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 Interference Periods of Raphanus raphanistrum L. in Sunflower Crop

2020 ◽  
Vol 38 ◽  
Author(s):  
D. AGOSTINETTO ◽  
N. WESTENDORFF ◽  
R.R. ZANDONÁ ◽  
A.R. ULGUIM ◽  
A.C. LANGARO
Keyword(s):  
Block Design ◽  
Dry Mass ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Total Period ◽  
Weed Interference ◽  
Randomized Block Design ◽  
Development Cycle ◽  
Sunflower Crop ◽  
Crop Cycle

ABSTRACT: Raphanus raphanistrum L. (wild radish) stands out among the weeds that cause greatest damage to the sunflower crop, due to the development cycle and adaptability. The objective of this research was to determine interference periods of sunflower interacting with wild radish, and the effects of competition on yield and its components. The experiment was conducted in the field in a randomized block design with four replications. The treatments were arranged in a factorial design with factor A composed of wild radish coexistence or control in sunflower, and factor B, for eight periods (0, 7, 14, 21, 28, 35, 42 and 135 days after crop emergence). It was evaluated height, diameter of chapters, achene yield and dry matter of weeds and crop. The presence of wild radish adversely affects the accumulation of dry mass, head diameter, thousand grain weight and reduces sunflower productivity when the wild radish interacts during the whole crop cycle, but does not affect on plant height. Chemical control of wild radish may be adopted at the end of period prior to interference, which for sunflower crop is 13 DAE, and the application is sufficient to avoid weed interference until the end of the total period of interference prevention which occurs until 17 days after crop emergence.

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 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 Interference of Urochloa plantaginea on Morphophysiology and Yield Components of Black Beans

2019 ◽  
Vol 11 (9) ◽  
pp. 272
Author(s):  
Milena Barretta Franceschetti ◽  
Leandro Galon ◽  
Maico André Michelon Bagnara ◽  
Renan Pawelkiewicz ◽  
Leonardo Brunetto ◽  
...  
Keyword(s):  
Block Design ◽  
Plant Morphology ◽  
Co2 Concentration ◽  
Crop Productivity ◽  
Dry Mass ◽  
Control Group ◽  
Total Period ◽  
Black Beans ◽  
Physiological Variables ◽  
Randomized Block Design

Among the factors which affect crop productivity, there are weeds which compete for environment resources. The objective of this work was to determine the periods of interference of alexandergrass on the morphophysiology and productivity components of black beans. The experiment was conducted in a complete randomized block design with four replications. The bean cultivar of the black type used was IPR Uirapuru, being the treatments separated in two models of interference: in the coexistence group, the crop of the bean lived with the alexandergrass by growing periods of 0, 7, 14, 21, 28, 35, 42 and throughout the cycledays after emergence and throughout the cycle; in the control group the crop was kept free of the infestation for the same periods described previously. At 42 DAE were evaluated the variables related to plant morphology and physiology (height of bean plants, number of trifoliate leaves, dry mass plant, number of grains pods, number od pods plants, stomatal conductance, internal CO2 concentration, photosynthetic activity, efficiency of carboxylation, efficient use of water, transpiration rate). Considering the results, it is possible to conclude that the critical period of interference prevention (CPIP) comprises 24 to 50 DAE, the period before the interference (PBI) was 24 DAE and the total period of interference prevention (TPIP) was 50 days and that the morphological and physiological variables of the plants were negatively affected in the coexistence with the alexandergrass when compared to the treatments kept free of weeds throughout the crop cycle.

scholarly journals Chemical Attributes of Soil and Response of Wheat to Serpentinite in Direct Seeding System

2019 ◽  
Vol 11 (6) ◽  
pp. 460
Author(s):  
Alves A. Alovisi ◽  
Munir Mauad ◽  
Alessandra M. T. Alovisi ◽  
Luciene K. Tokura ◽  
Robervaldo S. Silva ◽  
...  
Keyword(s):  
Block Design ◽  
Residual Effect ◽  
Magnesium Silicate ◽  
Crop Productivity ◽  
Dry Mass ◽  
Exchange Capacity ◽  
Wheat Crop ◽  
Randomized Block Design ◽  
Chemical Attributes ◽  
Ph Decrease

The serpentinite is an alternative for the correction of soil acidity and is composed of calcium and magnesium silicate. The objective of this study was to evaluate the residual effect of the serpentinite application on soil chemical attributes and the effects on wheat crop productivity in a no-tillage system. The experimental design was a randomized block design, in a subdivided plot scheme, with four replications. The plots were constituted by serpentinite doses (0, 2, 4, 8 and 16 Mg ha-1) and in the subplots the soil collection layers (0.0-0.10 and 0.10-0.20 m). The chemical attributes of the soil evaluated at 41 months after the application of serpentinite, presented favorable results of the residual power of this corrective. The main results observed are related to the increase of pH, decrease of aluminum content and potential acidity, and increase of Ca, Mg and Si contents, cation exchange capacity (CTC) and base saturation. The residual of the serpentinite in the soil contributed with an improvement in the chemical attributes of the soil, which favored the increase of the dry mass, number of spikes and yield of the wheat crop.

scholarly journals EFFECTS OF COMPETITION AND WATER DEFICIENCY ON SUNFLOWER AND WEED GROWTH

2019 ◽  
Vol 32 (2) ◽  
pp. 318-328 ◽  
Author(s):  
MURILO MEIRA SOARES ◽  
CLÁUDIA DAIANNY MELO FREITAS ◽  
FERNANDO SARMENTO DE OLIVEIRA ◽  
HÉLIDA CAMPOS DE MESQUITA ◽  
TATIANE SEVERO SILVA ◽  
...  
Keyword(s):  
Water Deficit ◽  
Block Design ◽  
Dry Mass ◽  
Co2 Assimilation ◽  
Water Deficiency ◽  
Weed Species ◽  
Negative Effects ◽  
Weed Interference ◽  
Weed Growth ◽  
Randomized Block Design

ABSTRACT In the agricultural environment, the occurrence of biotic and abiotic stresses, such as weed interference and soil water deficit is common. However, little is known about the effects of the interaction of these stresses on the growth of cultivated crops and weed species. Thus, the objective of this study was to evaluate the effects of competition and water deficiency on the growth of sunflowers and weeds. The experiment was performed in a randomized block design with four replications. The treatments were arranged in a 5 × 2 factorial design, with the first factor corresponding to the competition arrangements between the species (sunflower + Waltheria indica; sunflower + Amaranthus spinosus; and sunflower, W. indica, and A. spinosus in monoculture without competition) and the second factor corresponding to water regimes (irrigated and water deficit). The water deficit regime was established when the sunflower plants had six expanded leaves (V6 stage) and was maintained until the rate of CO2 assimilation of the plants reached values close to zero (6 days), after which irrigation was resumed and maintained until 40 days after emergence, when the plants were collected and evaluated. The growth components evaluated were plant height, leaf area, dry leaf mass, dry stem mass, dry root mass, and total dry mass. Competition between plants decreased sunflower, W. indica, and A. spinosus growth. W. indica and A. spinosus aggravated the negative effects of water deficiency on sunflower growth. The water deficit regime did not affect the growth of W. indica. A. spinosus was more competitive with the sunflower than was W. indica.

scholarly journals Weed Interference on the Accumulation of Dry Mass and Macronutrients of Eggplant ‘Nápoli’

2019 ◽  
Vol 37 ◽  
Author(s):  
L.J.P. MARQUES ◽  
M.S. BIANCO ◽  
S. BIANCO ◽  
A.B.C. FILHO ◽  
W.R. CERVEIRA JR ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Mineral Nutrition ◽  
Block Design ◽  
Dry Mass ◽  
Reproductive Organs ◽  
Agricultural Crops ◽  
Weed Interference ◽  
Maximum Reduction ◽  
Randomized Block Design ◽  
Growth And Nutrition

ABSTRACT: The presence of weeds may affect both growth and nutrition of agricultural crops due to interference. The objective was to evaluate the interference of weeds in the dry mass distribution and in the accumulation of dry mass and macronutrients in eggplant. The treatments consisted of increasing weed-free and weedy periods (0-14, 0-28, 0-42, 0-56, 0-70, 0-84, 0-98, 0-112, 0-126, 0-140 and 0-154 days after transplanting) in eggplant ‘Nápoli’. The experiment was arranged in a randomized block design with three replicates. Weeds affected the distribution of dry mass between vegetative and reproductive organs of eggplant. There was a significant reduction in the accumulation of dry mass and macronutrients when weeds grew with eggplant crop beyond 42 days after transplanting, reaching the maximum reduction of 79%, 75%, 80%, 82%, 83%, 83% and 80% in the accumulation of dry mass, K, N, Ca, Mg, P and S, respectively. Therefore, the weed community significantly affects the growth and mineral nutrition of eggplant ‘Napoli’, and there should be no weed-crop coexistence beyond 28 days after seedling transplanting.

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 Can Hydromulch Reduce the Emergence of Perennial Weeds?

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 393
Author(s):  
Maria Teresa Mas ◽  
Gabriel Pardo ◽  
Jorge Pueyo ◽  
Antoni M. C. Verdú ◽  
Alicia Cirujeda
Keyword(s):  
Weed Management ◽  
Cynodon Dactylon ◽  
Block Design ◽  
Management Strategies ◽  
Field Trials ◽  
Cyperus Rotundus ◽  
Perennial Crop ◽  
Perennial Weed ◽  
Randomized Block Design ◽  
Weed Emergence

Herbicide weed control is difficult in the first years of perennial crop establishment or in minor crops, and plastic sheet mulches can leave persistent residues. Liquid spray-on mulch (hydromulch) might be a solution in these cases. To test three hydromulch formulations on perennial weed emergence, greenhouse assays were conducted for two years in two localities to evaluate their rhizome sprouting and shoot emergence. Data, obtained from a completely randomized block design, were analyzed by means of generalized linear mixed models with binomial distribution and logit link function; the effects of hydromulch, species, and their interaction were considered fixed, while the other sources of variation (i.e., locality, year, block and rhizome length) were considered random. All three hydromulches, based on wheat straw, rice husk, and used substrate for mushroom cultivation, were capable of reducing rhizome sprouting of all four species tested when compared to the non-mulched treatment. Many rhizomes sprouted but were trapped under the mulch layer, especially those of Paspalum dilatatum (87%), Cynodon dactylon, and Sorghum halepense (around 50%), while Cyperus rotundus was least affected by the hydromulch treatments (16%). All three blends showed promising results in the reduction of perennial weed emergence, warranting field trials to test combined weed management strategies.

scholarly journals Biostimulant and substrates on litchi tree propagation by air layering

2016 ◽  
Vol 7 (1) ◽  
pp. 122
Author(s):  
Jackson Mirellys Azevêdo Souza ◽  
Sarita Leonel ◽  
Luis Lessi Dos Reis ◽  
Rafael Augusto Ferraz ◽  
Bruno Henrique Leite Gonçalves
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Block Design ◽  
Dry Mass ◽  
Root Volume ◽  
Randomized Block Design ◽  
Commercial Area ◽  
Crop Cycle ◽  
The City ◽  
Substrate Types

The production of quality seedlings is important for the crop cycle and the main propagation type is by the air layering technique, which can be enhanced by using different substrates and plant growth regulators. Therefore, the objective of this study was to evaluate the use of a biostimulant and substrate types in the propagation of litchi tree by air layering. The experiment was installed in a commercial area in the city of Mogi Mirim, SP, Brazil and conducted in a randomized block design with a 5x2 factorial with four replications. The treatments consisted of five Stimulate® biostimulant concentrations (0, 3, 6, 9, and 12 ml L-1) and two substrate types (Plantmax® and earthworm humus). After 120 days, the root length (cm), number of roots, calloused and rooted layers percentage (%), root fresh and dry mass (g) and root volume (cm3) were evaluated. Based on the results, it was found that the concentrations of 6.1 and 6.9 ml L-1 promoted greater success in litchi tree propagation and that the layers can be produced on both evaluated substrates.

Sign in / Sign up

Export Citation Format

Share Document