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The effect of true cinnamon tree and peppermint hydrolates on germination and seed health of carrot seeds
Carrot (Daucus carota) crop production can be reduced by some fungi that are associated with and spread by seeds. The effects of seed-borne fungi are low germination rate and weak seedling growth due to damage by causing fungal disease. As a by-product of essential oil distillation, hydrolates are increasingly being used as plant protection agents in sustainable agriculture. The aim of this study was to determine the effect of peppermint (Mentha x piperita) and true cinnamon tree (Cinnamomum zeylanicum) hydrolates on the germination, vigour and health of carrot seeds. Seeds of two samples varied in quality were soaked in hydrolate solutions at the concentrations of 5, 20, 50 and 100% for 30 minutes. Seed germination was evaluated according to ISTA Rules, and seed health was determined using the deep-freeze blotter method. The application of hydrolate solutions of true tree cinnamon tree reduced the occurrence of Alternaria alternata, A. radicina, Cladosporium spp., Fusarium spp. and Melanospora simplex on seeds of sample II (the most effective 20%) and A. alternata and Cladosporium spp. in the case of sample I (the most effective were 20 and 50%). Both samples showed an improvement in the germination rate parameters (T25 and MGT) after treatment with 5% true cinnamon tree hydrolate solution. For the poorer quality seed sample soaking in the peppermint hydrolate solutions at concentrations of 20 and 100% significantly its germination capacity about 21%. Therefore, seed treatment using hydrolates can be used in organic farming.
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.
The Impact of Acetic Acid Treatments on Stored Onion (Allium cepa L.) Seeds’ Quality
The aim of the studies was to evaluate the effects of acetic acid treatments on the quality of stored onion seeds. Seeds of two samples were soaked for 30 min in 0.25, 0.5, 1 and 2% acetic acid solutions. Controls included untreated seeds, seeds soaked in distilled water and seeds treated with fungicide Zaprawa Nasienna T 75 WS/DS (a.i. 75% thiram). Germination, vigour and health of untreated and treated seeds were evaluated before and after 2, 6 and 12 months of storage at 4 and 20 °C. Treating onion seeds with acetic acid solutions, especially at the concentrations of 1 and 2%, reduced their infestation with Alternaria alternata, Botrytis cinerea, Cladosporium spp., Penicillium spp. and Stemphylium botryosum after storage at both temperatures. Seeds stored at 20 °C showed lower infestation with fungi than seeds stored at 4 °C. The acetic acid treatments did not have any adverse effect on germination and vigour of stored onion seeds. In some cases, the increase in germination at the first and final counts and the improvement in mean germination time were observed.
Evaluation of the Use of Oregano and Coconut Hydrolates to Improve Onion Seed Quality
Onion seeds are often contaminated by pathogenic fungi, such as Botrytis spp., Fusarium spp., which decrease seed quality. The usage of hydrolates is an alternative method to chemical treatment, and is safe for the natural environment, human health and life. The aim of the experiment was the determination of the effect of treatment with oregano and coconut hydrolates on the quality of onion seeds. Germination, vigour and seed health of two samples of onion seeds were tested. Seed germination was evaluated according to ISTA Rules, seed health by agar test and vigour by seed speed and uniformity of germination. Seeds were treated with hydrolate solutions at concentrations of 10, 20, 50 and 100%; untreated seeds and seeds soaking in water and treated with fungicide were control. Generally, the use of hydrolates improved the germination capacity at first and final count for both analyzed samples. After treating with hydrolate solutions, less abnormal diseased seedlings were also observed. Higher concentrations of hydrolates were effective in the limitation of the incidence of fungi A. alternata, Cladosporium spp. and Fusarium spp., either by complete elimination or a reduction of their presence on the seeds.
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 occurrence of fungi on the commercial dietary supplements based on the milk thistle (Silybum marianum (L.) Gaertn.) available on Polish market
Summary Introduction: Milk thistle (Silybum marianum (L.) Gaertn.) is an important medicinal plant, its achenes contain a silymarin, which has a regenerating and stabilizing effect on liver cells. The milk thistle based dietary supplements are among the best-selling plant pharmaceuticals in the US and the UE. Objective: The goal of the experiment was to determine which – if any – fungi contaminated either the whole or ground milk thistle achenes, available on the Polish market. Methods: The mycological analyses were performed on 200 achenes, using deep-freeze blotter method. Ground material was assessed using agar test method. For each sample, 10 Petri dishes were used. The material was applied in five places per one Petri dish, with a micro scoop laboratory spatula. Then, Petri dishes with achenes and ground material were incubated at 20°C under alternating cycles of 12 h NUV light and 12 h darkness. The identification of fungi was performed using stereo microscope and compound microscope, if necessary. Results: The milk thistle achenes were infested with following fungi: Alternaria alternata, Alternaria sp., Aspergillus flavus, Aspergillus spp., Bipolaris sp., Cladosporium spp., Epicoccum nigrum, Fusarium spp., Melanospora simplex, Mucor spp., Penicillium spp., Phoma sp., Rhizopus stolonifer, Sarocladium strictum, Stemphylium botryosum, Trichothecium roseum, Ulocladium consortiale and Verticillium sp. Among them A. alternata predominated. Whereas, milled milk thistle achenes were occupied by Aspergillus flavus, A. niger, Aspergillus spp., Fusarium sp., Mortierella spp., Mucor spp., Penicillium spp. and R. stolonifer. Conclusion: Considering the significant fungal contamination of milk thistle achenes-based dietary supplements, it seems reasonable to introduce a system of achene control due to possible microbiological contamination.
Effect of acetic acid treatments and storage on the quality of lettuce (Lactuca sativa L.) seeds
Seedborne fungi negatively affect the quality of lettuce (Lactuca sativa L.) seeds and they are impact on their storability. Using the acetic acid can be an alternative to chemical treatment. Seeds were soaked for 30 minutes in a solution of acetic acid at concentrations of 0.25%, 0.5%, and 2%. Untreated seeds, seeds soaked for 30 minutes with distilled water and seeds treated with Dithane NeoTec 75 were controls. Seeds germination, vigour and seed health before and after 18 months of storage at 4 and 20 °C were tested. Before storage the acetic acid solution at concentrations of 0.25 and 0.5% significantly decreased number of dead seeds and increased germination at first and final counts, 2.0% solution worsened germination and vigour of seeds of both samples. Generally acetic acid solutions limited occurrence of fungi. Seeds stored at a lower temperature (4 °C) were characterized by significantly higher percentages of total germinating seeds (Gmax) and percentage of germination at first and final counts. Deterioration of the germination at first and final counts was found only after soaking the seeds in acetic acid solution at a concentration of 2%. Acetic acid solutions at concentration 0.5 and 2.0% effectively reduced occurrence of Alternaria alternata.