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Phosphorus (P) fertilizers applied to container-grown nursery crops readily leach through pine bark-based substrates and can subsequently runoff and contribute to surface water contamination. The objectives of this research were to determine the effect of adding a layer of FeSO4·7H2O-amended pine bark (FSB) to the bottoms of nursery containers on P leaching characteristics. Phosphorus and iron (Fe) leaching in response to FSB layer height (4 or 7.5 cm), FeSO4·7H2O rate (0.3, 0.6, or 1.2 kg·m−3 Fe), and form (i.e., granular versus liquid) used to formulate the FSB layer, and the inclusion of dolomite in the FSB layer were also investigated. Greenhouse studies lasting 15 and 19 weeks were conducted, in which 2.5 L nursery containers containing the FSB layer treatments below non-amended pine bark substrate were fertilized with 199 or 117 mg P from a soluble or controlled-release fertilizer, respectively. Leachate resulting from daily irrigation was collected and analyzed for P and Fe weekly. All FSB treatments leached less P than the control (non-amended pine bark only), with P reductions ranging from 22% (4 cm FSB with 0.3 kg·m−3 Fe) to 73% (7.5 cm FSB with 1.2 kg·m−3 Fe). Phosphorus leaching decreased linearly with an increase in Fe rate or layer height. The amount of Fe that leached from containers with FSB was <5% of that applied, regardless of the Fe rate. Granular- and liquid-applied FeSO4·7H2O with or without dolomite were equally effective at reducing P leaching. Adding 0.6 kg·m−3 Fe to the bottom 500 cm3 of pine bark increased P adsorption by 0.053 mg·cm−3 P, which equates to 17.9 mg P adsorbed per gram of FeSO4·7H2O added. Results from this research suggest that including an FSB layer in the bottom of nursery containers is an effective strategy for reducing P runoff from container-based nursery production sites. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to assess how the interaction of two treatments influenced the growth and flowering of two varieties of Panicle hydrangea shrubs. The first treatment was plant pruning. Simultaneously, the plants received one of the three following treatments: root application of Trichoderma atroviride, root application of BlackJak biostimulant, or foliar application of a multi-component fertilizer. Simultaneous pruning and inoculation of the plants with the Trichoderma atroviride mycelium improved the length of hydrangea shoots the most, as compared with the control plants (18%). These two treatments also increased the number of flowers (16–47%, depending on the variety) and the fresh weight of plants (10–28%) compared with the control plants. T. atroviride alone improved the number of flowers in both varieties (19–24%) and the diameter of inflorescences in the 'Silver Dollar' one (17%). The foliar nutrition increased the fresh weight of plants by 7–57%, depending on the cultivar and pruning. It also increased the diameter and number of inflorescences in one of the varieties. Together with pruning, it intensified the growth of shoots in both cultivars (5–10%). The BlackJak biostimulant treatment gave ambiguous results. In combination with pruning, it improved the length of shoots (15%) in one cultivar and the fresh weight in the other (18%). Without pruning, the treatment increased the number of flowers (16%) and the diameter of inflorescences (9%) in one cultivar. It increased the fresh weight of plants in both cultivars (19–21%). Regardless of the other treatments, pruning increased the length of the shoots and the fresh weight of the plants. On the other hand, it reduced the number of flowers and their diameter. In most cases, the biostimulant treatment and foliar fertilization improved the growth and flowering of the plants. In combination with pruning, they improved the growth of the hydrangea shrubs but reduced the number and diameter of flowers. The simultaneous Ta treatment and pruning were the most beneficial for the growth and flowering of the panicled hydrangea plants grown in containers in a nursery. [ABSTRACT FROM AUTHOR]

The basis of orchard production is rootstocks that reduce the vigor of sweet cherry trees. However, not all rootstocks for this species can be easily propagated using traditional methods of stooling or cutting. Some of these must be propagated using the in vitro method. This is expensive and, consequently, increases the price of maiden sweet cherry trees. Our experiment assessed the growth of maiden trees of selected sweet cherry varieties (‘Bellise’, ‘Earlise’, ‘Lapins’, ‘Vanda’) depending on the method of propagation of a semi-dwarf GiSelA 5 rootstock. Additionally, the intensity of physiological processes taking place in the obtained maiden trees was also examined. The experiment compared one type of GiSelA 5 rootstock, obtained using a cheaper softwood cuttings method, with another rootstock propagated using an in vitro method. During the two years of study, there were no significant differences in the percentage of maiden trees obtained in the case of the propagation methods for both types of rootstocks, ranging from 77.43% to 87.74%. The vigor of maiden tree growth in the first year of this study was stronger than in the second year. In particular, the stem diameter of maiden trees varied from 7% to 39%, depending on the variety considered. With the exception of one variety, maiden trees produced from a rootstock propagated by stem cuttings were characterized by a larger stem diameter for the three varieties, ranging from 23% to 29%, and by a greater number of side shoots, ranging from 73% to 172%, compared to those from in vitro. Additionally, when using the stem cutting method of propagation, the rootstocks had a better developed root system, except for the ‘Earlise’ variety. However, most often, no significant differences were found between the methods of propagation regarding the fresh weight of the maiden trees and leaves and their leaf blade area. The activity of physiological processes of maiden sweet cherry trees varied, and no constant regularities were found. In the second year of the experiment, maiden trees were more often characterized by lower levels of net photosynthetic intensity and internal CO2 concentration, which was associated with worse growth results. Based on the collected results, it is recommended to propagate the considered rootstock using stem cuttings, which yields maiden trees with similar and sometimes even better growth parameters than those propagated using the in vitro method.

Growing quality seedlings is a challenge for sustainable cacao production as the survival rate of young seedlings is strongly influenced by environmental factors that affect the productivity of cacao farmers. In this study, cacao (Theobroma cacao L.) seedlings were cultivated in a nursery, and the effects of elevated CO2 concentrations (approximately 800 ppm) applied to cacao seedlings during daytime (6:00–17:59) on the root growth, morphology, and leaf photosynthetic capacity were examined. Treatment with elevated CO2 significantly improved root growth, dry matter weight, and root/shoot ratio. Three-dimensional imaging of roots showed that lateral roots grew longer horizontally, lateral roots and fine roots were distributed over a larger area, and root surface and root volume increased significantly under elevated CO2 treatment. Accurate quantification of root morphology using X-ray CT indicated that the treatment with elevated CO2 concentrations may significantly affect root quality during the seedling stage by expanding the distribution range of lateral and fine roots, which increases the ability of lateral roots to elongate and absorb water and nutrients from the superficial layers. The photosynthetic characteristics of the aboveground leaves of cacao seedlings exposed to elevated CO2 concentrations showed a tendency to adapt to elevated CO2 concentrations by increasing light-use efficiency and CO2-use efficiency. Therefore, the treatment of cacao seedlings with elevated CO2 concentrations improved the growth quality of seedlings due to the characteristics of the roots as large sinks. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to assess how the interaction of two treatments influenced the growth and flowering of two varieties of Panicle hydrangea shrubs. The first treatment was plant pruning. Simultaneously, the plants received one of the three following treatments: root application of Trichoderma atroviride, root application of BlackJak biostimulant, or foliar application of a multi-component fertilizer. Simultaneous pruning and inoculation of the plants with the Trichoderma atroviride mycelium improved the length of hydrangea shoots the most, as compared with the control plants (18%). These two treatments also increased the number of flowers (16–47%, depending on the variety) and the fresh weight of plants (10–28%) compared with the control plants. T. atroviride alone improved the number of flowers in both varieties (19–24%) and the diameter of inflorescences in the ‘Silver Dollar’ one (17%). The foliar nutrition increased the fresh weight of plants by 7–57%, depending on the cultivar and pruning. It also increased the diameter and number of inflorescences in one of the varieties. Together with pruning, it intensified the growth of shoots in both cultivars (5–10%). The BlackJak biostimulant treatment gave ambiguous results. In combination with pruning, it improved the length of shoots (15%) in one cultivar and the fresh weight in the other (18%). Without pruning, the treatment increased the number of flowers (16%) and the diameter of inflorescences (9%) in one cultivar. It increased the fresh weight of plants in both cultivars (19–21%). Regardless of the other treatments, pruning increased the length of the shoots and the fresh weight of the plants. On the other hand, it reduced the number of flowers and their diameter. In most cases, the biostimulant treatment and foliar fertilization improved the growth and flowering of the plants. In combination with pruning, they improved the growth of the hydrangea shrubs but reduced the number and diameter of flowers. The simultaneous Ta treatment and pruning were the most beneficial for the growth and flowering of the panicled hydrangea plants grown in containers in a nursery.

Growing quality seedlings is a challenge for sustainable cacao production as the survival rate of young seedlings is strongly influenced by environmental factors that affect the productivity of cacao farmers. In this study, cacao (Theobroma cacao L.) seedlings were cultivated in a nursery, and the effects of elevated CO2 concentrations (approximately 800 ppm) applied to cacao seedlings during daytime (6:00–17:59) on the root growth, morphology, and leaf photosynthetic capacity were examined. Treatment with elevated CO2 significantly improved root growth, dry matter weight, and root/shoot ratio. Three-dimensional imaging of roots showed that lateral roots grew longer horizontally, lateral roots and fine roots were distributed over a larger area, and root surface and root volume increased significantly under elevated CO2 treatment. Accurate quantification of root morphology using X-ray CT indicated that the treatment with elevated CO2 concentrations may significantly affect root quality during the seedling stage by expanding the distribution range of lateral and fine roots, which increases the ability of lateral roots to elongate and absorb water and nutrients from the superficial layers. The photosynthetic characteristics of the aboveground leaves of cacao seedlings exposed to elevated CO2 concentrations showed a tendency to adapt to elevated CO2 concentrations by increasing light-use efficiency and CO2-use efficiency. Therefore, the treatment of cacao seedlings with elevated CO2 concentrations improved the growth quality of seedlings due to the characteristics of the roots as large sinks.

The experiment compared the use of a dose of mineral fertilisation reduced by half in a nursery, which was replaced by foliar treatment with biostimulants and fertilisers. The control combination was a full dose of mineral fertilisation without foliar treatments. The half dose of mineral fertiliser applied into the soil decreased its acidity and salinity. At the same time, it decreased the soil content of macro- and micronutrients, except for calcium and iron. In most cases the simultaneous foliar application of the four biostimulants tested in our experiment reduced the content of macronutrients in the leaves of maiden apple trees, except for calcium. On the other hand, it increased the iron (28.2% average) and manganese (24.8% average) levels in the leaves but reduced the levels of zinc (11.8% average) and copper (25% average). The foliar application of two fertilisers increased the leaf contents of phosphorus (12% average) and calcium (9.3% average). One of the fertilisers also increased the leaf contents of potassium, magnesium, and micronutrients.

The selection of most suitable propagation material, as well as the adjustment of existing seedling management practices, are gaining increasing importance to ensure the best outcomes under the long-term setting of climate change. One of the factors to consider is a predicted increase in the frequency and duration of high-temperature periods. Since heat often coincides with drought, these factors are typically assessed together, yet heat stress on its own has received less attention. In this study, we examined the effect of supra-optimal ambient temperature on nine Salix alba clone cuttings wilting under greenhouse conditions and sufficient moisture levels. Most plants are especially vulnerable to extreme conditions in early stages of development. Response to heat varied between clones but, overall, shoots that were taller than 350 mm were more sensitive to heat stress. The pruning of excess lateral shoots did not show significant improvement in heat tolerance. In total, 96% of the wilted cuttings proceeded to produce lateral shoots after the cessation of heat stress. It should be studied further if similar patterns are evident in field conditions and if earlier outplanting has a positive effect on cutting vitality.

Vegetable plants are more sensitive to salt stress during the early growth stages; hence, the availability of poor-quality brackish water can be a big issue for the nursery vegetable industry. Microbial biostimulants promote growth and vigor and counterbalance salt stress in mature plants. This study aimed to evaluate the application of plant growth-promoting microorganisms for improving salt tolerance of lettuce and tomato seedlings irrigated with different water salinity levels (0, 25, and 50 mM NaCl) during nursery growth. Two commercial microbial biostimulants were applied to the substrate before seeding: 1.5 g L−1 of TNC BactorrS13 containing 1.3 × 108 CFU g−1 of Bacillus spp.; 0.75 g L−1 of Flortis Micorrize containing 30% of Glomus spp., 1.24 × 108 CFU g−1 of Agrobacterium radiobacter, Bacillus subtilis, Streptomyces spp. and 3 × 105 CFU g−1 of Thricoderma spp. Many morpho-physiological parameters of lettuce and tomato seedlings suffered the negative effect of salinity. The use of the microbial biostimulants modified seedling growth and its response to salt stress. They had a growth-promoting effect on the unstressed seedlings increasing fresh and dry biomass accumulation, leaf number, and leaf area and were successful in increasing salinity tolerance of seedlings especially when using Flortis Micorizze that enhanced salinity tolerance up to 50 mM NaCl. The inoculation of the substrate with microbial biostimulants could represent a sustainable way to improve lettuce and tomato transplant quality and to use brackish water in vegetable nurseries limiting its negative effect on seedling growth.

The article describes an experiment conducted on maiden apple trees of selected cultivars growing in a nursery. The aim of the study was to investigate how the foliar application of four biostimulants (Aminoplant 0.4%, Biamino Plant 0.2%, Bispeed 0.2% and Fylloton 0.4%) and two fertilisers (Basfoliar 6-12-6 and Basfoliar 12-4-6+S both at a concentration of 0.5%) affected the growth of the trees cultivated with the mineral fertilisation reduced by half. The plants were sprayed with the preparations and fertilisers four times at three-week intervals, between late May and late July. Selected parameters of the plants’ physiological processes were also assessed: net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (C) and intracellular CO2 (I). The foliar application of all the biostimulants and fertilisers significantly improved the growth of the maiden apple trees. The lowest values of the plant growth parameters were noted in the control combination, which was treated with a full dose of mineral fertiliser. The foliar spraying of the apple trees particularly improved the total length and number of side shoots and the fresh weight of maiden apple trees. The apple tree cultivars differed in their growth parameters, and the influence of individual foliar treatments was not conclusive. The foliar application of selected preparations intensified the leaf transpiration coefficient and the internal concentration of carbon dioxide, but it did not increase the net photosynthesis intensity or stomatal conductance.

The experiment compared the use of a dose of mineral fertilisation reduced by half in a nursery, which was replaced by foliar treatment with biostimulants and fertilisers. The control combination was a full dose of mineral fertilisation without foliar treatments. The half dose of mineral fertiliser applied into the soil decreased its acidity and salinity. At the same time, it decreased the soil content of macro- and micronutrients, except for calcium and iron. In most cases the simultaneous foliar application of the four biostimulants tested in our experiment reduced the content of macronutrients in the leaves of maiden apple trees, except for calcium. On the other hand, it increased the iron (28.2% average) and manganese (24.8% average) levels in the leaves but reduced the levels of zinc (11.8% average) and copper (25% average). The foliar application of two fertilisers increased the leaf contents of phosphorus (12% average) and calcium (9.3% average). One of the fertilisers also increased the leaf contents of potassium, magnesium, and micronutrients. [ABSTRACT FROM AUTHOR]

The selection of most suitable propagation material, as well as the adjustment of existing seedling management practices, are gaining increasing importance to ensure the best outcomes under the long-term setting of climate change. One of the factors to consider is a predicted increase in the frequency and duration of high-temperature periods. Since heat often coincides with drought, these factors are typically assessed together, yet heat stress on its own has received less attention. In this study, we examined the effect of supra-optimal ambient temperature on nine Salix alba clone cuttings wilting under greenhouse conditions and sufficient moisture levels. Most plants are especially vulnerable to extreme conditions in early stages of development. Response to heat varied between clones but, overall, shoots that were taller than 350 mm were more sensitive to heat stress. The pruning of excess lateral shoots did not show significant improvement in heat tolerance. In total, 96% of the wilted cuttings proceeded to produce lateral shoots after the cessation of heat stress. It should be studied further if similar patterns are evident in field conditions and if earlier outplanting has a positive effect on cutting vitality. [ABSTRACT FROM AUTHOR]

The article describes an experiment conducted on maiden apple trees of selected cultivars growing in a nursery. The aim of the study was to investigate how the foliar application of four biostimulants (Aminoplant 0.4%, Biamino Plant 0.2%, Bispeed 0.2% and Fylloton 0.4%) and two fertilisers (Basfoliar 6-12-6 and Basfoliar 12-4-6+S both at a concentration of 0.5%) affected the growth of the trees cultivated with the mineral fertilisation reduced by half. The plants were sprayed with the preparations and fertilisers four times at three-week intervals, between late May and late July. Selected parameters of the plants' physiological processes were also assessed: net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (C) and intracellular CO2 (I). The foliar application of all the biostimulants and fertilisers significantly improved the growth of the maiden apple trees. The lowest values of the plant growth parameters were noted in the control combination, which was treated with a full dose of mineral fertiliser. The foliar spraying of the apple trees particularly improved the total length and number of side shoots and the fresh weight of maiden apple trees. The apple tree cultivars differed in their growth parameters, and the influence of individual foliar treatments was not conclusive. The foliar application of selected preparations intensified the leaf transpiration coefficient and the internal concentration of carbon dioxide, but it did not increase the net photosynthesis intensity or stomatal conductance. [ABSTRACT FROM AUTHOR]

Vegetable plants are more sensitive to salt stress during the early growth stages; hence, the availability of poor-quality brackish water can be a big issue for the nursery vegetable industry. Microbial biostimulants promote growth and vigor and counterbalance salt stress in mature plants. This study aimed to evaluate the application of plant growth-promoting microorganisms for improving salt tolerance of lettuce and tomato seedlings irrigated with different water salinity levels (0, 25, and 50 mM NaCl) during nursery growth. Two commercial microbial biostimulants were applied to the substrate before seeding: 1.5 g L−1 of TNC BactorrS13 containing 1.3 × 108 CFU g−1 of Bacillus spp.; 0.75 g L−1 of Flortis Micorrize containing 30% of Glomus spp., 1.24 × 108 CFU g−1 of Agrobacterium radiobacter, Bacillus subtilis, Streptomyces spp. and 3 × 105 CFU g−1 of Thricoderma spp. Many morpho-physiological parameters of lettuce and tomato seedlings suffered the negative effect of salinity. The use of the microbial biostimulants modified seedling growth and its response to salt stress. They had a growth-promoting effect on the unstressed seedlings increasing fresh and dry biomass accumulation, leaf number, and leaf area and were successful in increasing salinity tolerance of seedlings especially when using Flortis Micorizze that enhanced salinity tolerance up to 50 mM NaCl. The inoculation of the substrate with microbial biostimulants could represent a sustainable way to improve lettuce and tomato transplant quality and to use brackish water in vegetable nurseries limiting its negative effect on seedling growth. [ABSTRACT FROM AUTHOR]

Currently, vegetable production systems have been changed to improve yield and quality, leading to an improvement in sustainability. In horticultural cultivation, one of the most important sectors is the seedling production in nurseries. In the past, horticultural seedlings were produced directly by farmers. Nowadays, industrialized nurseries provide seedlings characterized by a uniform growth and an early and contemporaneous development. In addition, consumer concern about the impact of food production on the environment is driving an increased demand for organic vegetables with a consequent increase of agricultural land cultivated by organic methods. Hence, there is a need to produce high-quality seedlings suitable to be cultivated in the organic farming system. Root zone management, for improving seedling quality of organic horticultural crops, remains largely unexploited, such that this review highlights some of the current research and future development priorities, providing useful information to nursery growers. In particular, we reviewed all the scientific and modern knowledge on the production of organic, healthy and vigorous seedlings including the use of: (1) compost and compost tea; (2) agroindustrial byproducts; (3) microbial and non-microbial plant biostimulants; (4) beneficial microorganisms. [ABSTRACT FROM AUTHOR]