Response of vetch, lentil, chickpea and red pea to pre- or post-emergence applied herbicides

Broad-leaved weeds constitute a serious problem in the production of winter legumes, but few selective herbicides controlling these weeds have been registered in Europe. Four field experiments were conducted in 2009/10 and repeated in 2010/11 in Greece to study the response of common vetch (Vicia sativa L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.) and red pea (Lathyrus cicera L.) to several rates of the herbicides pendimethalin, S-metolachlor, S-metolachlor plus terbuthylazine and flumioxazin applied pre-emergence, as well as imazamox applied post-emergence. Phytotoxicity, crop height, total weight and seed yield were evaluated during the experiments. The results of this study suggest that common vetch, lentil, chickpea and red pea differed in their responses to the herbicides tested. Pendimethalin at 1.30 kg ha-1, S-metolachlor at 0.96 kg ha-1 and flumioxazine at 0.11 kg ha-1 used as pre-emergence applied herbicides provided the least phytotoxicity to legumes. Pendimethalin at 1.98 kg ha-1 and both rates of S-metolachlor plus terbuthylazine provided the greatest common lambsquarters (Chenopodium album L.) control. Imazamox at 0.03 to 0.04 kg ha-1 could also be used as early post-emergence applied herbicide in common vetch and red pea without any significant detrimental effect

Herbicidal potential of lavender (Lavandula angustifolia Mill.) essential oil components on bristly foxtail (Setaria verticillata (L.) P. Beauv.): Comparison with carvacrol, carvone, thymol and eugenol

Essential oils are a plentiful source of plant compounds for potential use in the development of natural herbicides. With this in mind, the phytotoxicity of ten major essential oil components of lavender (Lavandula angustifolia Mill.) on the weed species bristly foxtail (Setaria verticillata (L.) P. Beauv.) was determined using a perlite-based Petri-dish bioassay. Their phytotoxicity was also compared with that of well-known phytotoxic essential oil components (carvacrol, thymol, carvone and eugenol) of oregano (Origanum vulgare L.) and clove (Syzygium aromaticum (L.) Merr. & L.M. Perry) essential oils. Potential synergistic or antagonistic effects between carvacrol or eugenol with other components of lavender essential oil were investigated. Regarding the most phytotoxic components, terpinen-4-ol at 80 nL/cm3 completely inhibited the germination and root length of bristly foxtail, displaying similar phytotoxicity to carvone and thymol. Like carvacrol, lavandulol and linalyl acetate caused total (100%) germination and root length reduction of bristly foxtail at 160 nL/cm3, while the same effect was achieved by lavandulyl acetate at 320 nL/cm3. A synergistic effect was also observed when carvacrol or eugenol were combined with ocimene, 3-octanone, α-terpineol or terpinen-4-ol. Focusing on the development of alternative weed control strategies, lavender essential oils containing high concentrations of terpinen-4-ol, lavandulol or linalyl acetate could be useful for the production of natural herbicides. These essential oil components combined with selected oregano or clove essential oil components, increase phytotoxicity and weed control due to the synergistic effect observed when in mixture. © 2020 by the Serbian Biological Society

Response of vetch, lentil, chickpea and red pea to pre- or post-emergence applied herbicides

Broad-leaved weeds constitute a serious problem in the production of winter legumes, but few selective herbicides controlling these weeds have been registered in Europe. Four field experiments were conducted in 2009/10 and repeated in 2010/11 in Greece to study the response of common vetch (Vicia sativa L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.) and red pea (Lathyrus cicera L.) to several rates of the herbicides pendimethalin, S-metolachlor, S-metolachlor plus terbuthylazine and flumioxazin applied pre-emergence, as well as imazamox applied post-emergence. Phytotoxicity, crop height, total weight and seed yield were evaluated during the experiments. The results of this study suggest that common vetch, lentil, chickpea and red pea differed in their responses to the herbicides tested. Pendimethalin at 1.30 kg ha�1, S-metolachlor at 0.96 kg ha�1 and flumioxazine at 0.11 kg ha�1 used as pre-emergence applied herbicides provided the least phytotoxicity to legumes. Pendimethalin at 1.98 kg ha�1 and both rates of Smetolachlor plus terbuthylazine provided the greatest common lambsquarters (Chenopodium album L.) control. Imazamox at 0.03 to 0.04 kg ha�1 could also be used as early post-emergence applied herbicide in common vetch and red pea without any significant detrimental effect

Long-term cardoon (Cynara cardunculus) productivity under reduced irrigation and weed control inputs

The long-term productivity data for the energy crops under reduced inputs are decisive for farmers’ decisions. An 11-year field study was conducted in central Greece to evaluate the productivity of two cardoon varieties under reduced irrigation and weed control inputs. During the initial six plant stage ages, the cardoon total dry biomass, seed, oil and potential energy yields, averaged 21.65, 1.92 and 0.53 t ha−1, as well as 364.719 GJ ha−1, respectively, with the var. C12, in most cases, the most productive. Both conditions of non-irrigation and weed competition caused a slight reduction in cardoon yield components. However, during the next five plant stage ages, the corresponding yields were dramatically reduced and averaged 11.10, 0.52 and 0.15 t ha−1, as well as 185.153 GJ ha−1, mainly due to reduced regrowth and the shorter height of cardoon stems. In this period, irrigation and weed management did not affect in most cases cardoon productivity. So, the under-reduced inputs cultivation of cardoon after the sixth year may not be economically acceptable for farmers. Conclusively, cardoon can be cultivated under reduced inputs, at least for 6 years, constituting one of the eligible energy crops for farmers in the hot and semi-arid Mediterranean fields. © 2022 Informa UK Limited, trading as Taylor & Francis Group

Effectiveness of olive fruit polyphenol extract combined with aqueous extracts of solid wastes of pomegranate or/ and orange juice against important plant pathogens - Part 2 (in vivo studies)

Olive fruit extracts, combined with pomegranate and orange waste extracts, isolated using microwave assisted extraction technique, were used as a potential alternative crop protection method against Verticillium dahliae, Rhizoctonia solani, Botrytis cinerea and Pyrenochaeta lycopersici on tomato plants. For the evaluation of the antimicrobial activity, various mixtures of the extracts were applied on 15 days old tomato plants, variety “Bella Dona”, infected by the above-mentioned pathogens. After 40 days of treatments, plant growth parameters such as plant fresh and dry weight, root weight, plant height, number of blossoms and number of formed fruits were calculated in order to assess the extract effectiveness. The results indicated that the four pathogens dramatically reduced tomato growth. In contrast, most of the evaluated extracts provided satisfactory control of the pathogens resulting in tomato growth similar to that of the uninfected control plants. Conclusively, the use of these polyphenolic extracts could protect tomato plants in case of fungal infection. Copyright © 2021 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International Licens

Salinity tolerance evaluation of barley germplasm for marginal soil utilization

One greenhouse experiment was conducted to assess the tolerance to salinity and water deficit stresses of 184 barley varieties (breeding lines or registered varieties). Also, a 2-year field experiment was conducted to evaluate the growth and yield components of 16 of these varieties, representing tolerant, intermediate tolerant and susceptible ones, grown simultaneously in saline and nonsaline soils. In the greenhouse, the K-means cluster analysis shown that 17 varieties were tolerant, 72 varieties intermediate tolerant, 16 varieties intermediate susceptible and 79 varieties susceptible. In the field, soil salinity reduced the germination of the barley varieties except for the varieties ICB 100126, Scarlett and Meteor. Barley varieties grown in the saline soil produced 33.2-to 83.4% lower dry biomass, 0.0-to 78.9% fewer ears and 0.0-to 81.5% lower grain yield than those of varieties grown in the nonsaline soil. In the saline soil, the greatest grain yield was provided by the vars. Galt Brea ‘S’ and ICB 100126 (4.87 and 4.31 t ha-1, respectively), without significant differences between saline and non-saline soils. In most barley varieties, chlorophyll content and photosystem II quantum yield were greater under saline than under non-saline conditions. The results of this research indicated that, in barley germplasm, a remarkable genetic variation exists which would contribute to barley production in saline soils. © the Author(s), 2021 Licensee PAGEPress, Italy

Carbon assimilation, isotope discrimination, proline and lipid peroxidation contribution to barley (Hordeum vulgare) salinity tolerance

Barley (Hordeum vulgare L.) exhibits great adaptability to salt tolerance in marginal environments because of its great genetic diversity. Differences in main biochemical, physiological, and molecular processes, which could explain the different tolerance to soil salinity of 16 barley varieties, were examined during a two-year field experiment. The study was conducted in a saline soil with an electrical conductivity ranging from 7.3 to 11.5 dS/m. During the experiment, a number of different physiological and biochemical characteristics were evaluated when barley was at the two-to three-nodes growing stage (BBCH code 32–33). The results indicated that there were significant (p < 0.001) effects due to varieties for tolerance to salinity. Carbon isotopes discrimination was higher by 11.8% to 16.0% in salt tolerant varieties than that in the sensitive ones. Additionally, in the tolerant varieties, assimilation rates of CO2 and proline concentration were 200% and up to 67% higher than the sensitive varieties, respectively. However, in sensitive varieties, hydrogen peroxide and lipid peroxidation were enhanced, indicating an increased lipid peroxidation. The expression of the genes Hsdr4, HvA1, and HvTX1 did not differ among barley varieties tested. This study suggests that the increased carbon isotopes discrimination, increased proline concentration (play an osmolyte source role), and decreased lipid peroxidation are traits that are associated with barley tolerance to soil salinity. Moreover, our findings that proline improves salt tolerance by up-regulating stress-protective enzymes and reducing oxidation of lipid membranes will encourage our hypothesis that there are specific mechanisms that can be co-related with the salt sensitivity or the tolerance of barley. Therefore, further research is needed to ensure the tolerance mechanisms that exclude NaCl in salt tolerant barley varieties and diminish accumulation of lipid peroxides through adaptive plant responses. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Potential synergistic action of liquid olive fruit polyphenol extract with aqueous extracts of solid wastes of pomegranate or/and orange juice industry as organic phyto-protective agents against important plant pathogens - Part 1 (in vitro studies)

In this research study potential synergistic action of aqueous extracts of olive-pomegranate-orange fruits isolated by microwave assisted extraction were investigated as biocontrol agents against several plant pathogenic fungi. The aim of the research study was the production of mixed liquid extracts to be used as natural phytoprotective agents in organic farming. The results proved that the use of 100%-pure olive fruit polyphenol extract affected the mycelium growth of B. cinerea, V. dahliae, R. solani, E. lata, M. laxa, P. lycopersici and P. punicae. However, it did not affect the mycelium growth of F. oxysporum f. sp., lycopersici, A. niger, and G. graminis. Moreover, pomegranate polyphenol extract at 100% concentration inhibited mycelium growth of B. cinerea. Various olive-pomegranate-orange polyphenol aqueous extract combinations may be used in order to control the mycelium growth of the majority of the tested microorganisms. However, the use of any combination and concentrations of the tested samples (1-72) did not affect the mycelium growth of F. oxysporum f. sp., lycopersici, A. niger, and G. graminis thus, their use as biological control agent is not recommended. According to the findings of the present research, it can be suggested that the olive fruit polyphenol extract be used as potential biocontrol agent, in order to stimulate mycelium growth of various plant pathogenic fungi. Copyright © 2020 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International Licens