scholarly journals Effects of LED and HPS lighting on the growth, seedling morphology and yield of greenhouse tomatoes and cucumbers

2021 ◽  
Vol 48 (No. 1) ◽  
pp. 22-29
Author(s):  
Jacek Dyśko ◽  
Kaniszewski Stanisław
Keyword(s):  
Dry Mass ◽  
Marketable Yield ◽  
Seedling Morphology ◽  
Radiation Level ◽  
Artificial Lighting ◽  
Chlorophyll Index ◽  
Supplementary Lighting ◽  
Greenhouse Tomatoes ◽  
And Control ◽  
Led Arrays

In an experiment with tomato and cucumber transplants, light units equipped with purpose-built LED arrays were compared with HPS sodium lamps with a power of 600 W and a voltage of 230 V. For both the LED and HPS lamps, the same PAR radiation level was used at the plant height, which was about 70–80 μmol/m2/s in conditions without daylight. The supplementary lighting was carried out for 8 to 24 hours and was switched on during the day when the solar radiation outside the greenhouse was lower than 200 W/m2. The supplementary lighting with the LED and HPS lamps did not have a significant impact on the growth of the tomato and cucumber seedlings and the fresh and dry mass of the tomato and cucumber plants. The plants grown without the additional artificial lighting were significantly smaller in height, had fewer leaves, a smaller spread and produced lower fresh and dry weights. The tomato and cucumber plants grown under the LED lamps had a higher chlorophyll index than those grown under the HPS lamps and without any lighting. The supplementary lighting with the LED lamps increased the early yield of the tomatoes compared to the HPS and control plants but has no effect on the early yield of the cucumbers. Both the LED and HPS lighting significantly increased the total and marketable yield of the tomatoes and cucumbers.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

Yield and chlorophyll index in cabbage in function of enhanced-efficiency nitrogen fertilizers and urea

2020 ◽  
Vol 13 (2) ◽  
pp. 6
Author(s):  
J. J. Frazão ◽  
A. R. Silva ◽  
F. H. M. Salgado ◽  
R. A. Flores ◽  
E. P. F. Brasil
Keyword(s):  
Nitrogen Fertilizers ◽  
N Losses ◽  
N Sources ◽  
Promising Strategy ◽  
Applied Dose ◽  
Coated Urea ◽  
Chlorophyll Index ◽  
Polymer Coated Urea ◽  
N Rates ◽  
And Control

The increase of the efficiency of the nitrogen fertilization promotes reduction of the applied dose and decreases the losses of nitrogen (N) to the environment. The objective of this work was to evaluate the yield and the relative chlorophyll index (IRC) in cabbage crop under cover fertilization, using enhanced-efficiency nitrogen fertilizers, compared to urea, in variable doses. The experimental design was randomized blocks in a 3x4+1 factorial scheme (three sources, four rates and control), with four replications. The N sources used were: common urea (U), urea treated with urease inhibitor NBPT® (UN) and Kimcoat® polymer coated urea (UK). The N rates used were 0, 40, 80, 160 and 320 kg ha-1, divided in two fertilizations at 20 and 40 days after transplantation. Up to 160 kg ha-1 of N, there was no difference between N sources and N rates for both yield and RCI. The enhanced-efficiency N sources (UN and UK) promoted higher averages compared to common urea, possibly due to the higher N losses from common urea. Thus, the use of urease inhibitors or polymers associated with urea is a promising strategy to improve cabbage yield, as well as reducing N losses to the environment.

scholarly journals Integrated management of tough lovegrass (Eragrostis plana Nees): associating chemical control tools and plant physiology

2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Eduardo Avelino Faleiro ◽  
Diego Martins Chiapinotto ◽  
Fabiane Pinto Lamego ◽  
Carlos Eduardo Schaedler ◽  
Eduardo Bohrer de Azevedo
Keyword(s):  
Solar Radiation ◽  
Integrated Management ◽  
Dry Mass ◽  
Radiation Factor ◽  
Factor B ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Factor C ◽  
Resource Conditions ◽  
And Control

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

scholarly journals Effects of Five Growing Media and Two Fertilizer Levels on Polybag—Raised Camden Whitegum (Eucalyptus benthamii Maiden & Cambage) Seedling Morphology and Drought Hardiness

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 543 ◽  
Author(s):  
Mohammad Nasir Shalizi ◽  
Barry Goldfarb ◽  
Owen Thomas Burney ◽  
Theodore Henry Shear
Keyword(s):  
Seedling Growth ◽  
Lateral Roots ◽  
Dry Mass ◽  
Rice Hull ◽  
Fertilizer Treatment ◽  
Seedling Morphology ◽  
Growing Media ◽  
Shoot Height ◽  
Rice Hulls ◽  
Growing Period

In developing countries, tree seedlings are often produced in polybags filled with mixtures of locally available materials. Seedling growth and quality can be affected by the type and amount of these substrates used in the mixture. Differences in seedling growth and quality can also be significantly affected when fertilization is employed during the nursery growing period. In this study, we assessed the effects of five different growing media and two fertilization regimes on nursery growth, seedling morphology and early post-planting response to drought of Eucalyptus benthamii (Maiden & Cambage) seedlings. First, we evaluated the effects of each media by fertilizer treatment combination on morphological attributes during a nursery growing period. Seedlings raised in fertilized media without rice hulls yielded higher growth, root dry mass, shoot dry mass, total dry mass, Dickson quality index (DQI) scores, and number of first order lateral roots (FOLRs). Root to shoot ratio (R:S ratio) was, however, greater in non-fertilized media that contained rice hulls. We then conducted a simulated outplanting and drought hardiness experiment, in which seedlings were planted in 13.2 L containers and irrigated for one month, followed by the imposition of drought stress. Seedlings in fertilized media composed of sand, topsoil and compost showed greater growth than those in rice hull-containing media, during the irrigation phase. With the discontinuation of irrigation and prevention of precipitation reaching the seedlings, seedlings grown in non-fertilized media containing rice hulls survived longer than those in other media. There were no large differences in survival among other media or between fertilized and other non-fertilized seedlings. Seedling total size and shoot height at the time of planting played a major role in survival. Smaller seedlings with smaller shoot sizes and greater R:S ratios survived longer. This study demonstrates that growing media and fertilization can be manipulated to affect seedling morphology in the nursery and, ultimately, seedling performance and survival under water stressed conditions.

scholarly journals Cowpea yield on soils with residues of NPK and natural phosphate fertilizers in succession the area of degraded pasture

Revista CERES ◽  
2016 ◽  
Vol 63 (4) ◽  
pp. 553-567 ◽  
Author(s):  
Pedro Emerson Gazel Teixeira ◽  
Antonio Rodrigues Fernandes ◽  
Jessivaldo Rodrigues Galvão ◽  
Wendel Valter da Silveira Pereira ◽  
Sandro Rogério Almeida Casanova ◽  
...  
Keyword(s):  
Phosphorus Content ◽  
Block Design ◽  
Residual Effect ◽  
Dry Mass ◽  
Phosphate Fertilizers ◽  
Natural Phosphate ◽  
Randomized Block Design ◽  
Degraded Pasture ◽  
And Control ◽  
Degraded Pastures

ABSTRACT The cultivation of cowpea [Vigna unguiculata (L) Walp] can be an important alternative in succession to maize in areas of degraded pastures due to the use of residue from fertilizers . With this, we aimed to evaluate the productivity of cowpea as a successor culture to undergo corn doses of reactive natural phosphate Arad and combinations with NPK. The experimental design was a randomized block design in a split plot with four replications. The fertilizer was applied in previous cultivation (crop) using four phosphate doses in the form of Arad natural phosphate: 50, 100, 200 and 300 kg ha-1 of P2O5 and the sub-plots in combination with NPK, NK, NK + liming, and control (no liming and fertilizer). The cowpea yield components were evaluated in this work. The residues of P2O5 from the natural phosphate increased the phosphorus content in the plant and influenced the number of grains per pod. The residual effect of NK+ liming and only NK showed better results for the variables grain yield, number of pods per plant, number of seeds per pod and dry mass of aerial part. The residual effect of NPK showed better results for the mass of 100 grains.

scholarly journals Measuring and modelling seasonal variation of gross nitrification rates in response to long-term fertilisation

2009 ◽  
Vol 6 (10) ◽  
pp. 2181-2192 ◽  
Author(s):  
C. F. Stange ◽  
H.-U. Neue
Keyword(s):  
Soil Temperature ◽  
Temporal Variability ◽  
Dry Mass ◽  
Control Site ◽  
Field Conditions ◽  
Future Climate Change ◽  
Gross Nitrification ◽  
Mineral Fertiliser ◽  
And Control

Abstract. The formation of nitrate (nitrification) in soils is an important process that influences N availability for plant uptake and potential N losses as well. Gross nitrification is an effective measure by which to test mechanistic ecosystem models for predictability because gross rates can widely differ between sites, even if net production is similar between these sites. A field experiment was designed to (i) determine gross nitrification rates in response to fertilisation and (ii) to verify the idea that seasonal variations of gross rates in soils can be readily predicted by soil moisture and soil temperature. Gross nitrification rates were measured by a Barometric Process Separation (BaPS). The BaPS measurements were validated with the commonly used 15N pool dilution technique measurements at six times. In general, the rates determined from both measurement approaches were in the same order of magnitude and showed a good correlation. The effects of 100 years of fertilisation (mineral fertiliser, manure and control) on gross nitrification rates were investigated. During 2004 soil samples from the long-term "static fertilisation experiment" at Bad Lauchstädt were sampled weekly and were measured in the laboratory under field conditions and subsequently under standardised conditions (16°C soil temperature and −30 kPa matrix potential) with the BaPS system. Gross nitrification rates determined under standardised conditions did not show any seasonal trend but did, however, reveal a high temporal variability. Gross nitrification rates determined by the BaPS-method under field conditions showed also a high temporal variability and ranged from 5 to 77 μg N h−1 kg−1 dry mass, 2 to 74 μg N h−1 kg−1 dry mass and 0 to 49 μg N h−1 kg−1 dry mass with respect to manure, mineral fertiliser, and control. The annual average was 0.34, 0.27 and 0.19 g N a−1 kg−1 dry mass for the manure site, mineral fertiliser site and control site, respectively. On all sites gross nitrification revealed a strong seasonal dynamic. Three different models were applied for reproducing the measured results. Test models could explain 75% to 78% of variability at the manure site, 66% to 77% of variability at the mineral fertiliser site, and 39% to 63% of variability at the control site. The model parameterisation shows that the temperature sensitivity of gross nitrification differs between the three neighbouring sites. Hence, a temperature response function in an ecosystem model has to consider the site specificity in order to adequately predict the effects of future climate change on the soil N cycle.

Irrigation of greenhouse tomatoes grown in "Harrow" peat-bags

1991 ◽  
Vol 71 (3) ◽  
pp. 947-949 ◽  
Author(s):  
Athanasios P. Papadopoulos ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Key Words ◽  
Environmental Conditions ◽  
Total Yield ◽  
Fruit Size ◽  
Irrigation Frequency ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Greenhouse Tomatoes ◽  
Fertilizer Solution

Three spring and two fall crops of greenhouse tomato (Lycopersicon esculentum L. Mill; various cultivars) grown in "Harrow" peat bags were irrigated 1, 4, 8 or 16 times daily. All plants received the same volume of fertilizer solution which varied with time from 0.2 to 1.0 L plant−1 d−1 according to crop and environmental conditions. The results showed little or no effect of irrigation frequency on early or total yield, number of grade no. 1 fruit, or fruit size. Key words: Lycopersicon esculentum, marketable yield

Growth of Esteya vermicola in media amended with nitrogen sources yields conidia with increased predacity and resistance to environmental stress

2011 ◽  
Vol 57 (10) ◽  
pp. 838-843 ◽  
Author(s):  
Zhen Wang ◽  
Chun Yan Wang ◽  
Li Juan Gu ◽  
Yun Bo Wang ◽  
Yong An Zhang ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Ammonium Nitrate ◽  
Significant Influence ◽  
Pine Wilt Disease ◽  
Nitrogen Sources ◽  
Dry Mass ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Esteya Vermicola ◽  
And Control

Esteya vermicola , an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against nematodes. In this study to enhance the sporulation, predacity, and environmental resistance of E. vermicola, various nitrogen sources, such as glycine, l-leucine, and ammonium nitrate, were tested. The supplement of glycine and l-leucine had a significant influence on the growth rate of the colony, enhancing colony dry mass by 5-fold more than did ammonium nitrate or the control. Of the nitrogen sources tested, ammonium nitrate and l-leucine promoted sporulation, yielding more than 6 × 106 CFU/g, while glycine enhanced the proportion of lunate spores. Meanwhile, the supplement of nitrogen sources had a significant influence on adhesive rate and mortality rate against Bursaphelenchus xylophilus . Moreover, the supplement of glycine enhanced the survival rate against heat stress by more than 3-fold that of l-leucine, ammonium nitrate, and control. The spores produced in media amended with glycine, l-leucine, and ammonium nitrate had slightly but not significantly higher UV resistance and drought resistance than spores produced without nitrogen sources. These results suggested that the addition of glycine resulted in the production of E. vermicola conidia with increased predacity and resistance to environmental stress that may be more suitable for control of pine wilt disease.

scholarly journals Effect of Different Colored Polythene Mulches and Net House on Insect Incidence and Yield of Brinjal in Rampur, Chitwan

2021 ◽  
Vol 8 (2) ◽  
pp. 131-136
Author(s):  
Prakash Bharatee ◽  
Ankit Soti ◽  
Rajendra Regmi ◽  
Arjun Kumar Shrestha ◽  
Ananta Raj Devkota ◽  
...  
Keyword(s):  
Insect Pest ◽  
Winter Season ◽  
Residual Effect ◽  
Emamectin Benzoate ◽  
Marketable Yield ◽  
Minimum Residual ◽  
Fruit Borer ◽  
Pest Incidence ◽  
Different Color ◽  
And Control

Field experiment was conducted in single factor randomized complete block designed to evaluate effect of different color polythene mulch and net house on insect pest incidence of brinjal in chitwan, nepal during october 2016 to may 2017. Five different treatment were selected with four replications, included net house with black polythene mulch, black polythene mulch only, reflective polythene mulch only and black polythene mulch with emamectin benzoate 5%sg spray and control (no mulch+ no net + no pesticide spray)  . The result revealed that the net house totally restricts the brinjal shoot and fruit borer whereas black polythene mulch with emamectin benzoate spray plot reduced brinjal shoot and fruit borer larvae upto 70.58%. Total marketable yield was found highest in the black polythene mulch with emamectin benzoate spray plot (49.17 mt /ha) followed by black polythene mulch only (38.59 mt/ha) and lowest in control plot (28.53 mt/ha). Damaged fruit percentage by brinjal fruit and shoot borer was highest in the control (35.68%) followed by black polythene mulch (28.10%), reflective polythene mulch (19.02%) and lowest in net house with black polythene mulch (0%). The damaged weight inside the net house with black polythene mulch and black mulch with pesticide were significantly different whereas the damaged weight in other treatments similar which proved that there was no effect of mulch on brinjal shoot and fruit borer. The B:C ratio was the highest (3.34:1) in the black polythene mulch with emamectin benzoate spray plot while the lowest in net with black polythene mulch (1.68:1). Although the B:C ratio was lower in the net with black polythene mulch due to the low yield in the winter season. Creation of suitable soil environment by black polythene mulch and being biologically originated, having minimum residual effect and short half-life of emamectin benzoate, black polythene mulch with emamectin benzoate can be used for the eco-friendly management of brinjal shoot and fruit borer.

scholarly journals Magnesium Sources and Inoculation with Azospirillum brasilense in the Initial Development of Maize

2019 ◽  
Vol 11 (7) ◽  
pp. 170
Author(s):  
Roberto Cecatto Júnior ◽  
Vandeir Francisco Guimarães ◽  
Lucas Guilherme Bulegon ◽  
Anderson Daniel Suss ◽  
Adriano Mitio Inigaki ◽  
...  
Keyword(s):  
Azospirillum Brasilense ◽  
Dry Mass ◽  
Stem Diameter ◽  
Mineral Fertilization ◽  
Initial Development ◽  
Maize Seeds ◽  
Seed Inoculation ◽  
Leaf Dry Mass ◽  
Maize Plants ◽  
And Control

The aim was to evaluate the initial development of maize plants when submitted to mineral fertilization with magnesium sources in the presence or absence of seed inoculation with Azospirillum brasilense. To do so, was conducted an experiment in greenhouse. In the essay was adopted a randomized blocks design, in a factorial scheme 3 × 2, represented by the magnesium sources: magnesium sulfate (MgSO4), magnesium oxide (MgO) and control without Mg fertilization, in the presence or absence of inoculation with A. brasilense. The Mg sources were supplied with a dose of 30 kg ha-1, being homogenized in the substrate before sowing the crop. The analysis were carried out in the V4 stage, evaluating: basal stem diameter (BSD); relative chlorophyll content (SPAD index), leaf dry mass (LDM), stem + sheath blade dry mass (SSDM) and root dry mass (RDM). No differences were observed for the factors interaction and for the Mg sources. When considered the seed inoculation there was increases of 7.1%; 6.61%; 19.23%; 28.32%; and 15.17 %, for basal stem diameter, SPAD index, leaf dry mass, stem + sheath blade dry mass and roots, respectively. The inoculation of maize seeds with A. brasilense increases the initial development of maize plants and the SPAD index in greenhouse conditions in the V4, while the fertilization with the magnesium sources do not interfere in the maize development.

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