Plant Density Research Articles

Evolution from mixed to fixed handedness in mirror-image flowers: insights from adaptive dynamics.

Mirror-image flowers (enantiostyly) involve a form of sexual asymmetry in which a flower's style is deflected either to the left or right side, with a pollinating anther orientated in the opposite direction. This curious floral polymorphism, which was known but not studied by Charles Darwin, occurs in at least 11 unrelated angiosperm families and represents a striking example of adaptive convergence in form and function associated with cross-pollination by insects. In several lineages, dimorphic enantiostyly (one stylar orientation per plant, both forms occurring within populations) has evolved from monomorphic enantiostyly, in which all plants can produce both style orientations. We use a modelling approach to investigate the emergence of dimorphic enantiostyly from monomorphic enantiostyly under gradual evolution. We show using adaptive dynamics that depending on the balance between inbreeding depression following geitonogamy, pollination efficiency and plant density, dimorphism can evolve from an ancestral monomorphic population. In general, the newly emergent dimorphic population is stable against invasion of a monomorphic mutant. However, our model predicts that under certain ecological conditions, e.g., a decline of pollinators, dimorphic enantiostyly may revert to a monomorphic state. We demonstrate using population genetics simulations that the observed evolutionary transitions are possible assuming a plausible genetic architecture.

Methodology for selecting potential CO2 sinks in Macaronesia: The case of Gran Canaria

Carbon dioxide (CO2) accounts for 80% of the greenhouse gas emissions in the atmosphere. One of the several ways to mitigate CO2 emissions is through afforestation, which prevents catastrophic environmental consequences. The mean average emission per tourist in the Canary Islands on their way to the islands is 0.48 Tn. Like most urban cities, the island of Gran Canaria faces the problem of CO2 emissions due to anthropogenic and human activities. Vegetation coverage significantly influences the distribution of temperature. The correlation between Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) of Gran Canaria, using satellite images from Landsat 8 and Sentinel-2, revealed a strong inverse relationship within all land use types, with an R2 value of 0.39. Land suitability analysis is a prerequisite for optimum utilization of available land resources. This study developed a suitability map for afforestation based on land use land cover, topographic, meteorologic, and socio-economic factors. Eight factors, including distance from settlements, land use, distance from the road, distance from water, elevation, slope, precipitation, and temperature, were employed according to previous studies, expert consultation, and land suitability mapping experience. After the criteria decision and data acquisition, maps of each criterion were created and transformed using the Suitability Modeler of ArcGIS Pro. The current study results show that 87% of the total area is suitable for afforestation and reforestation projects in Gran Canaria. Instead of using reactive methods to lessen the effects, the study recommends a proactive approach to climate adaptation through nature-based solutions. The study is part of an umbrella project of the Canary Islands and Spain in general, which considers the contributions of local and institutional stakeholders at different stages of the project. The next stage will be to design a forest afforestation and reforestation project, considering the kind of tree species needed, the methods required to implement it, and the management guidelines about the initial years of installation and growth of the new trees. The most crucial technical choice is which forest species to choose, as it will determine the success of the reforestation effort. The new revegetated space's ability to sequester carbon dioxide will primarily rely on the productivity of the land used for forest reforestation, the species chosen, and the introduced planting density.

Meta-analysis revealed the factors affecting the functions of ecological floating bed in removing nitrogen and phosphorus from eutrophic water.

Ecological floating bed (EFB) has been widely used to remove nitrogen and phosphorus from eutrophic water. However, its effects on nitrogen and phosphorus removal are different in various studies. Presently it has not been systematically clear what factors produce effects on EFB removing nitrogen and phosphorus from eutrophic water. In this study, we performed a meta-analysis of 169 articles to discuss the effects of EFB characteristics and experimental conditions on EFB removing nitrogen and phosphorus. Results showed that EFB generally decreased nitrogen and phosphorus concentrations in eutrophic water regardless of EFB characteristics and experimental conditions. EFB showed better effects on simultaneously removing TN, NH4+-N, and TP when it had one of the characteristics: constructed by monocots, 2-3 plant species, an area of 1.1-3.0 m2, and the coverage of 21%-40%. However, NO3--N removal by EFB was complicated due to the effects of nitrification and denitrification. Moreover, EFB plant density also showed different effects on nitrogen and phosphorus removal. Experimental conditions produced evident effects on EFB removing nitrogen and phosphorus, and it showed better effects under one of the conditions: water temperature of 16-25℃, experimental duration of 31-60days, long hydraulic retention time, and aeration. This study indicates that EFB can significantly remove nitrogen and phosphorus from eutrophic water, and itis an effective technology to control water eutrophication, but the effects ofEFB characteristics and environmental conditions on EFB functionshould be considered in application.

Greenhouse gas emissions and mitigation potential of crop production in Northeast China

Agricultural management practices that reduce greenhouse gas (GHG) emissions have been identified as effective mitigation strategies. However, research on carbon emissions from major crops in Northeast China focuses on national and provincial data, overlooking city-scale variability and uncertainties, which prevents fine-scale assessment of crop emissions reduction potential. To address this, a life cycle assessment (LCA) combined with the Monte Carlo method was conducted to estimate the carbon footprint of rice, maize, and soybean production for different cities in Northeast China from 1991 to 2020. The results showed that the top one-third of cities with the highest total carbon emissions (TCE) account for approximately 40 % of the region's TCE. Nitrogen losses and production processes related to nitrogen fertilizer application were identified as the primary contributors to TCE from crop production, accounting for 29.6–62.5 % of the total, with a relative importance of 58.5–78.2 %. Scenario analysis indicated that optimizing nitrogen fertilizer management and reducing active nitrogen losses are the most effective strategies for reducing TCE from major crop production, offering a reduction potential of 34.5–60.6 %. Recommended strategies include phased application of nitrogen fertilizer, the addition of nitrification inhibitors, or using slow-release nitrogen fertilizers, combined with appropriate increases in crop planting density, straw return decomposition technologies and water-saving irrigation methods to reduce GHG emissions. These strategies aim to achieve low-carbon sustainable grain production and provide a foundation for exploring the emissions reduction potential of agricultural inputs and optimizing regional crop layouts, offering new insights for developing more effective GHG reduction strategies.

Fine-mapping of a QTL and identification of candidate genes associated with the lateral branch angle of peanuts (Arachis hypogaea L.) on chromosome B05.

Peanuts play a crucial role as an oil crop, serving not only as a primary source of edible oil but also offering ample protein and vitamins for human consumption. The lateral branch angle of peanuts is the angle between the main stem and the first pair of lateral branches, which is an important agronomic trait of peanuts, significantly impacts the peg penetration into the soil, plant growth, and pod yield. It is closely intertwined with planting density, cultivation techniques, and mechanized harvesting methods. Therefore, the lateral branch angle holds substantial importance in enhancing peanut yield and facilitating mechanization. In order to conduct in-depth research on the lateral branch angle of peanuts, this research is grounded in the QTL mapping findings, specifically focusing on the QTL qGH associated with the lateral branch angle of peanuts located on chromosome B05 (142610834-146688220). By using Jihua 5 and PZ42 for backcrossing, a BC1F2 population comprising 8000 individual plants was established. Molecular markers were then developed to screen the offspring plants, recombine individual plants, conduct fine mapping. he results showed that using the phenotype and genotype of 464 recombinant individual plants selected from 8000 offspring, narrow down the localization interval to 48kb, and designate it as qLBA. The gene Arahy.C4FM6Y, responsible for the F-Box protein, was identified within qLBA through screening. Real-time quantitative detection of Arahy.C4FM6Y was carried out using M130 and Jihua 5, revealing that the expression level of Arahy.C4FM6Y at the junction of the main stem and the first lateral branch of peanuts was lower in M130 compared to Jihua 5 during the growth period of the first lateral branch from 1 to 10 centimeters. Consequently, Arahy.C4FM6Y emerges as a gene that restrains the increase in the angle of the first lateral branch in peanuts. This investigation offers novel genetic reservoirs for peanut plant type breeding and furnishes a theoretical foundation for molecular marker-assisted peanut breeding.

Maize-Tripsacum-Teosinte allopolyploid (MTP), a novel dwarf mutant inducer tool in maize.

Dwarf plant architecture facilitates dense planting, and increased planting densities boost the maize yield. However, breeding applications of dwarfing materials for maize are currently limited. There is an urgent need remove the obstacles to applying dwarf resources. Here, we innovated a new method to add a novel maize dwarf germplasm through the distant hybridization of Maize-Tripsacum-Teosinte allopolyploid (MTP) with maize. We identified ten independent dwarf families with unique characteristics. Five germplasms in our library were controlled by their respective dwarf genes. However, no allele was controlled by Br2. Subsequently, d024 in the library was successfully fine mapped, revealing its linkage to indel-4 in ZmCYP90D1. The indel-4 polymorphism regulates the expression of ZmCYP90D1 and is controlled by an upstream transcription factor (ZmBES1/BZR1-5). The indel-4 of ZmCYP90D1 allele, which reduces plant height, originated from Tripsacum, a wild variety of maize. However, d024 exhibits sensitivity to brassinosteroids (BRs), with lower castasterone levels in the internodes than that in the wild type. Furthermore, ZmCYP90D1 interacted with ZmFDXs and ZmNAD(P)H to positively regulate the downstream BR synthesis pathway. Additionally, we showed that introgressing the indel-4 of the Tripsacum allele into modern hybrids ensures yield potential and improves the harvest index under high-density conditions. Overall, as we begin to manufacture highly engineered dwarf materials using the MTP, this approach will solve the problems faced by corn dwarfs.

Effects of Planting Density and Nitrogen Fertilization on Growth Traits and Leaf and Wood Characteristics of Three Poplar Clones

A comprehension of the effects planting density and nitrogen (N) fertilization have on the physiological and morphological characteristics of trees is critical for optimizing the require size and characteristics of wood products. We evaluated the growth traits and the leaf and wood characteristics of three clone poplars including Populus simonii × P. nigra ‘Xiaohei’, ‘Xiaohei-14’ and ‘Bailin-3’ under five planting densities (1666, 1111, 833, 666, and 555 tree ha−1) and four N fertilization rates (0, 100, 160, and 220 g tree−1 year−1). The results show that the clone type significantly affected all observed indicators, while planting density and N fertilization treatments had a significant effect on growth traits and leaf characteristics, but not on wood characteristics. Specifically, the clone ‘Bailin-3’ exhibited the largest annual increments in tree height and diameter at breast height (DBH), leaf width, N content, and soluble protein content. A decrease in initial planting density (from 1666 to 555 tree ha−1) led to an increased annual incremental tree height and DBH, regardless of clone type and N fertilization treatment. N fertilization treatment significantly impacted the annual increment in DBH, but not that of tree height. Further, the annual increments in tree height and DBH were positively correlated with leaf width, N content, chlorophyll content, and soluble protein content, and negatively correlated with hemicellulose content. In addition, the chlorophyll and soluble protein contents were identified as the most reliable predictors of the annual increments in tree height and DBH. Our results demonstrate the clone ‘Bailin-3’ with 555 tree ha−1 under 160 g N tree−1 yr−1 showed superior growth traits and leaf characteristics. Thus, it is recommended for future poplar silviculture of larger diameter timber production at similar sites. The results contribute to understanding of the effects of planting density and fertilization on the growth traits and the leaf and wood characteristics of three poplar clones, offering valuable guidance for the sustainable development and long-term productivity of poplar plantations.

The Influence of Planting Density on the Flowering Pattern and Seed Yield in Peanut (Arachis hypogea L.) Grown in the Northern Region of Japan

In peanut cultivation in the Tokachi region of Hokkaido, Japan, it is essential to complete the harvest by early October to prevent frost damage. Therefore, cultivation methods that can accelerate the flowering period are necessary. It is understood that planting density can influence the timing of flowering, with crops often flowering earlier at higher densities. This study aimed to investigate whether growing peanuts at higher densities could advance the flowering period and, consequently, enhance yield. The Japanese peanut variety, Tachimasari, was cultivated in 2022 and 2023 at a conventional planting density of 5.8 plant m−2 (D5.8) and at density conditions of 8.7 plant m−2 (D8.7) and 11.6 plant m−2 (D11.6). The D8.7 and D11.6 plants reached the peak of flowering 2.8 and 5.1 days earlier, respectively, and the end of flowering 3.7 and 8.0 days earlier than the D5.8 plants. Although the total number of flowers was higher in D5.8, pod fertility was greater in D8.7 and D11.6, where plants were able to reduce the occurrence of ineffective flowers and immature pods. Consequently, higher seed yields were observed in D8.7 (2709 kg ha−1) and D11.6 (2754 kg ha−1), where lower individual productivity was offset by higher planting densities, compared to the conventional density condition of D5.8 (2169 kg ha−1).

Optimizing transplanting densities for lowland rice production under low-yielding environments in the Madagascar highlands

ContextRice yield is low at 2.1 t ha−1 in sub-Saharan Africa. Increased yield is a critical challenge to food security and environmental conservation in this region. However, smallholder farmers have limited access to irrigation, mineral fertilizers, and improved crop varieties. One approach that even resource-limited farmers can easily manipulate is to optimize planting densities. However, there is limited empirical evidence to provide technical recommendations under such low-yielding conditions. ObjectiveThis study aimed to identify the effect of dense transplanting on lowland rice yields under low-yielding conditions, with a target range below 5 t ha−1. MethodsMulti-field trials were implemented with transplanting densities of a regular rate at 25–26.7 hills m−2, a doubled rate at 50–53.3 hills m−2, and a tripled rate at 88.9 hills m−2 in the central highlands of Madagascar, where rice yields are limited by nutrient deficiency and low temperature. Canopy coverage and cumulative intercepted radiation (CIR) were monitored from transplantation to maturity using digital imagery analysis. Field observations (n=306) and four-year household surveys (n=356) were combined to calculate the costs and benefits of changing transplanting densities. ResultsDoubling densities from 25.0–26.7 hills m−2 to 50.0–53.3 hills m−2 had a consistent yield advantage by approximately 0.4 t ha−1 across a yield range of 1.8 t ha−1–4.4 t ha−1. The yield was further increased by tripling the transplanting densities to 88.9 hills m−2 when the yield range was 1.9–2.3 t ha−1. The yield advantage of higher transplanting densities was attributed to a greater CIR at the initial growth stages and a significantly greater panicle number. Household surveys and field observations indicated that the benefit of yield gain was more than three times greater than the additional cost of doubling the seed amounts. No significant yield differences were observed by changing the transplanting densities when the yield level was higher than 5 t ha−1 or lower than 1.3 t ha−1 where substantial reductions in grain fertility occurred owing to low-temperature stress. ConclusionsA relatively high transplanting density of 50–53.3 hills m−2 or even higher is recommended to ensure initial canopy development and panicle number in low-yielding conditions where individual plant growth is stagnant, except in fields with high risks of grain set failure. ImplicationsThis study provides an easy-to-use opportunity for smallholder farmers to increase their rice yield. Further studies are required to determine whether these findings apply to warmer climatic conditions.

Canopy height uniformity: a new 3D phenotypic indicator linking individual plant to canopy

Canopy height uniformity (CHU) is a key indicator linking individual plants to populations. Determining CHU by the manual measurement of the height of individual plants is inefficient and subjective, making meeting the demand for a high-throughput assessment of CHU in high-yield crop management and variety selection challenging. Therefore, a high-throughput CHU estimation approach using unmanned aerial vehicle (UAV) light detection and ranging (LiDAR) data is proposed. First, individual plant point clouds were segmented by incorporating planting density, and the CHU was estimated based on the extracted plant heights (PHs). The CHU was then applied to quantify the effects of different cropping practices on maize canopy structure. In addition, 18 canopy structural parameters (SPs) were extracted from the canopy point cloud, and aboveground biomass (AGB) was estimated by combining these SPs with Pelican Optimization Algorithm (POA) machine learning models (POA-MLs). Finally, as an indicator of individual variability within the canopy, CHU was integrated into the training process to evaluate the accuracy of AGB estimation for different models and datasets. The results showed that the plant height extracted by the canopy population-individual plant segmentation was accurate, with R2 ranging from 0.85 to 0.93. The CHU was able to accurately quantify the effects of different cropping practices on canopy structure. An increase in applied nitrogen fertilizer and irrigation could significantly contribute to an increase in CHU and the formation of a clean and homogeneous canopy structure. Meanwhile, marginal effects can be accurately quantified through PHs estimation to further quantify the intra-canopy differences. In addition, the accuracy of the AGB estimation can be effectively improved by merging SPs, PH, and CHU. In this study, we demonstrated the efficacy of CHU as a phenotypic indicator for representing differences in canopy structure, thus providing practical phenotypic identification information for breeders and field managers.

PRODUCCIÓN Y RENTABILIDAD DE MAÍCES NATIVOS AZULES BAJO DIFERENTES DENSIDADES DE POBLACIÓN Y RÉGIMENES HÍDRICOS

<p><strong>Background:</strong> It is necessary to increase maize production due to the increase in global food demand. Producers in Mexico prefer to grow native varieties of maize, which have a wide genetic diversity that has not been fully studied. These native maize are being lost due in part to their low yields, as well as their low or no profitability. Despite this, in this germplasm it is possible the presence of genotypes that show high grain production and economic gains. Increasing plant density can be a viable strategy that contributes to improving the production systems of these native maize. <strong>Objective</strong>: To analyze the agronomic behavior and profitability of blue native maize genotypes in two population densities and two water regimes. <strong>Methodology</strong>: The study was carried out in the spring summer 2022 cycle in Nuevo León, Mexico (24°19'11.4"N, 99°56'34.8"W, 1980 m.a.s.l.). The treatments were the combination of four genotypes (Mimbres, Ascensión, Siberia and a Hybrid as a control), two water regimes (irrigated and rainfed) and two population densities (62,500 and 83,333 plants ha<sup>-1</sup>), which were distributed in a random complete block design with split-split plot design. Analysis of variance, Pearson correlation and principal components were carried out to understand the behavior and relationship between variables. <strong>Results</strong>: Grain yield was 38% higher in irrigation compared to rainfed. Increasing the density to 83,333 plants ha<sup>-1</sup> also contributed to increasing grain yield and economic profitability, only in native maize. The number of grains per m<sup>2</sup> and grain weight per ear were the components that were mostly associated with the benefit-cost ratio and grain yield. <strong>Implications</strong>: The native maize studied are important genetic resources with a favorable response to high plant density, therefore, increasing the density to 83,333 plants ha<sup>-1</sup> is a strategy that could be explored to increase grain production and profitability of native maize, in addition, this proposal could be more easily adopted by producers, since it would not significantly affect their production cost. <strong>Conclusions</strong>: It was feasible to cultivate native maize at a density of 83,333 plants ha<sup>-1</sup> both under irrigation and rainfed conditions, since only with this density and such maize genotypes was it possible to obtain the highest grain yield and economic gains.</p>

Optimizing growth: The role of plant density and nitrogen fertilization on dual-purpose yellow sorghum (PYPS-2)

Optimizing growth: The role of plant density and nitrogen fertilization on dual-purpose yellow sorghum (PYPS-2)

Cultivation Strategies to Modify Biomass Partitioning and Improve Yield in Controlled-environment Production of High-cannabidiol Cannabis (Cannabis sativa L.)

Two common challenges reported by cannabis growers are low yields and small profit margins. Although recent research of cannabis yield has focused on lighting and nutrition, little research has examined how changes in other cultivation practices may be beneficial. The objective of this study was to evaluate the following two techniques to potentially improve yield: fertilizer restriction (FR) to reduce plant size and, thus, increase plant density and shoot number manipulation (SNM) to reduce shoot length and improve biomass partitioning. The FR technique involves leaching the substrate and providing only tap water for 0, 1, or 2 weeks at the start of flower initiation, whereas SNM involves pinching shoot tips 2, 3, or 4 times to produce 4, 8, or 16 shoots/plant, respectively. This study used a full factorial treatment design for a total of nine treatments (three FR × three SNM). Plants were flowered under 12-hour photoperiods for 8 weeks and then destructively harvested for data collection. The results demonstrated that both techniques improve plant productivity in different ways. The FR technique reduced all mass measurements (g/plant) and decreased plant area (m2/plant); therefore, the yield metrics (kg·m−2) increased with the increasing FR treatments. The SNM technique did not affect plant area, but more pinching events resulted in a decrease in reproductive shoot length (cm/shoot) and an increase in inflorescence to trim the dry mass ratio (inflorescence:trim). Shorter shoot lengths are desirable for eliminating trellis support netting, which helps growers reduce material costs and improve labor efficiency during harvest. Increasing the inflorescence:trim may also reduce labor costs related to trimming, which comprise the largest cost of production by many growers. Although both techniques offer advantages, there are trade-offs that must be considered in the context of overall profitability.

CNGC20 plays dual roles in regulating plant growth and immunity in Brassica napus

Inflorescence architecture is determined by inflorescence length, branch angles and the density of siliques, which affects planting density, lodging resistance and mechanical operation in rapeseed. However, the molecular mechanisms controlling inflorescence architecture are poorly understood, restricting the progress of breeding varieties with ideal plant architecture in oilseed rape. In this study, we have identified and characterized a rapeseed inflorescence development mutant, reduced inflorescence length (ril), which exhibits determinate and shortened inflorescences, reduced plant height, compact branches, and increased silique density. Through BSA-seq and map-based cloning, we find that RIL encodes a cyclic nucleotide-gated channel 20 (BnaA01.CNGC20). A substitution of proline at the 304th position to leucine (P304L) was identified in the conserved transmembrane domain of BnaA01.CNGC20. This P304L substitution neither affects the subcellular localization and self-assembly of BnaA01.CNGC20, nor disrupts the interactions with BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1), which interacts with CNGC20 and phosphorylates it to regulate Ca2+ channel stability. However, the P304L substitution increases channel activity and Ca2+ influx, which in turn induces immune responses such as cell death, H2O2 accumulation, upregulation of pathogenesis-related genes, and pattern-triggered immunity. The enhanced immunity improves the resistance to Leptosphaeria biglobosa and Sclerotinia sclerotiorum. Transcriptome analysis further revealed that CNGC20 plays dual roles in regulating plant growth and immunity via the brassinosteroid and auxin signaling pathways. The findings in this study provide deeper insights into the intricate relationship between cytosolic Ca2+ level and plant development and immunity, as well as the trade-off between immunity and the performance of yield-related traits in the heterozygous plants (+/ril), which may serve as a guide for balancing yield and disease resistance in oilseed rape breeding.

Design and experiment of citrus picking system based on dual robot collaboration

AbstractFor citrus trees cultivated by dwarf dense planting, the fruits are randomly distributed in space, which poses difficulties for mechanized picking. To improve picking efficiency, a citrus picking system based on dual robot collaboration is designed and a global scanning picking scheme that scans the entire fruit tree to achieve orderly fruit picking is proposed in this research. The dual‐robot calibration with the iterative method and closed‐form method is completed in the research. The picking problem is attributed to the single traveling salesman problem, and the trajectory planning and the picking task are completed with genetic algorithm in the research. The picking experiments are designed in the research. As a result, in the picking experiments, the average time for planning the picking sequence of citrus was 0.1184 s, the longest time is 0.1560 s. In each group of citrus picking experiments, the total picking time averaged 158.9 s, the longest group took 170 s, the picking success rate is 82%. The picking results show that the built dual‐machine system can effectively complete the picking task and meet the real‐time requirement of picking. The proposed dual‐robot picking system can provide a reference for the establishment of other picking robot system.

Differences in Physicochemical Properties of Stems in Oat (Avena sativa L.) Varieties with Distinct Lodging Resistance and Their Regulation of Lodging at Different Planting Densities.

Planting density is an effective strategy for regulating both oat lodging and forage quality. To delve into the regulatory mechanisms of planting density on lodging and oat forage quality, lodging-resistant variety LENA and lodging-sensitive variety QY2 were grown in 2018 and 2019 growing seasons, and four planting densities were implemented: 2.25 × 106 plants/ha (D1), 4.5 × 106 plants/ha (D2), 6.75 × 106 plants/ha (D3), and 9 × 106 plants/ha (D4). At the milk stage, we measured the contents of potassium, calcium, magnesium, silicon, lignin, crude fiber, starch, soluble sugar, and soluble protein in the second and third stem internodes of the plants. The results revealed the lodging-resistant variety LENA demonstrated significantly higher contents of calcium, potassium, silicon, crude fiber, lignin, and lower contents of starch, soluble sugar, and soluble protein (p < 0.01). Similar trends in the physicochemical properties of stem internodes for both oat varieties with increasing planting density. Crude fiber, soluble sugar, magnesium, starch, potassium, and lignin were the key characteristics affecting the lodging coefficient, and variety and planting density affected the lodging coefficient mainly by regulating the synthesis of starch, soluble sugar, and crude fiber. At planting density D3, stem internodes exhibited higher physicochemical properties and a lower lodging coefficient, favoring oat forage production. The results offer a valuable theoretical foundation and practical reference for oat lodging-resistant cultivation.

Evaluation of new sorghum varieties for grain production cultivated in mineral soil

Sorghum bicolor L. (Sorghum) has been recognized as the fifth largest cereal crop in the world, following maize, wheat, rice, and barley, with a mean annual production of more than 5.89 million tons over the past five years. Grain sorghum is one of the cultivated varieties of the sorghum genus. It is primarily used as human food and animal feed due to the beneficial effects of bioactive compounds in the grain. Sorghum is less popular and unrecognizable in Malaysia, as it was not included in the reports by the Agriculture Department regarding plantation areas. In Malaysia, sorghum is limited because this crop is considered new, and no studies were conducted on the adaptability of its varieties to Malaysian soil and local climatic conditions. Crop production practices such as variety selection, planting density and fertilization will affect yield production. Therefore, a study on grain sorghum varieties (Brachy Sorgho, Jumbo Super, India and Pacific Seed 99) was conducted to evaluate the growth and yield performance of sorghum. Jumbo Super had a significantly higher value for plant height, followed by Brachy Sorgho, India and Pacific Seed 99. India showed the highest value of leaf fresh and dry weight, but no significant difference compared with Brachy Sorgho. Brachy Sorgho recorded the highest value of stem fresh and dry weight, while the least was recorded for Pacific Seed 99. Brachy Sorgho and India showed significantly higher grain yields than Jumbo Super and Pacific Seed 99 in terms of panicle length, panicle weight without grain, grain weight without panicle per plant, number of grains per panicle, and 100-grain weight. The highest gross weight of grain sorghum is Brachy Sorgho (140.00 g/plant), which showed no significant difference compared to the India variety (131.13 g/plant). Meanwhile, Jumbo Super and Pacific Seed 99 varieties showed the lowest grain weight, 77.27 g/plant and 80.16 g/plant, respectively. Overall, all four varieties are adaptable in mineral soil and are considered potential alternative crops for grain production. Bachy Sorgho and India varieties showed the best performance on grain yield compared to Jumbo Super and Pacific Seed 99 varieties. Thus, Brachy Sorgho and India varieties can be recommended for future grain production in mineral soil.

Pollinator behaviour and prevalence of the anther smut Antherospora vindobonensis in its host, the Hungarian two-leaf squill (Scilla vindobonensis).

Anther smuts are fungal diseases that have detrimental effects on the biology of their host plants. We investigated the transmission of Anther smut Antherospora vindobonensis to its host, Scilla vindobonensis under natural and laboratory conditions. Plants flowering early in spring were less vulnerable to disease (∼ 20-30% of plants which appeared early in the season were diseased) than flowers that bloom at the end of the season (∼ 60% of plants which appeared late in the season were diseased) which contradicts the patterns observed for other anther smuts species. Diseased plants showed thicker stems, lower nectar production and smaller flower radius than healthy plants. The disease prevalence in S. vindobonensis was not influenced by plant density. The production of spores in diseased flowers was 125 times higher than the production of pollen in healthy flowers. The number of pollen grains attached to pollinator bodies from healthy plants under controlled conditions was similar to the number of spores attached from diseased plants. Experienced honeybees in the field showed almost identical preferences for healthy plants (65%) over diseased ones, as did naïve bumblebees under controlled laboratory conditions (69%). eDNA metabarcoding revealed that healthy flowers attracted a significantly higher number of arthropod species (M = 6.23, SE = 1.48) than diseased flowers (M = 2.32, SE = 0.31). Strong seasonal differences in the risk of infection suggest that S. vindobonensis solves the trade-off between low pollinator availability and low risk of infection at the beginning of the season and high risk of infection and high pollinator availability at the end of season. By reproducing early in the season, plants can reduce the risk of disease.

Two Years of Cotton (Gossypium hirsutum L.) Data from the Georgia Coastal Plain, USA

The sustainable management of Earth’s complex ecosystems requires an abundance of field data to support long term stewardship. Remotely sensed satellite data provide crucial supplements to field measurements and are essential for deriving key operational products for monitoring Earth systems. However, to accurately calibrate and validate the models used to develop monitoring datasets, coincident field measurements are required. In 2018 and 2019, data related to cotton (Gossypium hirsutum L.) crops were collected from five fields in two farms located in Georgia, USA. Collections were timed to coincide with satellite overpasses to support the development of remote sensing-based crop and soil data products. Data collected include soil moisture, plant water content, above ground biomass, crop height, plant phenology, and field management practices (row direction, row spacing, and plant density). The datasets include 512 records collected in 2018 and 303 records collected in 2019. The data are archived in the National Agricultural Library Ag Data Commons repository and are available for use by researchers seeking crop and soil validation data.

Environmental impacts of cement production in Ewekoro, Ogun State, southwestern Nigeria from 2005 to 2006 on surface water quality, vegetation, and workers' health

ABSTRACT The present study investigated the environmental impacts of cement production on surface water quality and vegetation in the vicinity of the industry. A 2-year study was conducted, covering both wet and dry seasons. Water samples were collected from the Akinbo River, where the cement industry discharges its liquid waste and effluents, and analysed for physical and chemical parameters using standard procedures. The vegetation around the factory was analysed for chlorophyll, plant density, basal areas, and heights of woody species. The study also assessed the health impacts of cement production on the factory employees and the residents living in the vicinity of the factory. The health assessment was based on hospital information obtained from two clinics in the villages near the factory. The water quality results revealed elevated concentrations of Ca and Fe. All the trees sampled around the study area had small basal areas and short heights. There was also a significant reduction in the chlorophyll contents of the vegetation. The health study showed a high incidence of upper-respiratory tract infections, cardiovascular diseases, arthritis, and dermatitis among factory workers. This study suggests a review of the existing dust-suppressing system put in place by the industry, to protect public health.