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The response of pepper (Capsicum annuum L.) to Ammonium-N was studied in a multispan greenhouse under soilless culture using coir fiber as substrate. Ammonium-N application rates were 0, 2, 4, 6 an...

Made available in DSpace on 2018-12-11T17:15:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-08 An experiment was conducted to develop a model of vegetative growth based on the nitrate concentrations in nutrient solutions using the nutrient film technique and to determine the best cultivar for each concentration. The chicory cultivars (“Pão de Açúcar,” “Folha Larga,” “Precoce de Trieste” and “Catalonha”) and the subplots corresponded to different nitrate concentrations (6.68, 10.0, 13.32 and 16.64 mmol L−1). There was an interaction between the evaluated factors, such that there was no similarity in the response of the chicory cultivars to the N concentrations in the nutrient solution. The most productive chicory cultivar was “Pão de Açúcar,” which exhibited 10.5% higher productivity than the average, and the least productive was “Folha Larga,” which showed approximately 8.5% lower productivity than the average. Departamento de Produção Vegetal Faculdade de Ciências Agrárias e Veterinárias Campus de Jaboticabal UNESP–Universidade Estadual Paulista Departamento de Agronomía Universidad de Almería Departamento de Produção Vegetal Faculdade de Ciências Agrárias e Veterinárias Campus de Jaboticabal UNESP–Universidade Estadual Paulista

Thermography is a tool used in many scientific disciplines, including agriculture. Determining the behavior of a nutritive solution in soilless culture containers using substrates is very important in order to establish the position of drippers, drainage holes, the use of humidification agents, and fertigation management in culture units. This paper describes the application of thermography to determine the humidification bulb in horticulture crops to rapidly diagnose the best way to advance fertigation in different horticultural substrates in soilless culture. Thermography was seen to be an excellent tool for evaluating the movement and distribution of the nutritive solution within the soilless culture container with different substrates.

The bagasse of mezcal maguey and the fiber of coconut fruit are organic byproducts of the mezcal and copra agro-industries in Oaxaca, Mexico. The effects of different particle sizes and prior usage times as substrates on the production and quality of tomato (Lycopersicon esculentum Mill) were studied. Three independent and simultaneous experiments were conducted in multi-tunnel greenhouses. Three prior growing cycles of tomato crop, each 150 days in length days of use (DOU), were used for the usage time experiments with mezcal maguey bagasse as the growth medium. In the first experiment, tomato plants grown on substrate with 150 DOU produced the highest yields, the largest number of commercial quality fruits and the fewest non-commercial quality fruits. In the second experiment, the combination of fine particle size and maguey bagasse substrate with 150 DOU produced the highest yields. In the third experiment, fine and medium-sized particles of maguey bagasse and coconut fiber produced the highest yields....

The growth and essential oil (EO) production of parsley were evaluated in response to salinity and nutrient solution concentrations in a soilless culture. Parsley plants that were 60 days old were potted in a coconut fiber and peat moss medium and were treated with four different nutrient solutions, including T1, T2, T3 and T4. The T1 nutrient solution was the standard, the T2 and T3 solutions contained incremental macronutrient concentrations with an electrical conductivity (EC) of up to 2.2 and 3.2 dS m−1, respectively, and the T4 solution was the same as T2 but with sodium chloride (NaCl) and an incremental macronutrient concentration with an EC of 3.2 dS m−1. Next, these plants were grown for 90 days in a greenhouse with natural daylight in Nador, Morocco. Shoot and root growth significant decreased with increasing EC. However, the salinity that resulted from the addition of NaCl did not affect plant growth in the nutrient solutions. The optimum obtained growth and EO production were 1.2 and 2...

Commercialization of watercress in the Sierra Norte mountain range in Oaxaca, Mexico principally relies on harvesting plants growing on riverbanks; however, semi-intensive cultivation throughout the year could be established as an alternative for the region. With this as an objective, the present study was carried out using the laminar flow of nutrients technique to evaluate four solutions of different macronutrients and four shade percentages. Treatment distribution was formulated according to a bifactorial arrangement. Four harvest periods were employed, in April, June, September, and November of 2010. Yields and vegetative growth of watercress decreased linearly with increasing shade levels. The best results were obtained with a nutrient solution using an electrical conductivity (EC) of 0.90 dS m−1. Shade cloth percentages higher than 10% caused a significant decrease in total cycle production; the use of shade cloth is not recommended during seasons with low incident radiation.

This study evaluated the effects of salinity on thyme (Thymus vulgaris) and lavender (Lavandula angustifolia) plants grown alone and in combination with each other. After transplanting, two-month-old plants received nutrient solutions supplemented with 0, 50, and 100 mM sodium chloride (NaCl) for 21 d. Thyme and lavender grown alone were each more tolerant to salt stress than thyme and lavender grown together. In the 100 mM NaCl treatment, all lavender plants grown with thyme died. In thyme, the carbon (C) and nitrogen (N) contents of the roots increased. Ethylene production in thyme was stimulated by salinity only in plants that interacted with lavender. However, in lavender, ethylene production was not influenced by the presence of thyme. The production of essential oils (EOs) was increased by salinity in thyme plants, whereas the EO production of lavender plants depended on the presence of thyme.

Thermography is a tool used in many scientific disciplines, including agriculture. This paper describes the application of thermography to rapidly diagnosing salinity stress with a high degree of temperature resolution in potted ornamental crops. Syngonium podophyllum and Philodendron erubescens were transplanted to pots in a greenhouse in Almeria (Spain). Salinity treatments were 1, 2, 6 or 12 dS m−1 of electric conductivity in a nutrient solution. The comparison of thermography in relation to other assessment methods to measure salinity stress was studied. The results suggest that thermography can be an early useful method to diagnose saline stress in potted plants.

□ Plants from 60-day-old Lime Thyme (Thymus citriodorus) cuttings were potted in a medium of coconut fiber and peat moss and were treated with three different nutrient solutions: T1, T2, and T3. T1 was a standard nutrient solution; T2 was incremented with macronutrients up to an electrical conductivity (EC) of 2.8 dS m−1; and T3 was the same as T1 but incremented up to an EC of 2.8 dS m−1 with sodium chloride. The plants were then grown for 90 days in a greenhouse with natural daylight in Almeria, Spain. Root growth was not affected by the treatments. The dry weight of the leaves and the total dry weight of the plants benefited from the salinity. The specific salinity of the sodium chloride negatively affected growth compared to the same salinity in the complete nutrient solution.

The soilless culture of vegetables in protected environments has increased in southern Mexico. However, the use of materials such as mineral wool or perlite as substrates is expensive and unsustainable. Therefore, the use of alternative, local materials such as the waste from mescal and coconut industries, including maguey (Agave spp.) bagasse, coconut fruit fiber and dust, as well as non-metallic mining products, such as vermiculite, is desirable. In this study, the physical, chemical and biological properties of vermiculite, coconut fiber, and maguey bagasse were determined, and their potential for cultivating melons (c.v. ‘Magno F1’) and tomatoes (Mill. c.v. ‘Don Raul’) was evaluated. Moreover, 13 different substrates, based on combinations of the aforementioned materials, were analyzed. Materials were characterized at the Oaxaca Unit of the National Polytechnic Institute, and experiments were conducted in a multi-tunnel greenhouse in a randomized block design. Results indicated that materials possesse...

Rocket (Eruca sativa Mill.) is a green leafy vegetable that is increasingly used as an ingredient in salad. The floating system is a way to grow this crop, at high density from sowing to harvest and easy to use in relation substrate culture, and it is well known water culture can be limited by hypoxia. Few studies have examined the use of peroxides or peracetic acid in nutrient solutions as a source of oxygenation. The aim of the study was to evaluate the rocket grown in substrates as compared to the floating system, with a stabilized mixture of peracetic acid in the nutrient solution. The experiment was carried out in and Talca (Chile) from October to November 2008. The treatments were substrate culture perlite and composted pine bark (1:1); floating system with trays filled with the same substrate and 0, 40 and 80 mg·L−1 of stabilized peracetic acid mix (PA). The fresh and dry weight of rocket leaves at harvest we evaluated. We recorded total nutrient solution uptake; the average dissolved oxygen; pH an...

One of the main environmental impacts of forced systems in horticulture — such as plastic covered and soilless culture — is the generation of organic plant residues and substrate waste. Many people are keen on research and development of ecologically friendly substrates. Thus, leaching experiments have been carried out with distilled water to determine whether compost — from horticultural greenhouse crop waste — can be used as growing media in vegetable crop production. The compost was examined and compared to other substrate alternatives like coconut coir waste. Two experiments were conducted in order to compare the two composts with coconut coir waste in terms of yield and fruit quality of melon crops (Cucumis melo). Electrical conductivity decreased sharply with leaching and eventually reached acceptable levels despite the high initial value of this parameter in the composts. This drop in electrical conductivity was parallel to that experienced in the contents of soluble mineral elements, with mainly h...

Certain ecologically-friendly substrates have recently been shown to be perfectly viable alternatives to other more traditional ones such as rockwool, perlite, or some hydroponic systems. However, in order to be competitive for vegetable production in the Mediterranean region, substrates must be used for at least one year. The present study assessed random samples of two commercial substrates, almond shell and compost from greenhouse vegetable residue. The substrates were evaluated as growing media for long-term soilless production. Three experiments were conducted to evaluate the effects of reusing these substrates, comparing them with rockwool in terms of yield and fruit quality characteristics of melon and tomato. The physical, physico-chemical, and chemical properties studied differed significantly on reutilizing these materials. However, these differences did not prove to be limiting factors when fertigation parameters applied were adjusted according to substrate properties. The results sugg...

Root temperature may affect the production of greenhouse vegetables under soilless culture. Four independent experiments were carried out over two consecutive crop cy- cles using two different substrates: rockwool and coconut coir waste. Three heating treatments were applied: non heating (T0), nutrient solution at 12-16 ◦ C (T1), and at 18-22 ◦ C (T2). The experiments were carried out in greenhouses in Almer´ ia (SE Spain) on cucumber and melon. Mean substrate and air temperature were not affected by the treatments. Under conditions of nutrient solution heating EC and percentage of drainage volume decreased, while water and mineral nutrient absorption increased. However, re- sults showed great differences between both crops and substrates. A significant decrease in nitrate and phosphate emission from the substrates was also recorded, especially in rockwool substrate. Few effects were observed concerning yield and fruit quality param- eters, but in rockwool-grown melon early yield was enhanced. It follows that nutrient solution heating is a low-cost and environmentally friendly method of increasing early melon yield.

The suitability of compost from horticultural residues as a growing medium in vegetable crop production was compared with the popular rock wool and coconut coir waste substrate. Physical and physio-chemical properties were initially characterized to adjust the management of this substrate for horticultural purposes. Leaching experiments were carried out with acid solution and standard nutrient solution. Two experiments were conducted to compare this compost with rock wool and coconut coir waste in terms of yield and fruit quality of a melon crop. The compost was found to initially have high salt content and a high pH. The results suggested that compost seems to be an acceptable growing medium for soilless vegetable production, provided that it is leached prior to use. Once it is leached, the compost is an acceptable substitute for rock wool and coconut coir waste.

Soils with high gypsum content support specific vegetation, indicating a soil environment to which gypsophile plants have adapted. The goal of the present work was to compare the chemical composition, mainly the availability of micronutrients, of the rhizosphere soil of plants growing in gypsiferous soils to that of plants growing in nongypsiferous soils. Rhizospheres of populations of gypsophile (true and facultative) and nongypsophile plants were sampled, and concentrations of SO 2- 4 , Ca 2+ , Mg 2+ , K + , Fe, Cu, Mn, and Zn were determined. Sulphates and Ca 2+ concentrations were higher in the rhizosphere of gypsophile plants, either true and facultative, than in the rhizosphere of nongypsophile plants. The electrolytic conductivity (EC) is moderate in all cases (maximum 2.5dS m - 1 ), and pH values (between 7.6 and 7.9) were slightly basic and similar among the sampled rhizospheres. Largest differences were found in the micronutrient concentrations, especially Fe and Mn. Soils holding gypsophile pla...

Our objective was to find an experimental and theoretical relationship between the electrical conductivity (EC) of nutrient solutions applied in open and closed systems for hydroponically‐grown plants in the semi‐arid regions of southern Spain. The experiments took place in a plastic greenhouse and were conducted from 1995 to 1998. In the first two years, beans and cherry tomatoes were grown in the autumn and spring, respectively, and in the last year, cucumber was grown in the autumn and spring. Crops were grown in soilless culture using perlite bags. The treatments were as follows: (i) no re‐use of the drainage nutrient solution, i.e., an open system, and (ii) re‐use of 100% of the drainage nutrient solutions, i.e., a closed system. In our region, irrigation water EC varies from 1.2 to 0.6. In the closed system, we noted an increase in the salinity of the nutrient solution and have suggested different methods to avoid salinity in the closed system.

Nitrate accumulation in vegetable represents a serious threat to man's health. Different methods have been reported to reduce the nitrate accumulation in lettuce and other leafy vegetables with or without variation in the yield. The aim of this experiment was to show the different behavior of some cultivars of lettuce using the replacement of N‐NO3 for chloride in the nutrient solution during last week before harvest. The trial was carried out with three lettuce cultivars: Domino, Elvira, and Daguan and took place in southern Spain (Almeria) under greenhouse by NFT. The results indicated a correct method to decrease nitrate content in leafy vegetables and perhaps sulphate could be an anion to study their effect in this way.

Ten‐day‐old tomato plants Lycopersicon esculentum Mill. cv. Rambo were transplanted in a NFT special system. The experiment was repeated three consecutive times. Each experiment consisted of three replicates. The experiments were carried out with 45‐day‐old plants. Xylem sap samples were obtained by decapitating the plant during the 35th day in NFT at about 1 cm above the root system. The sap flux rate was strongly correlated (p > 0.999) with the proposed model of a chronophysiological rhythm. Diurnal variations of inorganic ions clearly indicate that ion transport rates varied widely with time and also followed a proposed chronophysiological rhythm. The rhythmic model presented may provide a framework for the explanation of short‐ and long‐term variations in xylem sap concentration‐flux relationships. Additionally they may contribute to the knowledge of long distance transport processes and the variations in nutrient uptake by plants.

The present study was conducted during four consecutive vegetative cycles in deciduous fruit trees of agricultural value, almond, apple, pear, pomegranate, hazelnut, persimmon, and fig. Leaves were sampled on six occasions from the middle third of branches from the entire circumference of the crown at different stages of the vegetative cycle, and analyzed in order to determine levels of total and soluble N, P, K, Ca, and Mg. The changes over time in total and soluble levels of the N‐10P‐K ternary group did not significantly affect the relative proportions of the components. Relative levels of P and N varied slightly in almond, hazelnut, persimmon, and fig. By constrast, antagonism between K and Ca led to significant changes in ion levels in the K‐Ca‐Mg ternary group. The optimal levels of ions varied among the different species. In apple, total N‐10P‐K showed a high optimal value (59–28–15), while soluble N‐10P‐K was comparatively low (30–44–26). The lowest figures for both total and soluble N‐10...

Perennial deciduous plants were studied during their vegetative cycles. Leaves were sampled regularly every 15 days throughout this period in order to determine total and soluble iron (Fe) indices, physiological balances, and micronutrient levels. Analysis of variance and coefficients of variation were high for Fe indices and micronutrients between samples. The values of interaction between variables were not high. The optimium value of total Fe index ranged from 0.72–0.74 in almond to 1.11–1.14 in pomegranate. Optimum values for soluble Fe index ranged from 0.77–0.83 in almond to 1.18–1.29 in pear. Similar ranges were observed for soluble and total micronutrients and ternary groups. The evolution of the physiological ternary groups demonstrates ionic imbalances in apple in total Fe and manganese (Mn) as a result of excess levels of total zinc (Zn) during the final phase of fruit development. During this phase, total and soluble Fe and Mn also show significant interactions in persimmon. In apple,...

Xylem sap extraction from decapitated plants by negative pressure will be discussed in this paper. This method of extraction, in which transpiration is simulated by a negative pressure, uses as a quantitative reference generated by non‐decapitated plants. For this method, several horticultural plant have been used with the main nutritive elements in the sap analyzed by ionic chromatography.

The concept of active Fe has been seldom applied to the extractable fraction to study its changes through time. Neither its relationships to physiological balance of Fe Index in plants has been investigated to any extent. The study reported here was conducted on Castanea sativa Miller trees, autoctonous, not grown by man, as the relationships il‐plant is better balanced. In this work we studied the contents and changes of P, K, Fe, Mn and Zn which are found in extractable form in leaves, the balances of Fe‐Mn‐Zn, and the Fe Index obtained from data of the extractable fraction and their changes throughout the vegetative cycle. The data obtained were related to those obtained from the analysis of the total plant to study their significance in the foliar analysis values, and the possibility to diagnose Fe disorders from balances Fe‐Mn‐Zn and Fe Index obtained from the extractable fraction. Likewise, the relationships among the extracted nutrients and the total present in the foliar tissues were also...

The Iron Index has been developed to permit its application to the diagnosis and correction of iron chlorosis in culture growth. The stress in the ratio Fe‐Mn‐Zn enables us to diagnose deficiences with respect to some of these elements in the absence of visual signs. Both Iron Index and ratio Fe‐Mn‐Zn, P/Fe, Ca/Fe, Mn/Fe and Zn/Fe were applied to the nutritional research into several lots of walnuts (Juglans regia L.) autochthonous from Sierra Nevada, Spain, in the same climatic and edaphologic conditions. These walnuts were sampled from the time their leaves were completely developed to their old age. Leaves were analysed and the mentioned index and equilibriums determined, being possible to verify the metabolic fluctuations and their correspondence with the morphological state in which the plants were every instant. There are no significant differences among each lot. They initially present very high nutritional levels, then they get stabliized, and decline abruptly later on. We deduce that dur...