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Trichoderma spp. Improves Flowering, Quality, and Nutritional Status of Ornamental Plants
Scientists all over the world conduct research to determine the influence of Trichoderma spp. on various groups of plants, mostly crops. However, there is little information on the influence of these fungi on ornamental plants. Therefore, the authors of this study analyzed the influence of Trichoderma spp. on the growth, flowering, quality, and nutritional status of ornamental plants. The research showed that Trichoderma spp. in this group of plants stimulate the elongation and thickening of shoots and the formation of leaves. These fungi also stimulate or inhibit leaf elongation. They also accelerate the flowering of plants, stimulate the elongation of inflorescence shoots and inflorescences, and the development of flowers. Apart from that, Trichoderma spp. positively influence the content of chlorophyll and carotenoids in leaves, and they stimulate the uptake of micro- and macroelements.
Role of Community Gardens in Development of Housing Estates in Polish Cities
The amount of green is relatively low in most cities. Often, the cause of this situation is urban policy which favours developers. Far-reaching urbanization results in various environmental and social problems. In those circumstances, a need for the wider revitalization and reorganization of urban space becomes even more important and necessary. Our article is a review. It discusses the significance of community gardens in Poland due to people’s limited access to private gardens and the growing development of housing estates in cities. In recent decades, cities have developed rapidly in Poland. However, this development was often uncontrolled because very compact building patterns were applied in new housing estates. As a result, in many places the urban tissue lacked common public space. Urban planners adopted a new approach to public goods, including green spaces, and reconsidered the development of cities. Common space was found to be fundamental for the development of the identity of individual neighbourhood groups and, consequently, for social changes. Community gardens are an example of changes introduced to the urban landscape as a consequence of considering common space significant. As a result, local residents can integrate and change their attitude to public space, which is perceived as part of the community. Users gain a sense of community, solidarity, and shared responsibility. The community garden becomes a reason for neighbourhood residents to integrate despite the fact that they may differ in their political views, background, and age. Community gardens are established in a similar way all over the world. However, there might be local differences in the legal system, people’s mentality, and access to land. Community gardens are a new phenomenon in Poland. They are established mainly in big cities, e.g., in Warsaw, Kraków, and Poznań. Community gardens have numerous advantages. Their users are physically active, and they are thus at lower risk of chronic and non-infectious diseases. They grow vegetables and thus change their eating habits. In addition, community gardens reduce stress. Due to gardening, users feel better, broaden their social contacts, participate in cultural events, and enrich their diet. This article shows how the intensive development of housing estates in Poland affects the availability of green areas. The advantages of community gardens in Poland and other countries, methods of plant cultivation and how community gardens functioned during the COVID-19 pandemic are discussed. With this short review, we want to broaden the knowledge about community gardens as their development in Poland is different than in other countries and to encourage their establishment due to the decreasing amount of green space and dense urban development.
Flowering, Nutritional Status, and Content of Chloroplast Pigments in Leaves of Gladiolus hybridus L. ‘Advances Red’ after Application of Trichoderma spp.
In this study, we attempt to assess the influence of Trichoderma spp. on the flowering and nutritional status of Gladiolus hybridus L. ‘Advances Red’, as well as on the content of chlorophyll a + b and carotenoids in the leaves. During both years of the experiment, there was a treatment in which Trichoderma fungi were not used (control), and in another treatment, plants were treated with these fungi. After five weeks of cultivation, when leaf apexes were visible above the surface of the substrate, each plant was irrigated with a suspension (20 mL) of mix of Trichoderma spp. (T. viride Schumach-Tv14, T. harzianum Rifai-Thr2, T. hamatum/Bonord/Bainier-Th15). The treatment of the plants Trichoderma-spp. improved their uptake of macro- (P, K and Ca) and micronutrients (Zn, Fe and B), and increased the chlorophyll a + b and carotenoids in their leaves. Trichoderma spp. accelerated the flowering of Gladiolus hybridus L. ‘Advances Red’ by 10–14 days. The fungi stimulated the elongation of inflorescence shoots and inflorescences, in which the number of flowers increased, but flower diameter did not change. Trichoderma spp. improved the nutrients uptake, chlorophyll a + b and carotenoids, and flowering; hence, Trichoderma spp. treatment is suggested for enhancing inflorescence and inflorescence shoots in Gladiolus hybridus.
Cytokinins and Gibberellins Stimulate the Flowering and Post-Harvest Longevity of Flowers and Leaves of Calla Lilies (Zantedeschia Spreng.) with Colourful Inflorescence Spathes
Since the 1990s, the world has seen an increased interest in Zantedeschia with colourful inflorescence spathes. In Poland, its cultivation began much later. The reasons for this phenomenon can be traced to the high price of rhizomes reproduced in the United States of America, the Netherlands, New Zealand and Kenya. The area of reproductive plantations is increasing every year, but this does not affect the decrease in the price of rhizomes, which is the main reason that only a few producers are cultivating Zantedeschia cultivars in Poland. Producers offer rhizomes in various sizes, with flowering expected only from the largest ones. However, the yield of cut flowers that can be obtained from them is often not very satisfactory and is not compensated by the price that can be obtained from the sale of the flowers. It is the low yield of cut flowers that is the main problem in the cultivation of Zantedeschia cultivars, hence research conducted worldwide focuses on the use of growth regulators from the group of cytokinins (CKs) and gibberellins (GAs) in the cultivation of Zantedeschia with colourful inflorescence spathes. The post-harvest life of flowers and leaves of cultivated Zantedeschia cultivars is also an important problem. This review presents the results of research conducted over the years to improve the flowering and post-harvest life of the flowers and leaves of Zantedeschia with colourful inflorescence spathes.
Flowering, Quality and Nutritional Status of Tropaeolum majus L. ‘Spitfire’ after Application of Trichoderma spp.
The aim of this study was to compare the influence of three species of fungi of the Trichoderma genus (T. aureoviride Rifai—Ta8, T. hamatum/Bonord/Bainier—Th15, and T. harzianum Rifai—Thr2) on the quality, flowering, and nutritional status of Tropaeolum majus L. ‘Spitfire’. Early flowering was only influenced by T. hamatum, which delayed it by 6 days. T. aureoviride, T. hamatum, and T. harzianum stimulated the flowering of the ‘Spitfire’ cultivar but did not affect the size of the flowers. The plants treated with T. harzianum after being planted in pots flowered the most abundantly. Trichoderma spp. caused the plants to grow more intensively, producing longer and more leafy shoots with a greater number of offshoots. Trichoderma spp. stimulated the uptake of macronutrients, except for phosphorus (P). In the case of calcium (Ca) and sodium (Na), this phenomenon was only observed in plants treated with T. aureoviride and T. hamatum, and for magnesium (Mg), only when T. hamatum was applied to sown seeds. As for the developed root systems, as far as the micronutrients are concerned, Trichoderma spp. stimulated the uptake of zinc (Zn) and manganese (Mn). Apart from that, there was a higher iron (Fe) content in the plants treated with T. harzianum on both dates and T. aureoviride after planting the plants in pots.
Effect of Osmopriming with Melatonin on Germination, Vigor and Health of Daucus carota L. Seeds
Carrot is one of the most frequently grown vegetables in Poland and in the world. Seed-borne pathogenic fungi negatively influence their quality as well as the quantity and quality of carrot root yield. Melatonin is a PGR, which includes protective effects against biotic and abiotic stress factors and antioxidant effects. The aim of this experiment was to determine the effect of osmopriming with melatonin on germination, vigor and carrot seeds health. Carrot seeds were osmoprimed in a solution of polyethylene glycol (PEG) with an osmotic potential of −1.5 MPa at 20 °C for 7 days; melatonin was added to the PEG solution at doses of 25, 50, 100 or 200 µM. Generally, osmopriming with the addition of melatonin significantly improved germination capacity at first and final counts (sample I about 7–14% and sample II 35–43%), reduced the incidence of Alternaria alternata, A. radicina and Fusarium spp. and increased the percentage of non-sporulating hyphae. Treating accelerated the germination of seeds at a significant rate in comparison with untreated seeds and treated with fungicide, especially at low dosage, i.e., 25–50 µM. MGT of primed seeds with the addition of melatonin at dose 25 µM shortened about 0.5 day (sample I) and 1 day (sample II) The effect of melatonin on seed quality parameters was comparable or better than treating with fungicide. The results suggest that melatonin could replace fungicides in the future, which are harmful to the environment.
The Vase Life of the Leaves of Selected Perennial Species after the Application of Growth Regulators
The aim of the study was to assess the post-harvest life of the leaves of Hemerocallis × hybrida ‘Agata’, Limonium latifolium, and Heuchera hybrida ‘Chocolate Ruffles’ after the application of growth regulators from the group of gibberellins (GAs) and cytokinins (CKs), ionic liquids (2-hydroxyethyl)dimethylethylammonium gibberellinate [Chol][Gib] and acetylcholine gibberellinate [Gib][Ach]), as well as quaternary ammonium salts with the gibberellinate anion (1-ethyl quinine gibberellinate [Q-C2][Gib]) and 1-dodecyl acetylcholine gibberellinate [Q-C12][Gib]). The leaves were conditioned for 4 h in aqueous solutions of benzyladenine (BA), meta-methoxytopolin (MemT) and its riboside (MemTR), gibberellic acid (GA3), [Q-C2][Gib], [Gib][Ach], [Chol][Gib], and [Q-C12][Gib] at concentrations of 50 and 100 mg·dm−3. Conditioning of Hemerocallis × hybrida ‘Agata’ with MemT and [Chol][Gib] at both concentrations, [Q-C2][Gib] (100 mg·dm−3) and [Gib][Ach] (50 mg·dm−3), extended the vase life of the leaves by 7–9 days. The application of [Gib][Ach] (50 and 100 mg·dm−3) and [Q-C12][Gib] (100 mg·dm−3) resulted in the longest vase life of the leaves of Limonium latifolium. Conditioning of the leaves of Heuchera hybrida ‘Chocolate Ruffles’ with BA, MemT, and MemTR (50 and 100 mg·dm−3) extended their vase life by 9.5–51.3 days. BA at a concentration of 100 mg·dm−3 was the most effective. MemT (50 mg·dm−3), MemTR (100 mg·dm−3), [Q-C2][Gib] (100 mg·dm−3), [Gib][Ach] (100 mg·dm−3), and [Chol][Gib] (50 mg·dm−3) inhibited the degradation of proteins in the leaves of Hemerocallis × hybrida ‘Agata’; [Chol][Gib] (50 and 100 mg·dm−3)—in the leaves of Limonium latifolium; all the conditioners except for BA—in the leaves of Heuchera hybrida ‘Chocolate Ruffles’. GA3, MemTR, [Gib][Ach], [Q-C12][Gib] at both concentrations, [Q-C2][Gib], and [Chol][Gib] (50 mg·dm−3) inhibited the degradation of chlorophyll in the leaves of Hemerocallis × hybrida ‘Agata’. All conditioners except for [Gib][Ach] and [Q-C12][Gib] inhibited chlorophyll degradation in the leaves of Limonium latifolium. All conditioners except for MemT and MemTR (50 mg·dm−3) inhibited chlorophyll degradation in the leaves of Heuchera hybrida ‘Chocolate Ruffles’. [Chol][Gib] (50 mg·dm−3) was the most effective.
The Role of Cytokinins and Gibberellins on Post-Harvest Longevity of Florists’ Greens
Florists’ greens are a very important element of floral compositions, and their vase life must match that of the flowers, hence this review presents the results of research that has been conducted over the years in order to improve the post-harvest longevity of species that are grown for florists’ greens using growth regulators from groups of gibberellins (GAs) and cytokinins (CKs). Florists’ greens include foliage, the leafy and non-leafy stems of herbaceous plants, trees, bushes, and phylloclades. The post-harvest longevity of florists’ greens is influenced by genetics. Also strongly affected by the growing conditions and the conditions of the transport of the florists’ greens and the conditions when supplying them to markets are also significant. Moreover, florists’ greens are not supplied with growth regulators, which play a critical role in their ageing process. The CKs and GAs are considered to be inhibitors of ageing; however, unfortunately, their content in plant tissues decreases during the progressive ageing process, while the amount of regulators that accelerate ageing increases. International research is focusing on the use of growth regulators in the post-harvest treatment of florists’ greens. Their effectiveness has been shown to depend on the species, the cultivar, the concentration, and the method of application, therefore, there is no ready-made recipe that can be used for all species. The growth regulators from the CK and GA groups are used to condition the florists’ greens. Few studies to date point to the possibility of using topolines (Ts) and ionic liquids in order to extend the post-harvest longevity of florists’ greens. The standard cut flower medium containing 2% sucrose and hydroxyquinoline esters—sulphate or citrate (8HQS and 8HQC)—at a concentration of 200 mg·dm−3, which is used to conditioning, does not have a positive effect on florists’ greens of most species.
Bioactive Chemicals and Biological Activity of Tropaeolum majus L. and the Importance of Trichoderma spp. in the Cultivation of This Species
Tropaeolum majus L. is a popular ornamental plant. All parts of T. majus plant (flowers, leaves, and seeds) are edible and are appreciated for their pungent taste, although their chemical composition varies. T. majus is known for its many health benefits. It is a source of trace elements and bioactive compounds that are easily absorbed by the human body. The flowers of T. majus contain flavonoids from the flavone and flavonol groups, as well as their glycosides, which exhibit antibacterial, antifungal and antiviral activity. They also inhibit the activity of certain enzymes. Among the flavonoids, the flowers and leaves of T. majus contain derivatives of kaempferol and quercetin. Flavonoids also include anthocyanins, which are responsible for the color of T. majus flowers. In red flowers, delphinidin predominates; in orange flowers, pelargonidin; and in yellow flowers, pelargonidin and delphinidin are present in similar amounts. In the flowers of T. majus, seven carotenoids have been identified: violaxanthin, antheraxanthin, lutein, zeaxanthin, α, β and γ-carotene. In the leaves, however, lutein, violaxanthin, β-carotene and neoxanthin were detected. In T. majus, the presence of two glucosinolates has been reported: glucotropaeolin and sinalbin. The flowers and leaves of T. majus also contain both macroelements (N, P, K, Ca, Mg, Na) and microelements (Fe, Mn, Cu, Zn, Mo), and essential oils which have anti-cancer, antibacterial, and antiviral properties. The quality and flowering of T. majus are enhanced by fungi of the Trichoderma genus, which is important both ecologically and in terms of increasing the yield of raw material extracted from the plant. T. aureoviride, T. hamatum, and T. harzianum stimulated the flowering of the T. majus ‘Spitfire’. The plants treated with T. harzianum after being planted in pots flowered the most abundantly. Trichoderma spp. caused the plants to grow more intensively, producing longer and more leafy shoots with a greater number of offshoots. Trichoderma spp. stimulated the uptake of macronutrients, except for P. In the case of Ca and Na, this phenomenon was only observed in plants treated with T. aureoviride and T. hamatum, and for Mg, only when T. hamatum was applied to sown seeds. As for the developed root systems, as far as the micronutrients are concerned, Trichoderma spp. stimulated the uptake of Zn and Mn. Additionally, there was a higher Fe content in the plants treated with T. harzianum on both dates and T. aureoviride after planting the plants in pots.