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Effects of Salicylic Acid on Growth, Biochemical Constituents in Pepper (Capsicum annuum L.) Seedlings
S. Canakci
Pakistan Journal of Biological Sciences , 2011,
Abstract: In the present study, the effect of different concentrations of salicylic acid which is an endogenous organic acid in plants and which is commonly cited as a hormone, on the growth and some other parameters of pepper (Capsicum annuum L. cv.) seedlings was investigated. The solutions were applied to the roots of seedlings using hydroponic method. In general, 1.5 mM concentration of salicylic acid had a stimulating effect while 5 and 10 mM concentrations had varying degrees of inhibitive effects on the seedlings. Although 0.3 mM SA application produced prominent results in the case of all parameters, the difference was not found statistically significant. The inhibitive effect produced by high SA was found much more dominant than the stimulating effect of low SA concentrations. Thus, it was established that SA had a bidirectional physiological effect on the seedlings in a concentration-dependent manner.
Growth and Production of Hydroponic Pepper under Salt Stress and Plant Density  [PDF]
Guilherme De Freitas Furtado, Antonio Ramos Cavalcante, Lúcia Helena G. Chaves, José Amilton Santos Júnior, Hans Raj Gheyi
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.89151
Abstract: The viability of the use of brackish water in the hydroponic cultivation of vegetables cannot dispense with auxiliary techniques such as water mixing and the use of plant densities. In this sense, the objective of the present work was to analyze the growth and production of sweet pepper, cv. All Big, under hydroponic conditions, under different levels of electrical conductivity of the nutrient solution (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS·m-1) in plants spaced every 0.2 m and 0.3 m. These treatments were distributed in a completely randomized experimental design, analyzed in a 6 × 2 factorial scheme, with five replications. The growth variables were evaluated at 60, 75 and 90 days after sowing and the production variables at the time of harvest; however, the results were submitted to analysis of variance, at a 0.05 probability level. The interaction between the electrical conductivity of the nutrient solution and the density of plants influenced the behavior of the growth and production variables of pepper (All Big). It was verified that the pepper plants had better performance of the biometric variables plant height, stem diameter and number of leaves when cultivated every 30 cm. At the time, in the analysis by plant, the production of pepper fruits was more expressive when spacing of 30 cm was adopted, however, in the tube of six meters, when 20 cm of spacing was used, the number of fruits was on average, 26.38% and 16.40% higher than lower density, in the electrical conductivities 1.7 and 11.7 dS·m-1.
Concentration of nutrient solution in the hydroponic production of potato minitubers
Novella, Manuel Benito;Andriolo, Jer?nimo Luiz;Bisognin, Dilson Ant?nio;Cogo, Clarissa Melo;Bandinelli, Maurício Guerra;
Ciência Rural , 2008, DOI: 10.1590/S0103-84782008000600006
Abstract: the effect of the nutrient solution concentration on potato plant growth and minituber yield were determined in a sand closed hydroponic system. minitubers and micropropagated plantlets of the cv. 'macaca' were used. treatments were five nutrient solution concentrations at electrical conductivities (ec) of 1.0 (t1), 2.2 (t2), 3.4 (t3), 4.7 (t4) and 5.8ds m-1 (t5). the split plot randomised experimental design was used with three replications. plants from minitubers produced higher fresh and mean weight of minitubers, shoot dry mass and leaf area index than the micropropagated ones. however, higher dry mass of minitubers was found with micropropagated plantlets compared to minitubers. the concentration of the nutrient solution did not affect minituber number. increasing the nutrient solution concentration decreased total and minituber dry mass production of micropropagated plantlets and plant growth and minituber production of minituber-originated plants. low concentration of nutrient solution at an ec of about 1.0ds m-1 can be used in the hydroponic production of potato minitubers of both micropropagated and minituber-originated plants.
Investigating the Traits of Green Pepper in the Three Substrates in Hydroponic System  [cached]
Razieh Ebrahimi,Mostafa Ahmadizadeh,Yaser Majdi
Current Research Journal of Biological Sciences , 2012,
Abstract: In order to investigate the properties of pepper fruit at different substrates as a factorial experiment in completely randomized design with four replications. The experiment was carried out in the Islamic Azad University, Jiroft branch, Iran, in 2011. Treatments included three green pepper cultivars (Sereno, LiricaRZ and Figaro) and three substrates of vermiculite + sand, peat + perlite and rock wool. Result showed that the most yield and average of fruit weight was 2003.91 and 129.14 g, respectively and number of fruit with average of 15.5, fruit length with 10.85 cm were obtained from substrate of peat + perlite. LiricaRZ had the most yield and average of fruit weight 1498.97 and 122.41 g, respectively than two other green peppers. There was significant interaction effect between green pepper and substrate in fruit's weight at 5% and fruit's length at 1%. It was known that the best substrate was peat + perlite and the best green pepper cultivar was LiricaRZ in hydroponic cultivation.
Comparison of eco-physiological characteristics of pepper in hydroponic and aquaponic systems  [cached]
A. R. Sajjadinia,A. Ershadi,H. R. Roosta
Journal of Science and Technology of Greenhouse Culture , 2010,
Abstract: Aquaponics is one of the recirculating aquaculture systems in which plant grows without soil. Considering the lack of information about aquaponic culture for main crops like pepper and the absence of comparison of plant conditions in soilless culture, in this experiment eco-physiological characteristics of pepper in hydroponics and aquaponics were investigated. After starting the plants to flowering, eco-physiological parameters were measured using potable far-red gas analyzer LCA-4, ADC. The results showed that photosynthesis, stomatal conductance, transpiration, photosynthesis active radiation (PAR) and water use efficiency were higher in aquaponics compared to hydroponics, while, stomatal resistance and leaf surface temperature were higher in hydroponics. However, there was no significant difference in leaf surface temperature in hydroponics and aquaponics. It seems that due to better eco-physiological characteristics of pepper in aquaponics, its growth and development will be better in this system.
Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives
Sutton, John Clifford;Sopher, Coralie Rachelle;Owen-Going, Tony Nathaniel;Liu, Weizhong;Grodzinski, Bernard;Hall, John Christopher;Benchimol, Ruth Linda;
Summa Phytopathologica , 2006, DOI: 10.1590/S0100-54052006000400001
Abstract: the etiology and epidemiology of pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. principal causal agents include pythium aphanidermatum, pythium dissotocum, members of pythium group f, and pythium ultimum var. ultimum. perspectives are given of sources of initial inoculum of pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. recent findings that a specific elicitor produced by p. aphanidermatum may trigger necrosis (browning) of the roots and the transition from biotrophic to necrotrophic infection are considered. effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances), the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature) and human interferences (cropping practices and control measures) are reviewed. recent findings on predisposition of roots to pythium attack by environmental stress factors are highlighted. the commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress pythium in the roots and root zone of the crop. new discoveries that infection of roots by p. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. the platform of knowledge and understandi
The Influence of salinity and nitrogen on tomato fruit quality and micronutrients concentration in hydroponic culture  [cached]
S. Safarzadeh Shirazi,A. M Ronaghi,A. S. Gholami,M. Zahedifar
Journal of Science and Technology of Greenhouse Culture , 2010,
Abstract: Salinity plays an important role in the reduction of tomato growth, especially in arid and semi-arid regions. Nitrogen (N) may increase tomato tolerance to salt stress by increasing plant growth. In order to investigate the interaction effect of salinity and nitrogen on tomato growth, fruit quality, and micronutrient concentration in tomato plants, a hydroponic experiment was conducted in a completely randomized design with three replications. Treatments included 3 salinity levels (0, 30 and 60 mM), and 3 nitrogen rates (0, 1.5, and 3 mM). Results indicated that salinity decreased tomato height, shoot and fruit fresh weight, and increased citric acid in tomato fruit and consequently caused blossom-end rot in tomato fruit. However, salinity improved fruit quality (flavor). The use of N increased plant height, shoot, and fruit fresh weight compared to control. By application of N to saline nutrient solution, plant height increased. Salinity increased concentration of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in roots, as`well as Fe and Cu in fruit. Increasing N rates in nutrient solution increased micronutrients concentration in tomato roots. Interaction of 60 mM salinity and N decreased micronutrients concentration in root, compared to control. Our tentative conclusion shows that the addition of N to the nutrient solution may decrease detrimental effect of salinity on the growth of tomato plants.
The effects of different levels of nitrogen and molybdenum in nutrient solution on quantitative and qualitative traits and nitrate concentration of cucumber in hydroponic culture  [cached]
S. Beigi,A. Golchin,S. Shafiei
Journal of Science and Technology of Greenhouse Culture , 2011,
Abstract: In order to study the effects of different levels of nitrogen (N) and molybdenum (Mo) in nutrient solution on quantitative and qualitative traits and nitrate concentration of cucumber (Sultan cv.), a factorial hydroponic-experiment with completely randomized design and three replications was conducted in the greenhouse of Soil Science Department, Zanjan University, in 2009. The concentrations of N in nutrient solution were 238 and 310 mg/L, and Mo was used at the rates of 0.01, 0.1 and 1 mg/L. The results showed that the effects of N and Mo levels were significant (P≤0.01) on plant yield and growth indices such as average weight, length and diameter of fruit and chlorophyll content of leaf. The chlorophyll content of leaf increased but fruit yield and average weight, length and diameter of fruits decreased as the N concentration of the nutrient solution increased. Increasing the Mo level in the nutrient solution decreased the growth indices and yield of cucumber. The highest fruit yield was obtained when the concentration of Mo in the nutrient solution was 0.01 mg/L. But it didn’t have significant difference with 0.1 mg/L treatment. However, the yield decreased significantly as the Mo concentration increased to 1 mg/L. The effects of N and Mo levels of nutrient solution were significant (P ≤ 0.01) on nitrate concentration of the fruits. As the N level of nutrient solution increased, the nitrate concentration of cucumber fruit increased from 1356 to 2122 mg/kg (on dry weight basis), and exceeded the toxicity limit of 1500 mg/L. Increasing the concentration of Mo of the nutrient solution from 0.01 to 0.1 mg/L decreased nitrate concentration of fruits from 1961 to 1703 mg/kg, without decreasing the fruit yield. With an increase in N concentration of the nutrient solution, the fruit concentrations of N, potassium and calcium increased, but those of phosphorus, magnesium and Mo decreased significantly. Also, as the concentration of Mo in the nutrient solution increased, the concentrations of iron, manganese and in fruit increased and that of copper decreased.
Growth and production of nasturtium flowers in three hydroponic solutions
Melo, Evanisa Fátima RQ;Santos, Osmar S dos;
Horticultura Brasileira , 2011, DOI: 10.1590/S0102-05362011000400023
Abstract: this experiment was carried out during april to august 2003 in a greenhouse at the universidade federal de santa maria, rio grande do sul state, brazil. the growth and production of nasturtium flowers (tropaeolum majus) in hydroponics nft system was typified. treatments were displayed in a 3x11 factorial, with six replications, in entirely randomized experimental design, and were composed of three nutrition solutions and 11 assessment dates. each plant was separated between aerial part and root for the evaluation of dry mass. the blossoming started 49 days after the transplant (dat). the plants presented good development in hydroponics, as well as growing dry mass, stature, leaf area and iaf, during the cycle. the culture's growth rate presented larger accumulation of leaf mass from 49 dat on, in linear relation. biological productivity was adjusted to a 2nd degree equation. nutrition solutions did not show statistical differences, however, furlani (1997) solution was the most reasonably priced.
Effect of Hydroponic Solution pH on the Growth of Greenhouse Rose
Hyun-Ju Kim,Young-Son Cho,Oh-Keun Kwon,Myung-Whan Cho
Asian Journal of Plant Sciences , 2005,
Abstract: High temperature and high light intensity during the summer season tend to induce an unbalance absorption of water and mineral elements of hydroponic cultured roses. In addition, differential uptake of various elements causes pH of the root zone to change constantly. To solve this problem, the experiment was carried out to examine the effect of pH of nutrient solution on the growth of rose plants in rockwool slabs. Nutrient solutions adjusted to pH 4.0, 6.0 and 8.0 were supplied at 5 days or 20 days after pinching. The pinching time and solution pH had little effect on pH of root zone. The pH 8.0 were supplied at 5 days after pinching maintained root zone pH slightly higher and at a more desirable level. Stem length was not significantly affected by either solution pH or pinching stage, except it was slightly smaller in pH 4.0 solution supplied at 20 days after pinching. The yield of cut flowers was the greatest when pH 8.0 solution was supplied from 5 days after pinching. A desirable pH of root zone was maintained by supplying a nutrient solution of pH 8.0 from 10 days to 25 days after pinching. When comparing the study of the higher concentration of pH 8.0 to conventional one must concentration of pH 8.0 to conventional one must considered being unable to supply to it to most of cultivar due to the different absorbing characteristics of water and nutrient according to the difference of cultivar.
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