randomized block design
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Author(s):  
Diemisson O. Nunes ◽  
João H. de S. Favaro ◽  
Hamilton C. de O. Charlo ◽  
Arcângelo Loss ◽  
Antônio C. Barreto ◽  
...  

ABSTRACT Special corn is cultivated all year conventionally round; however, its productivity increases when grown under a no-tillage system (NTS). This study aimed to evaluate the agronomic performance of sweet and green corn cultivated under residues of different cover crops and the NTS implantation stages. Two experiments were carried out in the randomized block design, with four replications, in each of the three areas. The experiments consisted of evaluating the sweet and green corn, simultaneously, in three areas at different stages of development of NTS: initial (1 year), transition (7 years), and consolidation (19 years) with six types of cover crops: Signal grass (SG), Pearl millet (PM), Sunn hemp (SH), a mixture of SG + SH, SG + PM, and PM + SH. The dry matter (DM) production of the cover crops, the productivity of husked and unhusked ears, straw, and grain yield were evaluated. The SH had the highest dry mass production among the studied cover crops in all phases of the NTS. The phase of the NTS did not influence the productivity of ears with or without husk in green corn. The cultivation of sweet corn in transition and consolidation areas of the NTS showed better yields when compared to the initial phase of the system.


Author(s):  
Itamar R. Teixeira ◽  
Paulo R. Lopes ◽  
Westefann S. Sousa ◽  
Gisele C. da S. Teixeira

ABSTRACT The response capacity of the bean to fix atmospheric nitrogen is questionable, mainly due to its inability to supply all the nitrogen in the flowering and grain filling phases when the crop needs it most. Thus, a new application of inoculant can keep the population of rhizobia in the soil at adequate levels, meeting all the nitrogen demands of the plant. This study aimed to investigate the nodulation capacity and the production of beans submitted to doses and reinoculation of Rhizobium in topdressing under field conditions in two growth stages. For this, an experiment was conducted using a randomized block design with four replicates in a 4 × 2 + 2 factorial scheme. The treatments consisted of the application of four doses of liquid inoculant containing Rhizobium tropici (SEMIA 4088), in the concentration 2 × 109 CFU g-1, in topdressing (0, 100, 200 and 400 mL ha-1), in two development stages (V4 and R5) of plants, and two additional treatments (inoculation via seed at a dose of 100 g of the product per 50 kg of seeds and mineral nitrogen fertilization at a dose of 16 kg ha-1 applied at sowing and 60 kg ha-1 in topdressing, divided into two stages, with half being applied at the stage V3 and the other half in V4 stage).The inoculant application increased the nodulation rates of bean cultivar BRS Cometa and the dry biomass produced by plants, using doses of 232 and 221 mL ha-1, respectively. The dose of 257mL ha-1 of the liquid inoculant applied in topdressing at the V4 stage, and the inoculation via seed provide greater common bean yield without supplementing mineral nitrogen.


Author(s):  
Sheila D. P. da Silva ◽  
Gracielle P. de Souza ◽  
Agnaldo R. de M. Chaves ◽  
Marcelle A. da Silva ◽  
Rafaela R. de Souza ◽  
...  

ABSTRACT Knowledge of how climatic conditions affect plant morphophysiology is essential for understanding how to manage the growth cycles of different crops. The aim of this study was to evaluate the effects of the growing seasons in a semi-arid area on the morphophysiological variables of ornamental sunflower plants. The experiment was carried out in a randomized block design in a split-plot arrangement with four replicates. Six cultivars (‘Bonito de Outono Sortido’, ‘Sol Noturno’, ‘Sol Vermelho’, ‘Jardim Amarelo Alto’, ‘Girassol F1 Sunbright Supreme’ and ‘Girassol F1 Vincents Choice’) were evaluated in the main plots and two different growing seasons (GS) in the subplots (GS1 - warm climate and GS2 - mild climate). Evaluations of gas exchange, chlorophyll indices, and leaf surface area were carried out at the reproductive stage (R5.5). The cultivation of ornamental sunflowers in semi-arid regions was significantly affected by the growing season. Changes in gas exchange variables and the morphophysiology of ornamental sunflower plants in the two growing seasons reflected the high phenotypic plasticity characteristic of this species. The cultivation of ornamental sunflowers under semi-arid conditions in the growing season, when air temperature and solar radiation are high, could be limited due to elevated transpiration rates. Therefore, it is recommended that they are grown mainly during the moderate climatic season in semi-arid regions.


2022 ◽  
Vol 43 (2) ◽  
pp. 751-774
Author(s):  
Francisco Thiago Coelho Bezerra ◽  
◽  
Marlene Alexandrina Ferreira Bezerra ◽  
Raiff Ramos Almeida Nascimento ◽  
Walter Esfrain Pereira ◽  
...  

Salinity interferes in the physiology of seedlings from germination and seedling emergence, so it is necessary to adopt measures to mitigate its effects. The objectives of this research were to evaluate irrigation frequency, saline water, polymer, and container volume in the emergence and physiology of Talisia esculenta (A. St.-Hil.) Radlk. The treatments were obtained from the combination of polymer doses (0.0; 0.2; 0.6; 1.0; and 1.2 g dm-3), electrical conductivities of the irrigation water (0.3; 1, 1; 2.7; 4.3; and 5.0 dS m-1), and irrigation frequencies (daily and alternate), plus two additional treatments to assess the volume of the container. A randomized block design was used. Emergence and leaf indices of chlorophyll, fluorescence, and gas exchange were analyzed 100 days after sowing. The increase in electrical conductivity reduced and delayed seedling emergence. Decreasing irrigation frequency reduced the chlorophyll b index, stomatal conductance, transpiration, net CO2 assimilation, and carboxylation efficiency. The magnitude of the effects of electrical conductivity of water and polymer were associated with the frequency of irrigation. However, both salinity and polymer reduced practically all physiological variables. The reduction in container volume also affected the physiology of the seedlings, with more effects when irrigated on alternate days. The T. esculenta seedlings are considered sensitive to salinity, should be irrigated daily with water with less electrical conductivity than 1.0 dS m-1, as well as higher capacity containers used (0.75 vs 1.30 dm3).


Author(s):  
Aline D. A. de L. Marcelino ◽  
Pedro D. Fernandes ◽  
Jean P. C. Ramos ◽  
Wellison F. Dutra ◽  
José J. V. Cavalcanti ◽  
...  

ABSTRACT Two multivariate methods were adopted to classify salt-tolerant cotton genotypes based on their growth and physiological traits. The genotypes were cultivated in a greenhouse and subjected to 45 days of irrigation with saline water from the V4 phase onwards. Irrigation was performed with saline water with electrical conductivity (ECw) of 6.0 dS m-1. A factorial-randomized block design was adopted with nine cultivars, two treatments of ECw (0.6 as the control, and 6.0 dS m-1), and four replicates. Plants were evaluated for growth, gas exchange, and photosynthesis. The data were statistically analyzed using univariate and multivariate methods. For the latter, non-hierarchical (principal component, PC) and hierarchical (UPGMA) models were used for the classification of cultivars. Significant differences were found between cultivars based on univariate analyses, and the traits that differed statistically were used for multivariate analyses. Four groups were identified with the same composition in both the PC and UPGMA methods. Among them, one contained the cultivars BRS Seridó, BRS 286, FMT 705, and BRS Rubi, which were tolerant to salt stress imposed on the plants. Photosynthesis, transpiration, and stomatal conductance data were the main contributors to the classification of cultivars using the principal component method.


2022 ◽  
Vol 43 (2) ◽  
pp. 809-826
Author(s):  
Mariana Alves de Oliveira ◽  
◽  
Claudemir Zucareli ◽  
André Prechlak Barbosa ◽  
Leandro Teodoski Spolaor ◽  
...  

Reduced row spacing promotes more uniform spatial distribution of plants in the field. However, the adoption of reduced row spacing only is possible with smaller plants, which may be obtained with the use of plant growth regulator. This study aimed to evaluate the agronomic performance of the first corn crop with Trinexapac-ethyl applied at the different plant development stages and grown under different row spacing, with the same plant population. The experiments were arranged in a split-plot randomized block design with four replications, with row spacing for the plots (0.45 and 0.90 m) and Trinexapac-ethyl (TE) application time to subplots (control without application, at the V3, V6, V9 and V12 phenological stages). The Trinexapacethyl application time interacted with row spacings changing the growth and yield performance of the corn crop. For 0.45 m spacing Trinexapac-ethyl application at V12 and for 0.90 m spacing application at V9 and V12 reduced plant height and ear height. Trinexapac-ethyl application at V9 for both row spacings changed the plant architecture without changing the ear length and grain yield.


Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 217
Author(s):  
Carlo Duso ◽  
Alberto Pozzebon ◽  
Mauro Lorenzon ◽  
Diego Fornasiero ◽  
Paola Tirello ◽  
...  

According to the European Directive 2009/128/EC and the subsequent provisions activated in member states, conventional pesticides should be progressively replaced by “non-chemical tools and/or measures”. The identification of reliable alternatives to pesticides is crucial to achieve this objective. A European project (PURE) was funded to investigate this topic with reference to annual and perennial crops. In this framework, a number of natural insecticides, in particular microbial and botanical ones (Bacillus thuringiensis subsp. kurstaki, Beauveria bassiana, azadirachtin, pyrethrins and spinosad) were selected to test their effectiveness against grape berry moths, the key pests in most European vineyards. Trials were conducted in 2011 and 2012 in two experimental vineyards located in Italy (Tuscany and Veneto regions), following a randomized block design. Additional investigations were carried out in the Veneto region during 2013. Trial results stressed the high performance of spinosad and B. thuringiensis in controlling berry moth densities and the related damage. The use of B. bassiana mixed with B. thuringiensis did not significantly improve the impact of B. thuringiensis alone. Azadirachtin, and especially pyrethrins, proved to be less effective on berry moths than previous insecticides. The use of selected insecticides caused side-effects on a number of secondary pests, in particular leafhoppers. In 2011, densities of Empoasca vitis were more abundant in spinosad-treated plots probably because of a reduced egg parasitism rate. One year later, population densities of Zygina rhamni were more abundant on spinosad and pyrethrin-treated plots. This trend was confirmed on spinosad-treated plots in the last experimental year. At the same time, spinosad and pyrethrins significantly reduced the predatory mite populations compared to other treatments. The use of these insecticides in viticulture is discussed in the framework of organic viticulture and Integrated Pest Management (IPM).


2022 ◽  
Vol 14 (2) ◽  
pp. 79
Author(s):  
Ismael Gaião da Costa ◽  
José Wilson da SiIva ◽  
Gheysa Coelho Silva ◽  
Mario de Andrade Lira Junior ◽  
Cybelle Souza de Oliveira ◽  
...  

The objective of this research was to evaluate the correlations between variables related to the biological nitrogen fixation (BNF) in segregating generations of cowpea and to unfold these correlations in direct and indirect effects, through path analysis. An outdoor bench experiment was conducted at Carpina Experimental Sugarcane Station of, located at the Zona da Mata region of the State of the Pernambuco, Northeast of Brazil (Federal Rural University of Pernambuco), between March and April 2016. The seeds were planted in 20 cm × 30 cm polyethylene bags, using a substrate composed of a mixture of vermiculite and sand washed in a ratio of 1:1. Bradyrhizobium references, recommended for culture, were used as a mixture of two strains. Parental and F2, F3 and F4 generations were evaluated in a randomized block design with four replicates. Data collection was performed 45 days after the emergency (DAE). Phenotypic correlations and path analysis of the number of nodules per plant (NN), nodules dry mass (NDM), dry roots mass (DRM), dry mass of aerial part (DMAP), nodulation efficiency (NODE) and nitrogen accumulated in the aerial part (NAAP). The phenotypic correlations between the variables related to the BNF showed high magnitudes, demonstrating that there is a great influence of each of the variables on the others, furthermore the path analysis of the coefficients indicated that all the primary components (NN, NDM, DRM, DMAP and NODE) must be considered when it is desired to increase the NAAP in segregating generations of cowpea.


Author(s):  
C Lee ◽  
J E Copelin ◽  
M T Socha

Abstract Three experiments were conducted with growing wethers to evaluate apparent excretion and retention of Zn from various sources. In Exp. 1 and 2, Zn-ethylene diamine (ZE), Zn hydroxychloride (ZHYD), Zn-lysine/glutamate (ZAA), and Zn-glycinate (ZG) were used and ZnSO4 (ZS), Zn hydroxychloride (ZHYD), Zn-lysine/glutamate (ZAA), and Zn-glycinate (ZG) were used in Exp. 3. In Exp. 1, 8 wethers were used in a replicated 4 × 4 Latin Square design. In Exp. 2 and 3, 40 wethers were used in a randomized block design. In Exp. 1, each period (total 4 periods) consisted of 14-day diet adaptation and 4 days of total collection of feces and urine. In Exp. 2 and 3, wethers received a basal diet for 14 days and received experimental diets for 9 days (diet adaptation), followed by 4 days of total collection of feces and urine. Total collection was conducted in wooden metabolic cages. All data were analyzed using the MIXED procedure of SAS as a Latin square design for Exp. 1 and a completed randomized block design for Exp. 2 and 3. In all experiments, dry matter intake did not differ among treatments except that it tended to be different in Exp. 2. In Exp. 1, no difference in Zn excretion (88%) and retention (11%) as proportion of Zn intake was observed among Zn sources. In Exp. 2, total tract digestibility of crude protein was greater (P < 0.01) for ZAA than ZE and ZG (82.0 vs. 79.1 and 77.8%, respectively) and greater (P < 0.01) for ZHYD than ZG (80.2 vs. 77.8%). However, total tract digestibility of neutral detergent fiber was low (on average 16%) for all treatments with no difference among treatments in Exp. 2. Apparent excretion and retention of Zn as proportion of Zn intake did not differ among treatments, and Zn retention (~1.4% of Zn intake) was very low for all treatments. In Exp. 3, ZHYD and ZAA had greater retention of Zn (17.8 vs. 1.5%; P = 0.01) than ZG. Fecal Zn excretion was greater (97.3 vs. 81.2%; P = 0.01) for ZG vs. ZHYD and ZAA, and Zn retention for ZG was only 1.5% of Zn intake. In conclusion, potential increases in Zn absorption and retention were observed for ZHYD and ZAA compared with ZS and ZG in Exp. 3 and these differences were not found in Exp. 1 and 2. Experiment 1 used a Latin square design and Exp. 2 used a diet containing largely undigestible fiber. These experimental conditions may have affected Zn metabolism in wethers. Inconsistent results on Zn balance for ZG among the experiments warrant further studies regarding its bioavailability.


2022 ◽  
Vol 5 (1) ◽  
pp. 6-14
Author(s):  
Henly Yulina ◽  
Wiwik Ambarsari

The objective of this research was to find out the effect of municipal solid waste compost and cow manure on plant height, leaf length, and harvest weight of pakcoy (Brasica rapa) in Andisols in Indramayu Regency. This study used a randomized block design factorial with two factors. The first factor is municipal waste compost and the second factor is cow manure. Each of them consisted of 4 levels : 0%, 3.0%, 6.0%, and 9.0% with two replication. The results showed that there was an interaction between municipal solid waste compost and cow manure on the plant heights of  pakcoy 14, 21, and 28 HST, but there was no interaction at 7 HST. The statistical results show that the combination of municipal solid waste compost with cow manure has an effect on the height of pakcoy 14, 21, and 28 HST, but the height of pakcoy 7 HST is influenced by the independent influence of cow manure. There was an interaction between municipal solid waste compost and cow manure on the leaf length of pakcoy 7, 14, 21, and 28 HST, and there was an interaction between municipal waste compost and cow manure on the harvest weight of pakcoy. The application of organic matter, both municipal solid waste compost and cow manure to the soil can increase plant height, leaf length, and harvest weight of pakcoy.


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