Physiological and sanitary quality of ryegrass seeds submitted to different defoliation frequencies

ABSTRACT: This study determined the effect of different defoliation frequencies in a long-cycle ryegrass cultivar on yield components and the physiological and sanitary quality of seeds. Four defoliation frequencies were applied (without, one, two, and three defoliations). The time between defoliations was 350 degree-days. At the first, second, and third defoliation time, the plants were 15 cm, 20 cm, and 35 cm, respectively, and were lowered to half their height. The yield components and plant structure were evaluated through the tillers, along with the physiological quality of the seeds, which was verified by germination tests, first germination count, accelerated aging, tetrazolium test, field emergence, and weight of a thousand seeds. For the sanitary quality analysis, the percentage (%) of fungi incidence in the seeds was verified. The second defoliation determined the seeds’ high physiological and sanitary quality due to the higher amount of primary and secondary tillers produced concerning the other treatments. However, there was no significant difference for the third defoliation since the aerial tillers issued the same quality of seeds originated from primary and secondary tillers. The average incidence of fungi such as Colletotrichum sp., Fusarium sp., Phoma sp., and Dreshslera spp. was lower in ryegrass plants subjected to three defoliations.

INVASÃO POR GRAMÍNEAS EXÓTICAS EM CAMPOS SOBRE PALEODUNAS: EFEITOS NA DIVERSIDADE FLORÍSTICA

O Refúgio de Vida Silvestre Banhado dos Pachecos localiza-se sobre a Coxilha das Lombas, Viamão/RS, e encontra-se em processo de invasão biológica por gramíneas exóticas na área de campo seco. Este fragmento de vegetação campestre sobre paleodunas é habitat da espécie endêmica Ctenomys lami (Rodentia, Ctenomydae) e apresenta composição florística peculiar em relação a maioria das áreas naturais dos Campos Sulinos, com espécies de Asteraceae sendo dominantes em comparação às espécies de Poaceae. Com o objetivo de caracterizar a composição florística e avaliar o grau e efeitos da invasão biológica sobre a comunidade de campo seco foi realizado um levantamento quantitativo. Foram amostradas 31 parcelas de 1 x 1 m e levantados dados de cobertura e altura da vegetação, solo descoberto e serrapilheira. Foram calculados parâmetros fitossociológicos para cada espécie. As parcelas foram classificadas quanto ao nível de invasão por gramíneas exóticas. O efeito da invasão sobre a composição e estrutura da vegetação foi avaliado a partir de Análise de Coordenadas Principais, regressão linear e análise de variância. As gramíneas exóticas invasoras Urochloa decumbens e Digitaria eriantha subsp. pentzii foram dominantes em grande parte da vegetação campestre, modificando a estrutura e composição vegetal conforme o nível de invasão. Cerca de um terço da área encontra-se altamente invadida. Ações de remoção e controle de invasoras se fazem urgentes, considerando que este é um dos poucos fragmentos de ecossistemas naturais abertos na Coxilha das Lombas e abriga espécies ameaçadas de extinção. INVASION BY EXOTIC GRASSES IN GRASSLAND ON PALAEODUNES: EFFECTS ON FLORISTIC DIVERSITY. The Banhado dos Pachecos Wildlife Refuge, located in the Coxilha das Lombas, in Viamão/RS, Brazil, is under a process of invasion by alien grasses in its areas of dry grassland. The grassland on palaeo-dunes is the habitat of the endemic species Ctenomys lami (Rodentia, Ctenomydae) and presents a peculiar floristic composition in relation to most natural grasslands in southern Brazil, with species of the Asteraceae dominating in comparison to grasses. In order to characterize the floristic composition and to evaluate the degree and effects of biological invasion on the grassland community, a quantitative vegetation survey was carried out. In 31 plots of 1 x 1 m, data on cover and height of vegetation, bare soil and litter were collected. Phytosociological parameters were calculated for each species. The plots were classified according to the level of invasion by exotic grasses and Principal Coordinate Analysis, linear regression and Analysis of Variance were performed to observe the species distribution in the community and the effects of the invasion on the richness and structure of the vegetation. The invasive exotic grasses Urochloa decumbens and Digitaria eriantha subsp.pentzii were dominant in grassland vegetation, modifying plant structure and composition according to the level of invasion. About a third of the area is heavily invaded. Invasive removal and control actions are urgent as this is one of the few fragments of natural grasslands in the Coxilha das Lombas and is habitat to species threatened with extinction.

USING OF BIOMASS AND WASTES OF BEANS (PHASEOLUS VULGARIS) AND PEAS (PISUM SATIVUM) PRO-CESSING AS SORPTION MATERIAL FROM POLLUTANTS REMOVING FROM WATER ENVIRONMENTS (LIT-ERATURE REVIEW)

Was reported literature findings of domestic and foreign articles about using of biomass components (leaves, straw, pods, seeds) and wastes of beans (Phaseolus vulgaris) and peas (Pisum sativum) pods shells processing as sorption material for pollutants (metals ions, colorants) removing from water environments. Concise literature findings about Pisum sativum and Phaseolus vulgaris plant structure, cultivation value, and chemical composition of some biomass components are described. Was revealed that composition of beans and peas pods has big amount of proteins, that can provide removing of metals ions such as (Cd(II), Co(II), Cr(III) и Cr(VI), Cu(II), Fe(III), Mo(VI), Ni(II), Pb(II), Sb(III) и Sb(V), Zn(II)) from water environments. Was showed the possibility of sorption characteristics increase for pollutants by Phaseolus vulgaris and Pisum sativum biomass treatment with different chemical reagents. Was revealed that pollutants sorption isotherms of wastes and biomass of considered legumes are described mostly by Langmuir model than by Freundlich model. The kinetic of process mostly match to pseudo-second order model. It is shown that using of seeds and pods shells of legumes is prospectively for removing of heavy metals ions and suspended particles from water. Was proposed to use charcoal, which was gotten by peas pods carbonization for removing of heavy metals ions from water environments. Concluded, that using of legumes pods extracts is more effective for clearing water environments from heavy metals ions.

Design of Forage Hedge Tube Filament for Ferm Growth

Ferms are reproductive plants capable of budding on stems. Owing to the delicate plant structure are not prominent in windy regions. Forages are a type of vertically place hedges. These go around the stem structure. Scanning microscopy was used to reveal the fibron structure. To locate and design regions of the stem for support of the plant. The findings yielded a design of the forage hedges. Hences increase the growth span of the plant. The height of the forage had the most effect. The mesh size had a change on the Ferm growth and stability of the plant.

Estimating Leaf Area Index in Row Crops Using Wheel-Based and Airborne Discrete Return Light Detection and Ranging Data

Leaf area index (LAI) is an important variable for characterizing plant canopy in crop models. It is traditionally defined as the total one-sided leaf area per unit ground area and is estimated by both direct and indirect methods. This paper explores the effectiveness of using light detection and ranging (LiDAR) data to estimate LAI for sorghum and maize with different treatments at multiple times during the growing season from both a wheeled vehicle and Unmanned Aerial Vehicles. Linear and nonlinear regression models are investigated for prediction utilizing statistical and plant structure-based features extracted from the LiDAR point cloud data with ground reference obtained from an in-field plant canopy analyzer (indirect method). Results based on the value of the coefficient of determination (R2) and root mean squared error for predictive models ranged from ∼0.4 in the early season to ∼0.6 for sorghum and ∼0.5 to 0.80 for maize from 40 Days after Sowing to harvest.

Cannabis Cultivator Phenotype and Attribute Preferences in Legal Recreational and Medical Cannabis Cultivation Operations in Oregon and Colorado

BackgroundAs recreational and medicinal Cannabis sativa production increases across the United States, concerns have arisen regarding declines in cannabis biodiversity. Studies have suggested genetic bottlenecking has occurred primarily because of breeder and cultivator preferences and practices which over-emphasize the selection of strains with high contents of the psychoactive cannabinoid, Δ-9-tetrahydrocannabinol (THC). No study to-date, however, has sought to systematically assess grower and breeder knowledge, preferences, and practices within legal operations within the United States. MethodsTwenty-one licensed recreational and medical cannabis growers in the states of Colorado and Oregon were provided with free lists to ascertain cultural domains of knowledge regarding cannabis phenotypes and attributes within commercial cannabis production operations. Semi-structured interviews were also conducted with participants to provide more nuanced explanations of free-list responses, and to clarify responses where necessary. Free-list results were initially ungrouped excepting those variables whose meanings had been triangulated utilizing interview data. Free list data was assessed utilizing Smith’s S formula to ascertain cultural salience for listed attributes and phenotypes. A second analysis was then conducted for grouped terpene-related data. Results Results from the ungrouped free list identified Yield as the most culturally salient category (.29) followed by High THC Content (.26) and Smell (.25). Overall, horticultural characteristics such as yield, plant structure, and morphology garnered were the most frequently listed, followed by chemometrics, economics, and phenology, with some overlap between these categorizations. Though THC content was described as important within commercial operations by most growers both within free-list responses and interviews, growers also expressed that this preference was due to state testing regulations and a misinformed consumer base, rather than grower partialities. Respondents also noted that they believed consumer preferences were changing as consumer demographics were beginning to trend towards “older” consumers. When terpene-related attributes within free-listed results were combined utilizing triangulation from semi-structured interviews to verify the free list data, terpenes became the most cultural-salient attribute listed by growers (.42). Conclusions The results from this study suggest that cannabis biodiversity may indeed be declining due to breeder practices that emphasize THC content, but that these practices are informed by state policies and consumer purchasing metrics rather than grower preferences.

Cold Stress during Flowering Alters Plant Structure, Yield and Seed Quality of Different Soybean Genotypes

The objective of the study was to evaluate the effect of cold stress at flowering stage on plant structure, yield and chemical composition of seeds of 15 soybean cultivars. The study was conducted in 2019–2020, using the complete randomization method, in three replications. Fifteen soybean cultivars belonging to three maturity groups: early (EC), middle-early (MC) and late (LC) cultivars were included. Weekly cold stress (17/13 °C day/night) was applied at plant flowering stage. In the control treatment, plants were kept under natural conditions (24/17 °C day/night). Our research showed that cold stress negatively influenced the elements of plant structure: height, number of nodes, stem dry mass, number and weight of pods, number and weight of seeds per plant, as well as yield of soybean seeds, reducing it on average by 24%, as compared to the control treatment. The highest yield decrease was found in LC cultivars (31.2%), while a smaller and similar one in EC and MC cultivars (by 19.7 and 20.1%, respectively). Significant varietal differences were found for plant biometric traits and seed yield. EC cultivars had the lowest set first pod, as well as the lowest number of nodes, number of pods and seeds, pod and seed weight per plant, and seed yield. MC cultivars had the highest set first pod, and the smallest stem DM and seed yield average by 29.2% higher compared to EC cultivars. LC cultivars had the highest stem DM, number of pods and seeds, and pod and seed weight per plant compared to the other cultivar groups, and yield by 22.8% higher compared to EC cultivars. The experimental factors significantly affected crude protein, crude fat, and crude ash content, while they did not differentiate water-soluble carbohydrate and crude fiber content. Cold stress at the flowering stage caused a significant increase in protein content (by 4.1% on average) and ash content (by 3.8%) and a decrease in fat concentration (by 6.9%) in soybean seeds. Differences in nutrient content among cultivars were a genetic trait not related to cultivar maturity.

Genotype-Dependent Variation of Nutritional Quality-Related Traits in Quinoa Seeds

Exploiting the relationship between the nutritional properties of seeds and the genetic background constitutes an essential analysis, which contributes to broadening our knowledge regarding the control of the nutritional quality of seeds or any other edible plant structure. This is an important aspect when aiming at improving the nutritional characteristics of crops, including those of Chenopodium quinoa Willd. (quinoa), which has the potential to contribute to food security worldwide. Previous works have already described changes in the nutritional properties of quinoa seeds due to the influence of the environment, the genotype, or their interaction. However, there is an important limitation in the analyses carried out, including the outcomes that can be translated into agronomical practices and their effect on seed quality. In the present study, several seed nutritional-related parameters were analyzed in 15 quinoa cultivars grown in a particular environmental context. Important agronomical and nutritional differences were found among cultivars, such as variations in mineral or protein contents and seed viability. More importantly, our analyses revealed key correlations between seed quality-related traits in some cultivars, including those that relate yield and antioxidants or yield and the germination rate. These results highlight the importance of considering the genotypic variation in quinoa when selecting improved quinoa varieties with the best nutritional characteristics for new cultivation environments.