Plant Choice Research Articles

Does the micro land snail, Kaliella barrakporensis (Mollusca: Gastropoda), exhibit plant preference and aggregation? A spatial scale analysis

The spatial scale occurrence of the micro land snail Kaliella barrakporensis (L. Pfeiffer, 1852) in the host plants was assessed in selected sites of West Bengal, India. In course of a survey, the collection of K. barrakporensis from randomly selected plants was accomplished for the purpose of highlighting – (a) distribution in host plants, (b) variation in abundance in different height and (c) the dispersion pattern. Although the snails were observed in seven different plants, the presence was more prominent in the lemon plant (Citrus limon), with an average of about 24 individuals / 100 leaves. The logit based principal component regression indicated significant differences in the choice of the host plants with abundance in C. limon followed by Hibiscus rosa sinensis and Nyctanthes arbor-tristis, which was further substantiated through ANOVA (F(1),6, 69 = 10.918; P < 0.001). The heterogeneity in the distribution of K. barrakporensis at different heights of the plant C. limon was also observed with maximum abundance at about 90cm height with least number of snails at the ground level (F(1)6,139 = 3.797;P < 0.0001). On the basis of the variance to mean ratio (s2/m = 1.847±0.161SE), negative binomial aggregation parameter k (1.034± 0.33 SE) and Lloyd mean crowding (ṁ) (1.083 ± 0.16SE) the dispersion of the snail appeared to comply with the clumped distribution in host plants. Apparently, the micro land snail K. barrakporensis exhibited clumped distribution in selected plant species that serve as the preferred resource and complies with the arboreal adaptation. However, further studies should be initiated on the resource preferences of the micro snail K. barrakporensis, to support conservation initiative and spread beyond native habitats.

Particulate Emission Reduction by Fuel Injection Timing Optimization in a Gasoline Direct Injection Engine

Abstract Optimized fuel injection timings in internal combustion engines exhibit superior performance, combustion characteristics, and lower emissions. Particularly, particulate emissions from a gasoline direct injection (GDI) engines are highly dependent on fuel injection timings. GDI engines have emerged as a popular choice of power plants for automobiles among customers worldwide. They are preferred over multiple-port fuel injection (MPFI) engines in the transport sector because of their superior fuel economy and performance characteristics. The main objective of this study is to optimize a GDI engine for the lowest particulate emission at different fuel injection timings. GDI engine was investigated for particulate matter (PM) mass/particulate number (PN) emissions at five fuel injection timings (230, 250, 270, 290, and 310 deg bTDC), covering the entire envelope. Once the optimum fuel injection timing was determined, an engine exhaust particle sizer was used to measure the particle size-number distribution. Particulate samples from the engine were also collected on a filter paper for morphological investigations of particulates collected under optimized fuel injection timings. These experiments confirmed the importance and need to optimize the fuel injection timings at every engine operating point to reduce the PM/PN emissions from a GDI engine, which remains one of the biggest unresolved challenges to this technology.

Renewable Feedstocks Present New and Complex Opportunities

Renewable Feedstocks Present New and Complex Opportunities

Gardens’ contribution to people and urban green space

Cities are experiencing numerous challenges, adversely affecting human health and wellbeing. Urban green space provides ecosystem services that are important to meet urban challenges. One type of urban green space is private gardens (yards) that make up an essential part of many urban areas. Gardens can support urban biodiversity and provide cultural ecosystem services (CES) to its owner. However, the provision of garden benefits depends on garden size, design and management. This study aims to explore private gardens contribution to urban biodiversity and garden owners’ wellbeing (in terms of CES), and to understand the influence of urban planning and garden design and management. We use a conceptual framework to illustrate complexities and interlinkages: the garden ‘human-nature’ nexus. The study is based on a garden land-use inventory and interviews with 35 garden owners in Lund, Sweden. Results show that urban development influence garden’s biodiversity potential by limiting available space or garden vegetation. New properties were mainly covered by buildings and paved surfaces and their small gardens contained few biodiversity features and large trees. Garden owners used multiple information channels to gain inspiration and knowledge, and aesthetic and edibility are important plant qualities governing garden plant choice. Many garden owners experienced gardens problems that influence design and management. The most important garden CES were social bonds, recreation, nature experiences and relaxation. Age and gender influence both garden CES and garden design and management. We conclude that private gardens have a potential to function as multifunctional spaces, but to harness their full potential there is a need to transform how we plan, develop, manage and not at least recognize private green space. We argue that the garden ‘human-nature’ nexus can help to illustrate the important interlinkages existing between e.g. urban planning, biodiversity and garden ES, and to foster sustainable urban green space governance.

EFFECT OF ABIOTIC STRESS IN WHEAT: A REVIEW

Wheat is the staple food in the Nepalese diet, and it is grown in most part of the country during the winter seasons. This brief analysis article discusses previous research and studies on the effect of abiotic stress on wheat. Different abiotic stresses induce a number of changes in plant metabolism, and several of these changes in plant in response to different abiotic stresses overlap. stress –induced metabolic changes cause crop growth to be impaired, resulting in low yield. Abiotic stresses are also an important factor that affects yield reduction, productivity decline, and net profit shrinkage according to long term research conducted by various researchers in various location .As a result abiotic stress such as drought, salinity, acidity, water logging and heat most be effectively addressed through management practices such as tillage and planting choices, residue management, sowing time, stress resistance cultivars, irrigation scheduling and integrated nutrient management to preserve natural resources while minimizing the negative effects and ensuring long term wheat output.

Plant scientists' research attention is skewed towards colourful, conspicuous and broadly distributed flowers.

Scientists' research interests are often skewed toward charismatic organisms, but quantifying research biases is challenging. By combining bibliometric data with trait-based approaches and using a well-studied alpine flora as a case study, we demonstrate that morphological and colour traits, as well as range size, have significantly more impact on species choice for wild flowering plants than traits related to ecology and rarity. These biases should be taken into account to inform more objective plant conservation efforts.

Plant selection for green roofs and their impact on carbon sequestration and the building carbon footprint

One of the most critical determinants of a green roof's performance is the type of vegetation planted on its surface. This study examines the factors influencing the choice of plant for green roofing, such as sunlight requirements, water requirements, and cold tolerance, in order to identify the preferred green roof plants for use in cold and dry climates such as Mashhad, Iran, and to provide a roadmap to assist decision making in this regard. For this purpose, initially, fifty different plant species were evaluated from four perspectives: (i) applicability in extensive green roofs, (ii) photosynthesis rate, (iii) availability, (iv) low cost. Then, green roofs with selected vegetation were used in a field test, and the amount of carbon uptake of each of them was measured over one year. Finally, by modeling these green roofs in Design Builder software, the reduction of building energy consumption was evaluated to comprehensively investigate the overall impact of green roofing on the carbon footprint of the building. This study found that the best plants for the climate experienced in the field test are Sedum acre, Frankenia thymifolia, and Vinca major, which enjoy good tolerance and performance characteristics and offer the best energy demand and carbon emission. Green roofs with these three plants could reduce a typical building's annual energy consumption by 8.5%, 8.0%, and 7.1%, respectively. After implementing a green roof with Sedum acre, Frankenia thymifolia, and Vinca major atop a 4-story building and measuring these plants' dry weight monthly over one year, the annual CO2 absorption of these plants through photosynthesis was estimated to be 0.14, 2.07, and 0.61 kg/m2. In addition to absorbing carbon through photosynthesis, the green roofs with these plants also reduced the building's CO2 emissions by 28.16, 26.48, and 23.44 kg/m2 respectively, by reducing the energy demand.

Susceptibility of Garden Plants to Phytophthora Root Rot.

Phytophthora root rot (PRR) is a serious disease of horticultural, forest, and ornamental plant species caused by species of the oomycete genus Phytophthora. Their wide host range makes the choice of resistant plants in the management of the disease difficult. We used the Royal Horticultural Society diagnostic dataset of PRR records from U.K. gardens to compare the susceptibility of different host genera to the disease. The dataset was compared with existing reports of plants recorded as notably resistant or notably susceptible to PRR. An index-based approach was used to separate 177 genera of woody plants into three categories: 85 were low index (<0.10: rarely affected), 34 were medium index (0.10 to 0.20: sometimes affected) and 58 were high index (>0.20: frequently affected). Similarly, genera of nonwoody plants were separated into: 45 low index (<0.22), 16 medium index (0.22 to 0.44), and 18 high index (>0.44). Taxus was the genus with the highest index, while most genera in the Malvales and Ericales were in the high-index group. Most genera in the Myrtales, Fabales, and Monocotyledons were low index. While 30 Phytophthora species were recorded in our study, the wide host range spp., P. plurivora, P. cryptogea, and P. cinnamomi, represented 63% of identifications. P. plurivora was the most common species on woody plants and P. cryptogea on nonwoody plants. These results provide confidence in the use of host resistance as part of the integrated management of PRR.

Impact of climate change and crop management on cotton phenology based on statistical analysis in the main-cotton-planting areas of China

Phenology is one of the prominent indicators for studying the impact of climate change on crop production. Based on cotton phenology and meteorological data from 79 agricultural weather stations in China between 1981 and 2017, the Pearson correlation, multi-variate linear regression and path analysis are applied to investigate the spatial and temporal changes of cotton phenological indices and climate variables (precipitation (Pre), sunshine duration (Sun), average (Tave), minimum (Tmin) and maximum temperatures (Tmax), influence degrees of Pre, Sun, and Tave on phenology, and isolated effects of climate change and crop management on cotton phenology. The results showed that: (1) Emergence (Eme), squaring (Squ), flowering (Flo), and boll opening (Bol) dates of cotton advanced by 0.026–0.351 days year−1, respectively. The cotton sowing (Sow) and maturity (Mat) dates were delayed by 0.170 and 0.337 days year−1. The average phenological stages from Sow-Eme, Squ-Flo, and Flo-Bol were shortened about 0.19–0.30 days year−1, Eme-Squ, Bol-Mat and the Sow-Mat were delayed by 0.11, 0.77, and 0.082 days year−1, respectively. (2) Pre had a positive effect on most of the lengths phenological stages of cotton except during Bol-Mat. The effect of Sun on the length of the various phenological stages of cotton was the opposite of that of Pre. Tave, Tmin, and Tmax on the general negative effects on the length of the cotton phenological stages. (3) Pre, Sun, and Tave had different influence degrees on the cotton phenological stages because of different regional climate characteristics. (4) The impact of climate change on cotton phenology was weaker than crop management or combined effects of climate change and crop management. Under the combined impacts, and isolated impact of crop management, the lengths of the stages from Sow-Eme and Squ-Flo were shortened while other phenological stages were extended. The isolated impact of climate change shortened the lengths of stages from Sow-Eme, Eme-Squ, and Flo-Bol, extended Squ-Flo, Bol-Mat, and Sow-Mat, implying that the longer-duration cotton varieties in a changing climate might be a better choice for planting. This could be a viable strategy for adapting to climate change. In addition, the study found that Seed cotton yield (Scy) decreased with the delay of Sow, Eme, Squ, Flo and Bol dates, increased with the increase of the lengths of Sow-Eme, Flo-Bol, Bol-Mat and Sow-Mat. And the change trend of Scy affected by climate change was less than that affected by crop management or combined effects.

In the tripartite combination\xa0Botrytis cinerea\u2013Arabidopsis\u2013Eurydema oleracea, the fungal pathogen alters the plant\u2013insect interaction via jasmonic acid signalling activation and inducible plant-emitted volatiles

In ecosystems, plants are continuously challenged by combined stress conditions more than by a single biotic or abiotic factor. Consequently, in recent years studies on plant relationships with multiple stresses have aroused increasing interest. Here, the impact of inoculation with fungal pathogens with different lifestyles on Arabidopsis plants response to the following infestation with the invasive crop pest Eurydema oleracea was investigated. In particular, as fungal pathogens the necrotroph Botrytis cinerea and the biotroph Golovinomyces orontii were used. Plants exposed to B. cinerea, but not to G. orontii, showed reduced herbivore feeding damage. This difference was associated to different hormonal pathways triggered by the pathogens: G. orontii only induced the salicylate-mediated pathway, while B. cinerea stimulated also the jasmonate-dependent signalling, which persisted for a long time providing a long-term defence to further herbivore attack. In particular, the lower susceptibility of B. cinerea-infected Arabidopsis plants to E. oleracea was related to the stimulation of the JA-induced pathway on the production of plant volatile compounds, since treatment with VOCs emitted by B. cinerea inoculated plants inhibited both insect plant choice and feeding damage. These results indicate that necrotrophic plant pathogenic fungi modulate host volatile emission, thus affecting plant response to subsequent insect, thereby increasing the knowledge on tripartite plant–microbe–insect interactions in nature.

Pressing issues: Setting a sustainability agenda through media coverage of green science museums

When museums commission green buildings, those buildings are often covered in the press. To understand the educational potential of green building press coverage, we qualitatively analyzed 96 articles about eight U.S. green science museums. We found that journalists who cover green buildings highlight green roofs, material choices, site/landscaping, and plant choices most often. Additionally, analyses showed that green building coverage catalyzed discussion of broader sustainability issues such as ecosystems, climate change, and water issues. Press coverage of sustainable architecture sets an agenda of sustainability and contributes to the larger aim of public science education.

Limited influence of gain and loss of symbionts on host plant selection in specialized pea aphid genotypes

Recent advances in insect-microbe interactions show that microbial associates can modulate the behaviors of their hosts, such as defensive or food choice behaviors. For phytophagous insects, host plant choice is of utmost importance, because most of them are specialized on a few plant species, which represent not only their food source but often their habitat and reproduction site. Therefore, identifying how microbial symbionts could influence host plant selection provides valuable information on their potential role in the evolution of the diet breath of phytophagous insects. In this study, we investigated whether bacterial symbiont loss or acquisition modulate host plant selection in the pea aphid Acyrthosiphon pisum Harris (Hemiptera: Aphididae). Several aphid lineages were considered, originating from three plant-specialized populations, each adapted to a different plant species. The symbiotic status of aphid lineages was experimentally manipulated to mimic natural events of symbiont loss and acquisition through horizontal transfer. Host plant selection was then tested by releasing aphids in a cage containing three plant species (1 host and 2 non-hosts) and determining the proportion of aphids on each plant. Our results show minor effects of the symbiotic status on aphid host plant choice, indicating that this trait is determined primarily by the aphid genome.

MORPHOPHYSIOLOGICAL CHARACTERISTICS OF ARABIC COFFEE

The understanding of the behavior of each cultivar under adverse climatic conditions is important in the choice of plants that best fit the region to be inserted. Due to the large number of cultivars available on the market it makes it difficult for producers to choose which material to plant. In view of the above, this study aimed to know the morphophysiological characteristics of coffee. The experimental design was in randomized blocks with 10 treatments, that is, arabic coffee varieties: Catuai IAC62; Catuai IAC99; Ouro IAC4397; Tupi RN IAC1669-13; Obatã IAC1669-20; Mundo Novo IAC379-24; Mundo Novo IAC 388-17-2; Mundo Novo SH3 Faz São José; Bourbon IACJ15 and Icatu IAC 2944-11 and with four replications totaling 40 plots, where each plot was composed of seven plants. The Mundo Novo IAC 388-17-2 coffee variety shows higher yield in the seventh year of cultivation. Variety of Bourbon IACJ15 coffee presented water use efficiency (EUW) which did not reflect in higher productivity. The Catuai V IAC99 arabica coffee variety stood out in the internal morphology of the leaves. The thickness of the adaxial and abaxial epidermis (TADE and TABE) and the CO2 assimilation rate (A) showed negative correlations with the productivity of processed coffee bags. Keywords: Coffea arabica; plant morphology; plant physiology; varieties.

Impact of Foliar Spray by Zinc Oxide Nanoparticles on Peanut Pro-duction Under New Valley Conditions

Increasing seed and oil yields production of oil crops in reclaimed soils is an important goal of vision Egypt 2030. Therefore, a field experiment was conducted in newly reclaimed sandy soil in Farafra, New valley Governorate, Egypt during the two summer seasons of 2017 and 2018 to examine the impact of Zn nano-fertilizer foliar spray on peanut production. The field experiment was laid out in a randomized complete block design (RCBD) using a strip plot arrangement with three replications. Zinc oxide nanoparticles concentrations (0 as control, 200, 400 and 600 ppm) were allotted horizontally while, the cultivars NC9, Gregory and Ismailia were a signed vertically. Highly significant differences were observed among zinc oxide nanoparticles (ZnO NPs) concentrations for most studied traits in both seasons. Furthermore, peanut cultivars had a significant effect on most studied traits in both seasons. All peanut cultivars showed remarkable positive responses to the spray of zinc nanoparticles. In most cases, an enhancement was observed in most studied traits by increasing the concentration from 200 ppm to 600 ppm. Also, NC9 cultivar gave the highest seed yield (kg/fed) in both seasons, while there were non-significant differences among peanut cultivars for oil yield (kg/fed) but as an average over both seasons, NC9 gave the highest oil yield (kg/fed). Therefore, the findings of this study suggest that NC9 cultivar with spraying by zinc nanoparticles might be a good choice for planting and production under newly reclaimed soils in the Farafra region with other ‎important recommended agronomical practices for such region.‎

ROLE OF BAMBOO FOR REVEGETATION OF POST COAL MINING IN SOUTH SUMATERA, INDONESIA

Coal mining activities have affected the soil and vegetation conditions on the mined land. Revegetation of ex-mining land is a must to balance environmental functions. The choice of plants must be adapted to the conditions of the ex-mining land so that growth continues. The use of local plants for revegetation is fascinating to study. This study aimed to investigate the soil characteristics of ex-coal mining land and bamboo growth as a plant used for revegetation. Bamboo is collected from around the former coal mining area. Bamboo growth is observed through its branching for 12 weeks of measurement. Soil is analyzed based on its physical and chemical properties. The Schmidt-Ferguson method was used to analyze the climate type in the study area. The results of the soil analysis show that the plants can still grow for revegetation. Of the three types of bamboo observed (Schizostachyum brachycladum kurz, Dendrocalamus asper, and Gigantochloa robusta), Schizostachyum brachycladum kurz is the best growing bamboo in ex-coal mining land with a branch length of 42 cm in 12 weeks of measurement. The climate in the ex-coal mining area studied is a wet type (Q = 0.184). Bamboo is a suitable plant for revegetation, especially in coal mining areas in South Sumatra, Indonesia.

Handed Flowers Pick High Quality Mates from Pollinators

Darwin devoted an entire book to stigma and anther polymorphisms, which exemplified the importance of pollen movement efficiency as a selective agent on floral form. However, five years after its publication, his interest was piqued by a description of floral handedness or enantiostyly. Todd described how left handed Solanum rostratum flowers have stigmas deflected to the left and anthers deflected to the right, while the opposite is true for right-handed flowers. In his final scientific correspondence, Darwin wrote to Todd for seeds so that he could … have the pleasure of seeing the flowers and experimenting on them. Darwin died days later on 19 April 1882. More than a century would elapse before the first experiments demonstrated that handedness leads to high rates of outcrossing [5, 6]. By attaching quantum dots to pollen grains, we tracked pollen movement, revealing the mechanisms behind high outcrossing rates in a plant with partial handedness (a majority of anthers deflected to one side). Handedness leads to outcrossing, because left- and right-handed morphs place most of their pollen on different sides of the pollinators. However, we also found that partial handedness results in pollen quality mosaics on each side of pollinators, comprising hotspots and coldspots of outcrossed pollen. Outcrossed pollen receipt was much higher than expected because stigmatic positions are fine-tuned to match the outcross pollen hotspots. Exploitation of these pollen quality mosaics suggests that like animals, female choice in plants can occur before or during the act of mating.

Индукция соматического эмбриогенеза у ели сибирской (Picea obovata) в культуре in vitro

The biotechnology of somatic embryogenesis in in vitro culture is the most promising direction in the reproduction of conifers. The use of this technology makes it possible not only to massively propagate the best genotypes of trees, but also serves a model for studying the structural, physiological and molecular and genetic mechanisms of both somatic and zygotic embryogenesis in conifers. The main aim of this research was to obtain embryogenic cultures (ECs) producing somatic embryos and embryonic suspension mass (ESM) of Picea obovata. The studies were carried out in 2014-2019 on 30 Siberian spruce trees growing in the vicinity of the city of Krasnoyarsk. To detect genotypes competent for somatic embryogenesis, new donor trees were selected every year for the experiment. 3-10 cones were collected from each tree at different stages of embryo development: globular embryo (the first decade of July), the initiation stage cotyledons (second decade of July), the stage of developed cotyledons (third decade of July) and mature embryos (August). Sterilized explants (zygotic embryos at different stages of development) were introduced into in vitro culture on basic media DCR (Gupta PK and Durzan DJ, 1985), ½LV (Litvay JD et al., 1985), MS (Murashige T and Skoog F, 1962) and AI (Tretyakova IN, 2012). All media were supplemented with myo-inositol - 100 mg/L, casein hydrolyzate - 500-1000 mg/L, L-glutamine - 500 mg/L, sucrose - 30 g/L and agar - 7 g/L. Ascorbic acid at a concentration of 400 mg/L was used as an antioxidant. The level of growth regulators was: 2,4-dichlorophenoxyacetic acid (2,4-D) - 2 mg/L and N6 -benzoaminopurine (BAP) - 1 mg/L. For the proliferation of the ESM, DCR and AI basic media containing 2,4-D (2 mg/L), BAP (0.5 mg/L) and sucrose (20 g/L) were used. The pH was adjusted to pH = 5.8. All culture medium and components were sterilized depending on their termolabile properties. Under aseptic conditions, embryos were removed from megagametophytes and inoculated into nutrient media, 10 explants per flask in 25 replicates. The cultures were incubated in the dark at 24 ± 1 °C. Subcultivation to fresh nutrient medium was carried out every 14 days. To control the quality of cell lines (CL) during subculturing, we performed cytological analyzes using temporary preparations (3-5 preparations for each CL). We evaluated the quality of the embryogenicity of the cultures by the presence of even single structures with pronounced polarity - a globular embryo with a suspensor. The results of the study showed that the induction of callus cultures of Siberian spruce is influenced by such factors as the development stage of the explant, the nutrient medium and the genotype of the donor tree. The introduction of P. obovata immature zygotic embryos into in vitro culture at the stage of the globular embryo, both with megagametophytes and extracted from them, turned out to be ineffective. The induction of callus cultures in Siberian spruce was significantly reduced when mature zygotic embryos were introduced into the culture in vitro. The highest response of explants of Siberian spruce was at the stage of developed cotyledons (See Table 1). In the DCR medium, 90% of explants formed callus (See Table 2). The mineral composition of the media did not significantly affect the induction of callus formation in Siberian spruce. The exception was the MS medium, in which callus cultures were formed only in 41% of explants (See Table 2). The growth of callus cultures was most active in the DCR medium. After 6 months of cultivation, 15-32% of calli remained viable (See Table 2). Cytological analysis of callus cultures showed that they include cells of different types (See Fig. 1 and 2). The first type of cells consisted of elongated cells reaching a length of 10 ± 3 μm, others consisted of isodiametric cells with a diameter of 60 ± 3.5 μm. The somatic embryo globule and embryonic tubes were formed from elongated cells. Isodiametric cells were actively dividing and forming callus. Only 3 cell lines (out of 300 cell lines) belonging to two donor trees had an active ability to proliferate. Globular somatic embryos were actively forming in these cell lines (See Fig. 3). An actively proliferating ESM was formed. Thus, we carried out a comprehensive assessment of the factors influencing the induction of somatic embryogenesis in Siberian spruce. The results obtained indicate that for the successful formation of somatic embryos, the determining factor is not only the choice of donor plants, but also the development stage of the explant. We found that the best stage in the development of zygotic embryos when introduced into in vitro culture of Siberian spruce is the stage of immature embryos with formed cotyledons, while the DCR, ½LV and AI nutrient medium supplemented with growth regulators (2.4-D and BAP) is optimal.

Lead toxicity in plants and phytoremediation potential of aromatic plants for lead contaminated soils

Lead contamination and subsequent degradation of the affected soil is a global environmental issue. Besides the natural weathering processes, the chief ways in which of lead contaminates the environment are anthropogenic. The plants which grow on such lead contaminated soils can uptake the heavy metal and translocate it to the various parts both in the intracellular and extracellular fashion. Lead toxicity can affect the overall plant health as it impacts basic physiological and metabolic processes such as germination, uptake of nutrients and minerals, photosynthesis, respiration, oxidative metabolism, mitosis etc. Plants in response to this toxicity can develop a certain degree of tolerance via passive and inducible mechanisms. These mechanisms have been exploited in the new era technology of phytoremediation which aims at a sustainable cleansing of lead contaminated soils by using plants. Aromatic plants because of their low risk of contamination in products consumption and a high demand over supply aspects are a suitable choice of plants that can be used for phytoremediation. This review addresses the aspects of lead contamination and its sources, the uptake of lead by plants, lead toxicity in plants, and the consequent tolerance developed as well as the potential and advantages of using aromatic plants for phytoremediation of soils which are contaminated with lead.

Adult Desert Locust Swarms, Schistocerca gregaria, Preferentially Roost in the Tallest Plants at Any Given Site in the Sahara Desert

The desert locust, Schistocerca gregaria, is a major migratory pest that causes substantial agricultural damage. Flying adult swarms disperse widely during the daytime, but they densely roost on plants at night. Swarm control operations are generally conducted during the daytime, but night-time control is a significant potential alternative. However, the night-roosting behavior of swarms is poorly understood. We determined night-roosting plant preferences of migrating sexually immature swarms of S. gregaria at four different sites in the Sahara Desert in Mauritania during winter. The night-roosting sites were divided into two types based on presence or absence of large trees. Swarms tended to roost on the largest trees and bushes at a given site. Swarms used medium-sized plants when large trees were not locally available, but the same medium-sized plant species were hardly used when large trees were available. Plant choice influenced roosting group size—large locust groups roosted on larger plants. Night-roosting locusts rarely fled from approaching observers. These results suggest that swarms of S. gregaria exhibit plasticity in their utilization patterns of night-roosting plants depending on the plant community encountered and they selectively use larger plants. We propose that this predictable plant-size dependent night-roosting can be used to particularly ease locust swarm control and to generally adopt anti-locust night control strategy.

Kõik värviks: Eestis kasvanud taimedest saadud värvid tekstiilil / All for colours: dyes from plants growing in Estonia on textile

The research carried out during practical work at the Department of Textile Design of the Estonian Academy of Arts focuses on the acquisition of plant and alternative synthetic textile dyes in Estonian weather conditions in the context of textile printing and dyeing. The aim is to study the effect of plant dyes on textiles, by modifying different variables. As the result of testing, the author wanted to select more intensive plants and techniques, which withstand at least a first warm washing, and which could be studied further via a more systematic experimenting and testing.&#x0D; In order to get multiple results at once, the majority of tests in fact comprise 12 tests, the results of which are presented on one page, including 12 samples of dye and the initial information about plants and procedures. A collection of dye samples comprises 132 test sheets, and presents the practical results of the research. All practical tests are documented with written descriptions compiled as an annex to the test sheets; some tests are also photographed.&#x0D; It was observed how the dyeing results depend upon different conditions, e.g. the time of collecting plants, the dyeing process, the dyed textile fibres or the acidity of the solution. In order to fix the dye in textile different methods were applied, and the impact of temperature, time, different tanning substances, water and oxygen on the tone of the dye and its intensity was studied. Most samples of dyes have been washed in water at least 50 °C warm and ironed at a minimum of 200 °C after the dyeing process.&#x0D; The author searched for possible sources of natural dyes in Estonia, taking into account the local tradition of natural dyes, and also exploring the options of introducing species not so well known as dyeing plants. The author cultivated plants for testing and collected species widespread in nature. The author discusses environmental problems connected with collecting and growing the plants, such as moving in nature and the hazard of the expansion of invasive non-native species on the local richness of species.&#x0D; The choice of plants for this research paper is based on several different principles, which typically occur when searching for a possible source of dye. Based on the courses of thought, the author divides the plants used into eight theme groups with conditional names is as follows: ‘Primeval’, ‘Exotic’, ‘Weeds’, ‘Name shows the destiny’, ‘Compost’, ‘Minor relatives’, ‘Plants with beautiful colour’ and ‘Two-in-one’. &#x0D; Common bright colours, which tolerated washing in warm water but needed technological improvement for increased light-resistance could be mentioned, e.g. the Dyer’s woad giving the blue dye, the Northern bedstraw giving red tones, Safflower that gives pink and yellow tones. Many plants gave warm brown tones. Among technologies, the most promising proved to be Joy Boutrup’s technique for reserve printing, during which the sodium alginate printed on the cloth is transferred into unsolvable form.&#x0D; Biological tanning substances, renewable energy like solar power, and the use of a high temperature by extending the low dyeing time and bacterial fermentation dyeing might be some further steps in the development of sustainable dyeing processes. Finding low-cost production dyeing plants among weeds, the restricted use of non-native species, and of plant residue of food industry and other sectors would be a valuable and sustainable source of dye.&#x0D; Key words: dyeing with plants, natural dyes, dye plants, textile printing, printing techniques, tannins