scholarly journals Effects of plant density and proportion on the interaction between wheat with alexandergrass plants

Bragantia ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Leonardo Bianco de Carvalho ◽  
Pedro Luis da Costa Aguiar Alves ◽  
José Valcir Fidelis Martins

Determination of competitive relationships among plant species requires appropriate experimental designs and method of analysis. The hypothesis of this research was that two species growing in coexistence show different growth and development due to their relative competitiveness. This research aims to measure the relative competitiveness of wheat crop compared to Alexandergrass by the interpretation of plant density and proportional effects using replacement series experiments. Monocultures were cultivated in densities of 1, 3, 5, 10 and 15 plants per pot and analyzed by regression of dry mass data. Mixture experiment was cultivated in wheat:Alexandergrass proportions of 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0 plants per pot and analyzed by graphical interpretation of growth and production characteristics. Both experiments were carried out in randomized complete block design with four replicates. Alexandergrass was more sensitive to intraspecific competition than wheat. Alexandergrass was lightly more competitive than wheat. Number and weight of spikes and number of tillers were the wheat characteristics more affected by Alexandergrass interference.

2016 ◽  
Vol 96 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Gan Yantai ◽  
K. Neil Harker ◽  
H. Randy Kutcher ◽  
Robert H. Gulden ◽  
Byron Irvine ◽  
...  

Optimal plant density is required to improve plant phenological traits and maximize seed yield in field crops. In this study, we determined the effect of plant density on duration of flowering, post-flowering phase, and seed yield of canola in diverse environments. The field study was conducted at 16 site-years across the major canola growing area of western Canada from 2010 to 2012. The cultivar InVigor® 5440, a glufosinate-resistant hybrid, was grown at five plant densities (20, 40, 60, 80, and 100 plants m−2) in a randomized complete block design with four replicates. Canola seed yield had a linear relationship with plant density at 8 of the 16 site-years, a quadratic relationship at 4 site-years, and there was no correlation between the two variables in the remaining 4 site-years. At site-years with low to medium productivity, canola seed yield increased by 10.2 to 14.7 kg ha−1 for every additional plant per square metre. Averaged across the 16 diverse environments, canola plants spent an average of 22% of their life cycle flowering and another 27% of the time filling seed post-flowering. Canola seed yield had a negative association with duration of flowering and a positive association with the days post-flowering but was not associated with number of days to maturity. The post-flowering period was 12.7, 14.7, and 12.6 d (or 55, 68, and 58%) longer in high-yield experiments than in low-yield experiments in 2010, 2011, and 2012, respectively. We conclude that optimization of plant density for canola seed yield varies with environment and that a longer post-flowering period is critical for increasing canola yield in western Canada.


2018 ◽  
Vol 48 (5) ◽  
Author(s):  
Esmael Lopes dos Santos ◽  
Victor José Agassi ◽  
Alessandro Sartor Chicowski ◽  
Julio Cezar Franchini ◽  
Henrique Debiasi ◽  
...  

ABSTRACT: In the last few cropping seasons, some soybean producers have tested the application of a hill drop sowing method, usually from three to four seeds every 30 to 40cm. However, there is a lack of information in the literature about the effect of this practice on soybean performance. Thus, the objective of this study was to evaluate the effect of a hill drop sowing with different number of plants per hole on soybean performance. The study was conducted in Londrina - PR, Brazil, during the 2013/14, 2014/15 and 2016/17 cropping seasons. The experiment was a randomized complete block design with four replications and a 2x5 factorial scheme. The first factor consisted of two soybean cultivars, BRS 359RR and NK 7059RR analyzed in the first two cropping seasons and BRS 359RR and BRS 1010IPRO in the last cropping season. The second factor was constituted by five in-hill hole-spacing treatments (HS) (8, 16, 24, 32 and 40cm), with rows spaced 50cm apart. To maintain the same plant density in all treatments (270,000 plants ha-1), sowing was performed manually, being then thinned out. After thinning, the distribution was one plant per hole at HS8, 2 plants at HS16, 3 plants at HS24, 4 plants at HS32, and 5 plants at HS40. The agronomic performance of soybean in hill drop sowing with different number of plants per hole is similar to that of an equidistant distribution of plants.


2013 ◽  
Vol 31 (3) ◽  
pp. 695-703 ◽  
Author(s):  
S.R. Marchi ◽  
D. Martins ◽  
N.V. Costa ◽  
J.R.V. Silva

This trial aimed to evaluate the effect of sequential applications of different plant regulators over growth and flower rachis emission of 'Meyer' zoysiagrass (Zoysia japonica). The study was conducted on 15-month old green turfgrass under a randomized complete block design with four replications. The following plant regulator and doses were tested: trinexapac-ethyl (113+113, 226+113, 226+226, 452+113, 452+226, 452+452, 678+339 e 904+452 g a.i./ha-1), prohexadione-calcium (100+100 e 200+200 g a.i. ha-1) and bispyribac-sodium (40+40 e 60+60 g a.i. ha-1), as well as an untreated control. The turfgrass was mowed again at 3.0 cm aboveground and the second plant regulator was applied when 'Meyer' zoysiagrass was between 5.0 and 6.0 cm high. The effect of the treatments was visually rated for visual injury, plant height, height and number of flower rachis, and total dry mass production of clippings. Only bispyribac-sodium had visual symptoms of injury on 'Meyer' zoysiagrass, and no intoxication was observed at 28 days after the second application (DAAB). The sequential applications of trinexapac-ethyl, prohexadione-calcium and bispyribac-sodium reduced by more than 80% the total clipping dry mass produced by 'Meyer' zoysiagrass. All the plant regulators tested also showed promising results in reducing the height and emission of rachis, especially when trinexapac-ethyl was applied at the doses 452+452, 678+339 and 904+452 g a.i. ha-1. 'Meyer' zoysiagrass turfgrass can be handled with the sequential application of a plant regulator, which reduces the need for mowing over a period up to 110 days after the application of the second plant regulator, and it also avoids deleterious visual effects over turfgrass.


Nativa ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 50
Author(s):  
Kassio Ewerton Santos Sombra ◽  
Andreza Cristina Chagas de Oliveira ◽  
Ronyce Do Nascimento Ferreira ◽  
Alexandre Caique Costa e Silva ◽  
Cleilson Do Nascimento Uchôa ◽  
...  

O trabalho objetivou avaliar os efeitos do excesso de ferro sobre a emergência e desenvolvimento inicial de genótipos de porta-enxertos cítricos. Adotou-se delineamento em blocos casualizados (DBC), em fatorial 5x2, com cinco porta-enxertos e dois substratos, repetidos quatro vezes, com parcela útil de 15 recipientes. Os genótipos consistiram do limoeiro ‘Cravo Santa Cruz’; citrandarins ‘Riverside’, ‘San Diego’ e ‘Índio’, além de, tangerineira ‘Sunki Tropical’, cultivados com ou sem óxido de ferro no substrato. Analisaram-se as porcentagens de emergência (PE) e calculou-se o índice de velocidade de emergência (IVE). Realizaram-se biometrias aos 30, 60 e 90 dias após a semeadura (DAS), mensurando-se a altura (H) e diâmetro de caule (D) das plântulas, determinando-se massa fresca (MV) e seca (MS). O excesso de ferro induziu subdesenvolvimento, e até mortalidade de plântulas já emergidas, o que refletiu diretamente nos resultados, porém, todos os genótipos apresentaram emergência superior a 75%, destacando-se o citrandarin ‘San Diego’, com maior altura e caule mais espesso, e o citrandarin ‘Riverside’ com maior sensibilidade ao estresse, registrando os menores valores. O citrandarin ’San Diego’ demonstrou tolerância o estresse e desenvolveu-se satisfatoriamente, necessitando estudos que avaliem a manutenção das características inferidas em combinação com a cultivar copa.Palavras-chave: ambiente protegido, citricultura, enxertia, estresse, mudas. EXCESS OF IRON ON THE DEVELOPMENT OF CITRUS ROOTSTOCKS ABSTRACT: The objective of this work was evaluated the effects of iron excess on the emergence and initial development of citrus rootstock genotypes. A randomized complete block design (DBC), factorial 5x2, with five rootstocks and two substrates, repeated four times, with useful plot of 15 containers was adopted. Genotypes consisted of the 'Santa Cruz' Rangpur lemon; 'Riverside', 'San Diego' and 'Indio' citrandarins, as well as 'Sunki Tropical' tangerine, grown with or without iron excess in substrate. The percentages of emergency (PE) were analyzed and the rate of emergency (IVE) was calculated. Biometry was performed at 30, 60 and 90 days after sowing (DAS), by measuring the height (H) and stem diameter (D) of the seedlings, determining fresh (MV) and dry mass (DM). The excess of iron induced underdevelopment, and even mortality of already emerged seedlings, which reflected directly in the results, however, all genotypes presented an emergency higher to 75%, standing out ’San Diego’ citrandarin, with greater height and more stem thick, and the ‘Riverside’ citrandarin with greater sensitivity to stress, registering the lowest values. 'San Diego’ citrandarin demonstrated stress tolerance and developed satisfactorily, requiring studies that evaluate maintenance of inferred characteristics in combination with cultivar canopy.Keywords: protected environment, citriculture, grafting, stress, seedlings.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Erasmus Narteh Tetteh ◽  
Eric Owusu Danquah ◽  
Akwasi Adutwum Abunyewa ◽  
Caleb Melenya Ocansey ◽  
Emmanuel Amoah Boakye ◽  
...  

A three-year field trial was conducted between 2014 and 2017 in the Ellembelle and Jomoro districts of the Western region of Ghana where rubber production is common to determine the optimum population density of plantain when grown in combination with immature rubber tree crops. The trials were arranged in a Randomized Complete Block Design with 3 replications. The treatments were sole rubber, sole plantain, and three intercrops of one row of plantain in between two rows of rubber, two rows of plantain in between two rows of rubber, and three rows of plantain in between two rows of rubber. The rubber clone used was GT1 while the variety of plantain used was false horn. The results showed that population density of plantain had significant effect on the growth of the associated rubber. Growing plantain at closer spacing of 1.5 m under the high-density plantain treatment significantly increased plantain yield compared to the other cropping systems. There was a significant positive relationship between population density of plantain and the rubber tree growth and development. The optimum population density of plantain when intercropped with rubber was 1,666/ha. The study showed intercropping was advantageous over sole cropping for both crops.


2017 ◽  
Vol 39 (3) ◽  
pp. 254-261 ◽  
Author(s):  
Fábio Henrique Krenchinski ◽  
Victor José Salomão Cesco ◽  
Danilo Morilha Rodrigues ◽  
Vinicius Gabriel Caneppele Pereira ◽  
Alfredo Junior Paiola Albrecht ◽  
...  

Abstract: Some desiccation techniques for harvesting wheat may affect seed quality. The objective of this study was to evaluate the effect of different desiccant herbicides applied to the wheat crop and their effects on the production and seed quality. The experiment was conducted with cultivar COODETEC 150 (CD 150) in two sites in Palotina (Paraná state, Brazil) with a randomized block design consisting of 7 treatments (desiccation herbicides) and 4 replications. Desiccation was realized when 50% of the plants were in stage 80 with seeds in powdery or mass consistency. The variables analyzed were percentage of moisture content after harvest, Yield, hectoliter weight, mass of 100 seeds, vigor, germination, fresh mass of seedlings, dry mass of seedlings and root length. The herbicides carfentrazone-ethyl and clethodim were the ones that promoted greatest reduction in vigor. The herbicide paraquat caused reduction in seedling length. There was a reduction in the mass of 100 seeds for glufosinate-ammonium, clethodim, diquat and carfentrazone-ethyl. Glufosinate-ammonium, paraquat, glyphosate, clethodim and diquat caused reduction in yield. Desiccation of Cultivar CD 150 at stage 80 is not recommended, since plant Yield and physiological seed parameters were adversely affected by herbicides.


2018 ◽  
Vol 39 (2) ◽  
pp. 455
Author(s):  
Daniele Cristina Fontana ◽  
Braulio Otomar Caron ◽  
Denise Schmidt ◽  
Daniela Meira ◽  
Thais Pollon Zanatta ◽  
...  

The lack of research about escarole cultivars adapted to each region, as well as technical information on plant growth have been some of the factors related to low yields. Therefore, the aim of this work was to evaluate the growth of escarole crop in four seasons of year in Santa Maria, RS. The experiment was conducted in a randomized complete block design, 1 x 4, being a escarole (cultivar Escorola Lisa®) evaluated in four seasons of year (summer, autumn, winter and spring), in six replications. The evaluations were performed in a destructive manner every seven days, from date of transplant to harvest point. The following components were analyzed: number of leaves, number of residues, dry mass of leaves, dry mass of leaves, stem and residue. Thus, it was determined the parameters for growth analysis. With the data obtained, we performed a variance analysis, and presented significant results, and the means of each season of the year submitted to the Tukey test at 5% of error probability. The air temperature and global radiation influence crop cycle. Lower temperatures and lower incidence of radiation result in cycle extended, as observed in autumn. The escarole growth is influenced by seasons of year in Rio Grande do Sul (RS), and summer and spring finish the cycle in advance to others, presenting a larger leaf area. Summer and spring are most indicated season to escarole crop in RS, Brazil.


2017 ◽  
Vol 47 (11) ◽  
Author(s):  
Enio Marchesan ◽  
Felipe Tonetto ◽  
Gustavo Mack Teló ◽  
Lucas Lopes Coelho ◽  
Bruno Behenck Aramburu ◽  
...  

ABSTRACT: This study investigated the effects of soil management systems, tillage, and application of gypsum agricultural to soil, on soybean development in lowland areas. The experiment was carried out on an Alfisol in a randomized complete block design in a factorial arrangement. The two soil tillage practices were without deep tillage and with deep tillage. Gypsum treatments were no gypsum application, 500kg of gypsum ha-1, 1000kg of gypsum ha-1, and 1500kg of gypsum ha-1. Deep tillage resulted in less soil resistance to root penetration during ryegrass cultivation during the soybean offseason, 11 months after applying the management treatments, resulting in higher dry mass of ryegrass in the offseason and higher soybean yield in the following year.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 679d-679
Author(s):  
Arvazena E. Clardy ◽  
Stephen Garton

Two cultivars of Tagetes erecta Marigolds—Hero Yellow and Safari Tangerine—were grown hydroponically in two different nutrient solutions. The experiment was implemented in the greenhouses on the campus of Alabama A&M Univ., from March to May 1995. The experiment was to assess the effects of growth and development of Marigolds. Heights of seedlings, germinated in grodan (rockwool) cubes were measured and placed randomly in the hydroponic units. Plants were drenched with five rates of either Paclobutrazol (Bonzi) and Uniconazole (Sumagic). The experiment was laid out as a randomized complete block design with either three or four replications of the treatment, which were factorial combinations of variables. After 75 days measurements were made of plants heights, flower bud numbers and dry weights of shoot and root systems. Shoot dry weights were affected by growth regulator treatments, variety, nutrient treatments and a combination of variety and nutrient treatments. Root dry weights were affected by nutrient treatments. Flower bud formation and numbers were affected by the combination of nutrient and variety. Heights were affected by growth regulator treatments, variety and nutrient treatments.


Author(s):  
Catherine Muriithi ◽  
Beatrice Nganga ◽  
Eliud Kagete ◽  
Donald Njarui ◽  
Alfred Micheni

Aims: To introduce brachiaria grasses in Meru and Embu Counties to increase the range of fodder/forage varieties available to smallholders through the use of climate-smart brachiaria grasses for increased income. The project also aimed at identifying the best brachiaria varieties suitable for the target Agro-Ecological ones through evaluation by the farmers and yield assessment. Study Design:  Randomized Complete Block Design (RCBD) Place and Duration of Study: The study was carried out in Embu and Meru Counties during the short rains of 2015. Methodology: Three varieties of brachiaria were introduced in the short rains of 2015 in KALRO Embu, Geeto Igoji in Meru, and Embu County. These were Brachiaria decumbense -Cultivar Basilisk, Brachiaria brizantha- Cultivar BRS Piata and Brachiaria brizantha- Cultivar Toledo. Plots of 5x5m were planted and replicated three times using Randomized Complete Block Design (RCBD) to increase the range of fodder/forage varieties available to smallholder and assess the yield and acceptability of the different brachiaria grasses varieties. The three varieties were planted in the mega demonstration sites. The grass performance was analyzed through pairwise ranking and the grass with the best attributes was selected. Yield data was also collected. Results: After ranking, the results indicated that the rate of growth and the amount of biomass as the most important attributes followed by the animals' response after feeding and the rate of rejuvenation after harvesting respectively. Using the attributes, the group members concluded that Brachiaria decumbense- Cultivar basilisk was the best followed by brachiaria brizantha- Cultivar piata and finally brachiaria brizantha- Cultivar Toledo. Conclusion: In conclusion, based on the attributes, the best brachiaria varieties for use in Embu and Meru Countries are Brachiaria decumbense –Cultivar Basilisk and Brachiaria brizantha- Cultivar Toledo. Based on yield, Brachiaria brizantha- Cultivar Toledo is the best in Embu County while Brachiaria brizantha- Cultivar Basilisk is the best in Meru County.


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