees ◽  
Mechanical Weed Control

Herbicides and mechanical methods of weed control were tested on 1 and 2-year-old peach trees(Prunus persica(L.) Batsch) on two soil types and locations. Several herbicide methods gave season-long weed control without detriment to growth or yield of peach trees. In general, a cultural system where herbicides were used in rows and 8-ft sodded strips maintained in row middles did not decrease the growth or yield of trees when compared to overall mechanical methods of weed control.

scholarly journals 189 BLOOM THINNING WITH ARMOTHIN®, AN AKZO SURFACTANT

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 456b-456
Author(s):  
Dean R. Evert
Keyword(s):  
Growth Regulators ◽  
Tree Growth ◽  
Prunus Persica ◽  
Leaf Abscission ◽  
Full Bloom ◽  
The Third ◽  
Wide Range ◽  
Peach Trees ◽  
Normal Variability

Armothin® thinned `Sentinel' fruit on peach trees (Prunus persica L.) in 1993. Thinning increased as Armothin® rate in the single spray increased from 1.5X, to 3.0% to 6.0% (v:v) and as the percentage of open blossoms increased from 30% to 61%. The 1.5 % rate of Armothin® thinned significantly only on the third date, and the 6.0% rate overthinned slightly on the third date. Minor discoloration developed on the expanding leaves of a few of trees but disappeared in a few days. No leaf abscission occurred on treated trees and tree growth was normal. Variability between trees treated alike probably reflects the variability in bloom when sprayed. According to Akzo, Armothin® prevents pollination by reacting with the surface of the receptive stigma. Spraying after full bloom should selectively prevent fertilization of the last blossoms to open without destroying the fertilized fruit. This possibility will be tested in 1994. Armothin®, which is a contact thinner, seems to avoid the problems associated with thinners that act as growth regulators and with nonselective caustic thinners. Because of its low phytotoxicity and wide range of effective rates, Armothin® has great potential as a chemical thinner.

Weed Control in Immature Pecan (Carya illinoensis) and Peach (Prunus persica) Plantings

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 638-641 ◽  
Author(s):  
C. E. Arnold ◽  
J. H. Aldrich
Keyword(s):  
Field Experiments ◽  
Prunus Persica ◽  
Cynodon Dactylon ◽  
Cyperus Rotundus ◽  
Cyperus Esculentus ◽  
Carya Illinoensis ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Weed Growth ◽  
Peach Trees

Field experiments were conducted in 1974 and 1975 to evaluate the effect of seven herbicides applied preemergence and two herbicides applied postemergence on weed growth around 7-yr-old pecan [Carya illinoensis(Wang.) K. Koch ‘Elliott’ and ‘Desirable’] and 3-yr-old peach [Prunus persica(L.) Batsch ‘June Gold’] and to observe herbicidal tolerance as noted from visually expressed phytotoxicity. After 12 weeks, the best control of bermudagrass [Cynodon dactylon(L.) Pers.], purple nutsedge(Cyperus rotundusL.), and wild blackberry (Rubus cuneifoliusPursh) was obtained with glyphosate [N-(phosphonomethyl)glycine], napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] + glyphosate, and napropamide + terbacil (3-tert-butyl-5-chloro-6-methyluracil) + paraquat (1,1′dimethyl-4,4′-bipyridinium ion). The most effective overall control of yellow nutsedge (Cyperus esculentusL.), camphorweed [Heterotheca subaxillaris(Lam.) Britt. & Rusby], dogfennel [Eupatorium capillifolium(Lam.) Small], large crabgrass [Digitaria sanguinalis(L.) Scop.], and Florida pusley (Richardia scabraL.) resulted from napropamide + terbacil + paraquat. Herbicides used caused no visible toxicity to the immature pecan or peach trees.

Fate of applied phosphate and sulfate in weathered acid soils under leaching conditions

Soil Research ◽  
1995 ◽  
Vol 33 (1) ◽  
pp. 135 ◽  
Author(s):  
RDB Lefroy ◽  
D Santoso ◽  
GJ Blair
Keyword(s):  
Soil Layer ◽  
Acid Soils ◽  
Soil Surface ◽  
Field Capacity ◽  
Solution Concentration ◽  
The Third ◽  
Phosphate Ions ◽  
Soil Adsorption ◽  
P Fertilizer ◽  
S Application

The ability of a soil to sorb ionic forms of phosphorus (P) and sulfur (S) is a major determinant of the movement of sulfate and phosphate ions in the profile. Earlier research is equivocal concerning the effect of concurrent applications of phosphate and sulfate on soils. Any interaction could have significant consequences for fertilizer management. An experiment was conducted with two contrasting acid soils in open PVC columns. The soils were a gleyed podzolic (Aquic Haplustalf) (GP) (30 �g P g(-1)) soil adsorbed at a soil solution concentration of 0.2 �g P mL(-1)), 13 �g S g(-1)) soil adsorbed at a soil concentration of 5 �g S mL(-1))), and a red earth (Haplohumult) (RE) (30 �g P g(-1)) soil, 48 �g S g(-1)) soil adsorption). A lime x P x S factorial combination was applied to simulate residual P and a topdressing of 32P- and 35S-labelled fertilizer was made as a recent application. The columns were watered to 125% field capacity, at 3 day intervals, until no labelled S or P appeared in the leachate. There was considerable movement of applied P downward in the column of the low-sorbing GP soil. At the end of nine intermittent leachings, the 32P-labelled P recently applied to the surface had moved to the second soil layer (7.5-15 cm), thereby increasing the Colwell P content of this layer from 16 to between 40 and 50 �g P g(-1)) soil. If the soil had been previously treated with P, the recently applied P was leached to the third (15.0-22.5 cm) and fourth (22.5-30 cm) soil layers. In contrast, applied P moved little in the medium-sorbing RE soil. Lime and S application also had no effect on the distribution of applied P in the coil columns. The amounts of recently applied P fertilizer lost by leaching from the RE were less than 2 �g P column-1) of less than 2% of the native+fertilizer P present in the leachate. The S, applied as Na2SO4, was completely leached out of the GP soil by the nine intermittent leachings irrespective of lime or P treatment. The losses of 35S-labelled S recently applied to the surface (>70%) occurred mostly with the second and the third leachings. In the RE soil, a previous application of S resulted in a loss of 34-57% of the applied S after 13 intermittent leachings. Most of his S was lost during the leaching episodes. The application of 98 mu g S g(-1)) soil as a recent S application to the soil surface resulted in increased losses of about 74-121 �g S g(-1)) soil or 37-60% of the applied S. If the soil had a previous S treatment, the S leached amounted to between 36% and 52% of the total S applied. Liming enhanced leaching losses of applied S, and P application only increased S losses in the limed treatment.

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