scholarly journals Competitive analysis of soybean and sudangrass using replacement series design

Revista CERES ◽  
2016 ◽  
Vol 63 (5) ◽  
pp. 668-675
Author(s):  
Mauro Antônio Rizzardi ◽  
Alana Cristina Dorneles Wandscheer ◽  
Andrea Ferreira Hoffmann

ABSTRACT Competition is the best known form of direct interference of weeds on agricultural crops. However, there is relatively little information on the competition of the weed sudangrass on soybean, which has been common in agricultural areas in the southern of Rio Grande do Sul. The objective of this study was to evaluate the competition between sudangrass and soybeans using replacement series experiments. The experiment was carried out in a greenhouse in a completely randomized design with four replications. The treatments consisted of soybean and sudangrass associations. The experimental units were 8-L plastic pots, in the proportions 0: 8, 2: 6, 4: 4, 6: 2, 8: 0, corresponding to 0, 25, 50, 75 and 100% of the crop and weed respectively. Shoot, root and total dry matter and plant height were analyzed through diagrams applied to replacement series and competitive indices. Soybean showed competitive superiority in coexistence with sudangrass in relation to shoot, root and total dry matter. The intraspecific competition was more significant for the crop and inter-specific competition was more important for the weed.

2015 ◽  
Vol 33 (3) ◽  
pp. 413-423 ◽  
Author(s):  
L. GALON ◽  
L. R. AGAZZI ◽  
L. VARGAS ◽  
F. NONEMACHER ◽  
F. J. M. BASSO ◽  
...  

ABSTRACTThe objective of the study was to assess the relative competitive ability of canola hybrids in the presence of turnip (Raphanus sativus) and ryegrass (Lolium multiflorum) in different ratios of plants in the mixture. The experiments were conducted in a greenhouse, in a completely randomized design with four replications. Treatments were arranged in ratios of canola against turnip or ryegrass: 100:0, 75:25, 50:50, 25:75 and 0:100. Competitive analysis of the species was accomplished by means of diagrams usually applied to replacement series and also by the relative competitiveness indices. Fifty days after the emergence of the species, measurements of leaf area and shoot dry mass were performed. There was a competition between canola hybrids and weeds, with reduction for all variables. There was a differential competitive ability among canola hybrids in the presence of turnip and/or ryegrass. Canola hybrid Hyola 433 was more competitive in the presence of turnip than Hyola 61, 76 and 571 CL. Hyola 61, 76, 433 and 571 CL do not differ in terms of competition ability when growing with ryegrass.


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
D.M. CHIAPINOTTO ◽  
C.E. SCHAEDLER ◽  
J.P.S. FERNANDES ◽  
A. ANDRES ◽  
F.P. LAMEGO

ABSTRACT Cyperus iria (CYPIR) is one of the main weeds in irrigated rice crops. The intense chemical control with acetolactate synthase (ALS) inhibiting herbicides favors the selection of cross-resistance. This study aimed to evaluate the crossresistance of CYPIR to ALS-inhibiting herbicides in irrigated rice in Rio Grande do Sul. Two experiments arranged in a factorial scheme, in a completely randomized design, with four replications were conducted. Experiment I consisted of resistant (CYPIR-R) and susceptible (CYPIR-S) biotypes and ALS-inhibiting herbicide doses: imazethapyr (106 g a.i. ha-1); pyrazosulfuron-ethyl (20 g a.i. ha-1); penoxsulam (36 g a.i. ha-1) and, as an alternative herbicide, bentazone (960 g a.i. ha-1); corresponding to 0; 1/16; 1/8; 1/4; 1/2; 1; 2; 4; 8 and 16x (x = maximum registered dose). Experiment II followed the same procedures, with doses of 0; 1/64; 1/32; 1/16; 1/8; 1/4; 1/2; 1 and 2x for CYPIR-S and 0; 1/2; 1; 2; 4; 8; 16; 32; 64 and 128x for CYPIR-R; including bispyribac-sodium (50 g a.i. ha-1). The variables evaluated were: visual control at 7, 14, 21 and 28 days after the treatments (DAT) and shoot dry matter (SDM) at 28 DAT. The results, fitted by nonlinear regression, show varied and high levels of cross-resistance of CYPIR-R to ALS-inhibiting herbicides from the group of imidazolinones, sulfonylureas, triazolopyrimidines and pyrimidinyl(thio)benzoates. Bentazone can be used as an alternative herbicide, however, not exclusively in the control of this biotype.


2015 ◽  
Vol 39 (2) ◽  
pp. 121-130 ◽  
Author(s):  
Leandro Oliveira da Costa ◽  
Mauro Antônio Rizzardi

The occurrence of Raphanus raphanistrum ALS herbicide-resistant in wheat crops causes crop yield losses, which makes it necessary to understand the factors that influence the interference of this weed to develop safer management strategies. This study aimed to evaluate the competitive ability of wheat in coexistence with biotypes of R. raphanistrum that are resistant (R biotype) and susceptible (S biotypes) to ALS herbicides and to determine whether there are differences in the competitiveness of these biotypes. The experiments were conducted in a greenhouse using a completely randomized design with four replications. The treatments were placed in pots and arranged in replacement series for three experiments (1 - wheat with the R biotype; 2 - wheat with the S biotype; and 3 - the R biotype with the S biotype) at the following ratios: 100:0, 75:25, 50:50, 25:75, and 0:100. The competitiveness was analyzed through diagrams applied to replacement experiments and competitiveness indices, including the evaluation of the shoot dry matter of the plants (experiments 1, 2, and 3) and the leaf area (experiment 3). The R and S biotypes significantly decreased the shoot dry matter of the wheat cultivar and demonstrated superior competitive ability compared with the culture. The interspecific competition was more important for the wheat and for the S biotype. The competitiveness of the R biotype compared to the S biotype was similar, with synergism in the leaf area production, which indicates the predominant intraspecific competition exhibited by the R biotype.


2018 ◽  
Vol 84 (0) ◽  
Author(s):  
Diecson Ruy Orsolin da Silva ◽  
Dirceu Agostinetto ◽  
Leandro Vargas

ABSTRACT: The objective of this study was to evaluate the relative competitive ability of soybean with different development stages of hairy fleabane. Two experiments were conducted in greenhouse, in a completely randomized design. In the experiment it was tested soybean and hairy fleabane competition at different stage of development (rosette and 15 cm height) at the proportions 100:0, 75:25, 50:50, 25:75 and 0:100, and total plant population was 315 plant m-2. The variables evaluated were plant height, leaf area, and shoot dry matter (leaves and stems). Competitive analysis was performed by diagrams and interpreting the competitiveness index. The soybean has greater competitive ability that horseweed for both development stages. The intraspecific competition is more intense for soybean when in hairy fleabane rosette stage, and the competitive relations are equivalent between soybean and hairy fleabane of 15 cm tall. The both hairy fleabane stages were injured in the soybeans competition.


2017 ◽  
Vol 30 (4) ◽  
pp. 1001-1008
Author(s):  
JOÃO PEDRO ALVES DE AQUINO ◽  
ANTÔNIO AÉCIO DE CARVALHO BEZERRA ◽  
FRANCISCO DE ALCÂNTARA NETO ◽  
CARLOS JOSÉ GONCALVES DE SOUZA LIMA ◽  
RAYLSON RODRIGUES DE SOUSA

ABSTRACT Cowpea is broadly cultivated worldwide, especially in semi-arid or arid regions where soil or irrigation water salt contents can negatively influence the species’ productive capacity. The objective of this study was to evaluate the morphophysiological responses of cowpea genotypes to irrigation water salinity. The experiment was conducted in a greenhouse, under a completely randomized design with nine replications and in a 5x3 factorial scheme. Treatments consisted of five levels of irrigation water electrical conductivity - EC (EC0: 0.55; EC1: 1.60; EC2: 3.20; EC3: 4.80 and EC4: 6.40 dS m-1), applied from the 15th day after sowing (DAS), and three cowpea genotypes (G1: BRS Imponente; G2: MNC04-795F-168 and G3: MNC04-795F-159). EC increases at 35 DAS promoted stem diameter reductions of 8.0% (G1), 11.4% (G2), and 7.7% (G3), indicating different resistance to salinity by each genotype. Leaf area reductions at 25 and 38 DAS were 30.9% and 38.8% for EC0 and EC4, respectively. The BRS Imponente cultivar presented a performance superior to those of G2 and G3 in relation to stem diameter and stem dry matter at 25 DAS, and root-shoot and root-leaf ratios at 38 DAS.


2010 ◽  
Vol 28 (3) ◽  
pp. 515-522 ◽  
Author(s):  
A.C.R. Dias ◽  
S.J.P. Carvalho ◽  
L.W. Marcolini ◽  
M.S.C. Melo ◽  
P.J. Christoffoleti

Weeds compete with field crops mainly for water, light and nutrients, and the degree of competition is affected by the weed density and the intrinsic competitive ability of each plant species in coexistence. The objective of this research was to compare the competitiveness of alexandergrass (Brachiaria plantaginea) or Bengal dayflower (Commelina benghalensis) in coexistence with soybean, cv. M-Soy 8045. A factorial experiment (2 x 5) with two weed species and five competition proportions was carried out in a completely randomized design with four replicates. Proportions were based on a replacement series competition design, always maintaining the total density of four plants per 10 L plastic pots, which corresponded to 60 plants m ². The weed-crop proportions were: 0:4; 1:3; 2:2; 3:1; 4:0; that corresponded to the proportion of 100, 75, 50, 25 and 0% of soybean plants and the opposite for weeds, B. plantaginea or C. benghalensis plants. Leaf area, shoot dry mass of the weeds and soybean and number of soybean trifoliate leaves were evaluated when the soybean reached the phenologic stage of full flowering. B. plantaginea was a better competitor than soybean plants. Otherwise, C. benghalensis revealed a similar competitive ability that of the soybean. In both cases, there were evidences that intraspecific competition was more important.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
C. ALVES ◽  
L. GALON ◽  
R.R. KAIZER ◽  
F.L. WINTER ◽  
C.M. HOLZ ◽  
...  

ABSTRACT: The use of plant species for the phytoremediation of soils contaminated with herbicides is an alternative that has been emphasized to minimize the effects of the persistence of agrochemicals in the environment. The objective of this study was to evaluate the tolerance potential of winter species in soils contaminated with sulfentrazone and fomesafen. The experiment was in a completely randomized design with four replications. Doses of fomesafen (0.0, 0.125, 0.250, and 0.5 kg ha-1) and sulfentrazone (0.0, 0.3, 0.6 and 1.2 kg ha-1) were applied during the pre-emergence of phytoremediate species (black oat, vetch, birdsfood trefoil, radish and lupin). Forty five days after the emergence of the species, the phytotoxicity (%), leaf area (cm2), stalk and/or stem diameter (mm), height (cm) and dry matter (g) variables of the plants were evaluated. Data were submitted to analysis of variance by F test; when significant, linear or non linear regressions were applied to evaluate the effect of herbicide doses on the studied species. Birdsfood trefoil was the less tolerant species to fomesafen and sulfentrazone. Black oat was less affected by the application of fomesafen doses, but it was highly susceptible to sulfentrazone. Radish presented tolerance only up to the fomesafen dose of 0.25 kg ha-1; as for sulfentrazone, the species showed tolerance. The most tolerant species to fomesafen and sulfentrazone, regardless of the dose, was the lupine, which is a possible alternative for the phytoremediation of soils contaminated with these herbicides.


2017 ◽  
Vol 39 (4) ◽  
pp. 363-373 ◽  
Author(s):  
Jaciara de Souza Bispo ◽  
Danielle Carolina Campos da Costa ◽  
Samara Elizabeth Vieira Gomes ◽  
Gilmara Moreira de Oliveira ◽  
Janete Rodrigues Matias ◽  
...  

Abstract: Angico is a species found in several environments in Brazil, with several applications. It is used in the timber industry and mainly in folk medicine. In order to verify a variation in the biometric characteristics and the quality of seeds from different mother-plants in different harvesting years, the following variables were studied: moisture content, diameter, density, electrical conductivity, fresh and dry matter of seedlings, germination percentage and kinetics, in a completely randomized design with a 2x3 factorial arrangement (lots x size). The obtained results showed that angico seeds from different lots showed different physiological quality, possibly due to the climate variations to which mother-plants were submitted in the different years. Seed size directly interferes with seedling growth under both controlled and greenhouse conditions, and it can be used as a vigor indicator for angico seeds.


2015 ◽  
Vol 2 (3) ◽  
pp. 17
Author(s):  
Indrayani Indrayani ◽  
Harapin Hafid ◽  
Dian Agustina

ABSTRACTThis study aims to determine the digestibility of dry matter and organic matter level waste silage mixed vegetables and Gliricidia leaves were tested in vitro. This study used a completely randomized design with 3 treatments and 3 replications. Each of these treatments is R0 (Gliricidia leaves 100%), R1 (Gliricidia leaves 70% + 30% silage vegetable waste), and R2 (Gliricidia leaves 40% + 60% silage vegetable waste). Data were analyzed using analysis of variance (ANOVA) and further testing using the test Honestly Significant Difference (HSD). The results of ANOVA showed that the mixture of vegetable waste silage was highly significant (p <0.05) on dry matter digestibility and significantly (p <0.05) on the digestibility of organic matter. It can be concluded that the mixed of vegetable waste silage and Gliricidia leaves can improved digestibility of dry matter and organic matter, treatment of 40% and 60% Gliricidia leaves plus waste vegetable produce silage dry matter digestibility and percentage of organic matter is best (72,24% and 68,19%).Keyword: Silage vegetable waste, gliricidia leaves, dry and organic matter digestibilityABSTRAKPenelitian ini bertujuan untuk mengetahui kecenaan bahan kering dan bahan organik tingkat campuran silase sampah sayur dan daun gamal yang diuji secara in vitro. Penelitian ini menggunakan Rancangan Acak Lengkap dengan 3 perlakuan dan 3 ulangan. Masing-masing perlakuan tersebut ialah R0 (daun gamal 100%), R1 (daun gamal 70% + silase sampah sayur 30%), dan R2 (daun gamal 40% + silase sampah sayur 60%). Data yang diperoleh dianalisis dengan menggunakan analisis sidik ragam (ANOVA) dan uji lanjut menggunakan uji Beda Nyata Jujur (BNJ). Hasil analisis sidik ragam menunjukkan bahwa campuran silase sampah sayur berpengaruh sangat nyata (p<0,05) terhadap kecernaan bahan kering dan berpengaruh nyata (p<0,05) terhadap kecernaan bahan organik. Dapat disimpulkan bahwa perlakuan campuran silase sampah sayur dan daun gamal dapat meningkatkan kecernaan bahan kering dan bahan organik, perlakuan 40% daun gamal dan 60% silase sampah sayur menghasilkan persentase kecernaan bahan kering dan bahan organik yang terbaik yaitu (72,24% dan 68,19%).Kata kunci : Silase sampah sayur, daun gamal, kecernaan bahan kering, dan bahan organik.


Author(s):  
Lourenço M. C. Branco ◽  
Claudivan F. de Lacerda ◽  
Albanise B. Marinho ◽  
Carlos H. C. de Sousa ◽  
Amanda S. F. Calvet ◽  
...  

ABSTRACT The objective of this study was to evaluate the influence of irrigation with brackish water on the production of bamboo seedlings (Bambusa vulgaris). The experiment was carried out at the Fazenda Experimental Piroás, in the municipality of Redenção, CE, Brazil (4° 14’ 53” S, 38° 45’ 10” W, and altitude of 230 m), in a completely randomized design with five treatments and six repetitions. The treatments consisted of five irrigation water electrical conductivity (ECw): 0.5 (control); 1.5; 2.5; 3.5 and 4.5 dS m-1. At 120 days after the beginning of the application of the treatments the leaf gas exchange, relative chlorophyll index (RCI), plant height (H), shoot dry matter (SDM), H/SDM ratio, and the concentrations of Na+ and K+ in stems and leaves were evaluated. Salt tolerance indexes were calculated based on SDM, H, photosynthesis rate and RCI. The increase in the ECw reduced leaf gas exchange, and the reduction in the photosynthesis rate was caused by stomatal and non-stomatal effects. The salinity affected negatively the growth and quality of bamboo seedlings, with the greatest effects being with ECw equal to or greater than 2.5 dS m-1. Bamboo seedlings present Na+ retention in the stems and low Na+/K+ ratio in the leaves. Bamboo seedlings are tolerant to salinity up to 1.5 dS m-1, indicating that waters with this salinity can be used for seedling production of this species, without loss of growth and quality.


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