scholarly journals Do Greenhouse Cover Materials Affect Cannabis Performance?

Author(s):  
Antonios MAVROEIDIS ◽  
Dimitrios BILALIS ◽  
Alexandros TATARIDAS ◽  
Ioannis ROUSSIS ◽  
Ioanna KAKABOUKI ◽  
...  

A greenhouse pot experiment was conducted in the Agricultural University of Athens in order to evaluate the effect of several greenhouse cover materials on the performance and yield of hemp. The experiment was set up in a completely randomized design (CRD) with five treatments/greenhouses (G1, G2, G3, G4/Control, and G5). Measurements included plant height, PAR (Photosynthetic Active Radiation), chlorophyll content, solar irradiance, soil and leaf temperature, and yield components (the number of buds, their weight, length, and compact index, CBD content, and CBD yield per plant). The results of the present study suggest that the different polyethylene cover films alter the environment within the greenhouse and thus, affect the agronomic characteristics and yield traits of hemp. G1 reported the best results as it increased soil temperature and PAR values by 11-16% and 50-110% respectively, compared to G4. Concurrently, the majority of the bud characteristics were significantly improved in G1. Even though further research should be conducted in order to define the most suitable films for greenhouse hemp production, our results indicate that the optical properties of the greenhouse cover materials affect its yield and should always be considered.

2020 ◽  
pp. 1236-1241
Author(s):  
Gustavo H. Sera ◽  
Filipe G. Carvalho ◽  
Inês C. de B. Fonseca ◽  
Luciana H. Shigueoka ◽  
Santino A. da Silva ◽  
...  

The aim of this study was to prove that Arabica coffee introgressed with C. liberica, have resistance to Meloidogyne paranaensis (Mp). Open pollinated fruits were harvested from mother plants of 29 Arabica coffee genotypes from the IAPAR germplasm bank. Seeds were collected from the fruits and were sown to obtain seedlings to test the resistance to Mp. The experiment was set up in a completely randomized design with 29 coffee genotypes, 8 replications, and one plant per plot. Cultivars Catuaí Vermelho IAC 99 and IPR 100 were used as susceptible and resistant checks, respectively. Seedlings with three to four pairs of leaves were inoculated with 1,400 eggs and juveniles J2 of Mp (IP). At 120 days after inoculation, seedlings were evaluated by counting the nematodes per gram of roots, and the final nematodes population was obtained (FP). The reproduction factor (RF) was calculated using the formula: RF = FP/IP. The reproduction factor reduction was used to classify the resistance levels of genotypes, which were classified as highly resistant (HR), resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) an highly susceptible (HS). All genotypes differed from Catuaí in resistance factor (RF), five of which did not differ from IPR 100 for RF, and only the line IAPAR 15242 had RF < 1.0. Out of 28 Arabica genotypes introgressed with C. liberica, five HR, 11 R, 11 MR and one MS were identified. However, only IAPAR 15242 and IPR 100 were classified as HR and presented 100% of HR plants, but only the first showed an RF < 1.0. Results revealed that these Arabica coffee genotypes with introgression of C. liberica genes have great potential to be used in breeding programs and they are a new alternative as a source of resistance.


2015 ◽  
pp. 13-26
Author(s):  
Premadhis Das ◽  
Ganesh Dutta ◽  
Nripes Kumar Mandal ◽  
Bikas Kumar Sinha

2015 ◽  
Vol 46 (4) ◽  
pp. 590-592 ◽  
Author(s):  
Cibele Mantovani ◽  
Kathia Fernandes Lopes Pivetta

ABSTRACT: The objective of this paper was to evaluate the effects of different honey concentrations in culture media, in comparison to sucrose medium, for the in vitro development of the epiphytic Encyclea cordigera orchid, in order to improve the process of propagation of the species. The in vitro germination was prepared on a reduced Murashige & Skoog (MS) medium. After 90 days, the seedlings were divided into different treatments, where they remained for another 90 days. Six treatments were set up (30g L-1 of sucrose; 15, 30, 45, and 60g L-1 of honey; and absence of any carbohydrates) in a completely randomized design. Plants were removed from the vials 270 days after the start of the experiment, and the number of roots, length of the largest leaf, length of the longest root, number of leaves, and fresh and dry masses were evaluated. Data concerning the number of leaves and roots were (x+1)1/2 transformed and subjected to an analysis of variance (ANOVA); the means were compared by a Tukey's test set at 5% probability. Medium containing 60g L-1 of honey proved to be superior to the sucrose medium traditionally used, favoring the in vitro growth and development of Encyclea cordigera. This medium can therefore be recommended for the propagation of this species, which is usually cultivated as an ornamental plant.


Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 456
Author(s):  
Bruno Fróes Campos ◽  
Anselmo Junior Corrêa Araújo ◽  
Cristina Aledi Felsemburgh ◽  
Thiago Almeida Vieira ◽  
Denise Castro Lustosa

The application of Trichoderma fungus can be used to obtain seedlings of higher quality for plantations. The objective of this study was to evaluate the effects of Trichoderma isolates on the germination and initial growth of açaí seedlings. Two trials were set up. In the laboratory, the seeds were inoculated in suspensions prepared with each of the isolates for 24 h, and they were arranged in trays containing filter paper in a completely randomized design with five replicates containing 50 seeds each. For the control, the seeds were submerged only in water. Part of the seedlings resulting from seeds treated and not treated with Trichoderma were transferred to bags containing forest soil and were submitted to seven modes of application of Trichoderma and kept in a nursery. The speed of germination and hypocotyl were not influenced by the biological treatment. The application of the different Trichoderma isolates positively influenced the height, collar diameter, number of leaves, root size, leaf area and root, and aerial part dry mass of the açaí seedlings. The application of the Trichoderma isolate TAM01 on the preplanting substrate and biweekly applications on the postplanting substrate was the combination that most positively influenced the development of açai seedlings.


Agrologia ◽  
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Reginawanti Hindersah ◽  
H Yulina ◽  
Ane Nurbaity

Azotobacter chroococcum based biofertilizers have been widely used in the production of environmentally agriculture. For commercial scale, cheap growth media for Azotobcter inoculant  will affect the quality and price of liquid biofertilizer. Growth medium should support cell proliferation as well as its  nitrogen fixation and phytohormone production.  The objective of this study was to determine whether  liquid organic fertilizer (LOF) containing low N can be used as a medium for scaling up  A. chroococcum inoculant without lowering the survival of bacteria and its activity in N2 fixation and phytohormones production. LOF generally contains a complete nutrient although in a small quantities. Experiment was set up in completely randomized design which tested two types of commercial LOF. The results showed that both of  LOF were only able to support cell growth up to 72 hours and at 96 hours cell viability began to decline compared to the control medium,  free-N Ashby. At 72 hour total N and cytokinin  concentration in LOF was lower than those in Ashby media. This study revealed  that LOF  could be used as A. chroococcum growth media, but without optimization of its composition, cell density and cytokinin content would be lower than those of inoculant  in Ashby Media.


Agrologia ◽  
2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Evawani Tomayahu

Pest is one of the biological limiting factors that led to low production of potatoes. The use of pesticides is a solution in controlling pests. The objective of this study was to determine the diversity and evenness of insect; and potato yield losses due to insecticide applications methods. The treatment was controlled and intensive insecticide application which were compared with no insecticide application.  The experiment was set up in completely randomized design with five replications. The results showed that the insects are dominated by Empoasca sp, Liriomyza sp and Miridae. The highest insect population was Empoasca sp. i.e 80.83 Empoasca sp. which was found in control treatment. Controlled and intensive  application of insecticides decreased insect  population up to 56.50 and 26.17. Evenness index of insect and economic value of lost results unaffected by differences in pesticide application methods


2016 ◽  
Vol 9 (1) ◽  
pp. 28 ◽  
Author(s):  
Iswari S Dewi ◽  
Yusie Arisanti ◽  
Bambang S. Purwoko ◽  
Hariyadi Hariyadi ◽  
M. Syukur

<p>The interest in using Jatropha curcas L. from the<br />family Euphorbiaceae for the production of biofuel is rapidly<br />growing. The research objective was to determine genetic<br />variation of several high yielding physic nuts based on their<br />morphology, agronomy, and isozyme characters. The<br />research used Completely Randomized Design with three<br />replications. The treatment was consisted of 8 genotypes i.e.<br />IP-1A, IP-1M, IP-2P, Lombok Timur, Lombok Tengah,<br />Lombok Barat, Sumbawa, and Bima. Analysis of isozyme of<br />the eight genotypes was also conducted according to 5<br />enzyme systems, i.e. peroksidase, esterase, aspartat<br />aminotransferase, malat dehidrogenase, and alcohol<br />dehidrogenase. Observation was done on qualitative and<br />quantitative characters as well as banding pattern derivedisozymes.<br />The results showed that genetic variation was low<br />when based on qualitative characters and isozyme (0-25%)<br />but relatively high when based on selected quantitative<br />characters analysis (17-81%). Analysis of combined<br />qualitative, quantitative, and isozyme characters still gave<br />low genetic variation (6-33%). Based on the quantitative<br />characters at similarity coefficient of 46% the genotypes can<br />be devided into three clusters. Improved population<br />genotypes, i.e. IP-1A, IP-1M, and IP-2P were placed in 3<br />different clusters, while other genotypes from NTB area<br />were grouped in the same cluster. Therefore, selection<br />among population of the same ecotype based on agronomic<br />characters such as yield components, yield and oil content<br />was suitable in Jatropha improvement, especially when<br />genetic variation was low. Furthermore, introduction,<br />mutation and crossing are suggested to increase genetic<br />variation of current Jatropha collection.</p>


2020 ◽  
Vol 9 (8) ◽  
pp. e430985428
Author(s):  
Edilson Costa ◽  
Thamíris Campaneli Lopes ◽  
Abimael Gomes da Silva ◽  
Tiago Zoz ◽  
Josiane Souza Salles ◽  
...  

The study aimed to evaluate the influence of reflective materials on the cultivation bench and the use of rice husks over the substrate in the formation of Dipteryxalata seedlings. The experiment was carried out in the experimental area of the Mato Grosso do Sul State University, in Cassilândia-MS, from November 1st, 2016 to January 26th, 2017. A completely randomized design in a 5 x 2 factorial scheme was used, with five replications and five plants per plot. Four reflective material for the cultivation bench and treatment without reflective material (control), combined with or without rice husks over the substrate (0.5 cm layer), were evaluated. Laminated paper tray, mirror, reflective fabric (known as “fake sequin fabric”), and aluminum foil were used as reflective materials. The reflecting materials did not differ in the reflectance of photosynthetically active radiation. However, the mirror and the aluminum foil reflected more than the control. The use of rice husk over the substrate did not increase the Dipteryxalata seedlings' quality. The mirror as a reflective material produced Dipteryxalata seedlings of higher quality than the system without material reflector called control.


2000 ◽  
Vol 35 (11) ◽  
pp. 2181-2189 ◽  
Author(s):  
WILMAR FERREIRA LIMA ◽  
JOSÉ FRANCISCO FERRAZ DE TOLEDO ◽  
CARLOS ALBERTO ARRABAL ARIAS ◽  
MARCELO FERNANDES DE OLIVEIRA

Soybean yield is highly affected by sowing period and there are significant productivity losses when sowings are done outward a relatively restricted period in many regions of Brazil. Breeding cultivars less sensitive to photoperiod and to temperature variations is desirable for adaptation to wider sowing period and wider latitude range and also make irrigated soybean cultivation possible during the fall-winter seasons in frost free regions. The possibility of selecting high yielding and stable lines for yield during various sowing periods was studied by analyzing the behavior of 100 non-selected advanced lines (F9 and F10), from each one of all possible biparental crosses involving the genotypes BR85-29009, OCEPAR 8, FT-2, and BR-13. Experiments were set up in a completely randomized design with single-plant hill plots and received supplementary irrigation. Sowing was on Sept 27, Oct 20, Nov 17, and Dec 17 in 1993/94 and Sept 20, Oct 20, Nov 17, and Dec 14 in 1994/95 at Londrina, PR, Brazil. Procedures of regression analysis and minimum variance among planting date means were efficient for selecting stable lines during the four sowing seasons. It was possible to select stable and high yielding genotypes through the four sowing periods in all the crosses. No specific cross was clearly better to produce a greater number of stable genotypes.


2019 ◽  
Vol 41 (1) ◽  
pp. 44826
Author(s):  
Pedro Leonardo de Paula Rezende ◽  
João Restle ◽  
Ubirajara Oliveira Bilego ◽  
Juliano José de Resende Fernandes ◽  
Regis Luis Missio ◽  
...  

Carcass and meat characteristics of 48 Nellore heifers at 24 to 30 months of age, with an initial weight of 263.4 ± 13.9 kg, were evaluated. The experiment was set up as a completely randomized design with four treatments, which consisted of four slaughter-weight classes, namely <340, 340-370, 370-400, or >400 kg. Back fat thickness was not influenced (p > 0.05) by slaughter weight in any of the forms it was expressed (mm or %), averaging 5.3 mm. Loin eye area in cm2 increased (p < 0.05) with the increase in slaughter weight. Animals slaughtered at a live weight (LW) of more than 400 kg showed better (p < 0.05) carcass conformation than the other experimental groups (9.8 points). Heifers slaughtered at over 400 kg LW had a more compact (p < 0.05) carcass (1.65 cm kg-1 cold carcass). The marbling degree of meat was lower (p < 0.05) in the animals slaughtered at less than 340 kg LW. In conclusion, cull heifers must not be slaughtered at a LW of less than 340 kg and slaughter weights greater than 400 kg have positive implications on important carcass characteristics, notably conformation and marbling.


Sign in / Sign up

Export Citation Format

Share Document