scholarly journals Weed Interference in Semi-Erect and Semi-Prostate Cowpea Cultivars

2019 ◽  
Vol 37 ◽  
Author(s):  
T.S. CASTRO ◽  
P.R.R. ROCHA ◽  
G.F. BARRETO ◽  
S.S. MAIA ◽  
J.A.A. ALBUQUERQUE ◽  
...  
Keyword(s):  
Experimental Design ◽  
Weed Management ◽  
Critical Period ◽  
Block Design ◽  
Control Period ◽  
Management Control ◽  
Cowpea Cultivars ◽  
Weed Interference ◽  
Maximum Productivity ◽  
Randomized Block Design

ABSTRACT: This study aimed to determine weed interference periods in semi-erect and semi-prostrate cowpea cultivars. Two simultaneous experiments were conducted with the cowpea cultivars BRS Guariba (semi-erect) and BRS Aracê (semi-prostrate). The experimental design was a randomized block design with four replications in a 7 × 2 factorial scheme, seven periods × two weed management (control and coexistence). Control and coexistence periods consisted of 0, 0-8, 0-16, 0-24, 0-32, 0-45, and 0-60 days after emergence (DAE) for the semi-erect cultivar and 0, 0-8, 0-16, 0-24, 0-32, 0-45, and 0-64 DAE for the semi-prostrate cultivar. Competition throughout the cycle reduced productivity by up to 39.81% for BRS Guariba and 37.27% for BRS Aracê. The cultivars BRS Guariba and BRS Aracê presented critical period of interference prevention of 9 to 41 DAE and 15 to 32 DAE, respectively. The semi-prostrate cultivar BRS Aracê was more competitive with weeds, requiring a shorter control period to express maximum productivity.

scholarly journals Interference Periods in Soybean Crop as Affected by Emergence Times of Weeds

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
R.R. ZANDONÁ ◽  
D. AGOSTINETTO ◽  
B.M. SILVA ◽  
Q. RUCHEL ◽  
D.S. FRAGA
Keyword(s):  
Weed Management ◽  
Critical Period ◽  
Block Design ◽  
Crop Productivity ◽  
Dry Mass ◽  
Weed Interference ◽  
Randomized Block Design ◽  
Intermediate Time ◽  
Crop Cycle ◽  
Weed Emergence

ABSTRACT: Weeds emergence times modify competition with crops. Thus, the hypothesis was that the increase in weed emergence flow decreases the period prior to interference (PPI) in soybeans and increases the critical period of interference prevention (CPIP). The objective was to determine the PPI and the CPIP of weeds in soybean crops as affected by the preferred time of weeds emergence flow. Three experiments were conducted in the field in a randomized block design with four replications. The treatments were arranged in a factorial design with factor A consisting of coexistence or weed control in soybeans and factor B for eight periods (0, 7, 14, 21, 28, 35, 42 and 135 days after crop emergence (DAE)). The numbers of emerged plants and weed dry mass by genus and crop productivity were evaluated. The weed interference in culture during all the crop cycle reduces the soybean average yield 73, 94 and 89% in the first, second and third sowing times, respectively. Chemical control may be adopted at the end of PPI, which must be done at 14, 15 and 5 DAE crop, for the first, second, third times, respectively. The sowing in advance and intermediate time of recommendation increase the PPI in about 10 days, favoring the weed management in soybean crops.

scholarly journals The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

2015 ◽  
Vol 43 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Dogan ISIK ◽  
Adem AKCA ◽  
Emine KAYA ALTOP ◽  
Nihat TURSUN ◽  
Husrev MENNAN
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Critical Period ◽  
Field Experiments ◽  
Yield Loss ◽  
Cropping Systems ◽  
Control Period ◽  
Relative Yield ◽  
Yield Data ◽  
Weed Interference

Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days) which corresponded to 8 to 66 days after crop emergence (DAE) and between 135-958 GDD (10 to 63 DAE) in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

scholarly journals Weed Management in Rice under Sprinkler and Flood Irrigation Systems

2018 ◽  
Vol 36 ◽  
Author(s):  
D.B. HELGUEIRA ◽  
T. D’AVILA ROSA ◽  
L. GALON ◽  
D.S. MOURA ◽  
A.T. MARTINI ◽  
...  
Keyword(s):  
Experimental Design ◽  
Weed Management ◽  
Irrigation System ◽  
Block Design ◽  
Sprinkler Irrigation ◽  
Flood Irrigation ◽  
Irrigation Systems ◽  
Factor B ◽  
Randomized Block Design ◽  
Herbicide Treatments

ABSTRACT: This study aimed to assess the efficiency and selectivity of herbicides in rice submitted to sprinkler and flood irrigation systems. The experimental design was a randomized block design arranged in a 2 × 9 factorial scheme. Factor A consisted of irrigation systems (sprinkler and flood) and Factor B consisted of herbicide treatments (T1 - control; T2 - imazethapyr + imazapic, 75 + 25 g a.i. ha-1; T3 - imazethapyr + imazapic, 150 + 50 g a.i. ha-1; T4 - imazapic + imazapyr, 73.5 + 24.5 g a.i. ha-1; T5 - imazapic + imazapyr, 147 + 49 g a.i. ha-1; T6 - imazethapyr, 106 g a.i. ha-1; T7 - imazethapyr, 212 g a.i. ha-1; T8 - sequential application of imazethapyr + imazapic, 75 + 25 g a.i. ha-1; and T9 - sequential application of imazapic + imazapyr, 73.5 + 24.5 g a.i. ha-1). The application of imazethapyr and formulated mixtures of imazethapyr + imazapic and imazapyr + imazapic provided a control higher than 97% in flood and sprinkler irrigation systems. Herbicide selectivity is not altered in the sprinkler irrigation system when compared to the flood irrigation system.

scholarly journals Interference periods of velvet bean in sugarcane

2016 ◽  
Vol 46 (8) ◽  
pp. 1329-1337 ◽  
Author(s):  
Fernanda Nunes Bressanin ◽  
Nelson Jayme Neto ◽  
Mariluce Pascoalina Nepomuceno ◽  
Pedro Luís da Costa Aguiar Alves ◽  
Willians César Carrega
Keyword(s):  
Critical Period ◽  
Block Design ◽  
Velvet Bean ◽  
Total Period ◽  
Sugarcane Cultivar ◽  
Weed Interference ◽  
Randomized Block Design ◽  
Bud Sprouting ◽  
Sugarcane Yield

ABSTRACT: The objective of the present study was to determine the periods of interference of velvet bean on ratoons of sugarcane cultivar 'RB855536' and to identify its potential for decreasing the crop yield and the quality of the harvested product. The experiment was arranged in a randomized block design, with 18 treatments divided into two groups and four replicates per treatment. In the first group, the sugarcane was kept free from velvet bean interference for nine different periods, beginning at bud sprouting: 0-15, 0-30, 0-45, 0-60, 0-90, 0-120, 0-150, and 0-180 days after budding (DAB) and 0-harvest. In the second group, sugarcane was grown in coexistence with velvet bean during the same periods described for the first group. The critical period of interference prevention for velvet bean in ratoons of sugarcane cv. 'RB 855536' lasted 138 days, from 50 DAB (pre-interference period [PIP]) to188 DAB (total period of weed interference prevention [TPIP]). Velvet bean interference caused a 50% decrease in sugarcane yield and negatively affected the quality of the harvested product.

scholarly journals Phytosociological Survey and Weed Interference in Eggplants Cultivation1

2016 ◽  
Vol 34 (2) ◽  
pp. 309-318 ◽  
Author(s):  
L.J.P. MARQUES ◽  
S. BIANCO ◽  
A.B. C. FILHO ◽  
M.S. BIANCO
Keyword(s):  
Weed Management ◽  
Block Design ◽  
Cyperus Rotundus ◽  
State University ◽  
Important Species ◽  
Total Period ◽  
Weed Interference ◽  
Randomized Block Design ◽  
High Relative Importance ◽  
Phytosociological Study

ABSTRACT Eggplants are vegetables of great importance in the South and Southeast regions of Brazil, which are subject to interference from weeds. In order to collaborate with weed management in this vegetable, this study was carried out to determine the periods of weed interference in growing eggplants. The study was conducted in the Brazilian municipality of Jaboticabal, SP, at the Faculty of Agricultural and Veterinary Sciences, UNESP [Universidade Estadual Paulista "Júlio de Mesquita Filho" (São Paulo State University)], in the period from February to July 2013. The experiment was arranged in a randomized block design with 22 treatments, three replications divided in 11 periods of coexistence and weed control with eggplants: 14, 28, 42, 56, 70, 84, 98, 112, 126, 140 and 154 days after transplanting (DAT). In each treatment, a phytosociological study was carried out to identify the important species of weeds in eggplant crops. The main weeds were Eleusine indica, Nicandra physaloides, Portulaca oleracea and Cyperus rotundus due to their high relative importance. The interference of these weeds caused losses of up to 96% to the standard commercial fruit yield. The period before interference was 6 DAT and the total period of interference was 102 DAT. Therefore, it is concluded that after the initial six days after transplanting eggplants, the crop should be free of weeds within the next 96 days.

scholarly journals WEED INTERFERENCE IN CARROT YIELD IN TWO LOCALIZED IRRIGATION SYSTEMS

2021 ◽  
Vol 34 (1) ◽  
pp. 119-131
Author(s):  
LAÍS TEREZA RÊGO TORQUATO REGINALDO ◽  
HAMURÁBI ANIZIO LINS ◽  
MATHEUS DE FREITAS SOUSA ◽  
TALIANE MARIA DA SILVA TEÓFILO ◽  
VANDER MENDONÇA ◽  
...  
Keyword(s):  
Critical Period ◽  
Yield Loss ◽  
Irrigation System ◽  
Block Design ◽  
Sprinkler Irrigation ◽  
Irrigation Systems ◽  
Weed Interference ◽  
Randomized Block Design ◽  
Relative Production ◽  
Crop Cycle

ABSTRACT Weed interference is one of the factors that reduces carrot yield considerably. The aim of this study was to determine the periods of weed interference in carrots cultivated under two localized irrigation systems. The experiment used a completely randomized block design, with three replications, using the split plot scheme. The plots consisted of two irrigation systems (drip and micro sprinkler) and the subplots corresponded to the duration of coexistence of the crop with weeds, comprising periods of control (weed -free) or coexistence (with weeds) (0, 10, 20, 30, 40, 50, and 120 days after emergence (DAE) of the crop). Considering a yield loss of 2.5%, 5%, and 10% in marketable carrots, the beginning and end of the critical period of weed control (CPWC) was determined by adjusting a sigmoid model to the relative production data. The presence of the weed community throughout the crop cycle resulted in yield losses of up to 98%. The CPWP varied for the irrigation systems used. Carrot cultivation with and without competition, under the micro sprinkler irrigation system showed a higher yield than with the drip system. Considering a yield loss of 5%, the CPWC was 23 DAE and 7 DAE in the drip irrigation and micro sprinkler irrigation systems, respectively.

scholarly journals Technical and Economic Viability of Wheat with Forms of Application and Doses of Boron

2018 ◽  
Vol 10 (4) ◽  
pp. 306 ◽  
Author(s):  
Fernando S. Galindo ◽  
Marcelo C. M. Teixeira Filho ◽  
Salatiér Buzetti ◽  
Eduardo H. M. Boleta ◽  
Willian L. Rodrigues ◽  
...  
Keyword(s):  
Experimental Design ◽  
Block Design ◽  
Leaf Tissue ◽  
Economic Viability ◽  
No Tillage ◽  
Wheat Grain ◽  
Economic Return ◽  
Randomized Block Design ◽  
Tillage System ◽  
Irrigated Wheat

Boron is one of the most limiting micronutrients in grains production system in Brazil. In this way, the objective was to evaluate the effect of forms of application and doses of boron in irrigated wheat grain yield evaluating the economic terms in Cerrado region. The experiment was conducted in no-tillage system in an Oxisol with clay texture in Selvíria, MS, Brazil. The experimental design was a randomized block design with four replicates, arranged in a 4 × 3 factorial scheme: four doses of boron (0, 1, 2 and 4 kg ha-1) with boric acid source (B = 17%); and three apllication forms: a) in desiccation of the predecessor straw, together with herbicide; b) at the time of sowing, in soil along with the formulated fertilization seeding and c) via leaf tissue with the application of post emergent herbicide. The application of 2 kg ha-1 provides greater grain yields, but the highest economic return was obtained at the dose of 1 kg ha-1, with application in soil, ensuring profitability from production of irrigated wheat in the Cerrado.

scholarly journals Nutritional Requirement of Sugarcane Cultivars

2018 ◽  
Vol 10 (4) ◽  
pp. 361 ◽  
Author(s):  
Vinicius S. G. da Silva ◽  
Mauro W. de Oliveira ◽  
Vilma M. Ferreira ◽  
Terezinha B. A. Oliveira ◽  
Elaine R. Galvão ◽  
...  
Keyword(s):  
Experimental Design ◽  
Block Design ◽  
Nutritional Requirements ◽  
Nutritional Requirement ◽  
Sugarcane Varieties ◽  
The Past ◽  
Randomized Block Design ◽  
Productive Potential ◽  
New Varieties

Sugarcane produces a large amount of biomass, extracts and accumulates high amounts of nutrients. In the literature the nutritional requirements for most cultivated varieties in the past are found, however there is little information on the new varieties currently planted. The objective of this study was to evaluate the nutritional requirement of four sugarcane varieties, currently very planted, in the cycles of plant-cane, first and second ratoon. The study was installed in a Yellow Oxisol. The experimental design was a randomized block design, with five replications, and four treatments: RB867515, RB92579, SP813250 and VAT90212. During maturation of the cane, in the three evaluation cycles, the productivity of natural biomass and the nutritional requirement of macronutrients of the varieties were determined. It was evidenced that the cultivars of sugarcane are of high productive potential and resemble the accumulation of biomass, observing a yield of 158, 128 and 107 t ha-1 in the cycles of plant-cane, first and second ratoon. Regarding the nutritional requirement, the varieties did not differ among them and expressed the following order of need in the plant-cane K > N > Ca > Mg > S > P, in the first and second ratoon, the sequence observed was K > N > Ca > S > Mg > P.

scholarly journals Phenotypic stability and genetic gains in six-year girth growth of Hevea clones

1999 ◽  
Vol 34 (7) ◽  
pp. 1223-1232 ◽  
Author(s):  
Paulo de Souza Gonçalves ◽  
Alberto Kazutoshi Fujihara ◽  
Altino Aldo Ortolani ◽  
Ondino Cleante Bataglia ◽  
Nelson Bortoletto ◽  
...  
Keyword(s):  
Experimental Design ◽  
Regression Coefficient ◽  
Block Design ◽  
Rubber Tree ◽  
Phenotypic Stability ◽  
Plateau Region ◽  
Genetic Gains ◽  
Paulo State ◽  
Randomized Block Design ◽  
Clonal Variance

Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.] budgrafts of seven clones were evaluated on five contrasting sites in the plateau region of the São Paulo State, Brazil. The objective of this work was to study the phenotypic stability for girth growth. The experimental design was a randomized block design with three replications and seven treatments. Analysis of variance of girth at six-year plant growth indicated a highly significant clone x site interaction. Only linear sites and clone x site components of clone x year interaction were significant, indicating that the performance of clones over sites for this trait could be predicted. The clones GT 1 and PB 235 showed the greatest stability in relation to girth growth, with foreseen responses to change, introduced in the sites. The clones PB 235 and IAN 873 showed significative difference in relation to regression coefficient, representing clones with specific adaptability on favorable and unfavorable sites respectively. The clone GT 1 became the most promissory one in the study of stability and adaptability even showing low girth growth. Expected genetic gains from planting sites, along with estimates of clonal variance and repeatability of clonal means are generally greatest or close to the greatest when selection is done at the same site.

scholarly journals Seleção de genótipos de batata-doce quanto à eficiência ao uso do fósforo em solos da região de cerrado

2013 ◽  
Vol 4 (4) ◽  
pp. 356-364
Author(s):  
Luziano Lopes Da Silva ◽  
Márcio Antônio Da Silveira ◽  
Rodrigo Ribeiro Fidelis ◽  
Rodrigo de Castro Tavares ◽  
Valéria Gomes Momenté ◽  
...  
Keyword(s):  
Experimental Design ◽  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Block Design ◽  
Tuberous Root ◽  
Phosphorus Fertilization ◽  
Germplasm Bank ◽  
Randomized Block Design ◽  
The Family ◽  
Selection Of

The sweet potato (Ipomoea batatas (l.) Lam.) Lam) is a plant that produces tuberous root belonging to the family convolvulácea explored in practically all states of Brazil. The objective of this work was to select genotypes of the sweet potato as the efficiency of phosphorus use in cerrado soils with high and low availability of this nutrient. Were evaluated nine genotypes of sweet potato coming from the germplasm bank from the Federal University of the Tocantins, Brazil. The experimental design was in randomized block design with three replications being nine genotypes grown in two environments with low and high phosphorus availability, using doses of phosphorus fertilization from 20 and 120 kg ha-1 P2O5, applied at planting. To select genotypes suitable for environments proposed was used methodology for selection of the efficient use and response to phosphorus fertilization (efficiency and response). Genotype Amanda was classified as efficient and responsive, Barbara, Julia, Marcela and Carolina Vitoria as efficient, but not responsive and Livia, Duda, Ana Clara and Beatriz were classified as non-efficient, responsive but the absorption and utilization of phosphorus.

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