Gesunde Pflanzen

A six-year experiment was carried out with natural variation in temperature and rainfall during grain filling period between 2011–17 growing seasons to investigate the effects of different environments and cultivars on quantity and quality of bread wheat. The experiments were laid out in a randomized complete block design arranged with three replicates. Eight wheat cultivars (Pishgam, Sirvan, Parsi, Bahar, Pishtaz, Sepahan, Sivand and Arg) were selected for evaluation. Grain and biological yields, protein and wet gluten contents, hectoliter weight, and Zeleny sedimentation value were measured. The results indicated that the main effects of year and cultivar were significant on grain and biological yields, hectoliter weight, and Zeleny sedimentation value. There were significant differences in the interaction effect of year × cultivar on protein and wet gluten contents. Although, Parsi cultivar contained the highest grain yield and hectoliter weight (averaged by years, 6603.83 kg ha−1 and 78.10 kg hl−1, respectively), the greatest protein content, and Zeleny sedimentation value belonged to Sivand (12.68% and 23.53 ml, respectively) and Sirvan (12.63% and 23.14 ml, respectively) cultivars. According to the results, there was a statistically significant correlation between grain yield, hectoliter weight, and rainfall during grain filling period. There was a negative and significant correlation between grain yield, Zeleny sedimentation value, and protein and wet gluten contents. Our findings suggested that Sivand and Sirvan cultivars are potentially suitable for making bread and could be cultivated in similar climates due to high protein content and Zeleny sedimentation value.

In this study, the influence of potato cultivars Irga, Satina, Valfi, Blaue St. Galler and Highland Burgundy Red (HB Red), growth regulators: Bio-Algeen S‑90, Kelpak SL and Trifender WP, and the biostimulator Asahi SL on the health status of potato plants and tuber yield was investigated. The severity of late blight and early blight was estimated during the growing season. After harvest, potato tuber yield was determined according to size fractions. The applied treatments significantly reduced the severity of late blight in cv. Irga (Kelpak SL), Valfi (Bio-Algeen S-90, Kelpak SL, Trifender WP) and Blaue St. Galler (Trifender WP) in 2013. In 2015, the symptoms of early blight were significantly reduced in cv. Irga after the application of all tested bioregulators. HB Red was characterized by the best health status among the evaluated cultivars. Kelpak SL and Bio-Algeen S-90 increased the tuber yield of cvs. Irga and HB Red, respectively, in 2013, and Trifender WP increased the tuber yield of cv. Satina in 2014. In the first year of the study, the applied growth regulators and biostimulator significantly increased the percentage of medium-sized tubers of cv. Blaue St. Galler, and Bio-Algeen S-90 increased the percentage of medium-sized tubers of cv. HB Red.

Soil salinity is one of the ecological problems limiting plant growth and development, especially in semi-arid and arid regions where water availability is very limited. Stevia rebaudiana Bertoni (Asteraceae) is known for its sweetness and non-caloric products (steviol glycosides). It can be considered as a plant for the future sugar industry and human health nutrition. The present work aims to study the modulation of salt stress (NaCl: 80 mM) effects on Stevia rebaudiana Bertoni plants by an exogenous application of salicylic acid (0 mM, 0.1 mM and 0.5 mM). The results obtained show that saline stress influences the growth and development of the plant through several metabolism aspects. The exogenous application of salicylic acid to plants subjected to saline stress has improved plant biomass, chlorophyll content, chlorophyll fluorescence, stomatal conductance, antioxidant enzyme activity, MDA content and electrolyte leakage. All these results show a potential role of salicylic acid in strengthening tolerance mechanisms and mitigating physiological and biochemical damage caused by saline stress on Stevia rebaudiana Bertoni plant.

Die Pulsweitenmodulation ist eine Möglichkeit, die Durchflussmenge an Feldspritzgeräten zu regeln, indem die Düsen mit einer hohen Frequenz von 10 bis 20 Hz getaktet werden. Der Vorteil gegenüber einer üblichen über den Druck gesteuerten Volumenstromregelung liegt darin, dass die Tropfengröße und somit das Abdriftverhalten und die Benetzungseigenschaften nicht maßgeblich verändert werden. Aufgrund theoretischer Überlegungen ist jedoch zu erwarten, dass das schnelle Ein- und Ausschalten der Düsen einen Einfluss auf die Längsverteilung bei der Applikation nehmen könnte. Ziel der Untersuchungen war es, unter definierten Bedingungen im Labor die Längsverteilung bei Einsatz der Pulsweitenmodulation mit einer Frequenz von 10 Hz bei unterschiedlichen Fahrgeschwindigkeiten und Einschaltdauern zu quantifizieren. Zur Auswertung wurde eine optische Methode eingesetzt, die die Bedeckung auf wassersensitivem Papier als Zielfläche erfasst. Die Ergebnisse zeigen, dass bei Einsatz der Pulsweitenmodulation optisch ein regelmäßig ungleichmäßiges Verteilungsmuster entsteht, das von Fahrgeschwindigkeit und Einschaltdauer beeinflusst wird. Hohe Variationskoeffizienten im Vergleich zu dauerhaft eingeschalteten Düsen bestätigen den visuellen Eindruck. Erste Wirkungsmessungen mit einem Kontaktherbizid im Feld zeigen jedoch keine ungleichmäßige Wirkung im Pflanzenbestand. Weiterhin zeigen Voruntersuchungen im Labor mit einer Frequenz von 20 Hz eine gleichmäßige Längsverteilung mit Variationskoeffizienten unter 10 %. Die Ergebnisse deuten darauf hin, dass die Pulsweitenmodulation eine gleichmäßige Dosierung auf der Fläche ermöglicht und zur Volumenstromregelung ohne Veränderung der Tropfengröße eingesetzt werden kann.

Field trials were conducted in spring wheat to observe effects of jasmonic acid (JA) on aphids, thrips and wheat blossom midge (WBM). Two spring wheat varieties (Triso and Kadrilj) were sprayed twice, with two concentrations of JA plus control. Wheat pests and associated natural enemies (Coccinellidae, Empididae and Aphelinidae) were surveyed by direct count and sweep net methods. Thrips larvae and adults and WBM larvae were estimated by dissecting wheat ears. Wheat midge larvae were monitored using white traps in treated and untreated plots. At the end of season, wheat yield was assessed in treated and control plots. There was a significant difference in the number of insect pests and their natural enemies between treatments in both varieties. Plants in control plots had higher numbers of aphids, thrips and midges than in treated plots. There were more aphids, thrips and midges on the variety ‘Triso’ than on ‘Kadrilj’. JA application enhanced wheat yield in treated plots compared to control plots. The results indicated that JA mediated induction of plant defense in wheat plants can improve resistance against insect herbivores. JA could be used to develop environmentally sound crop management with reduced insecticide applications.

Different techniques, including exogenous application of different chemicals as seed priming, are in practice to improve seed germination or seedling emergence for better crop production, especially under water-deficit conditions. The present study was conducted to compare the effects of seed priming with glutathione alone or in combination with Zn on seed germination behavior, seedling growth, photosynthetic pigments, and lipid peroxidation in relation to alterations in seed metabolites, seedling antioxidative potential, and biochemicals under polyethylene glycol (PEG)-induced water stress. Three levels of glutathione (1.5, 3.0, and 4.5 mM) were applied separately as well as in combination with 0.5% Zn as seed priming. Water deficit significantly adversely affected seed germination potential, seedling growth, and biosynthesis of photosynthetic pigments in association with disturbed metabolic activities in germinating seeds, and increased lipid peroxidation in terms of the contents of H2O2 and malondialdehyde (MDA). Seed priming with glutathione alone or in combination with Zn significantly reduced the adverse impacts of water stress on seed germination and seedling growth in association with positive boosting influences on seed metabolic activities and increased biosynthesis of photosynthetic pigments, activities of antioxidant enzymes, and contents of non-enzymatic antioxidants, with more accumulation of reducing sugars (RS), non-reducing sugars (NRS), total soluble sugars (TSS), and total soluble proteins (TSP). Overall, combined application of glutathione and Zn for seed priming was found to be better than separate applications. The 3 mM level of glutathione in combination with Zn was most effective in ameliorating the adverse impacts of water stress.

Winter triticale (Triticale) cv. Dinaro and winter rye (Secale cereale L.) cv. Dańkowskie Diament were grown in 2012 and 2013 in a field-plot experiment in Tomaszkowo near Olsztyn (NE Poland). The experiment consisted of 7 treatments: absolute control (without fertilizers or the growth stimulator), control-NPK fertilizer, NPK fertilizer + micronutrients applied alone or in combination (4 treatments), NPK fertilizer + Nano-Gro growth stimulator. The severity of disease symptoms on the leaves and stem-bases of triticale and rye was evaluated throughout the growing season. Symptoms of powdery mildew on the leaves of winter triticale and winter rye were noted only in the growing season of 2013, and disease severity remained at a low level. In the growing season of 2012, weather conditions were conducive to the spread of Septoria tritici blotch (STB) and brown rust on triticale (the highest values of infection index were 41.6 and 23.8%, respectively), and scald and brown rust on rye (29.0 and 38.1%, respectively). Foliar application of micronutrients influenced the rates of infections caused by Zymoseptoria tritici and Puccinia recondita f. sp. tritici on triticale leaves. Symptoms of eyespot and Fusarium foot and root rot were noted on the stem-bases of both cereal species, whereas symptoms of take-all disease and sharp eyespot were observed sporadically. Significant differences were found between treatments in the severity of infections caused by Gaeumannomyces graminis on the stem-bases of triticale, and by Tapesia spp. and Rhizoctonia spp. on the stem-bases of rye.