Natürliche Mechanismen der Unkrautunterdrückung in ‚Elstar‘-Apfelanlagen

ZusammenfassungIm Rahmen einer Masterarbeit sollte untersucht werden, warum der Baumstreifen in ausgewachsenen Elstar-Anlagen wesentlich weniger Aufwuchs aufweist als bei anderen Apfelsorten auf der gleichen Unterlage am gleichen Standort. Daher wurde die Vegetation in Baumstreifen von ‘Elstar’-Anlagen im Vergleich zu drei anderen Apfelsorten in 150 Vegetationsaufnahmen an drei Terminen in einjährigen Untersuchungen am Campus Klein-Altendorf bonitiert. Daneben wurde die Lichtdurchlässigkeit der Baumkrone mittels 300 Ceptometer- und 100 Schachbrettmessungen der Sonnenflecken im Baumstreifen im Juni und September – nach der Herbizidapplikation im Mai 2019 – ermittelt.Die mit der Schachbrettmethode bzw. mit dem Ceptometer ermittelte Lichteinstrahlung durch die Baumkrone auf den Baumstreifen unter den ‘Elstar’-Apfelbäumen war im September um ca. 35 % bzw. ca. 10 % signifikant geringer als unter Bäumen gleichen Alters der Sorte ‘Golden Delicious’ in der Nachbarreihe auf der gleichen Unterlage M 9.Der Baumstreifen unter ausgewachsenen ‘Gala’- und ‘Braeburn’-Apfelbäumen wies einen statistisch signifikant höheren Bodenbedeckungsgrad mit Beikräutern mit Boniturnoten von 3,8–4,3 im Vergleich zu 1,7–1,9 bei ‘Elstar’ auf (auf der Skala 1–5) – auf zwei nach IP-Richtlinien und einer biologisch bewirtschafteten Fläche, d. h. die Art der Baumstreifenbehandlung (chemisch oder mechanisch) hatte keinen Einfluss auf das Phänomen der Beikrautunterdrückung bei ausgewachsenen ‘Elstar’-Apfelbäumen.Sowohl Kreuzkraut (Senecio spp.) als auch Gänseblümchen (Bellis perennis) traten in den Baumstreifen unter ausgewachsenen ‘Elstar’-Apfelbäumen mit wesentlich geringerer Stetigkeit auf als unter ‘Golden Delicious’ in der benachbarten Reihe. Die in der Literatur beschriebene indirekte Selektion durch langjährige Glyphosatanwendung auf Vogelmiere (Stellaria media) und Kreuzkraut (Seneccio spp.) durch Auskeimen der Samen nach der Herbizidapplikation wurde bestätigt; im vorliegenden Versuch traten jedoch Behaartes Schaumkraut (Cardamine hirsuta) und Rispengräser (Poa spp.) stärker auf.Keimtests in Aussaatschalen – aufgestellt in den Baumstreifen – unter den Apfelbäumen der beiden Apfelsorten ‘Elstar, Michielsen’ und als Vergleich ‘Golden Delicious’ mit einem Licht- (Lepidium sativum) und einem Dunkelkeimer (Borago officinalis) zeigten keinen Unterschied in der Keimrate. Keimtests mit Kressesamen (Lepidium sativum) in mit Falllaub vermischtem Substrat in Aussaatschalen im Gewächshaus zeigten keine keimhemmende und damit keine allelopathische Wirkung des Falllaubes der Sorte ‘Elstar’.Die vorliegenden Ergebnisse der Beikrautunterdrückung im Wiederaufwuchs nach Beikrautbekämpfung stimmen mit denen unter starkwüchsigen ‘Ingrid Marie’ auf M 2 aus der Literatur überein. Diese Wirkung ausgewachsener Apfelbäume der Sorte ‘Elstar, Michielsen’ auf M 9 ist durch die Schattierung dieser wüchsigeren Bäume bedingt und hängt nicht von der Bewirtschaftungsform (IP mit Herbizideinsatz oder Öko mit mechanischer Beikrautbekämpfung), aber eventuell noch von weiteren Faktoren, ab.

It Works! Organic-Waste-Assisted Trichoderma spp. Solid-State Fermentation on Agricultural Digestate

This study aimed at valorizing digestate through Trichoderma spp. solid-state fermentation (SSF) to produce a potentially ameliorated fertilizer combined with fungal biomass as a value-added bioproduct. Plant-growth-promoting Trichoderma atroviride Ta13, T. reesei RUT-C30, T. asperellum R, and T. harzianum T-22 were tested on different SSF substrates: whole digestate (WD), digestate dried up with wood sawdust (SSF1), and digestate enriched with food waste and dried up with wood sawdust (SSF2). The fungal biomass was quantified by using a qPCR assay. The growth of the four Trichoderma spp. was only observed on the SSF2 substrate. The highest quantity of mycelium was produced by T. reesei RUT-30 (689.80 ± 80.53 mg/g substrate), followed by T. atroviride Ta13, and T. asperellum R (584.24 ± 13.36 and 444.79 ± 91.02 mg/g substrate). The germination of Lepidium sativum seeds was evaluated in order to assess the phytoxicity of the Trichoderma-enriched substrate. The treatments with 7.5% SSF2-R, 3.75% SSF2-T-22, and 1.8% SSF2-Ta13 equally enhanced the root elongation in comparison to the non-fermented SSF-2. This study demonstrated that digestate, mixed with agro-food waste, was able to support the cultivation of Trichoderma spp., paving the way to the valorization of fermented digestate as a proper biofertilizer.

Assessment of Allelopathic Potential of Senna garrettiana Leaves and Identification of Potent Phytotoxic Substances

Senna garrettiana (Craib) Irwin & Barneby (Fabaceae) is a medicinal plant known to be rich in biologically active compounds that could be exploited to produce bioherbicides. The present study was conducted to explore the allelopathic potential and phytotoxic substances of S. garrettiana. Extracts of S. garrettiana leaves were found to significantly inhibit the growth of Lepidium sativum L. and Echinochloa crus-galli (L.) P. Beauv. (p ≤ 0.05). The phytotoxic substances were isolated and identified as vanillic acid and ferulic acid by bioassay-directed fractionation and spectral data analysis. The two compounds were shown to significantly inhibit the seed germination, seedling growth, and dry biomass of L. sativum. Based on the concentration required for 50% growth inhibition (defined as IC50), the roots of L. sativum were the most sensitive to the compounds, and the inhibitory effect of ferulic acid (IC50 = 0.62 mM) was >1.3 times more potent than that of vanillic acid (IC50 = 0.82 mM). In addition, a mixture of the two compounds (0.3 mM) resulted in synergistic inhibitory activity against the L. sativum roots compared with the individual compounds. These results suggest that the extracts of S. garrettiana leaves and their phytotoxic compounds have potential as candidate natural herbicides.

Microgreens - biologically complete product of the XXI century

Microgreens are a new functional food crop that can facilitate adaptation to urbanization and global climate change, and improve human health. The research was carried out in 2021 at the Department of Landscape Architecture of the Kuzbass State Agricultural Academy. The aim of the research was to study the technology of cultivation of microgreens of the Brassicaceae family on an aqueous substrate. The objects of research were the seeds of cultivated plants of the Brassicaceae family: Brassica oleracea Broccoli Group broccoli or asparagus, Fortuna, Raphanus sativus radish, Violetta, Lepidium sativum, watercress, Dansky, and Eruca versicaria, arugula, Sicily. It was revealed that microgreens can be obtained from seeds of the Brassicaceae family in 6-12 days. Such a product does not have time to accumulate harmful substances from the atmosphere in a short period of time. When growing microgreens, it is not necessary to use mineral fertilizers, pesticides and, thus, it is possible to obtain environmentally friendly, biologically useful products with low material costs. It was found that, depending on the seeds of the studied crops and their genotype, the cycle of growing microgreens lasts from 6 to 10 days after germination. Depending on the type of culture, the sprouts reached a height of 5-10 cm. The laboratory germination rate was 96-98%.

Allelopathy and Allelopathic Substances of Fossil Tree Species Metasequoia glyptostroboides

Metasequoia glyptostroboides Hu et W.C. Cheng is one of the oldest living conifer species, and it has remained unchanged for millions of years compared to its fossils from the Cretaceous period. The species are cultivated in the parks, gardens, and roadsides in many countries. We investigated the allelopathy and allelopathic substances in fallen leaves of M. glyptostroboides. An aqueous methanol extract of the fallen leaves inhibited the growth of cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), alfalfa (Medicago sativa L.), Lolium multiflorum Lam., Phleum pretense L., and Vulpia myuros (L.) C.C.Gmel. The extract was then purified by several chromatographic steps, and two allelopathic substances were isolated and determined by spectral data to be (+)-rhododendrol and 9-epi-blumenol C. The compound inhibited the growth of cress and L. multiflorum. M. glyptostroboides is a deciduous perennial tree, and accumulation of its fallen leaves occur on the soil under the trees. Therefore, those allelopathic substances in the fallen leaves may be liberated into the rhizosphere soil during the decomposition process of fallen leaves and provide a competitive advantage for M. glyptostrob through the growth inhibition of competing plant species nearby. Therefore, M. glyptostroboides is allelopathic, and (+)-rhododendrol and 9-epi-blumenol C may be contribute to the allelopathy.

Improving the Effects of Salt Stress by β -carotene and Gallic Acid Using Increasing Antioxidant Activity and Regulating Ion Uptake in Lepidium Sativum L.

Background: Plant growth, physiological and biochemical processes are severely affected by soil salinity. In the present study, toward investigating the interaction of antioxidants and salt stress in Lepidium sativum seedlings, two antioxidants (β-carotene and gallic acid) were sprayed on the plants. Results: The findings revealed that total dry and fresh weight were adversely affected by 25 mM NaCl salinity stress. Moreover, K+ content decreased while Na+ content increased significantly. The application of β-carotene and gallic acid significantly improved tolerance to salt stress by regulating ion uptake, reducing H2O2 and malondialdehyde (MDA) content, as well as increasing enzymatic antioxidant activity and phenolic, glutathione, and chlorophyll content. Conclusions: Our findings are indicative of β-carotene and gallic acid in the induction of salt tolerance in economically important crops.

Assessment of Brassicaceae Seeds Quality by X-ray Analysis

A serious problem of vegetable production is the quality of sown seeds. In this regard, assessment of seed quality before sowing and storage is of great practical interest. The modern level of scientific research requires the use of instrumental automated methods of seed quality evaluation, allowing to obtain more information and in a shorter time. The material for the study was a variety of samples from the collection of Brassica oleracea L., var. capitata, Raphanus sativus L., var. radicula, and Lepidium sativum L. seeds from the Federal Scientific Center of Vegetable Breeding and the Timofeev Selection Station. Digital X-ray images of seeds were obtained using a mobile X-ray diagnostic device PRDU-02. Automatic analysis of digital X-ray images was performed in the software “VideoTesT-Morphology 5.2.” The following latent defects of cabbage seeds of economic importance were revealed and identified: irregular darkening, significant “patterning” with deep separation of embryo parts, “angularity of seeds” leading to the loss of their viability. Automatic analysis of digital X-ray images of seeds confirmed the informativeness of brightness indices of digital X-ray images, as well as shape indices. Their connection with sowing qualities of the studied seeds was established.

Phenetic phytoindication and biotesting of soils in recreation zones of Tver city

Исследованы фенофонды ценопопуляций подорожника большого (Plantago major L.) и сныти обыкновенной (Aegopodium podagraria L.) в рекреационных зонах г. Твери с разным уровнем загрязнения почв тяжелыми металлами (ТМ). Параллельно проведено биотестирование почв модельных биотопов по параметрам развития семян тест-растений - горчицы белой (Sinapis alba L.), кресс-салата (Lepidium sativum L.), сорго черного (Sorghum nigrum L.) в соответствии с ГОСТ Р ИСО 18763-2019. По мере возрастания суммарной токсической нагрузки на биотопы среднее число фенов у сныти и подорожника снижается. Однако доля редких фенов у сныти возрастает, а у подорожника уменьшается. Общие показатели фенетического разнообразия (среднее число и доля редких фенов) у сныти коррелируют с суммарной токсической нагрузкой на почвы в большей степени, чем у подорожника. Параметры развития семян разных видов тест-растений неоднозначно отражают фитотоксичность почв. В большей степени с суммарным содержанием ТМ в почве коррелируют показатели всхожести семян и размеры корней проростков у горчицы. Данные по фитоиндикации биотопов на основе фенетических показателей ценопопуляций сныти и, в меньшей степени подорожника, в целом согласуются с результатами биотестирования почв. The phenofonds of Plantago major L. and Aegopodium podagraria L. cenopopulations in recreation zones of Tver with different levels of soil contamination with heavy metals (HM) were studied. In parallel, biotesting of soils of model biotopes was carried out according to the parameters of test plants seeds development - Sinapis alba L., Lepidium sativum L., Sorghum nigrum L. in accordance with ISO 18763:2016. With an increase in the total toxic load on biotopes, the average number of phenes in P. major and A. podagraria decreases. However, the share of rare phenes increases in A. podagraria, and decreases in P. major. The general indicators of phenetic diversity (average number and proportion of rare phenes) in A. podagraria correlate with the total toxic load on soils to a greater extent than in P. major. The development parameters of seeds of different species of test plants ambiguously reflect the phytotoxicity of soils. To a greater extent, the indicators of seed germination and the seedlings root size in S. alba correlate with the total content of HM in the soil. The data on the phytoindication of biotopes based on the phenetic indices of the cenopopulations of A. podagraria and, to a lesser extent, P. major, are generally consistent with the results of soil biotesting.