The allelopathy of alien plants is critical to their successful invasion. In nature, two alien plants can co-invade the same habitat. Changes in the forms of nitrogen may have the potential to alter ...the invasion process of alien plants by causing alterations in their allelopathy. This study aimed to evaluate the individual and combined allelopathy of two alien plants from the Asteraceae family, Solidago canadensis L. and Conyza canadensis (L.) Cronq. This study examined the effects of aqueous leaf extracts of the two alien plants with different nitrogen forms (NOsub.3−N, NHsub.4−N, and CO(NHsub.2)sub.2−N, and the mixed nitrogen forms at a 1:1:1 ratio) on the seed germination and seedling growth of the horticultural Asteraceae species Lactuca sativa L. using a germination bioassay. The allelopathy of the two alien plants significantly reduced the seed germination and seedling growth of L. sativa. Extracts from S. canadensis produced stronger allelopathy on the seed germination and seedling growth of L. sativa compared with those from C. canadensis. The mixture of extracts from the two alien plants produced an antagonistic effect when compared with the effects of extracts from each plant species. The addition of nitrogen intensified the allelopathy of the two alien plants on the seed germination and seedling growth of L. sativa. The degree of influence of nitrogen on the individual and combined allelopathy of the two alien plants was similar. Thus, nitrogen deposition may facilitate the independent invasion and co-invasion of the two alien plants via intensified allelopathy.
Hydroponic experiments were conducted to investigate the effects of varying particle sizes (5 μm, 0.1 μm, and 0.08 μm) and concentrations (0, 50, 100, 200, 500, 1000, and 2000 mg/L) of polystyrene ...plastic microspheres (PS-MPs) on the germination and growth of P. sativum seeds in order to investigate the effects of the microplastic environment on crop seed germination and seedling growth. The findings demonstrated that PS-MPs significantly harmed P. sativum seed germination. Specifically, low concentrations or high particle sizes weakened or promoted P. sativum seed germination, indicating varying susceptibilities to PS-MP treatment at different particle sizes. The strongest inhibitory effect on growth was observed under small particle size (0.08 μm) and high concentration (2000 mg/L). Stress had less of an impact on P. sativum in environments with low concentrations of PS-MPs, but in environments with medium and high concentrations, physiological and biochemical indicators like germination rate, stem length, and root length were significantly impacted. Furthermore, the particle size and concentration of PS-MPs had an impact on the growth effect of P. sativum seedlings. The indices of P. sativum seed germination were significantly impacted by the particle size of PS-MPs, despite the fact that PS-MP concentration was low. When the concentration of PS-MPs is low, the effects of varying PS-MP particle sizes on seed germination and root length are as follows: 0.1 μm > 5 μm > 0.08 μm. The concentration of PS-MPs had a significant impact on how it affected the buildup of dry matter and photosynthetic pigment.
Acmella radicans (Jacquin) R.K. Jansen is a new invasive species recorded in Yunnan Province, China, and little is known about its allelopathic potential and allelochemicals. In this study, the ...allelopathic effects of the essential oil (EO) of A. radicans on seed germination and seedling growth of four common plants, Brassica napus, Brassica rapa ssp. chinensis, Digitaria sanguinalis, and Lolium multiflorum, were explored. The results showed that the seed germination index, germination rate, root length, stem length, and biomass of B. napus and B. rapa ssp. chinensis were significantly inhibited at all EO concentrations of A. radicans, but there was a ‘low-promotion and high-inhibition effect’ on the root length of D. sanguinalis and L. multiflorum at low concentrations of 0.5 μL·mLsup.−1 and 0.5–1.0 μL·mLsup.−1, respectively. With increasing concentrations of EO, the inhibition rates of seed germination and seedling growth of four common plants gradually increased, and D. sanguinalis and L. multiflorum were the most inhibited, followed by B. rapa ssp. chinensis, and the least inhibited was B. napus. Thirty-two components were identified using GC–MS, representing 99.07% of the EO in A. radicans. The major components were 2-tridecanone (30.46%), caryophyllene oxide (19.18%), 4,8,11,11-tetramethylbicyclo7.2.0undec-3-en-5-ol (7.84%), β-caryophyllene (7.67%), and widdrol (4.7%). Among the compounds we identified, (E,E)-2,4-decadienal, 2-tridecanone, γ-cadinene, δ-cadinene, (E)-α-cadinol, spathulenol, caryophyllene oxide, and widdrol have been previously reported as having possible allelopathic effects. Our study was the first to show that A. radicans could potentially release allelochemicals to influence neighboring plants during its invasion and expansion.
Kiwano na podrucju istocne Slavonije Stefanic, Edita; Lukacevic, Marin; Rasic, Sanda ...
Journal of Central European agriculture,
09/2022, Letnik:
23, Številka:
3
Journal Article
Recenzirano
Seed germination, growth, flowering and yields of kiwano (Cucumis metuliferus E. Meyer Ex. Naudin) were examined in eastern Slavonia during 2021 growing season. The objective of this study was to ...determine agro-morphological diversity within kiwano growing under different weed management practices and sowing time. The experiment was arranged as a 3 x 3 factorial design with three replications. Factors included three weed management options (wheat straw mulch, cultivation and un-weeded control) and three planting dates (early, mid and late May). Atypical summer weed community that develops during experiment dominated with bristly foxtail (Setaria verticilata (L.) P. Beauv.) and redroot pigweed (Amaranthus retroflexus L.) while the others were with lower relative density and frequency per unit area and with the lower impact on the crop. Weed control was very effective compared to weedy check. However, sowing date appears as a critical factor in kiwano production, influencing not only emergence, growth and flowering, but also fruit number and size. This study concluded that mid sowing time and cultivation as a weed control measure has a highest agronomic potential for a kiwano production following by mid and early sowing time with mulch as a weed control measure. Keywords: kiwano, weed community, mulch, cultivation, sowing time U pokusu provedenom u istocnoj Slavoniji tijekom 2021. godine analizirano je nicanje, rast, cvatnja i prinos kivana (Cucumis metuliferus E. Meyer Ex. Naudin). Cilj istraživanja bio je utvrditi agromorfološke razlike pri proizvodnji kivana uzgajanog s razlicitim sustavima kontrole korova te razlicitim rokovima sjetve. Pokus je postavljem kao 3 x 3 faktorski plan s tri ponavljanja. Faktori su ukljucivali tri varijante suzbijanja korova (primjena slame kao malca, kultivacija i kontrolna zakorovljena varijanta) te tri roka sjetve (rani, srednji i kasni). Tijekom pokusa se razvila tipicna zajednica ljetnih korova u kojoj su dominirali pršljenasti muhar (Setaria verticilata (L.) P. Beauv.) i oštrodlakavi šcir (Amaranthus retroflexus L.), dok su ostali korovi bili niske relativne gustoce i frekvencije po jedinici površine i slabog utjecaja na uzgajane biljke. Tretmani suzbijanja korova bili su vrlo ucinkoviti u usporedbi sa zakorovljenom kontrolom. Medutim, vrijeme sjetve pokazalo se kao kritican faktor u proizvodnji kivana, i imalo je utjecaja ne samo na nicanje, rast i cvatnju, vec i na broj i velicinu plodova. Zakljucno, srednji rok sjetve i kultivacija kao mjera suzbijanja korova pokazali su najveci agronomski potencijal za proizvodnju kivana, a slijede srednji i rani rok sjetve uz primjenu malca za suzbijanje korova. Kljucne rijeci: kivano, korovna zajednica, malc, kultivacija, vrijeme sjetve
Seed germination, growth, flowering and yields of kiwano (Cucumis metuliferus E. Meyer Ex. Naudin) were examined in eastern Slavonia during 2021 growing season. The objective of this study was to ...determine agro-morphological diversity within kiwano growing under different weed management practices and sowing time. The experiment was arranged as a 3 x 3 factorial design with three replications. Factors included three weed management options (wheat straw mulch, cultivation and un-weeded control) and three planting dates (early, mid and late May). Atypical summer weed community that develops during experiment dominated with bristly foxtail (Setaria verticilata (L.) P. Beauv.) and redroot pigweed (Amaranthus retroflexus L.) while the others were with lower relative density and frequency per unit area and with the lower impact on the crop. Weed control was very effective compared to weedy check. However, sowing date appears as a critical factor in kiwano production, influencing not only emergence, growth and flowering, but also fruit number and size. This study concluded that mid sowing time and cultivation as a weed control measure has a highest agronomic potential for a kiwano production following by mid and early sowing time with mulch as a weed control measure.
Pimelea trichostachya Lindl is a little-understood Australian native plant, with irregular field emergence, causing significant poisoning to grazing livestock. The study aims to examine the form of ...dormancy exhibited by P. trichostachya and determine how key environmental conditions, such as alternating temperature and light conditions, moisture availability, substrate pH and burial depth, affect its germination and emergence. The study concludes that P. trichostachya has a complex dormancy mechanism. This comprises a physical component that can be partly removed by fruit scarification, a metabolic dormancy that can be overcome by gibberellic acid (GAsub.3), and a suspected third mechanism based on a water-soluble germination inhibitor. The results showed that scarified single seeded fruit (hereafter seed) with GAsub.3 treatment gave the highest germination percentage (86 ± 3%) at 25/15 °C, with good germination rates at other temperature regimes. Light exposure stimulated germination, but a significant proportion of seeds still germinated in the dark. The study also found that seeds could germinate under water-limited conditions and a wide range of pH levels (4 to 8). Seedling emergence was inhibited when seeds were buried below 3 cm in soil. Pimelea trichostachya emergence in the field commonly occurs from Autumn to Spring. Understanding its dormancy mechanism and recognizing its triggers for germination will enable better prediction of outbreaks. This can help landholders prepare for emergence and help manage seedbank build-up in pastures and crops.
Oil tea (Camellia oleifera Abel.) is one of the most important woody edible oil tree species in China, with intraspecific polyploid. In order to study the variation in pollen size and vigor of C. ...oleifera at ploidy level, four ploidy covers a total of 32 types of Camellia pollens as the material for the experiment. The results showed that the pollen sizes of diploid, tetraploid, hexaploidy, and octaploid were positively correlated with the ploidy level. Pollen viability of C. oleifera was determined by fluorescein diacetate (FDA) dye solution staining and medium containing 10% sucrose, 0.01% boric acid, and 1% agar germination in vitro, which indicated that the pollen viability and germination rate of the hexaploid were relatively high among the four ploidy levels, at 79.69% and 71.78% respectively. The pollen vigor of diploid NR-3, tetraploid DP43, hexaploid CJ-12, and octoploid YNYC-1 was higher than that of other materials with the same ploidy level. Knowledge of different ploidy pollen sizes and pollen viability provides basic information for formulating pollen breeding plans and pollination methods of C. oleifera.
PDF
