Filters
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.
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.
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.
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.