scholarly journals Selectivity of chemical weed control systems in conventional cotton

2014 ◽  
Vol 32 (4) ◽  
pp. 827-841 ◽  
Author(s):  
J.G.Z. Arantes ◽  
J. Constantin ◽  
R.S. Oliveira Jr. ◽  
G.B.P. Braz ◽  
C.A.S. Barbosa ◽  
...  

Cotton is highly susceptible to the interference imposed by weed community, being therefore essential to adopt control measures ensuring the crop yield. Herbicides are the primary method of weed control in large-scale areas of production, and usually more than one herbicide application is necessary due to the extensive crop cycle. This study aimed to evaluate the selectivity of different chemical weed control systems for conventional cotton. The experiment took place in the field in a randomized block design, with twenty nine treatments and four replications in a split plot layout (adjacent double check). Results showed that triple mixtures in pre-emergence increased the chance of observing reductions in the cotton yield. To avoid reductions in crop yield, users should proceed to a maximum mixture of two herbicides in pre-emergence, followed by S-metolachlor over the top, followed by one post-emergence mixture application of pyrithiobac-sodium + trifloxysulfuron-sodium.

Author(s):  
S. Selvakumar ◽  
R. Ajaykumar ◽  
A. Ammaiyappan

Background: Time of pre-emergence herbicide application is an important factor that decides the efficiency of herbicide. If the pre-emergence herbicide is not applied at appropriate time, it may cause ineffective weed control or toxicity to crops. With this background, a field experiment was conducted at TNAU, Madurai to optimize the time of pre-emergence herbicides namely pendimethalin and oxyfluorfen application for effective weed management in irrigated blackgram. Methods: The experiment was laid out in randomized block design with three replication. Treatments were application of pendimethalin at 0.75 kg ha-1 and oxyfluorfen at 0.2 kg ha-1 on 1, 2, 3, 4 days after sowing, weed free check and unweeded check. Result: Results of the study revealed that oxyfluorfen gave maximum weed control efficiency as compared to pendimethalin, but toxicity to the crop was observed when oxyfluorfen was sprayed after 2 days of sowing. Yield and economics were achieved higher with application of 0.75 kg ha-1 of pendimethalin at 2 DAS, which was on par with application of 0.2 kg ha-1 of oxyfluorfen at 1 DAS due to lesser toxicity. Application of 0.75 kg ha-1 of pendimethalin and 0.2 kg ha-1 of oxyfluorfen didn’t leave any herbicide residue after harvest. Hence, application of 0.75 kg ha-1 of pendimethalin at 2 DAS and 0.2 kg ha-1 of oxyfluorfen at 1 DAS can be recommended for effective weed management in irrigated balckgram.


2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Estevam Matheus Costa ◽  
Adriano Jakelaitis ◽  
Jacson Zuchi ◽  
Leandro Spíndola Pereira ◽  
Matheus Vinícius Abadia Ventura ◽  
...  

The use of soybean varieties resistant to the herbicides dicamba and 2,4-D may lead to drifts towards areas grown with non-resistant varieties. The aim of this study was to evaluate the effects of dicamba and 2,4-D underdoses applied at the phenological stages V4 and R2 of soybeans. Two experiments were conducted with dicamba or 2,4-D in a randomized block design with four replications. The 4 × 2 + 1 factorial scheme was composed of four doses (0.028, 0.28, 2.8, and 28 g ae ha−1) of dicamba or 2,4-D applied at two phenological stages (V4 and R2) + a control treatment (without herbicide application). Dicamba underdoses caused damage to soybean crop affecting its vegetative growth and yield; the injuries caused by 2,4-D were neither enough to damage crop nor affect yield components. Dicamba underdoses applied at V4 caused injuries of up to 41%, while in R2 they reached 70%. Plant height decreased by up to 61% when treated with dicamba. Soybean yield was reduced by 29 and 76% when the simulated drift occurred at V4 and R2, respectively, and at a dose of 28 g ae ha−1 of dicamba. For the tested underdoses, only 2,4-D had no effect in soybean crop yield.


Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 380
Author(s):  
Sabine Andert

Intercropping results in high overall system productivity on a given piece of land due to the efficient use of available plant growth resources. Weed control in intercropping systems is, however, still a challenge. This study focuses on the effect of the type of weed control (chemical/mechanical) and the timing of chemical herbicide application (pre-emergence/post-emergence) on weed control and crop productivity in a maize bean mixture. For this purpose, the results of a three-year field experiment (2017 to 2019) in northeast Germany will be presented. The experimental setup included a control, three chemical methods, and one mechanical method of weed control. Except for the mechanical treatment, a completely randomized block design was established. Weeds were assessed at BBCH 12 of the maize, immediately before the first weed control treatments to estimate the initial weed infestation, and twice in the six to eight leaf stage of the maize. The weed coverage (%) was estimated. The maize bean mixture was harvested and yields (t ha−1) were measured. The results confirm that the type of weed control, as well as the timing of herbicide application, significantly affects the weed coverage of the maize bean mixture. The most successful weed control strategy was the double chemical herbicide application, in which chemical herbicides are in used pre-emergence beans (BBCH 12 maize) and post-emergence beans (BBCH 12 bean). Weed coverage was reduced by up to 75% using this most effective herbicide strategy and by up to 61% through mechanical weed control, compared to the control. The additional effects of post-emergence treatment on the pre-emergence herbicide control resulted in a 16.5% weed coverage decline. The yield surplus of double chemical herbicide application (pre/post-emergence) was up to 53%, and for the mechanical weed control up to 23%. Additionally, post-emergence herbicide use in intercropped maize and bean resulted in a 16% yield surplus, compared to the single pre-emergence chemical weed control. Optimal timing of weed control during the most sensitive phenology stages of the maize bean mixture is crucial for productivity. The results of this study provide an additional option for suitable weed control of intercropped maize and bean.


2018 ◽  
Vol 10 (2) ◽  
pp. 716-722
Author(s):  
K. Ghosh ◽  
K. A. Chowdary ◽  
B. C. Patra ◽  
S. Sardar

A field experiment was carried out during the Kharif season of two consecutive years 2015 and 2016 at Instructional Farm, Jaguli, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal with the focal objective to assess the effect of different weed control measures on yield of transplanted kharif rice, IET 4786. Experiment having 3 replications was conducted in Randomized Block Design with nine treatments, namely, T1- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 675 + 15 g a.i, T2- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 900 + 200 g a.i, T3- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 1125 + 25 g a.i, T4- Pendimethalin 30% EC @ 1500 g a.i, T5- Pyrazosulfuron ethyl 10 % WP @ 15 g a.i, T6- Pyrazosulfuron ethyl 10 % WP @ 20 g a.i, T7- Metsulfuron methyl 10 % + Chlorimuron ethyl 10 % WP @ 4 g a.i, T8- Hand weeding and T9- Weedy check. Significant variations were observed on the mixed weed flora as well as on performance of rice under the different herbicidal treatments.Pendimethalin 30% EC + Pyrazosulfuron ethyl 10% WP @ 1125+25 g a.i) was found to be the most effective recording the lowest weed population and weed dry weight with  the highest weed control efficiency (83.5% in 2015 and 79.8 % in 2016) and the highest number of panicles m-2 (215.1 in 2015 and 231 in 2016), number of filled grains panicle-1 (85.39 in 2015 and 115.47 in 2016) and grain yield of rice (3.60 t/ha in 2015 and 5.30 t/ha in 2016). The lowest grain yield(2.20 t/ha in 2015 and 3.40 t/ha in 2016) and the highest weed density were observed in weedy check plots.


2016 ◽  
Vol 35 (1) ◽  
pp. 63 ◽  
Author(s):  
Achmad Yozar Perkasa ◽  
Munif Ghulamahdi ◽  
Dwi Guntoro

Weed is a problem on the soybean saturated culture in tidal swamp land. The objective of this study was to obtain the most effective herbicide for weed control on soybean planted under saturated culture in the tidal swamp land. Research was conducted in tidal swamp land at Banyu Urip village, Tanjung Lago districs, Banyuasin, South Sumatra Province, from July to December 2013, using a randomized block design consisted, of the eight treatments, with three replications. The treatments were: control (P0), manual weeding 4 weeks after planting (P1), paraquat 2 l/ha 4 weeks after planting (P2), glyphosate 3 l/ha 4 after planting (P3), oxyfluorfen 2 l/ha 3 days before planting (P4), oxyfluorfen 3 days before planting 2 l/ha followed application of paraquat 4 weeks after planting 2 l/ha (P5), oxyfluorfen 3 days before planting 2 l/ha followed application of glyphosate 4 weeks after planting 3 l/ha (P6), penoxulam 1 l/ha 2 weeks after planting (P7). Results showed that herbicide paraquat effectively suppressed total dry weight of weeds at 4, 6, and 8 weeks after planting. Cyperus iria was the most dominant weed in the field, with Sum Dominance Ratio 37.7%. The highest soybean productivity was 3.7 t/ha obtained from glyphosate treatment. Pre-emergence herbicide applications should be done prior to soybean planting and the post-emergence herbicide application must be done carefully by using nozzle lid to prevent toxicity to the crop plants.


Kultivasi ◽  
2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Denny Kurniadie ◽  
Yayan Sumekar ◽  
Subhan Nulkarim

Sari. Rendahnya produktivitas kelapa sawit salah satunya disebabkan oleh adanya kompetisi tanaman dengan gulma. Pengendalian gulma dengan herbisida kalium glifosat 660 g/L sudah banyak dilakukan dan dinilai efektif. Hambatan yang terjadi yaitu terkadang turun hujan setelah aplikasi herbisida yang menyebabkan efikasi kurang efektif. Penelitian ini bertujuan untuk mengetahui ketahanan herbisida kalium glifosat 660 g/L akibat pencucian air hujan dalam mengendalikan gulma dominan pada tanaman kelapa sawit. Penelitian dilaksanakan di Rumah Kaca Fakultas Pertanian Universitas Padjadjaran Jatinangor pada bulan Februari sampai bulan April 2018. Rancangan yang digunakan dalam penelitian ini yaitu Rancangan Acak Kelompok yang terdiri dari 7 perlakuan dan 4 ulangan. Perlakuan yang diberikan adalah waktu turun hujan setelah aplikasi herbisida kalium glifosat 660 g/L, yang terdiri dari 0, 1, 2, 3, dan 4 jam setelah aplikasi, tanpa hujan, serta tanpa aplikasi herbisida. Perlakuan diterapkan pada 6 jenis gulma, yaitu Asystasia intrusa, Imperata cylindrica, Borreria alata, Ageratum conyzoides, Paspalum conjugatum dan Setaria plicata. Hasil percobaan menunjukkan bahwa herbisida kalium glifosat 660 g/L mampu mengendalikan 5 jenis gulma yaitu I. cylindrica, A. conyzoides,  S. plicata (persentase kerusakan masing-masing 100%); B. alata (persentase kerusakan 90 – 100%); dan P. conjugatum (persentase kerusakan 51,5 – 100%); secara efektif walaupun tercuci air hujan  antara 2 – 4 jam setelah aplikasi. Herbisida kalium glifosat 660 g/L mampu mengendalikan gulma I. cylindrica (persentase kerusakan 79,6%); B. alata, dan A. conyzoides (persentase kerusakan masing-masing 100%); dengan rentang waktu kurang dari 2 jam setelah aplikasi sebelum tercuci air hujan. Kata kunci: Kelapa Sawit, gulma dominan, Kalium glifosat 660 g/L, turun hujanAbstract. The low productivity of oil palm is caused by competition between crop with weeds. Weed control with potassium glyphosate 660 g.L-1 herbicide has been done and is considered effective. Rainfall after herbicide application can be a problem because efficacy can be less effective. This study aims to determine the effect of rainfall on effectivity of potassium glyphosate 660 g.L-1 herbicide in controlling the dominant weeds of oil palm. The study was carried out at the Ciparanje Experimental Greenhouse, Faculty of Agriculture, Padjadjaran University, from February to April 2018. The experimental design used Randomized Block Design, that consisted of 7 treatments and 4 replications. The treatments were the time of rainfall after application of potassium glyphosate 660 g.L-1 herbicide. It consisted of 0, 1, 2, 3, and 4 hours after herbicide application, without rainfall, and without herbicide application. The treatment was applied to 6 types of weeds. There were Asystasia intrusa, Imperata cylindrica, Borreria alata, Ageratum conyzoides, Paspalum conjugatum, and Setaria plicata. The experimental results showed that potassium glyphosate 660 g.L-1  was able to control 5 types of weeds. There were I. cylindrica,  A. conyzoides, S. plicata (each percentage of damage was 100%); B. alata (90-100% damage percentage); P. conjugatum (51.5 – 100% damage percentage); was controlled in rainfall at 2 – 4 hours after herbicide application. Potassium glyphosate 660 g.L-1 herbicide controlled I. cylindrica (79.6% damage percentage); B. Alata and A. conyzoides (each percentage of damage was 100%); in rainfall at less than 2 hours after herbicide application.Keyword: Palm oil, Dominant Weed, Potasium Glyphosate, Rainfall


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 695-699 ◽  
Author(s):  
Steven M. Brown ◽  
James M. Chandler ◽  
John E. Morrison

A field experiment was conducted to evaluate weed control systems in a conservation tillage rotation of grain sorghum [Sorghum bicolor(L.) Moench.] – cotton (Gossypium hirsutumL.) – wheat (Triticum aestivumL.). Herbicide systems included fall and spring/summer inputs of high and low intensity. Tillage regimes were no-till (NT) and reduced-till (RT) systems; the latter included fall primary tillage followed by spring stale seedbed planting. Both tillage systems utilized controlled traffic lanes and wide, raised beds. Effective johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control required intense herbicide inputs at one or both application periods, i.e., in the fall and/or spring/summer. Grain sorghum and cotton yields for the most intense weed control system, which included high inputs in both the fall and spring/summer, were not superior to systems that included high inputs in only one of the two application periods. Seedling johnsongrass emergence occurred before spring planting in RT (but not in NT) in 2 of 3 yr, and control measures were ineffective. After 3 yr, the predominant weeds were johnsongrass and browntop panicum (Panicum fasciculatumSw. # PANFA).


2015 ◽  
Vol 87 (4) ◽  
pp. 2301-2307 ◽  
Author(s):  
MATHEUS G. SILVA ◽  
ORIVALDO ARF ◽  
PAULO E. TEODORO

ABSTRACT The objective of this study was to investigate the effect of interaction between nitrogen topdressing and different application ways (active ingredients) a.i. fluazifop-p-butyl + fomesafen in weed control and agronomic performance of common bean. The experiment was conducted during winter 2003 in Selvíria/MS. The experimental design used was a randomized block design with four replications in a factorial scheme 2x7. The first factor was composed by the absence or presence of nitrogen topdressing, while the second factor consisted of different application ways of fluazifop-p-butyl + fomesafen. The following variables were measured: leaf N content, dry matter of plants, yield components (number of pods plant-1, number of grains plant-1, the average number of grains pod-1 and mass of 100 grains), grain yield, phytotoxicity and weed control percentage. The nitrogen topdressing with 75 kg ha-1provided higher dry matter of plants, higher weed control and higher common bean yield of irrigated winter. In the absence of nitrogen topdressing in the application of urea before or together to fluazifop-p-butyl + fomesafen increased their effectiveness in controlling weeds without interference in the agronomic performance of common bean.


2014 ◽  
Vol 32 (1) ◽  
pp. 51-59 ◽  
Author(s):  
L.B. Tavella ◽  
P.S.L. Silva ◽  
V.R. Oliveira ◽  
P.L.O. Fernandes ◽  
R.P. Sousa

The objectives of this study were to evaluate baby corn yield, green corn yield, and grain yield in corn cultivar BM 3061, with weed control achieved via a combination of hoeing and intercropping with gliricidia, and determine how sample size influences weed growth evaluation accuracy. A randomized block design with ten replicates was used. The cultivar was submitted to the following treatments: A = hoeings at 20 and 40 days after corn sowing (DACS), B = hoeing at 20 DACS + gliricidia sowing after hoeing, C = gliricidia sowing together with corn sowing + hoeing at 40 DACS, D = gliricidia sowing together with corn sowing, and E = no hoeing. Gliricidia was sown at a density of 30 viable seeds m-2. After harvesting the mature ears, the area of each plot was divided into eight sampling units measuring 1.2 m² each to evaluate weed growth (above-ground dry biomass). Treatment A provided the highest baby corn, green corn, and grain yields. Treatment B did not differ from treatment A with respect to the yield values for the three products, and was equivalent to treatment C for green corn yield, but was superior to C with regard to baby corn weight and grain yield. Treatments D and E provided similar yields and were inferior to the other treatments. Therefore, treatment B is a promising one. The relation between coefficient of experimental variation (CV) and sample size (S) to evaluate growth of the above-ground part of the weeds was given by the equation CV = 37.57 S-0.15, i.e., CV decreased as S increased. The optimal sample size indicated by this equation was 4.3 m².


2015 ◽  
Vol 33 (3) ◽  
pp. 607-614
Author(s):  
G. A. M. PEREIRA ◽  
L. H. BARCELLOS JR ◽  
D. V. SILVA ◽  
R. R. BRAGA ◽  
M. M. TEIXEIRA ◽  
...  

ABSTRACTInadequate herbicide application can result in failures in weed control and/or poisoning of the crops, resulting in yield losses. In this research were assessed the effects of the sprayer nozzle boom height in the distribution of the spray solution for weed control, influencing intoxication of beans and crop yield. Experiments were conducted in laboratory and field conditions. In laboratory, the performance of flat spray tip TT 11002 was assessed at heights 0.20, 0.30, 0.40 and 0.50 meters with respect to the target surface. In the field the same heights were assessed in applications of herbicides fomesafen, fluazifop-P-butyl and fomesafen + fluazifop-P-butyl. There was an inverse relationship between the height of the spray boom and the coefficients of variation of the patterns. The mixture better efficiency in a tank of fluazifop-P-butyl + fomesafen was obtained with the height of 0.50 m from the target. This treatment resulted in better weed control, lower poisoning of the bean plants and better crop yield rates.


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