Ropewick Applicator Research Articles

Use of a wiper applicator for the control of the invasive species Eragrostis plana with glyphosate salts

Background: Eragrostis plana is an invasive plant in native grassland areas associated with degradation of the Pampa biome. Selective control of E. plana is difficult due to its similarity to other grassland species. There is a lack of information about E. plana control using selective herbicide application equipment. Objective: The present study aimed to evaluate the efficacy of a pressurize rope wick applicator for controlling the invasive plant E. plana as function of different salts of glyphosate, application volumes, [...]

Effect of different doses of glyphosate applied through rope-wick applicator for the control of Sorghum halepense L. growing in pomegranate (Punica granatum L.) orchards

A field experiment was carried out in Diyala province/Al-Muqdadiya district during growing season of 2016–17. The aim of the present study was to control Sorghum halepense L. growth in newly planted pomegranate orchards by using glyphosate and two application methods-first by knapsack spryer in rate (4.8 kg a. i./ha) and the second use of ropewick wiper technique in different rates (1 l herbicide diluted with water from 1–6 l) parts of herbicide to water (h: w) treatments. The experiment was set out as factorial design in randomized complete block design (CRBD) with three replicates. Total eight treatments of glyphosate were used in this study. In the first control treatment (C1), only water without glyphosate. The second treatment (C2) contained 1 litre glyphosate in 1 litre of water. The third treatment (C3) contained 1 litre glyphosate in 2 litres of water. Likewise, C4, C5, C6 and C7 treatments contained 1 litre glyphosate in 3, 4, 5 and 6 litres of water, respectively. In eighth treatment (C8), herbicide glyphosate @ 4.8 kg a. i./ha was sprayed with a knap sack pressure sprayer. The results showed superiority treatment C2 1: 1 (h: w) gave high degree killing up (7.69), degrees (in a scale of 1 to 10) and treatment C2 1: 1 (h: w) and C3 1: 2 (h: w) gave average less effect in percentage of regrowth got 6.44 and 6.88, respectively, and gave time periods 90 and 120 days after control high degree killing up 8.07 and 8.34 and reduced average percentage of regrowth after control 120 and 360 days got to 6.45 and 6.78, respectively, and method application rope-wick wiping gave less effect in tree pomegranate compared with sprayer. Moreover, the efficacy of glyphosate in weed continued until 360 days after control. The treatment C4 1: 3 (h: w) gave significantly less plant height (35.66 cm) and rhizome (37.33 cm). Significantly less foliage dry weight of rhizomes (92.21 g/m2) was recorded under treatment C2 1: 1 (h: w) as compared to treatment C8 (4.8 kg a. i/ha).

Ropewick Application to Control Old World Bluestems

Old world bluestems (OWB) were introduced into the United States in the early 1900s for conservation and forage purposes. The two main OWB species found throughout the southern Great Plains are Caucasian bluestem (Bothriochloa bladhii) and yellow or King Ranch bluestem (Bothriochloa ischaemum). These introduced OWB grasses are warm-season grasses with excellent persistence and production characteristics for regions with low rainfall. These grasses also produce abundant seed and establish more easily under arid conditions compared to some of our most common native warm-season grasses of the Great Plains. The characteristics that enable OWB to be well adapted and to grow and persist in the Great Plains also enable OWB to become invasive and encroach areas where it is not wanted. Several studies have examined herbicides to control OWB, and glyphosate products showed the most economical and promising short-term control success. However, glyphosate is a non-selective herbicide and has the potential to injure almost all vegetation with which it comes into contact, including desirable native species that may be growing among a stand of sprayed OWB. Wick applicators have been used extensively in grain row crop systems to wipe herbicide on weedy species that grow taller than the desirable grain crop. Because OWB matures more quickly than many native species, OWB could potentially be treated with a wick applicator as it matures following its elongation and elevation above native grass species. Therefore, applying glyphosate with a ropewick applicator to control OWB warranted investigation.

Efficacy and Costs of Handheld Sprayers in the Subhumid Savanna for Cogongrass Control

Cogongrass continues to be one of the most invasive weeds in the subhumid savanna. Herbicide application expenses depend on equipment costs, costs of water transport for spraying, and chemical costs. In three on-farm experiments on land heavily infested with cogongrass, the effectiveness of a knapsack sprayer (KS), a very low volume sprayer (VLV), and a rope wick (RW) applicator was tested at Ijaye, Nigeria, from 2000 to 2001. The sprayers differed in application method, price, and carrier volume required. The dose–response curves for the three applicators were identical in all parameters except at very high doses for the RW. Consequently, there were no apparent differences in glyphosate effectiveness, even when it was applied with different equipment and different carrier volumes. However, even at very high doses, the RW was not as efficient as was the KS and VLV. Actual biomass reduction of cogongrass was greater with the KS and VLV. Even though the KS and VLV generally gave better control levels than the RW, the latter is more user-friendly because it does not require protective masks, which are often unavailable in sub-Saharan Africa. In a situation with labor scarcity, weeding with the RW was cheaper than hand weeding with hoes. The VLV was more economical when used on areas larger than 10 ha than was the RW. The KS was more economical than all other methods when used on areas larger than 2 ha.

Introduction to the symposium on site-specific weed management

Since the dawn of civilization, humans have practiced site-specific weed management. In its earliest form, weeds were visually identified as such and removed by hand (should this be referenced as “sight” specific weed management?). Hoeing or hand weeding is even today one of the most important weed management tools worldwide. Even with the development of herbicides, a number of methods have been used for site-specific management. Producers and land managers mentally mark the location of a weed patch and later apply a pre- or postemergence herbicide at that location. The rope-wick applicator is based on the principle of applying a herbicide only where a weed is standing above the crop. I can remember as a teenager spending days on a tractor driving up and down peanut (Arachis hypogea L.) rows and turning a sprayer loaded with 2,4-DB off and on based on where horsenettle (Solanum carolinense L.) patches were located. It was common for a number of years in the Mississippi Delta to see a tractor with a bar on the front that had four to eight seats welded to it, with riders watching for johnsongrass [Sorghum halepense (L.) Pers.] in cotton (Gossypium hirsutum L.) fields and applying a nonselective herbicide such as glyphosate, or later selective ACCase-inhibiting herbicides.

Effects of Glyphosate and Surfactant Concentrations on Giant Burreed (Sparganium eurycarpum) Control with a Ropewick Applicator

Field and laboratory experiments were conducted to evaluate the effect of glyphosate concentration, surfactant concentration, and ammonium sulfate on the control of giant burreed when applied through a ropewick applicator. Under non-flooded conditions, a 30% (v/v) solution of glyphosate applied with a ropewick applicator gave the highest giant burreed injury in 1987 and 1988, and reduced corm and rhizome viability compared to the nontreated control in 1987. Warm, dry conditions may have been responsible for poor long-term control in 1988 by reducing translocation of glyphosate to rhizomes. Addition of ammonium sulfate or surfactant did not influence glyphosate toxicity to giant burreed when applied with a ropewick applicator. In the laboratory, leaf necrosis at the point of application was observed with surfactant at 0.6% or 1.2% regardless of glyphosate concentration. Absorption of14C-glyphosate increased two-fold with the addition of surfactant, and translocation to roots and rhizomes decreased almost two-fold as surfactant concentration was increased from 0 to 1.2%. Electrolyte leakage increased with 30% glyphosate when surfactant concentration was increased from 0 to 1.2%. Localized leaf necrosis and disruption of tissues inside the leaf may be responsible for reduced giant burreed control with glyphosate and surfactant applied in high concentrations.

Ropewick Application of Picloram for Leafy Spurge (Euphorbia esula) Control

Picloram was applied to leafy spurge using flexible and rigid ropewick applicators for 3 yr at each of two upland pasture sites. The ropewick applicators were a cost-effective way to apply picloram to control leafy spurge compared to broadcast application, but minimal advantage was demonstrated for the segmented, flexible unit compared to the rigid applicator. Picloram applied as an 80 g ae/L solution through ropewick applicators controlled leafy spurge equal to broadcast picloram at 1.1 kg/ha while using 36% as much picloram.

CONTROL OF QUACKGRASS IN FALLOW FROM SEVERAL GLYPHOSATE PLUS TILLAGE TREATMENTS AND ITS EFFECT ON THE SUBSEQUENT YIELD OF BARLEY

The control of quackgrass (Agropyron repens (L.) Beauv.) using glyphosate applied with either a conventional sprayer or a rope wick applicator, each followed by several levels of tillage, was studied in 1983, 1984 and 1985. With the conventional sprayer, glyphosate was either applied alone or with ammonium sulfate (3.4 kg ha−1) and the surfactant, nonylphenoxy polyethoxy ethanol (0.5% vol/vol of spray volume). Applications made with the sprayer were more effective in reducing quackgrass culm density than those made with the rope wick applicator. The density of quackgrass culms declined as the number of tillage operations increased from one, performed at 115 or more days after herbicide application (DAT), to three performed at 5–8, 39–60 and 115 or more DAT. Doubling the rate of sprayer-applied glyphosate, from 0.8 to 1.7 kg acid equivalent ha−1, did not result in a reduction in the density of quackgrass culms. However, in 1 of the 2 years in which comparisons were made, both of these treatments reduced the density of quackgrass culms more than a similar application of glyphosate alone at 0.5 kg ha−1. The addition of ammonium sulfate and surfactant to glyphosate enhanced quackgrass control only at the 0.5 kg ha−1 rate and only in 1 of 2 yr at that rate. Glyphosate, applied at 0.5 kg ha−1 with the sprayer, and followed by three tillage operations consistently reduced the density of quackgrass culms by 95% or more. Both the herbicide and the tillage treatments resulted in increases in the yield of barley seeded the following year. In 2 of the 3 years, barley yields, averaged across tillage treatments, were greater in the plots where the sprayer had been used to apply the glyphosate treatments than in the plots where the rope wick applicator had been used. Barley yields decreased as the quackgrass culm density increased, although other factors seemed to have influenced the yields in one of the years.Key words: Glyphosate, tillage, barley, quackgrass, fallow

Aplicador de herbicidas com pavios de corda: primeiros resultados de controle

Os aplicadores de herbicidas baseados em pavios de corda foram introducidos e largamente aceitos nos EUA a partir de 1978, devido a sua grande simplicidade, baixo custo operacional e economia do herbicida. Um protótipo fabricado com material inteiramente nacional, montado sobre duas rodas de bicicleta, tracionado pelo homem, tendo uma barra de 2 metros de comprimento, foi desenvolvido pelo departamento de defesa fitossanitária da Faculdade de Ciência Agrárias e Veterinárias de Jaboticabal - UNESP e submetido a um ensaio preliminar. A área estava uniformemente coberta com vegetação natural, com altura média de 55 cm e a maioria das plantas daninhas em estádio de maturação das sementes. O aplicador foi deslocado à velocidade de 2,7 km/h, com consumo médio de 9,3 litros de calda por hectare, tendo aplicado diluições de glyphosate em água, nas proporções de 1:2, 1:4 e 1:6 (produto comercial: água) e comparado à pulverização convencional tratorizada, efetuada com velocidade de 4,2 km/h e consumo de 4 litros de produto comercial com 310 litros de água por hectare. As avaliações do controle foram efetuadas através da determinação da biomassa epígea por ocasião de aplicação aos 15 e 33 dias após , além da atribuição de notas aos 33 dias da aplicação. Os resultados mostraram-se promissores para o protótipo, que pode desde já ser considerado um precioso instrumento para o manejo de plantas daninhas.

A Flexible Ropewick Applicator for Use on Uneven Terrain

A 4.6-m-long, segmented, flexible-pipe ropewick applicator was constructed to apply picloram (4-amino-3,5,6-trichloropicolinic acid) to leafy spurge (Euphorbia esulaL. ♯ EPHES) and other weed species. Gauge wheels on each ropewick applicator segment permit height adjustments, and a loose, independent, vertical flexing action permits the segments to effectively traverse depressed or raised areas. The applicator was designed for use in pastures with rough, uneven terrain where it is difficult to uniformly wipe herbicide solution on plants with a rigid-pipe ropewick. The applicator was found to be durable and effective in applying picloram to leafy spurge.

Use of electricity to control bolters in sugar beet (Beta vulgaris L.): a comparison of the electrothermal with chemical and mechanical cutting methods

SummaryA machine was built to kill reproductive plants (‘bolters’) in sugar beet by high‐voltage electricity. A generating system producing 10, 13 or 17 kV each at 54 kW was connected to a set of guarded electrodes spanning twelve rows, suspended 5–15 cm above the top of a sugar‐beet crop. With 13 kV the system travelling at 5 km h−1 could clear a light‐to‐moderate infestation of bolters at a rate of 2·4 ha h−1 with the tractor's diesel‐fuel consumption at 3·51 ha−1. In 1979, the electrothermal machine, used twice, reduced viable seed returns by 83%; the flail mower used once or twice by 44 and 76–84%; the wire reel mower used once or twice by 45 and 80–87%; and the roller chemical applicator used once by only 13%. Further trials were made in 1981 with an improved electrothermal machine, a rope wick applicator and a flail mower when all gave over 90% control of viable seeds. The electrothermal machine killed between 38 and 41% of bolters compared with 65% for the chemical applicator. The flail mower did not kill any plants.Although possessing many advantages, the electrothermal machines are heavy and more expensive than alternative methods. Development has ceased in the U.K. on electrical weed control but one company in the U.S.A. is selling such equipment.

Comparison of Ropewick Applicators for Control of Johnsongrass (Sorghum halepense) in Cotton (Gossypium hirsutum) with Glyphosate

Three annual applications of glyphosate [N-(phosphonomethyl)glycine] with three ropewick applicators were compared to hoeing and cultivation for the control of johnsongrass [Sorghum halepense(L.) Pers. ♯3SORHA] in cotton (Gossypium hirsutumL. ‘Acala SJ-2′) in 1980 and 1981. The three applicators provided about equal control of johnsongrass. Averaged over treatments, years, and dates of application, plots treated with glyphosate contained 83% fewer live johnsongrass shoots (14/m2) than cultivated control plots (84/m2) 2 to 3 weeks after each application. Glyphosate-treated plots yielded an average of 81% more seed cotton (2010 kg/ha) than cultivated control plots (1110 kg/ha). However, yields of treated plots averaged 33% less than plots maintained weed-free by hoeing. Although applications of glyphosate reduced johnsongrass populations 83%, the competitive effect of johnsongrass on cotton prior to the initiation of treatments, plus the competition from escape plants between treatments, prevented cotton from yielding normally.

Control of Johnsongrass (Sorghum halepense) in Cotton (Gossypium hirsutum) with Glyphosate

Three applications/yr of glyphosate [N-(phosphonomethyl)glycine] with a ropewick applicator (RWA), a roller applicator (RA), and a recirculating sprayer (RCS) were compared to hoeing and cultivation for the control of johnsongrass [Sorghum halepense(L.) Pers. ♯3SORHA] in cotton (Gossypium hirsutumL. ‘Acala SJ-2′) in six field experiments from 1979 to 1981. Averaged over the 3 yr and dates of application, plots treated with glyphosate contained 78% fewer live johnsongrass shoots (15/m2) than cultivated-control plots (68/m2). Although applications of glyphosate with the RWA and RA improved or tended to improve yields of cotton, only plots treated with the RWA yielded significantly more seed cotton than cultivated control plots in all years. However, yields of plots treated with the RWA still averaged 38% less than hoed plots. Plots treated with the RA produced significantly more cotton than cultivated-control plots only in 1981.

Pasture weed control by rope wick applicator

Pasture weed control by rope wick applicator

Roller Applicator for Shattercane (Sorghum bicolor) Control in Row Crops

Greenhouse and field experiments were conducted with a roller applicator at Lincoln, Nebraska, during 1979 and 1980. Glyphosate [N-(phosphonomethyl)glycine] concentrations of 5, 10, and 20% and carpet saturations of 50 and 75% controlled shattercane [Sorghum bicolor(L.) Moench] when applied to the top 30 cm of the plant in greenhouse research. In the field, glyphosate concentrations of 5 to 20% with a carpet saturation of 50% controlled shattercane acceptably in soybeans [Glycine max(L.) Merr.], but a concentration of 2.5% with 25% carpet saturation did not. Weed control was comparable whether speed of application was 3.2, 6.4, or 9.6 km/h. Shattercane control in grain sorghum [Sorghum bicolor(L.) Moench.] was excellent at glyphosate concentrations of 5, 10, and 20% and at carpet saturations of 50 and 75%, and sorghum injury was minimal at 25 and 50% carpet saturations. The roller applicator was compared to a ropewick applicator for shattercane control in sorghum. Excellent weed control (90% or greater) with minimal crop injury was obtained with the roller applicator at glyphosate concentrations of 10 and 20% at application speeds of 3.2 and 6.4 km/h and with the ropewick applicator with glyphosate concentrations of 35 and 50% applied at 3.2, 6.4, and 9.6 km/h.

Controlling Volunteer Corn (Zea mays) in Soybeans (Glycine max) with Diclofop and Glyphosate

We compared diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid}, as an early over-the-top spray treatment, and glyphosate [N-(phosphonomethyl)glycine], applied twice in repeated applications with a rope-wick applicator, for control of simulated volunteer corn (Zea maysL.) planted in clumps at various intervals in rows of soybeans [Glycine max(L.) Merr.]. Uncontrolled corn at the lowest density (clumps 2.4m apart in the row) reduced soybean yields an average of 31%. Both herbicides were highly effective in controlling corn, but when corn densities were high, diclofop treatments often resulted in greater soybean yields than did glyphosate treatments — presumably because corn interfered with the soybeans for a longer time before glyphosate was applied.

Control of Johnsongrass (Sorghum halepense) and Volunteer Corn (Zea mays) in Soybeans (Glycine max)

Rhizome johnsongrass [Sorghum halepense(L.) Pers.] in late-planted soybeans [Glycine max(L.) Merr. ‘Forrest’] was effectively controlled with glyphosate [N-(phosphonomethyl)glycine] applied twice by a rope-wick applicator at 0.1 kg/ha each time. At crop maturity, wick-applied glyphosate controlled an average of 92% of the johnsongrass over a 2-yr period as compared to 51% where 2.2 kg/ha of glyphosate was applied conventionally to rhizome johnsongrass prior to planting. There was no difference in soybean yields and no visible injury to soybeans. Rhizome johnsongrass and volunteer corn (Zea maysL.) were effectively controlled in soybeans planted at the proper time with glyphosate applied by either the rope-wick applicator or recirculating sprayer. Soybean yields were reduced more when volunteer corn was treated with glyphosate that was applied with a recirculating sprayer than with a rope-wick applicator. This reduction in yield was attributed to splattering of the herbicide.

Developments in post-emergence herbicide applicators

Post-emergence herbicide application has always presented problems of drift and insufficient selectivity. Recirculating sprayers and a variety of ‘wipe-on’ applicators have been developed more to counter such difficulties than to conserve spray material though, clearly, with the high cost of chemicals, minimal dosage is an important factor. The development of rope wick applicators to apply glyphosate has made most progress, but much remains to be learned in this new technology.