scholarly journals Weed Control in Yellow Squash Using Sequential Postdirected Applications of Pelargonic Acid

2014 ◽  
Vol 24 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Charles L. Webber ◽  
Merritt J. Taylor ◽  
James W. Shrefler

Squash (Cucurbita pepo) producers could benefit from additional herbicide options that are safe to the crop and provide effective weed control. Research was conducted in southeastern Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of pelargonic acid (PA) on weed control efficacy, crop injury, and squash yields. The experiment included PA applied unshielded postdirected at 5, 10, and 15 lb/acre, plus an untreated weedy control and an untreated weed-free control. ‘Enterprise’ yellow squash was direct-seeded in single rows into raised beds. Weeds included smooth crabgrass (Digitaria ischaemum), cutleaf groundcherry (Physalis angulata), spiny amaranth (Amaranthus spinosus), and yellow nutsedge (Cyperus esculentus). Pelargonic acid was applied each year in mid-July and then reapplied 8 days later. The maximum smooth crabgrass control (98%), broadleaf weed control (94%), and yellow nutsedge control (41%) was observed with the 15-lb/acre PA treatment at 9 days after initial spray treatment (DAIT), 1 day after sequential treatment (1 DAST). Pelargonic acid at 15 lb/acre provided equal or slightly greater smooth crabgrass and broadleaf (cutleaf groundcherry and spiny amaranth) control compared with the 10-lb/acre application, and consistently greater control than the 5-lb/acre rate and the weedy control. Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. Yellow nutsedge control peaked at 9 DAIT (1 DAST) with 10-lb/acre PA (41%). As the rate of PA increased from 5 to 15 lb/acre, yellow nutsedge control also increased significantly for all observation dates, except for 28 DAIT. Increasing the PA application rate increased the crop injury rating at 1 and 3 days after each application (1 and 3 DAIT, 1 and 3 DAST). Maximum squash injury occurred for each application rate at 9 DAIT (1 DAST) with 4.4%, 8.0%, and 12.5% injury for PA rates 5, 10, and 15 lb/acre, respectively. The 10-lb/acre PA treatment produced the highest squash yields (kilograms per hectare) and fruit number (fruit per hectare) compared with either the 5- or 15-lb/acre rates, and equivalent yields and fruit number as the hand-weeded weed-free treatment. The 10-lb/acre PA rate applied in a timely sequential application has the potential of providing good weed control with minimal crop injury resulting in yields equivalent to weed-free hand-weeding conditions.

2014 ◽  
Vol 24 (6) ◽  
pp. 663-667 ◽  
Author(s):  
Charles L. Webber ◽  
Merritt J. Taylor ◽  
James W. Shrefler

Pepper (Capsicum annuum) producers would benefit from additional herbicide options that are safe to the crop and provide effective weed control. Research was conducted in southeastern Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of pelargonic acid on weed control efficacy, crop injury, and pepper yields. The experiment included pelargonic acid applied unshielded postdirected at 5, 10, and 15 lb/acre, plus an untreated weedy control and an untreated weed-free control. ‘Jupiter’ sweet bell pepper, a tobacco mosaic virus-resistant sweet pepper with a 70-day maturity, was transplanted into single rows on 3-ft centered raised beds with 18 inches between plants (9680 plants/acre) on 28 May 2010 and 27 May 2011, respectively. Weeds included smooth crabgrass (Digitaria ischaemum), cutleaf groundcherry (Physalis angulata), spiny amaranth (Amaranthus spinosus), and yellow nutsedge (Cyperus esculentus). Pelargonic acid was applied postdirected each year in mid-June and then reapplied 8 days later. The 15-lb/acre pelargonic acid treatment resulted in the maximum smooth crabgrass control (56%) and broadleaf weed control (66%) at 1 day after the initial spray treatment (DAIT), and 33% yellow nutsedge control at 3 DAIT. Pelargonic acid at 15 lb/acre provided equal or slightly greater smooth crabgrass and broadleaf (cutleaf groundcherry and spiny amaranth) control compared with the 10-lb/acre application, and consistently greater control than the 5-lb/acre rate and the weedy control. Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. As the rate of pelargonic acid increased from 5 to 15 lb/acre, yellow nutsedge control also increased significantly for all observation dates. Increasing the pelargonic acid application rate increased the crop injury rating. The maximum crop injury occurred for each application rate at 1 DAIT with 7%, 8.0%, and 13.8% injury for pelargonic acid rates 5, 10, and 15 lb/acre, respectively. There was little or no new crop injury after the second postdirected application of pelargonic acid and crop injury following 3 DAIT for application rates was 2% or less. Only the 15-lb/acre pelargonic acid application produced greater fruit per hectare (4784 fruit/ha) and yields (58.65 kg·ha−1) than the weedy control (1196 fruit/ha and 19.59 kg·ha−1). The weed-free yields (7176 fruit/ha, 178.11 kg·ha−1, and 24.82 g/fruit) were significantly greater than all pelargonic acid treatments and the weedy control. Pelargonic acid provided unsatisfactory weed control for all rates and did not significantly benefit from the sequential applications. The authors suggest the pelargonic acid be applied to smaller weeds to increase the weed control to acceptable levels (>80%).


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 615-621 ◽  
Author(s):  
John W. Wilcut ◽  
John S. Richburg ◽  
Gerald L. Wiley ◽  
F. Robert Walls

Field studies in 1990 and 1991 at six locations in Georgia and one location in North Carolina evaluated AC 263,222 for weed control, peanut tolerance, and yield. AC 263,222 applied early postemergence at 71 g ai ha−1controlled bristly starbur, coffee senna, common lambsquarters,Ipomoeaspecies, prickly sida, sicklepod, smallflower morningglory, and yellow nutsedge at least 91%. AC 263,222 controlled common cocklebur 77% and Florida beggarweed from 47 to 100%. Crop injury was 4% for AC 263,222 applied once and 12% or less from two applications. Mixtures of bentazon with AC 263,222 did not improve control compared to AC 263,222 alone. Imazethapyr did not improve control of AC 263,222 systems. In several locations, bentazon reduced control of Florida beggarweed with AC 263,222 when applied in a mixture compared to AC 263,222 alone. Weed control from the standard of paraquat plus bentazon applied early postemergence followed by paraquat, bentazon plus 2,4-DB applied POST did not provide the level or spectrum of weed control as AC 263,222 systems.


1997 ◽  
Vol 11 (3) ◽  
pp. 520-526 ◽  
Author(s):  
Theodore M. Webster ◽  
John W. Wilcut ◽  
Harold D. Coble

Experiments were conducted in 1991 and 1992 to evaluate the weed control effectiveness from several rates of AC 263,222 applied PPI and PRE (36 and 72 g ai/ha), early POST (EPOST) (18, 36, 54, or 72 g/ha), POST (18, 36, 54, or 72 g/ha), and EPOST followed by (fb) POST (27 fb 27 g/ha or 36 fb 36 g/ha). These treatments were compared to the commercial standard of bentazon at 0.28 kg ai/ha plus paraquat at 0.14 kg ai/ha EPOST fb bentazon at 0.56 kg/ha plus paraquat at 0.14 kg/ha plus 2,4-DB at 0.28 kg ae/ha. Application method had little effect on weed control with AC 263,222. In contrast, application rate affected control. Purple nutsedge, yellow nutsedge, prickly sida, smallflower morningglory, bristly starbur, common cocklebur, and coffee senna were controlled at least 82% with AC 263,222 at 36 g/ha (one-half the maximum registered use rate) regardless of application method. AC 263,222 at 72 g/ha (registered use rate) controlled sicklepod 84 to 93%, Florida beggarweed 65 to 100%, andIpomoeamorningglory species 89 to 99%. A single application of AC 263,222 at 36 g/ha or more controlled all weeds (with the exception of Florida beggarweed) as well or greater than sequential applications of bentazon plus paraquat fb bentazon, paraquat, and 2,4-DB. All rates of AC 263,222 applied POST and all application methods of AC 263,222 at 72 g/ha had better yields than the pendimethalin control.


Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 138 ◽  
Author(s):  
Hilary Sandler

Integrated weed management (IWM) has been part of cranberry cultivation since its inception in the early 19th century. Proper site and cultivar selection, good drainage, rapid vine establishment, and hand weeding are as important now for successful weed management as when the industry first started. In 1940, Extension publications listed eight herbicides (e.g., petroleum-based products, inorganic salts and sulfates) for weed control. Currently, 18 herbicides representing 11 different modes of action are registered for use on cranberries. Nonchemical methods, such as hand weeding, sanding, flooding, and proper fertilization, remain integral for managing weed populations; new tactics such as flame cultivation have been added to the toolbox. Priority ratings have been developed to aid in weed management planning. Despite many efforts, biological control of weeds remains elusive on the commercial scale. Evaluation of new herbicides, unmanned aerial systems (UAS), image analysis, and precision agriculture technology; investigation of other management practices for weeds and their natural enemies; utilization of computational decision making and Big Data; and determination of the impact of climate change are research areas whose results will translate into new use recommendations for the weed control of cranberry.


HortScience ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Renee H. Harkins ◽  
Bernadine C. Strik ◽  
David R. Bryla

A study was conducted in western Oregon to assess the impact of cultivar and weed management strategy on accumulation and loss of plant biomass and nutrients during the first 3 years of establishment when using organic fertilizer. The study was conducted in trailing blackberry (Rubus L. subgenus Rubus Watson) planted in May 2010 and certified organic in May 2012. Treatments included two cultivars, Marion and Black Diamond, each with either no weed control after the first year after planting or with weeds managed by hand-weeding or the use of weed mat. Each treatment was amended with organically approved fertilizers at pre-plant and was drip-fertigated with fish emulsion each spring. Most primocane leaf nutrient concentrations were within the range recommended for blackberry. However, leaf nitrogen (N) was low in ‘Black Diamond’, especially when grown without weed control, whereas leaf boron (B) was low in all treatments. In many cases, leaf nutrient concentrations were affected by cultivar and weed management in both the primocanes and the floricanes. The concentration of several nutrients in the fruit differed between cultivars, including calcium (Ca), magnesium (Mg), sulfur (S), B, and zinc (Zn), but only fruit Ca was affected by weed management and only in ‘Marion’. In this case, fruit Ca was higher when the cultivar was grown with weed mat than with hand-weeding or no weeding. Total biomass production of primocanes increased from an average of 0.3 t·ha−1 dry weight (DW) during the first year after planting to 2.0 t·ha−1 DW the next year. Plants were first cropped the third year after planting and gained an additional 3.3 t·ha−1 DW in total aboveground biomass (primocanes, floricanes, and fruit) by the end of the third season. Fruit DW averaged 1.4 t·ha−1 in non-weeded plots, 1.9 t·ha−1 in hand-weeded plots, and 2.3 t·ha−1 in weed mat plots. Biomass of senesced floricanes (removed after harvest) averaged 3.2 t·ha−1 DW and was similar between cultivars and among the weed management treatments. ‘Marion’ primocanes accumulated a higher content of N, phosphorus (P), potassium (K), Mg, S, iron (Fe), B, copper (Cu), and aluminum (Al) than in ‘Black Diamond’. Weeds, however, reduced nutrient accumulation in the primocanes in both cultivars, and accumulation of nutrients was greater in the floricanes than in the previous year’s primocanes. Total nutrient content declined from June to August in the floricanes, primarily through fruit removal at harvest and senescence of the floricanes after harvest. Depending on the cultivar and weed management strategy, nutrient loss from the fruit and floricanes averaged 34 to 79 kg·ha−1 of N, 5 to 12 kg·ha−1 of P, 36 to 84 kg·ha−1 of K, 23 to 61 kg·ha−1 of Ca, 5 to 15 kg·ha−1 of Mg, 2 to 5 kg·ha−1 of S, 380 to 810 g·ha−1 of Fe, 70 to 300 g·ha−1 of B, 15 to 36 g·ha−1 of Cu, 610 to 1350 g·ha−1 of manganese (Mn), 10 to 260 g·ha−1 of Zn, and 410 to 950 g·ha−1 of Al. Overall, plants generally accumulated (and lost) the most biomass and nutrients with weed mat and the least with no weed control.


1989 ◽  
Vol 7 (4) ◽  
pp. 129-133 ◽  
Author(s):  
Jeffrey F. Derr ◽  
Bonnie Lee Appleton

Abstract Six polypropylene landscape fabrics were compared with black plastic and preemergence herbicides for weed control. Large crabgrass [Digitaria sanguinalis (L.) Scop.] shoots and roots and yellow nutsedge (Cyperus esculentus L.) shoots penetrated all of the fabrics tested and developed into large plants. In greenhouse studies, black plastic plus mulch, and pennant (metolachlor) [2-chloro-N-(2ethyl-6-methylphenyl)-N-(methoxy-1-methylethyl)acetamide] at 4.5 kg ai/ha (4.0 lb/A) plus mulch provided equal, or greater control of large crabgrass than the landscape fabrics. In the field study, more time was required to hand-weed landscape fabrics covered with mulch than uncovered fabrics. When covered with mulch, hand-weeding time and weed shoot fresh weights were similar for black plastic, surflan (oryzalin) [4-(dipropylamino)-3,5-dinitrobenzenesulfonamide] at 2.2 kg/ha (2.0 lb/A), and the landscape fabrics.


Weed Science ◽  
1969 ◽  
Vol 17 (4) ◽  
pp. 428-431 ◽  
Author(s):  
D. L. Linscott ◽  
A. A. Akhavein ◽  
R. D. Hagin

Land was prepared conventionally in early spring for the planting of small seeded legumes. Planting was delayed to allow emergence of weeds. We applied 1,1'-dimethyl-4,4'-bipyridinium salts (paraquat) and planted legumes immediately afterwards. Stage of weed growth, time of herbicide application, rate of chemical applied, and the methods of seeding were variables imposed. Paraquat (plus surfactant) applied at 1.1 and 2.2 kg/ha to emerged weeds prior to the seeding of legumes controlled quackgrass [Agropyron repens(L.) Beauv.] sufficiently to allow excellent establishment of alfalfa (Medicago sativaL.) and birdsfoot trefoil (Lotus corniculatusL.). A paraquat application delayed until yellow nutsedge (Cyperus esculentusL.) was at least 10 cm in height, followed by a disking, controlled the sedge sufficiently to allow legume establishment. For annual weed control, 0.3% kg/ha of paraquat was sufficient. Drilling as a method of seeding gave better legume stands than did surface-seeding techniques.


1970 ◽  
Vol 33 (3) ◽  
pp. 399-408 ◽  
Author(s):  
MH Kabir ◽  
MN Bari ◽  
M Moynul Haque ◽  
GJU Ahmed ◽  
JMS Islam

A study was conducted from June to December 2003 to assess weed dynamics and yield performance of transplanted aman rice (cv. BRRI Dhan39) in different weed control treatments e.g. two hand weedings at 15 and 40 DAT; Weeding by BRRI Weeder at 20 and 40 DAT; Rifit 500EC @ 1L/ha at 7 DAT; Rifit 500EC @ 1 L/ha at 7 DAT and one hand weeding at 40 DAT; Butachlor 5G @ 2 kg/ha at 7 DAT; Butachlor 5G @ 2 kg/ha at 7 DAT and one hand weeding at 40 DAT along with weed free and unweeded check under both good and poor water management practices. Weed density, weed biomass and weed control efficiency were significantly influenced by different weed control treatments under both water management practices. Other than weed free treatment, Butachlor 5G @ 2 kg/ha applied at 7 DAT along with one hand weeding at 40 DAT showed the best performance under good water management with minimum weed density (16 g/m2) as well as weed biomass (9.27 g/m2) and the highest weed control efficiency (82.57%). Yield and yield components were also significantly influenced by different weed control treatments and water management. The highest grain yield (5.22 t/ha) was obtained under good water management in weed free treatment followed by Butachlor 5G @ 2 kg/ ha and one hand weeding (4.96 t/ha) under same water management. Results revealed that integration of approaches, particularly Butachlor application along with one manual weeding accompanied by proper water management might be the best option to combat weed problems as well as to obtain satisfactory grain yield in transplanted aman rice. Key Words: Transplanted aman rice, water management, weed control treatment and yield. doi:10.3329/bjar.v33i3.1599 Bangladesh J. Agril. Res. 33(3) : 399-408, September 2008


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M.A. NADEEM ◽  
T. ABBAS ◽  
F. BASHIR ◽  
R. MAQBOOL

ABSTRACT: Crop row spacing adjustment and adjuvants have a significant role in decreasing herbicide cost and environmental damage by reducing herbicide application rate. A field study was conducted to assess the impact of two row spacing values and reduced herbicide rates along with adjuvant on weeds in maize in 2014 and 2015. The experiment consisted of atrazine plus mesotrione plus halosulfuran methyl (pre-mixed herbicide) at label rate (719.2 g a.i. ha-1); reduced rates of 75% (539.4 g a.i. ha-1) and 50% (359.6 g a.i. ha-1) alone and in combination with alkyl ether sulphate at 396.8 mL ha-1 as an adjuvant along with weedy check in maize sown at 60 and 75 cm row spacing. Alkyl ether sulphate increased weed control efficacy (13-35%) of the pre-mixed herbicide. Herbicide along with adjuvant provided effective weed control at 60 cm as compared to 75 cm apart sown maize. The most effective control of weeds, and increase in maize grain yield (33-45% as compared to non-treated control) and net income were obtained by the pre-mixed herbicide at 539.4 g a.i. ha-1 (75% of recommended rate) with adjuvant and pre-mixed herbicide at 719.2 g a.i. ha-1 (recommended dose) without adjuvant. The results revealed that the rate of pre-mixed herbicide can be reduced by up to 25% of the recommended field rate by the addition of alkyl ether sulphate as an adjuvant at 60 cm row spacing of maize to increase maize yield and net income.


Author(s):  
A.A. Chavan ◽  
W.N. Narkhede ◽  
H.S. Garud

Background: Weeds are widely reported as a key constraint in organic agriculture. Soybean-chickpea is important cropping sequence adopted in Maharashtra State under irrigated condition. Weed management is a serious problem in both the crop and it mostly controlled through chemical weed control. Today, widespread use of herbicides has resulted in purporated environmental and health problem as well as residual problems to succeeding crops. Now a days residue free food requirement is high. In organic farming cultural and mechanical methods are necessary to break the weed cycle. So, keeping this point in view present investigation was carried out to evaluate organic weed management practices on growth, yield and weed control in soybean-chickpea sequence under irrigated condition. Methods: A field experiment was conducted during Kharif and rabi seasons of 2017-18 and 2018-19. The present investigation consisted of ten weed management practices viz. two hand weeding at 20-25 and 45-50 DAS, one hoeing 20-25 DAS + one hand weeding at 45-50 DAS, soybean + sunhemp incorporation after 35-40 DAS in kharif season and chickpea + safflower (2:1) in rabi season, stale seed bed + reduced spacing + 2 tonne of wheat straw + one hand weeding at 25 DAS, soil mulch at the time of sowing + one hand pulling at 25 DAS, incorporation of neem cake 1.5 tonne/ ha 15 days before sowing + one hand weeding at 25 DAS, soil solarization with 25 μ polythene mulch during summer + one hand weeding at 25 DAS, mulching with straw, weed free and weedy check. Result: The higher values of growth attributes was recorded by weed free treatment which was on par with two hand weeding at 20-25 and 45-50 DAS and soil solarization with 25 μ polythene mulch during summer + one hand weeding at 25 DAS and significantly superior over rest of the treatments during both the year study. Application of stale seed bed with reduced spacing and 2 tonne of wheat straw along with one hand weeding 25 DAS recorded higher soybean equivalent yield followed by soybean + sunhemp incorporation (35-45DAS) in kharif and chickpea + safflower (2:1) in rabi season during both the year. The lower weed density, dry weight and highest weed control efficiency at 40 days after sowing for both monocot and dicot weeds was recorded by weed free treatment followed by soil solarization with 25 μ polythene mulch during summer + one hand weeding at 25 DAS in soybean and chickpea during both the year.


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