Medicinal and aromatic plants with allelopathic effect are a potential source of natural herbicides. The experiment was conducted in order to assess herbicidal potential of meadow sage (Salvia ...pratensis L.) on germination and growth of weed species velvetleaf (Abutilon theophrasti Med.) and common corn-cockle (Agrostemma githago L.). Water extracts from S. pratensis dry biomass in different concentrations were evaluated under controlled laboratory conditions in Petri dish bioassay. Herbicidal effect of S. pratensis extracts depended on the extract concentration and weed species. In general, higher concentrations of water extract showed greater negative effect on germination and growth parameters of weed seedlings. A. githago had greater sensitivity to S. pratensis extracts with reductions in germination and seedlings growth up to 100% in treatments with 7.5% and 10% extract concentrations. A. theophrasti germination was not affected by water extracts, however, substantial reductions of root and shoot length as well as fresh weight of seedlings were recorded. S. pratensis proved as promising plant species for further studies.
Ljekovite i aromatične biljke s alelopatskim djelovanjem potencijalni su izvor prirodnih herbicida. Pokus je proveden kako bi se utvrdio herbicidni potencijal livadne kadulje (Salvia pratensis L.) na klijanje i rast korovnih vrsta Teofrastov mračnjak (Abutilon theophrasti Med.) i poljski kukolj (Agrostemma githago L.). Vodeni ekstrakti od suhe biomase S. pratensis u različitim koncentracijama procijenjeni su u kontroliranim laboratorijskim uvjetima u pokusu u Petrijevim zdjelicama. Herbicidni utjecaj ekstrakata S. pratensis ovisio je o koncentraciji ekstrakta i vrsti korova. Općenito, više koncentracije vodenog ekstrakta pokazale su veći negativan učinak na klijavost i parametre rasta klijanaca korova. Vrsta A. githago pokazala je veću osjetljivost na ekstrakte S. pratensis sa smanjenjem klijavosti i rasta klijanaca do 100 % u tretmanima s koncentracijama ekstrakta od 7,5 % i 10 %. Vodeni ekstrakti nisu imali utjecaja na klijavost A. theophrasti, ali je zabilježeno značajno smanjenje duljine korijena i izdanaka kao i svježe mase klijanaca. S. pratensis pokazala se kao perspektivna biljna vrsta za daljnja istraživanja.
Alfalfa (Medicago sativa L.) is one of the most important forage species and is recently more in focus for human consumption mainly due to its content of bioactive phenolics. Samples of the seventeen ...alfalfa cultivars/populations were collected at the Agricultural Institute Osijek with the aim to evaluate their forage quality, phenolic profiles, and antioxidant potential. Significant differences (p < 0.05) existed among studied alfalfa in all analyzed traits. The cultivar OS 99 and populations L7 and L20 were characterized by high crude protein content (22.5−24.7%) and the lowest neutral (40.2−42.9%) and acid detergent fibres (33−35.5%). The soluble-free phenolics from alfalfa leaves were extracted by methanol while insoluble cell-wall bound phenolics were released by alkaline hydrolysis. The bound phenolic extract showed a stronger DPPH scavenging capacity (20.8 mg TE/g dm) than the soluble (11.4 mg TE/g dm). The HPLC data revealed that more phenolics were found in the bound (3638.0 μg/g dm) than in the soluble form (912.3 μg/g dm). In the soluble extract of the alfalfa leaves, the major compound was catechin (338.3 μg/g dm), while rutin, epicatechin, and ferulic acid were minor ones. In the bound phenolic extract, the most abundant was ferulic (2198.2 μg/g dm) and p-coumaric acid (983.7 μg/g dm), followed by myricetin, apigenin, and quercetin. The principal component analysis revealed that alfalfa cultivars/populations were better discriminated based on the data on phenolics, rather than on forage quality. The cultivars/populations Florida 66, OS 66, L 40, L 42, Seed Force 4, and Torlesse were the most interesting in terms of phenolic health-promoting characteristics.
Allelopathy, a biological phenomenon, is a valuable tool for weed management and minimization of synthetic pesticide use in sustainable agricultural production. The aim of the study was to evaluate ...the allelopathic potential of nine sunflower genotypes. Water extracts from dry sunflower leaves collected in two growth stages (butonisation and flowering) were tested in two concentrations (1 and 2.5%) on germination and growth of lettuce under laboratory conditions. The allelopathic effect of extracts was influenced by genotype, growth stage and extract concentration. The majority of extracts exhibited negative allelopathic potential with seed germination being the least affected, and root length reduced up to 85% compared to the control. A higher concentration of water extracts resulted in a greater reduction of lettuce growth parameters. On average, extracts collected in the flowering stage inhibited lettuce shoot length to a greater degree. Several genotypes showed a greater negative impact, especially on shoot length and seedlings’ fresh weight. Further investigations of selected sunflower genotypes with the highest allelopathic potential on weed species and studies on phytochemical analysis are needed.
Cilj istraživanja bio je utvrditi alelopatski potencijal lucerne (Medicago sativa L.) na klijavost sjemena i rast klijanaca rotkvice (Raphanus sativus L.), radiča (Cichorium intybus L. var. foliosum) ...i rajčice (Lycopersicon esculentum Mill.). Vodeni ekstrakti pripremljeni od suhe nadzemne mase lucerne u tri koncentracije (1 %, 2,5 % i 5 %) testirani su u laboratorijskim uvjetima. Alelopatski potencijal lucerne ovisio je o test vrsti, koncentraciji vodenog ekstrakta te mjerenom parametru. Najslabije djelovanje zabilježeno je na klijavost te rast klijanaca rajčice. Povećanjem koncentracije vodenog ekstrakta povećavao se i negativni alelopatski potencijal. Najmanji utjecaj vodenih ekstrakata zabilježen je na suhu masu klijanaca test vrsta.
The aim of the study was to determine the allelopathic potential of alfalfa (Medicago sativa L.) on seed germination and seedling growth of radish (Raphanus sativus L.), radicchio (Cichorium intybus L. var. foliosum) and tomato (Lycopersicon esculentum Mill.). Water extracts prepared from dry alfalfa biomass in three concentrations (1%, 2.5% and 5%) were tested under laboratory conditions. The allelopathic potential of alfalfa depended on the test species, the water extract concentration, and the measured parameter. The weakest effect was recorded on germination and growth of tomato seedlings. As the concentration of the water extract increased, the negative allelopathic potential also increased. Dry weight of seedlings of test species was the least affected.
Fuzarijska palež klasova (FHB) pšenice ekonomski je značajna bolest koja može imati nepovoljne posljedice na prinos i kvalitetu pšenice. Do danas ne postoji mjera zaštite koja osigurava potpunu ...zaštitu usjeva pšenice, ali kombinacija više mjera može dati dobre rezultate. Učinkovitost svake pojedine mjere pod utjecajem je okolišnih uvjeta koji prevladavaju tijekom vegetacijske sezone, a učinkovitost će ovisiti i o osjetljivosti pojedine sorte na FHB. Sve veći broj istraživanja potvrđuje kako je integrirana zaštita bilja (IZB) ključ za što uspješniju borbu protiv FHB-a. Kako bi primijenjene mjere zaštite bile što uspješnije, od iznimne je važnosti dobro poznavati uzročnika bolesti, njegov životni ciklus i ekologiju. Budući da je F. graminearum dominantni uzročnik FHB-a na području Republike Hrvatske, osobiti naglasak je stavljen na sve dostupne mjere zaštite u njegovu suzbijanju.
Fusarium head blight (FHB) is an economically devastating disease that may exert an adverse impact on the wheat yield and quality. To date, no measure ensures a complete protection of wheat crops, but the combination of multiple protection measures may produce the promising results. The effectiveness of each measure is influenced by environmental conditions during the growing season and cultivar susceptibility to the FHB. The Integrated Pest Management (IPM) is the most effective approach to the management of FHB. For a successful control, it is essential to acquire a good knowledge of the pathogen, its life cycle, and its ecology. Since the F. graminearum is a predominant species causing the FHB on the wheat in Croatia, this paper aims to describe all available measures for its control.
The current series of experiments was conducted to assess the allelopathic potential of fennel, rue, and sage seed and plant biomass on weed species hoary cress (Lepidium draba). The effect of plants ...was evaluated through: seed cogermination in Petri dishes, effect of water extracts from fresh and dry plant biomass in two concentrations (50 and 100 g l-1) in Petri dishes and pots, and effect of fresh and dry plant residues in rates of 10 and 20 g kg-1 of soil. The cogermination of seeds affected germination and seedling length of hoary cress with fennel seeds having the highest inhibitory effect and reducing germination up to 34.9%. The water extracts in Petri dish essay had various effects, however the dry plant biomass in higher concentration reduced germination and seedlings growth for up to 100%. The applications of the extracts from fresh biomass in pots with soil differed from results in Petri dishes. Sage extract in higher concentration inhibited germination for 34.2%, and fennel extract reduced root length for 22.7%. The effect of incorporation of plant residues depended on the plant species and amount of the plant residues and was both stimulatory and inhibitory. The emergence reduction was the highest with incorporation of fresh rue residues.
Laboratory bioassay was carried out to study the insecticidal effect of 9 Croatian inert dusts against Sitophilus oryzae (L.) and to test their influence on bulk density of treated wheat. In order to ...compare effectiveness of Croatian inert dust samples, a standard USA diatomaceous earth (DE) Celatom® Mn 51, registered as an insecticide for stored-products protection, was used. Wheat kernels with approximately 13% moisture content were treated with inert dusts at doses 300, 400, 500 and 600 ppm and mortality of S. oryzae adults was assessed after 7 and 14 days and progeny after 49 days. The most effective Croatian inert dust samples were D-02B, D-01 and MA-4 with the LD90 values of 359.6, 447.2 and 458.7 ppm, respectively. In addition, effective dose that reduced F1 progeny in half was lower in regard to the other tested samples including the standard DE Mn 51, with the ED50 values 71.9, 54.6 and 137.6 ppm, respectively. According to the XRF analytical results, the highest amount of biogenic silica (BSi) was found in samples D-02B, D-01 and MA-4 (45.98, 35.09 and 21.28%, respectively). Paleontological data analysis confirmed diatoms species in only 5 samples of Croatian inert dusts (D-01, D-02B, PD-1, MA-4 and JU-1). All tested inert dusts affected reduction in bulk density of treated wheat at the LD90 concentrations, from 4.4 (D-02B) to 5.6 (JU-1) kg hL-1. More effective inert dusts at lower doses equally reduced bulk density as less effective inert dusts at much higher doses.
In recent decades, there has been an increase in the use of diatomaceous earth (DE) as a natural insecticide because of its low mammalian toxicity, worker safety, low risk of food residues and the ...occurrence of resistant insect populations associated with the use of chemical insecticides. Therefore there is potential for research into known but previously undescribed Croatian mid-Miocene marine diatomites from the perspective of their potential as proper DE that could be mixed with plant extracts as a new formulation for grain storage protection. The marine diatomites belong to the Paratethyan near shore environment, deposited in the upwelling zone during a mid-Miocene temperate climate. Palaeontological, mineral and geochemical analyses were done on ten promising marly sediments from 26 outcrops and one borehole from the North Croatian Basin. The most important ingredient of diatomaceous sediments is silica (biogenic opal-A and SiO^sub 2^ bound in other silicate minerals including quartz, clay minerals, micas, etc.). The amorphous silica content of the tested Croatian diatomites is relatively low (< 70%) in comparison with the DE MN-51 standard (medium to high efficient DE) (73.6%), nevertheless they show in some part even slightly better efficacy against insects. It seems that the enhanced content of smectite in diatomaceous sediments also influences increased absorption of DE. Based on palaeontological results, the most efficient diatomites from the Podsusedsko Dolje and Markusevec (Medvednica Mt.) consist of the mid-sized planktonic Coscinodiscus group of species where Thalassionema nitzschioides dominate and is positively correlated with their absorption. The usage of Boströms' standard formula for getting opal-A from geochemical data was abandoned because of negative results and the modified Murdmaas' formula for hemipelagic sediments was applied. Preliminary results on the aforementioned diatomite (as inert dusts) show good efficacy against tested insects Sitophilus oryzae (LINNAEUS), Tribolium castaneum (HERBST) and Rhyzopertha dominica (FABRICIUS).
Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, ...conservation and augmentative (inoculative and inundated) biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides) or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chemical herbicides are not allowed, if resistant weed species are present or in the integrated pest management against weeds with reduced herbicides doses and other non-chemical measures, but it has certain limitations and disadvantages.
The aim of the study was to examine allelopathic effect of parsley (Petroselinum crispum Mill.) on germination and growth parameters of weed species hoary cress (Lepidium draba (L.) Desv.). ...Cogermination of hoary cress with parsley seeds, water extracts from fresh and dry parsley biomass in concentrations of 5 and 10% (50 and 100 g per litre of distilled water) were evaluated in Petri dishes. Effect of water extracts from fresh parsley biomass in aforementioned concentrations as well as effects of fresh and dry parsley residues in two rates (10 and 20 g/kg of soil) were examined in pots with soil. Cogermination of seeds stimulated root length, but decreased shoot length and fresh weight of hoary cress seedlings. In the Petri dish assay, extracts from fresh and dry parsley biomass reduced germination of hoary cress, but had both stimulatory as well as inhibitory effect on other parameters. The highest concentration of dry biomass extract completely reduced germination rate of hoary cress (by 100%). In the pot experiment, extracts from fresh parsley biomass had stimulatory effect on weed growth parameters except for root length which was inhibited with higher concentration by 4.2%. Fresh parsley residues reduced germination, root and shoot length of hoary cress, while dry parsley residues promoted measured parameters, with the exception of root length.
PDF
