Stages Of Vegetative Development Research Articles

Expression patterns of Arabidopsis thaliana RecQ-like (AtRecQl) genes and the roles of AtRecQl2 and AtRecQl3 in response to abiotic stress.

Helicases are involved in almost every nucleic acid metabolism process. Within this family, RecQ helicase proteins protect genome integrity across all organisms through DNA recombination, repair, and replication. This study focused on five Arabidopsis thaliana RecQ-like (AtRecQl) genes with diverse functionalities. Analysis of ProAtRecQl:GUS expression during vegetative and reproductive development stages revealed organ- and tissue-specific patterns. Changes in AtRecQls transcript levels in response to abiotic stressors suggest their involvement in diverse stimuli responses. Notably, germination and growth rates were lower in atrecql2 and atrecql3 mutants under various salt concentrations and cold conditions. These findings indicate that AtRecQl2 and AtRecQl3 act as positive regulators of abiotic stress tolerance during the germinative and postgerminative phases.

Prevalence of Snails and Farmers' Practice Towards the Management of Giant African Snail, Achatina fulica Bowdich, 1822 in Kapilvastu, Nepal

The Giant African Snail (GAS), Achatina fulica Bowdich, 1822, is the world's largest, most damaging, and highly invasive land snail, capable of consuming about 10% of its body weight daily and affecting at least 500 types of plants. Despite the high incidence of this pest, management options are limited and ineffective. In this context, this study was carried out to assess overall snail distribution, damage and management practices adopted by farmers against GAS. A household survey of randomly selected 60 households was carried out using semi-structured questionnaires at Banganga Municipality-01, Kapilvastu, Nepal. The results revealed the prevalence of three different snails: the GAS, Achatina fulica Bowdich, 1822, the Common snail, Indoplanorbis exustus (Deshayes, 1834), and the Paddy Snail or Ghonghi or Ghongi, Pila globose (Swainson, 1822) in moist areas, drains, and grassy lands, among them, GAS causing the most significant damage during the rainy season. The most vulnerable stage of crops to GAS was the vegetative stage of development (53.3%) in vegetables and fruits, with the most preferred crop family being the Cucurbitaceae (45%). The majority of respondents (48%) believed that the lack of effective control measures was the main reason for the growing infestation and extent of damage. The 'Hand-picking and killing' method was considered the most effective and suitable method in the farming community over other control measures. It has been reported that the snail problem has increased over the years, and very little effort has been made by the concerned authorities to manage this pest. In conclusion, snails, especially GAS, pose major challenges to agricultural production in Nepal. Therefore, appropriate and cost-effective management strategies are required for their sustainable management.

Competition between brown stink bug (Hemiptera: Pentatomidae) and corn earworm (Lepidoptera: Noctuidae) in field corn.

Interspecific competition is an important ecological concept which can play a major role in insect population dynamics. In the southeastern United States, a complex of stink bugs (Hemiptera: Pentatomidae), primarily the brown stink bug, Euschistus servus (Say), and corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), are the 2 most common pests of field corn, Zea mays L. (Poales: Poaceae). Stink bugs have the greatest potential for economic injury during the late stages of vegetative corn development when feeding can result in deformed or "banana-shaped" ears and reduced grain yield. Corn earworm moths lay eggs on corn silks during the first stages of reproductive development. A 2-year field study was conducted to determine the impact of feeding by the brown stink bug during late-vegetative stages on subsequent corn earworm oviposition, larval infestations, and grain yield. Brown stink bug feeding prior to tasseling caused deformed ears and reduced overall grain yield by up to 92%. Across all trials, varying levels of brown stink bug density and injury reduced the number of corn earworm larvae by 29-100% and larval feeding by 46-85%. Averaged across brown stink bug densities, later planted corn experienced a 9-fold increase in number of corn earworm larvae. This is the first study demonstrating a competitive interaction between these major pests in a field corn setting, and these results have potential implications for insect resistance management.

Chronology and main stages of vegetation development in the central region of the East European Plain during the Mikulino interglacial

The chronology of the Mikulino Interglacial and its individual phases have been the subject of discussion. The goal of this study was to evaluate the time limits of the main stages of the Mikulino Interglacial on the Russian Plain according to ²³⁰Th/U dating and paleobotanical studies of lake and peat sediments from the known sections located within the Tver region on the Bolshaya Dubenka River, Malaya Kosha River, Granichnaya River, and Sizhina River (“Kileshino-2” section). An improved geochronological approach has been applied to identify layers suitable for the ²³⁰Th/U isochronous approximation. In combination with pollen and carpological studies of the deposits, this made it possible to date units corresponding to relatively narrow time intervals in the development of plant formations at different stages of the Last Interglacial. New paleobotanical studies of buried lake and peat sediments from the sections located on the Bolshaya Dubenka River, Malaya Kosha River, and Granichnaya River allowed us to restore the vegetation development during the Mikulino Interglacial in the interval of pollen zones M1–M7, i.e., more pollen zones have been analyzed and in greater detail than in 1960–1970. A chronological scheme of the main stages of vegetation development in the Mikulino Interglacial is proposed based on the results of ²³⁰Th/U dating and paleobotanical studies of organic-rich deposits from the Tver region sections in combination with previously published data obtained for the “Nizhnyaya Boyarshchina” section from the Smolensk region. The Mikulino Interglacial had begun about 130–126 kyr ago. Its first phase, corresponding to the M2 zone, ended ca. 118 kyr ago. The pre-optimal stages of vegetation development (M3 and M4 zones) fit into the time range of ca. 118–112 kyr ago. The climatic optimum of the interglacial (M5 and M6 zones) began ca. 112 kyr ago and ended ca. 100 kyr ago. The duration of the Mikulino Interglacial was probably at least 25 thousand years.

Plant lipases – molecular structure, role in ontogeny and biotechnological potential

Lipases are enzymes commonly found in microorganisms, fungi, plants and animals. Their main function in cell metabolism is the hydrolysis (lipolysis) of ester bonds between fatty acids and glycerol in mono-, di- and triacylglycerols. In plants, lipases play an important role in ontogeny, participating in both vegetative development and generative stages. These enzymes may also be a component of plant responses to biotic and abiotic stresses. Based on the similarity of the amino acid sequence and vacuolar localization of some plant lipases to yeast Atg15, we present a hypothesis about the participation of lipases in autophagy (precisely, in the degradation of the autophagic body) in plants. Despite the narrow substrate specificity and the type of reactions catalysed in cells, lipases find numerous biotechnological applications. The physicochemical features of lipases, which determine, for example, wide substrate specificity in vitro or high stability in a wide range of pH and temperature, make these enzymes the subject of applied research, and plant lipases show an increasing potential in this area of science and industry.

Development of a temperate rainforest zonation on the Pacific slopes of the North Patagonian Andes since ∼18 ka

Few studies along the western slopes of the Andes in Northwestern Patagonia (NWP: 40°-44°S) allow examining vegetation development through environmental gradients in latitude and elevation along a time continuum since the Last Glacial Termination (T1, ∼18-11 ka). This complete biostratigraphic context is necessary for assessing the sequence, timing, rates, and direction of compositional/structural changes of the former vegetation, and for deciphering their environmental drivers. Here we report palynological results from two NWP sites spaced ∼22 km apart on the western Andean slopes, Caleta Puelche roadside section located near sea level and Lago Reflejos at mid elevations (∼800 m a.s.l.) and assess their continuous records since local ice-free conditions against other NWP sites. We find that cold-tolerant early successional trees dominated the initial stages of vegetation development in the Seno Reloncaví lowlands (∼18-17 ka), followed by thermophilous shade-tolerant North Patagonian rainforest (NPRF) trees, which achieved their maxima between ∼17 and 15 ka at low-elevations. A spread of cold- and shade-tolerant hygrophilous NPRF conifers ensued (∼14.8-13 ka) reaching similar magnitude at low- and mid-elevations, interrupted by increases in trees favored by canopy fragmentation linked to fire and explosive volcanism (∼13-11 ka). Thermophilous, shade-intolerant, summer-drought tolerant Valdivian rainforest (VRF) trees increased and achieved maxima between ∼10 and 8 ka, most notably in the lowlands, coeval with peak abundance of the NPRF conifers Fitzroya/Pilgerodendron and Podocarpus nubigena in mid-elevation Lago Reflejos, contemporaneous with their virtual disappearance near sea level. Widespread increases in cold-tolerant hygrophilous NPRF trees occurred after ∼8 ka, followed by mixing of NPRF and VRF elements in the lowlands after ∼6.3 ka with centennial-scale alternations. Inter-site and regional coherences of our findings suggest that variations in Southern Westerly Wind influence, along with disturbance regimes of natural and human origin, have driven the composition, structure, dynamics, and zonation of temperate rainforests in NWP since T1. We observe that Lago Reflejos features the highest abundance of Fitzroya cupressoides at regional scale since ∼12 ka, attesting to the importance of mid-elevation Andean environments for the persistence of these highly valued trees in the context of postglacial climate evolution, shifts in fire regimes, volcanic, and human disturbance in NWP.

Plant tolerance to drought stress: Complexity and mechanism across physiological, molecular and biochemical scales

Drought stress limits crop yield globally and is growing as a result of climate change. Water deficit of soil frequently reduces crop growth and yield regardless of developmental stages and nature of genotypes. There are a variety of mechanisms involved in plants in response to drought stress and they trigger the plant drought tolerance strategies. Plants subjected to drought undergo a sequence of physiological, biochemical, and molecular mechanisms to combat the effects of drought, just like plants exposed to other environmental stressors. Using various methods, researchers are currently attempting to understand the intricate operation of the drought stress response in plants. During particular crucial stages such as seed germination, and formation of seedlings, flowering, and grains, plants are particularly vulnerable to drought stress. Through the activation of tolerance mechanisms, plants successfully mitigate the impacts of drought stress during vegetative development stages. However, drought stress during the generative phase might result in yield losses that are irreversible. The present review highlights the tolerance mechanisms in plants and the functioning of physiological, molecular, and biochemical processes involved in plants' resistance to water deficit as well as how various crops react to drying conditions at various developmental points.

Application of Biostimulant in Seeds and Soil on Three Chickpea Varieties: Impacts on Germination, Vegetative Development, and Bacterial Facilitation of Nitrogen and Phosphorus.

Chickpeas (Cicer arietinum L.) are a valuable legume crop due to their nutritional value. To maintain chickpea productivity and avoid the adverse effects of climate change on soil and plant processes, it is crucial to address demand. Achieving this necessitates implementing sustainable agricultural practices incorporating the use of biostimulants, adaptable crops for arid conditions, as well as pest and disease-resistant crops that are sustainable over time. Three varieties of chickpeas were analysed to determine the effect of two different biostimulant application methods on both germination and vegetative growth. Possible effects due to location were also examined by conducting tests at two different sites. Significant variations in biostimulant response were evident only during the germination period, but not during the vegetative development stage, where the observed statistical differences were influenced more by the location or variety of chickpeas employed. Furthermore, this study examined the effect of biostimulants on nutrient cycling within the soil-plant microbiota system. Nitrogen-fixing bacteria (NFB) are present in the soil of chickpea crops at an order of magnitude of 107 CFU/g DS. Additionally, an average concentration of 106 CFU/g DS of phosphorus-mobilising bacteria was observed. Applying biostimulants (BioE) to seeds resulted in a successful germination percentage (GP) for both Amelia (AM) and IMIDRA 10 (IM) varieties.

The Effects of Legacy Sediment Removal and Floodplain Reconnection on Riparian Plant Communities

Stream restoration includes a number of different approaches intended to reduce sediment and nutrient export. Legacy sediment removal (LSR) and floodplain reconnection (FR) involve removing anthropogenically derived sediment accumulated in valley bottoms to reconnect incised streams to their floodplains. These projects also present an opportunity to create high-quality riparian and wetland plant communities and provide information about the early stages of wetland vegetation development and succession. We surveyed vegetation immediately after restoration at three sites and at three additional sites 1–3 years post-restoration to determine how LSR/FR affects riparian plant communities. Restoration increased the prevalence of hydrophytic herbaceous species at all sites, suggesting these projects successfully reconnected the stream to the floodplain. Pronounced decreases in woody basal area and stem density likely also influenced an increase in native and graminoid species after restoration. Only 16% of the indicator species identified for restored reaches were planted as part of the restoration, suggesting the local seed bank and other seed sources may be important for vegetation recovery and preservation of regional beta diversity. Although vegetation quality increased after restoration in reaches with initially low-quality herbaceous vegetation, vegetation quality did not improve or decreased after restoration in reaches with higher-quality vegetation before restoration. The practice of LSR/FR has the potential to improve the quality of some riparian vegetation communities, but the preservation of high-quality forested areas, even if they are atop legacy sediment terraces, should be considered, particularly if reductions in nutrient export do not offset losses in tree canopy.

Botanical Leaf Extracts and Mulching Materials in Organic Eggplant (Solanum Melongena L.) Off Season Production

The extensive use of pesticides and the risk they pose to human and the environment requires safe alternatives in crop production hence the study on the efficacy of botanical leaf extracts and mulching materials in organic eggplant production. This study determined the best level combination of botanical leaf extracts that has repellent and knockdown effects on major eggplant insect pest, best level combination of botanical leaf extracts that produces the highest marketable yield; best mulching materials; best level combination of botanical leaf extracts and mulching; correlation of infestation to yield; profitability of eggplant production using botanical leaf extracts and mulching materials combined; and evaluate the effects of botanical leaf extracts and mulching materials on soil chemical properties. A Bioassay test on the botanical leaf extracts was conducted prior to field experiment. Mass rearing the test insects was done to ensure uniform number of insect in eggplant per treatment. A Split- plot in Factorial Design was used in the study with three blocks. The main plot were the leaf extracts of Neem, Madre de Cacao+ Guava at 1:1:1 ratio were: P0 – No Application, P1 –250 ml leaf extract/16 li water, P2 –500 ml leaf extract /16 li water, P3 –750 ml leaf extract /16 li water, P4 – 40 ml Commercial insecticide/16 li water. The sub-plot was: M1 – Black Plastic mulch, M2 – Carbonize Rice Hulls, and M3 – Saw Dust. Results of the bioassay showed highly significant knockdown effect in the application of 500-750ml leaf extract/16 li water on fruit and shoot borer, lady spotted beetle and white flies comparable to application of commercial insecticide/16 li water. Significant repellent effects on Fruit Shoot Borer and Lady spotted beetles but no repellent effects on white flies for an application of 250ml botanical leaf extracts/16li water. Results under field condition showed that plants applied with 750ml botanical leaf extracts/16 li water is more effective than commercial insecticide/16 li water in reducing damaged leaves during the early vegetative stage of development (2nd WAT) and at reproductive stage of development (10th WAT). Highly significant difference was obtained in terms in weight of non-marketable fruit. No significant interaction was registered between botanical leaf extracts and mulching materials. Regression correlation analysis revealed that there was a direct correlation between the numbers of damaged leaves to yield. Combined application of botanical leaf extracts at 750ml/16 li water + carbonized rice hulls obtained Php 797,635.15 net for organic off-season eggplant production. Soil pH, OM, P, and K were increased with application of sawdust, carbonized rice hulls and plastic mulch.

Polyploidy in the history of breeding at the Yaltushkiv Experimental Breeding Station: new methods of differentiation and stabilisation of sugar beet tetraploids

Purpose. To analyse the history of the polyploid breeding at the Yaltushkiv Experimental Breeding Station, in particular the improvement of genetic models of new hybrids, new methods of induction of meiotic tetraploids, differentiation and selection of breeding genotypes by genome ploidy.
 Methods. Cytological analysis of metaphase chromosomes of the apical meristems of the growth points of seed plants and beets of the first year for the selection of tetraploid plants 4x = 36 chromosomes; cytophotometric analysis using computer programs AP Partec to study ploidy based on the quantitative content of nuclear DNA; field methods (selection of tetraploid seed plants according to the types of pollen grains, formation of synthetic populations of tetraploid multigerm plants on a cytogenetic basis according to the structure of bivalent conjugation of homologous chromosomes in meiosis.
 Results. In the process of tetraploid induction, cytological methods of ploidy analysis at the station were improved using computer programs of AP Partec for the selection of sugar beets 4x by the quantitative content of nuclear DNA in the cell on plants of the first year of vegetation and for the formation of tetraploid populations after colchicine induction in seed plants. In the process of studying the structure of polyploid populations by ploidy, the percentage of tetraploids varied from 82.0±2.22% in Ya/Hen pollinator to 58.1±2.81% in Ya/Man pollinator. It was established that the selection for fertility and pollen uniformity depends on the genetic characteristics of the breeding genotypes and affects the pollen-forming ability in the first generations after induction with colchicine, reducing the number of 4x IIa and IIb biotypes according to cytological classification. Using the example of the multigerm pollinator Ya/Roi, it was established that selection for sugar content and productivity had, to a certain extent, a stabilising effect on the degree of ploidy. The biotechnological methods used to deposit 4x genotypes with a high percentage of bivalent conjugation of homologous chromosomes in metaphase I of meiosis (70–90%) contributed to the cytogenetic stability of polyploid gametes and their high yield – 92.9% of 4x in the next generation of seeds. It was investigated that the productivity of triploid hybrids obtained with the use of the tetraploid pollinator Ya/DA 4x based on the germplasm of the wild species Beta patula at the early stages of vegetative development varied in triploid plants from 325 to 465 g, and the sugar content in some numbers reached 21.5%.
 Conclusions. The development of polyploid selection at the Yaltushkiv Experimental Breeding Station evolved from the development polyhybrids to the development of triploid hybrids based on CMS using tetraploid multigerm pollinators. For the formation of populations of tetraploid multigerm pollinators, the methods of fluorescent cytophotometry and computer programs AP Partec were used, as well as biotechnological methods for creating synthetic populations of tetraploid multigerm pollinators on a cytogenetic basis, which ensure the yield of tetraploids in seeds up to 92.9%.

Effect of Spraying with Humic Acid and Active Yeast Suspension on the Growth Indicators and Active Substances of Calendula officinalis L.

The purpose of this study was to examine the impact of spraying C. officinalis L. with Humic acid and active yeast suspension on growth indicators for both the vegetative and floral stages of development. Humic acid was sprayed on the plants in varying quantities (0, 2, or 4 g) in a factorial experiment with 9 treatments (two factors overlapped). and a suspension of live yeast at 3, 6, or 0 mg/L-1, and the treatment consisted of three sprays, with a 15-day gap between each application. Using a Factorial Experiment with three replicates and three plants per experimental unit, I compared means at the 5% probability level using the Revised Least Significant Differences (R.L.S.D.) test. The most significant findings, in her opinion, are as follows: Humic acid spraying at a dosage of 4 mg/L-1. While this concentration greatly slowed flowering, L-1 significantly increased plant height, number of lateral branches, percentage of dry matter of shoot, number of flowers, number of petals, flower diameter, flower stand length, and percentage of dry matter in flowers. The greatest concentration, 6 mg.L-1, was achieved through spraying with an active yeast suspension. Although this concentration greatly slowed flowering enhanced plant height, lateral branching, leaf count, flower count, petal count, flower diameter, and floral dry matter percentage. There was a statistically significant impact on all attributes measured by the binary interactions.

The Effects of Rhizophagus irregularis Inoculation on Transcriptome of Medicago lupulina Leaves at Early Vegetative and Flowering Stages of Plant Development.

The study is aimed at revealing the effects of Rhizophagus irregularis inoculation on the transcriptome of Medicago lupulina leaves at the early (second leaf formation) and later (flowering) stages of plant development. A pot experiment was conducted under conditions of low phosphorus (P) level in the substrate. M. lupulina plants were characterized by high mycorrhizal growth response and mycorrhization parameters. Library sequencing was performed on the Illumina HiseqXTen platform. Significant changes in the expression of 4863 (padj < 0.01) genes from 34049 functionally annotated genes were shown by Massive Analysis of cDNA Ends (MACE-Seq). GO enrichment analysis using the Kolmogorov-Smirnov test was performed, and 244 functional GO groups were identified, including genes contributing to the development of effective AM symbiosis. The Mercator online tool was used to assign functional classes of differentially expressed genes (DEGs). The early stage was characterized by the presence of six functional classes that included only upregulated GO groups, such as genes of carbohydrate metabolism, cellular respiration, nutrient uptake, photosynthesis, protein biosynthesis, and solute transport. At the later stage (flowering), the number of stimulated GO groups was reduced to photosynthesis and protein biosynthesis. All DEGs of the GO:0016036 group were downregulated because AM plants had higher resistance to phosphate starvation. For the first time, the upregulation of genes encoding thioredoxin in AM plant leaves was shown. It was supposed to reduce ROS level and thus, consequently, enhance the mechanisms of antioxidant protection in M. lupulina plants under conditions of low phosphorus level. Taken together, the obtained results indicate genes that are the most important for the effective symbiosis with M. lupulina and might be engaged in other plant species.

The Fungal Root Endophyte Serendipita indica (Piriformospora indica) Enhances Bread and Durum Wheat Performance under Boron Toxicity at Both Vegetative and Generative Stages of Development through Mechanisms Unrelated to Mineral Homeostasis.

While the importance of beneficial soil microorganisms for soil health and crop performance has been receiving ever-increasing attention, Serendipita indica has been widely studied as a fungal root endophyte with significant potential for increasing the stress tolerance of host plants. Boron (B) toxicity as an adverse soil condition is particularly prevalent in arid and semi-arid regions and threatens crop production. Studies on S. indica-wheat symbiosis are limited, and effects of S. indica on crops have never been reported in the context of B toxicity. Here, two pot experiments were conducted under greenhouse conditions to investigate the effects of S. indica on the growth and yield parameters of bread (Triticum aestivum) and durum wheat (Triticum durum) grown at different levels of B toxicity in native vs. sterilized soil, and parameters related to root colonization, membrane damage, oxidative stress, chlorophyll, and mineral nutrition were measured to elucidate the physiological mechanisms of damage and benefit. Boron toxicity decreased early vegetative growth and grain yield, but it did not affect the straw dry weight of mature plants, whereas S. indica significantly enhanced the vegetative growth, straw dry weight, and the grain number of both wheat species. Membrane damage as demonstrated by increased lipid peroxidation and relative electrolyte leakage was caused by B toxicity and alleviated by S. indica. The benefits provided by S. indica could not be attributed to any significant changes in tissue concentrations of B or other minerals such as phosphorus. Soil sterilization generally improved plant performance but it did not consistently strengthen or weaken the effects of S. indica. The presented results suggest that S. indica may be used as an effective microbial inoculant to enhance wheat growth under adverse soil conditions such as B toxicity through mechanisms that are possibly unrelated to mineral homeostasis.

Phospholipid:diacylglycerol acyltransferase1-overexpression stimulates lipid turnover, oil production and fitness in cold-grown plants

BackgroundExtensive population growth and climate change accelerate the search for alternative ways of plant-based biomass, biofuel and feed production. Here, we focus on hitherto unknow, new promising cold-stimulated function of phospholipid:diacylglycerol acyltransferase1 (PDAT1) – an enzyme catalyzing the last step of triacylglycerol (TAG) biosynthesis.ResultOverexpression of AtPDAT1 boosted seed yield by 160% in Arabidopsis plants exposed to long-term cold compared to standard conditions. Such seeds increased both their weight and acyl-lipids content. This work also elucidates PDAT1’s role in leaves, which was previously unclear. Aerial parts of AtPDAT1-overexpressing plants were characterized by accelerated growth at early and vegetative stages of development and by biomass weighing three times more than control. Overexpression of PDAT1 increased the expression of SUGAR-DEPENDENT1 (SDP1) TAG lipase and enhanced lipid remodeling, driving lipid turnover and influencing biomass increment. This effect was especially pronounced in cold conditions, where the elevated synergistic expression of PDAT1 and SDP1 resulted in double biomass increase compared to standard conditions. Elevated phospholipid remodeling also enhanced autophagy flux in AtPDAT1-overexpresing lines subjected to cold, despite the overall diminished autophagy intensity in cold conditions.ConclusionsOur data suggest that PDAT1 promotes greater vitality in cold-exposed plants, stimulates their longevity and boosts oilseed oil production at low temperature.

Response of peanut (Arachis hypogaea L.) to sublethal rates of dicamba plus glyphosate at different growth stages

AbstractThe widespread adoption of dicamba‐resistant crops has increased the applications of newer dicamba formulations for weed control. However, there is a concern for potential off‐target injury and yield reduction to peanuts (Arachis hypogea L.) planted in close proximity to dicamba‐resistant crops. Field experiments were conducted in the summer of 2019 and 2020 to evaluate peanut response to reduced rates (1/512X, 1/128X, 1/32X, and 1/8X the label rate, 564 + 1280 g ae ha−1) of dicamba plus glyphosate (XtendiMax plus Roundup PowerMax) at 25, 50, and 75 days after planting (DAP) which corresponds to vegetative, flowering, and pod development stages, respectively. Peanut exposure to dicamba plus glyphosate at 25 DAP resulted in 1.6–2.3 times greater injury and 3.4–8.5 times greater height and canopy width reductions compared to 50 and 75 DAP exposures. Peanuts suffered greater yield reduction (18%–19%) when exposed to dicamba plus glyphosate at 25 and 75 DAP than at 50 DAP (10%). Regression analysis indicated a significant linear response for peanut injury (except at 8 weeks after treatment), canopy width reduction, and yield reduction with an increasing rate of dicamba plus glyphosate. Dicamba plus glyphosate at 1/512X rate resulted in a 3% peanut yield reduction, whereas a 41% yield reduction was observed at 1/8X rate. Correlation analysis, with Pearson's rho values ranging from 0.81 to 0.86, showed that peanut injury can be a useful predictor for estimating yield reduction. Therefore, extreme care must be taken to prevent drift occurrence or spray‐tank contamination when applying dicamba plus glyphosate on XtendFlex crops near peanut fields.

Light interception and radiation use efficiency in quinoa (Chenopodium quinoa Willd.)

AbstractQuinoa (Chenopodium quinoa Willd.) is an annual plant belonging to the Amaranthaceae family. The total accumulated incident photosynthetic active radiation (PAR) in a plant is a function of the site, year, sowing date, and phenology, whereas the amount of PAR intercepted by the plant is dependent on its leaf area index (LAI) and light extinction coefficient (KPAR). This study investigated changes in KPAR and radiation use efficiency (RUE) levels in quinoa before and after inflorescence (fruit set) color change under various temperature and light conditions through the sowing date. This study was conducted in the Jihad Keshavarzi allocated field of Khalilabad city in Khorasan Razavi province, Iran, using a randomized complete block design with three replications over two seasons, 2017–2018 and 2018–2019. Treatments included eight and seven sowing dates in the first and second season years, respectively. The results showed that the mean of KPAR was 0.66 and 0.31 in the first and second years, respectively. Also RUE in vegetative stages of development was higher than during the grain‐filling period. The mean of RUE was 2.60 ± 0.06 and 0.78 ± 0.17g/MJ in the first year before and after changing the color of the inflorescence (fruit set), respectively; these values were 2.12 ± 0.04 and 1.01 ± 0.61 g/MJ in the second year. The results indicated the base (TBRUE), lower optimum (TP1RUE), upper optimum, and ceiling temperatures of quinoa for RUE were determined to be 3, 18.8, 25.5, and 35°C, respectively.

Nitrogen Use Efficiency Regulates Drought Stress in Pearl Millet Genotypes: Morpho-Physiological Evaluation

In this paper, the author discusses the effects of drought stress on pearl millet genotypes during the vegetative stage of development and the plant’s mechanisms for survivability under stress with various nitrogen treatment regimes. A total of six treatment conditions were imposed on plants, i.e., N0 (no Nitrogen-0 mM), N0+PEG-10%, LN (low Nitrogen-2.5 mM), LN+PEG-10%, HN (high Nitrogen-7.0 mM), and HN+PEG-10%. Five days of moderate drought stress caused significant morphophysiological changes, as evidenced by a reduction in fresh and dry biomass, as well as relative water content (RWC), relative electrolyte leakage, and chlorophyll fluorescence,. A significant reduction in plant biomass and RWC when compared to the controls was seen. Reactive oxygen species (ROS) and lipid peroxidation (MDA) levels increased in the shoot in response to drought stress along with a loss of membrane integrity. A nitrogen treatment regime regulated the drought stress. In relation to N0-treated batches, proline accumulation increased in various N-treated batches. Results revealed that GHB-538 is less tolerant to drought stress in different N treatment conditions, while RHB-234 and 223 showed better tolerance to drought under nitrogen treatments. The significance of this study is to uncover the regulatory role of nitrogen over the drought stress in pearl millet.

Distribution of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) and incidence of maize rayado fino virus and Candidatus Phytoplasma asteris in corn succession planting systems.

Corn is one of the main crops grown globally to produce food for human consumption and animal feed, including raw materials for bioenergy. Effective pest management is critical for the economic viability of corn production. The leafhopper Dalbulus maidis and the diseases transmitted by it have become relevant to corn production. Our study aimed to determine environmental parameters that affect D. maidis populations and the impacts of pathogen dispersion on corn productivity under different rotation systems and sowing seasons. The population density of leafhoppers found in the studied crops was low but capable of establishing the diseases and spreading them widely in the crops. The leafhopper's highest occurrence was in the corn vegetative development stage, and its population peaks were earlier in the corn off-season. The incidence of maize rayado fino virus and maize bushy stunt phytoplasma were higher in corn off-season than in the growing season. The incidence of diseases was higher in the final stages of the cultivation cycle. Yield losses were significantly higher for maize bushy stunt phytoplasma and not significant for maize rayado fino virus. Our study observed that corn's physiological stage was the main factor influencing D. maidis dynamics. The occurrence of D. maidis at low densities was sufficient to ensure the efficient transmission and dissemination of maize rayado fino virus and maize bushy stunt phytoplasma, which had a higher incidence in the reproductive stage and the corn sowed off-season. © 2023 Society of Chemical Industry.

Rhizobacteria-Based Biostimulant Mixture Effect on Chickpea (Cicer arietinum L.) in Greenhouse and Cultivation Assays

This study aims to contribute to the improvement of the chickpea agri-food industry and adapt it to future challenges. For this, the effect of a Rhizobacteria-based biostimulant mixture was analyzed in Amelia variety of chickpea (Cicer arietinum L.) in two different experiments: one in flowerpots in a greenhouse and the other one in the field grown under rainfed conditions. Germination success, vegetative development and phenological stages of the plants were studied after applying liquid biostimulant mixture on the seeds 24 h before sowing or spraying it on the soil after sowing. The results indicated that the way of application of the biostimulant was relevant concerning germination success, vegetative development, and phenological state of chickpea plants and it should be adapted to intensive agriculture with the use of seed drill that requires dry seeds. Regarding germination success, vegetative development and phenological stages in the flower pot assay, the volume of biostimulant mixture applied to the seeds was remarkable as higher volumes affected negatively while lower volumes were positive. Biostimulant had a negative effect on the development of chickpea plants in the field assay, probably because it also promoted the growth of weeds, which lessened the growth of the chickpea plants.