Flowering Growth Stages Research Articles

Metabolomic profiling of Greyia radlkoferi on water stress, phenological growth stages, and leaf age using 1H NMR

Greyia radlkoferi Szyszyl (Melianthaceae) is a native plant to southern Africa identified as a viable commercial crop. The leaf extract is rich in flavonoid compounds with the ethanolic leaf extract found to treat skin hyper-pigmentation of humans without adverse effects (anti-tyrosinase activity value IC50 17.86 μg/ml). Anti-tyrosinase activity is found to be variable between plants, even when planted at the same site, which raises concerns regarding commercial production, necessitating the need for cultivation interventions that will not compromise the activity of the extract. Interventions to limit the variation were thus explored by imposing targeted water stress (different durations) before harvesting and determining the effect on the different phenological growth stages and activity of different leaf ages. The inhibitory tyrosinase activity was evaluated using mushroom tyrosinase and kojic acid as a control and data was presented as IC50 values. The metabolomics investigation was conducted through the use of nuclear magnetic resonance (1H NMR) analysis coupled with the multivariate statistical data set. Pattern recognition methods such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA) were employed to obtain the metabolic discrimination between the treatments. No clear pattern was observed in the grouping of samples exposed to targeted water stress on both plant age and leaf position, except for younger leaves of one month and four months old which had a strong clustering of high activity samples as compared to older leaves of six months old. However, plant materials harvested during the flowering growth stage had a strong grouping of samples producing high anti-tyrosinase activity as compared to the budding and vegetative growth stages. The study determined the changes in the concentration of various compounds, although quantification of compounds should be determined in the future.

Assessment of florpyrauxifen-benzyl in water-seeded rice systems as affected by application timing

Florpyrauxifen-benzyl (FPB) is a novel auxin mimic rice herbicide used to control selected grasses, sedges, and broadleaves. Field experiments were conducted in 2020–2022 to 1) characterize the effects of FPB on rice crop safety and weed control when applied alone or in a mixture, 2) determine the FPB application timing to optimize smallflower umbrella sedge (SMF) control, and 3) evaluate the effect of late season application on rice flower sterility. In the first study, FPB was applied alone at 15, 30, and 60 g ai ha−1 and in mixture with bispyribac-sodium, penoxsulam, and propanil. FPB applied alone at 30 g ha−1 at 4–5-leaf (LF) rice stage controlled more than 80% of watergrasses, ricefield bulrush, and SMF and more than 99% of all broadleaf weeds at 28 days after treatment (DAT). The mixture treatments of FPB plus bispyribac-sodium applied at maximum use rate had the greatest grass weed control whereas, FPB plus propanil at the maximum use rate provided the greatest sedge control. In the second study, FPB at 40 g ha−1 was applied at 1-LF, 10-, 15-, 20-, and 25-cm tall SMF, where treatments controlled 95%, 86%, 89%, 87%, and 85% of SMF at 42 DAT, respectively. In the third study, FPB at 40 and 80 g ha−1 rate was applied at rice panicle initiation (PI) and 50% flowering (FL) growth stages. While the weed control was more than 90% at 42 DAT for all applications, the FL stage application caused 26% and 35% rice panicle blanking at 40 and 80 g ha−1 rate, respectively. This research suggests, the window of FPB application should be from 2-LF rice to rice PI stage to ensure crop safety and highest weed control.

Response of Wheat to Nano fertilizers Added at the Beginning of the Vegetative and Flowering Growth Stages

Response of Wheat to Nano fertilizers Added at the Beginning of the Vegetative and Flowering Growth Stages

Impact of flowering temperature on litchi yield under climate change: A case study in Taiwan

Litchi is a subtropical fruit tree that undergoes flower bud differentiation under low-temperature conditions. However, climate change has affected litchi production in Taiwan, causing litchi farmers to experience economic losses. This study explored the influence of flowering temperature on litchi yield under climate change in Taiwan by analyzing litchi production data from 2001 to 2020 and observation data from meteorological stations in litchi-producing areas. Historical observed data were used to construct several regression models relating temperature to yield, with the performance of the models used to determine critical temperature thresholds for litchi flower bud differentiation. Analytical climate data (CMIP5) were used to project yield changes in Taiwan’s litchi-producing regions under anticipated low-temperature conditions for the mid- (2036–2065) and late- (2071–2100) 21st century. The variable that exhibited the highest correlation with yield changes was the number of days with an average flowering temperature below 16 °C. The production yield, in terms of yield variation per hectare, is expected to decrease by 12 % to 35 % by the end of the 21st century (2071–2100). Given the projected decline in the number of cooler days due to climate change, existing litchi cultivars may become unsuitable for cultivation in production areas in southern Taiwan. Practical ImplicationsSome fruit trees require a period of low temperature before their flowering stage. Climate change is expected to cause warming of winter temperatures in Taiwan, which is likely to lead to reduced litchi flowering. The current study assessed the potential effects of climate change on litchi flowering in the future.Historical observed data were used to establish models, and critical temperature thresholds for litchi flowering were determined on the basis of model performance. Days with average temperatures below 16 °C exhibited the highest correlation with litchi yield among the tested thresholds. According to our results, farmers can use this 16 °C threshold to evaluate the potential effects of future climate change at their current farm locations and to identify other areas with similar or more favorable conditions for litchi cultivation. For agricultural researchers, this temperature threshold could provide a target for new litchi variety breeding and a reference basis for research on optimal cultivation methods.Notably, because climate change projection data have a high degree of uncertainty, the results of this study may differ from those of studies using different databases. In this study, we used an ensemble of CMIP5 projections incorporating data from models from various research centers around the world, which can provide more robust results based on an ensemble mean than those obtainable from a single model or a few models. In addition, rainfall is a crucial factor during the flowering growth stage. Future studies should consider the effects of rainfall and temperature on yield and should consider using a model with yield being considered a function of both of these variables to improve model accuracy.To conclude, the present study provides researchers, policymakers, and other stakeholders with insights into the primary effects of climate change on litchi production. It also lays the groundwork for future climate adaptation strategies in Taiwan’s litchi industry.

Pumpkin Injury and Yield Response to Low Rates of 2,4-D Choline and Dicamba

The recent release of 2,4-D- and dicamba-tolerant soybean traits has increased the risk of off-target herbicide injury and yield loss for specialty crop growers in the midwestern United States. Most dicotyledonous plants, including many specialty crops like pumpkin (Cucurbita pepo), are susceptible to synthetic auxin herbicides; however, the relationship between off-target herbicide rate, visible crop injury, and eventual yield loss is not well documented. The objective of this 2-year field study in 2019 and 2020 was to determine the effect of sublethal herbicide rates of 2,4-D and dicamba on visible injury and crop yield loss in pumpkin when applied at the vegetative and flowering growth stages. Herbicides included 2,4-D choline salt (1066 g ae·ha−1 labeled rate) and dicamba diglycolamine salt (560 g ae·ha−1 labeled rate) ranging from 1/500 to 1/4 of the labeled rate. Visible injury ratings were recorded every 7 d after application and pumpkins were harvested and weighed when ripe. Injury and yield data were fit to a four-parameter log-logistic regression model to estimate effective doses (ED) required for 5% to 50% visible injury or yield loss. Pumpkin treated with the 1/10 and 1/4 rates of 2,4-D at both growth stages had visible injury (± 1 SE) ranging from 8% (± 3%) to 55% (± 3%), but injury did not always result in yield loss. Maximum yield loss from 2,4-D was 32% (± 2%), observed following the 1/4 rate at the vegetative growth stage in 2020 (estimated ED for 20% yield loss was ∼1/50). Pumpkin treated at the vegetative growth stage with the 1/10 and 1/4 rates of dicamba resulted in 65% (± 6%) to 82% (± 1%) visible injury and 33% (± 2%) to 86% (± 14%) yield loss (estimated ED for 20% yield loss was ∼1/10 in 2019 and ∼1/15 in 2020). At the flowering stage, dicamba rates of 1/10 and 1/4 caused visible injury of 31% (± 2%) to 74% (± 5%) and yield loss of 26% (± 10%) to 60% (± 14%) (estimated ED for 20% yield loss was ∼1/20 in 2019 and ∼1/5 in 2020). Susceptibility of pumpkin to 2,4-D and dicamba suggests herbicide applicators and pumpkin growers should consider strategies that mitigate off-target movement, including using nozzles that increase droplet size, shielded sprayers, thorough tank cleanout, buffer zones, and programs that facilitate communication between applicators and growers.

Predicting rice phenology and optimal sowing dates in temperate regions using machine learning

AbstractCrop phenology modeling often involves determining variety‐specific growing degree day thresholds, or parameterizing mechanistic crop models. In this work, we used machine learning methods to develop models that provide daily predictions of the probability that rice (Oryza sativa) crops had reached the panicle initiation and flowering growth stages. These per‐date classifications were summarized into per‐paddock growth stage transition dates, which were then compared with field‐sampled reference data, encompassing 15 rice varieties, 10 years, and 380 sites. Leave‐one‐year‐out cross validation was used to provide realistic estimates of model errors. Compared with more complex and computationally intensive algorithms, logistic regression produced competitive results (mean cross‐season validation RMSE 3.9 and 5.2 days for panicle initiation and flowering, respectively). Logistic regression had additional advantages: providing confidence of growth stage predictions at each date (as it is a probabilistic algorithm), and straightforward explainability (as model parameters directly indicated how the various input variables contributed to growth stage predictions). Input variables included accumulated weather, rice variety, and sowing methods. The models were applied to forecasting phenology transition dates of the rice crops planted throughout the Murray and Murrumbidgee valleys. In addition, recommendations for optimal sowing dates were developed, using simulations involving more than 40 years of weather data, with the goal of minimizing the risk of cold‐temperatures during the microspore growth phase, which can severely degrade yield in temperate rice growing regions.

Training Machine Learning Algorithms Using Remote Sensing and Topographic Indices for Corn Yield Prediction

Methods using remote sensing associated with artificial intelligence to forecast corn yield at the management zone level can help farmers understand the spatial variability of yield before harvesting. Here, spectral bands, topographic wetness index, and topographic position index were integrated to predict corn yield at the management zone using machine learning approaches (e.g., extremely randomized trees, gradient boosting machine, XGBoost algorithms, and stacked ensemble models). We tested four approaches: only spectral bands, spectral bands + topographic position index, spectral bands + topographic wetness index, and spectral bands + topographic position index + topographic wetness index. We also explored two approaches for model calibration: the whole-field approach and the site-specific model at the management zone level. The model’s performance was evaluated in terms of accuracy (mean absolute error) and tendency (estimated mean error). The results showed that it is possible to predict corn yield with reasonable accuracy using spectral crop information associated with the topographic wetness index and topographic position index during the flowering growth stage. Site-specific models increase the accuracy and reduce the tendency of corn yield forecasting on management zones with high, low, and intermediate yields.

Evaluation of Florpyrauxifen-benzyl for the control of Cyperus aromaticus (Navua sedge)

Background: Cyperus aromaticus (Navua sedge) is a creeping perennial sedge common to tropical environments, currently threatening many agroecosystems and ecosystems in Pacific Island countries and northern Queensland in Australia. Objective: A glasshouse study was conducted to evaluate the efficacy of florpyrauxifen-benzyl on C. aromaticus plants with and without established rhizomes. Methods: The plants with established rhizomes were treated at three application times being mowed, pre-flowering and flowering growth stages and plants without established rhizomes were treated at seedling, pre-flowering [...]

Cacopsyllapruni (Hemiptera, Psyllidae) in an apricot orchard is more attracted to white sticky traps dependent on host phenology.

The colour preference of the plum psyllid, Cacopsyllapruni (Hemiptera, Psyllidae), is yet poorly studied. This species is the only known vector of the 'Candidatus Phytoplasma prunorum', the agent of European stone fruit yellows (ESFY), a devastating disease of several cultivated Prunus species in Europe. As ESFY is still uncurable, vector control, thus vector monitoring, is pivotal to protect these trees. Cacopsyllapruni is a univoltine, host-shelter-alternating species; overwintered adults migrate from conifer to wild or cultivated Prunus species (family Rosaceae) in late winter-early spring. To select the most effective colour indicating the arrivals of the immigrants, yellow, fluorescent yellow, white, red and transparent sticky traps were deployed in an apricot orchard in Hungary. The two most abundant species in sticky traps were C.pruni and C.melanoneura. Catches of white traps were significantly biased towards C.pruni as compared to C.melanoneura specimens. Moreover, white sticky traps were better at catching plum psyllids than the other colours. Attraction to white was strongest when immigrants from shelter plants kept arriving in the orchard, coinciding with the blooming principal phenophase of apricot trees. When the host flowering growth stage was over, catches of C.pruni in white traps declined sharply to the level of yellow traps that was highest during this post-blooming period. We recommended white sticky traps for promptly monitoring C.pruni in apricot orchards because it is more potent and more selective than yellow ones during the critically important early flowering interval.

Temporal transcriptome analysis provides molecular insights into flower development in red-flesh pitaya

BackgroundPitaya is an important economic fruit worldwide due to its numerous health benefits. A systematic understanding of the mechanism underlying flower development is essential to obtain higher fruit yield and quality. However, the genetic mechanism of flower development is not yet investigated in pitaya. Herein, a transcriptome analysis was performed to determine the transcriptional changes during flower development in red-flesh pitaya by utilizing nine different stages of flower development. ResultA total of 95,412 unigenes were generated with a mean length of 913 nt, and N50 value of 1878 nt. Comparative transcriptomic analysis showed many differentially expressed genes (DEGs) among the flower growth stages. Furthermore, an array of key DEGs were enriched in hormone signaling, transcription, carbohydrate transport, and energy production pathways. In particular, indole-3-acetic acid, abscisic acid, ethylene-responsive transcription factor, constans-like, teosinte branched 1/cycloidea/proliferating cell nuclear antigen factor, apetala1-like, agamous-like MADS-box protein, sepallata, growth-regulating factor, putative axial regulator yabby, leafy/floricaula homolog, and MYB gene-associated transcription factors displayed altered expression, suggesting their critical roles in floral organ development of pitaya. Besides, genes related to sugar synthesis, transportation, and utilization mediate flower growth regulation in pitaya. Eleven genes were selected to perform qRT-PCR analysis to verify the results of the RNA sequencing. ConclusionsOur results provide important insights into the transcriptional regulation of pitaya flower development. These data resources will be a cornerstone for future research that aims at exploring the genetic control of flower development in pitaya.How to cite: Wu Z, Huang L, Huang F, et al. Temporal transcriptome analysis provides molecular insights into flower development in red-flesh pitaya. Electron J Biotechnol 2022;58 https://doi.org/10.1016/j.ejbt.2022.05.005

The effect of tillage depth and traffic management on soil properties and root development during two growth stages of winter wheat (<i>Triticum aestivum</i> L.)

Abstract. The management of agricultural soils during crop establishment can affect root development due to changes in the soil structure. This paper assesses the influence of tillage depth (250 mm, 100 mm, and zero tillage) and traffic management (conventional tyre pressure, low tyre pressure, and no traffic) on wheat root system architecture during winter wheat (Triticum aestivum L.) tillering and flowering growth stages (GS) at a long-term tillage trial site. The study revealed that zero-tillage systems increased crop yield through significantly greater root biomass (P<0.001), root length density, and deeper seminal rooting analysed using X-ray computed tomography (CT) (P<0.001) compared with trafficked treatments. In general, conventional-pressure traffic had a significant negative influence on the crop yield (P<0.01), root development (0.001), bulk density (P<0.05), and total soil porosity (P<0.05) of deep- and shallow-tillage conventional-pressure systems compared with no-traffic zero- and deep-tillage systems. Visual improvements in soil structure under zero-tillage conditions may have improved crop rooting in zero-tillage treatments through vertical pore fissures (biopores), enhancing water uptake during the crop flowering period. This study highlights the increasing implications of soil structural damage on root system architecture created by machinery traffic in crop production. Although the tillage method was less important, the constricted root systems were more pronounced in conventional-pressure shallow-tillage and deep-tillage systems, emphasizing the importance of using controlled-traffic farming methods to improve soil management and reduce the trafficked areas of agricultural fields.

Efficacy of halosulfuron-methyl in the management of Navua sedge (Cyperus aromaticus): differential responses of plants with and without established rhizomes

AbstractNavua sedge is a creeping perennial sedge commonly found in tropical environments and is currently threatening many agroecosystems and ecosystems in Pacific Island countries and northern Queensland, Australia. Pasture and crop productions have been significantly impacted by this weed. The efficacy of halosulfuron-methyl on Navua sedge plants with and without well-established rhizomes was evaluated under glasshouse conditions. Halosulfuron-methyl was applied to plants with established rhizomes at three stages; mowed, pre-flowering, and flowering growth stages, whereas plants without established rhizomes were treated at seedling, pre-flowering and flowering growth stages. At each application time, halosulfuron-methyl was applied at four dose rates of 0, 38, 75, and 150 g ai ha−1. Mortality of 27.5%, 0%, and 5% was recorded in rhizomatous Navua sedge when treated with 75 g ai ha−1 of halosulfuron-methyl at the mowed, pre-flowering stage and flowering stages, respectively. At 10 wk after treatment (WAT), there were no tillers in surviving plants treated at any of the application times. By 16 WAT, the number of tillers increased to 15, 24, and 26 in mowed, pre-flowering, and flowering stages, respectively. Although halosulfuron-methyl is effective in controlling aboveground growth, subsequent emergence of new growth from the rhizome confirms the failure of the herbicide to kill the rhizome. Application of 75 g ai ha−1 of halosulfuron-methyl provided 100% mortality in plants treated at seedling and pre-flowering stages, and 98% mortality when treated at flowering stage in non-rhizomatous plants. A single application of halosulfuron-methyl is highly effective at controlling Navua sedge seedlings but not effective at controlling plants with established rhizomes.

Variations in Chemical Compositions and Biological Activities of Artemisia vulgaris L. (Common Mugwort) Essential Oils at Different Growth Stages

The current study is aimed to investigate the essential oil (EO) yields, chemical compositions, antioxidant and antimicrobial activities of Artemisia vulgaris L. EOs were isolated before flowering, initial flowering and post-flowering growth stages. Before the flowering stage, major constituents of the EO were α-thujone (30.68%) and β-caryophyllene (22.05%). Parallel to plant development, sesquiterpene hydrocarbons (mainly β-caryophyllene) decreased and an increase was recorded in oxygenated monoterpenes, especially in α-thujone. These significant changes in the EO compositions caused various alterations in antioxidant and antimicrobial activities. Antioxidant activities of EOs were drastically decreased as the amount of β-caryophyllene dropped off from 22.05 to 7.92% and α-thujone increased from 30.68 to 47.41%. Spearman's correlation coefficients exhibited that α-thujone was quite weak against oxidative stress. In contrast to antioxidant activities, correlation analysis revealed that antimicrobial activities of EOs were enhanced with the increase of α-thujone.

Substâncias húmicas: efeito no crescimento e na produtividade de plantas de batata

ABSTRACT The results from humic substances (HS) application in varied crops and conditions are controversial, and the experiments with the potato crop in Brazil are scarce. The objective of this study was to evaluate the effects of HS doses on the growth and yield of two potato cultivars. Four doses of HS were tested: 0, 5.05, 10.10, and 15.15 L ha-1, applied in the planting furrows of cvs. Agata and BRS F63 Camila, in Guarapuava-PR, in the 2015 and 2016 crop seasons, between October and February. The experiment was carried out using a randomized complete block design, in a factorial scheme (crop season x dose x cultivar), with four replications. Plant samplings were performed at tuber initiation, flowering, tuber bulking, and plant maturation growth stages. After shoot senescence, the total and commercial tuber yields were evaluated. Cultivars responded similarly to HS application, with no significant interaction between HS and cultivars, for most assessed variables. At tuber initiation, there was a negative linear effect of HS doses on leaf area index, number of formed tubers, and tuber and total plant dry weight. In the other evaluations, the effect of HS application was not observed regarding the assessed variables. Likewise, no effects were detected on the number and fresh weight of tubers in total and commercial yields. We concluded that HS application affected both cultivars similarly, hampering initial plant growth and not increasing potato yield.

Maturity selection but not sowing date enhances soybean productivity and land use in a winter camelina–soybean relay system

AbstractEnhancing crop diversification is needed to ensure sustainable food and energy production in the soybean [Glycine max (L.) Merr.] and maize (Zea mays L.) dominated cropping systems of the US Midwest. Relay‐cropping soybean with winter camelina [Camelina sativa (L.) Crantz] is a means to sustainably intensify food and energy production while adding cropping system diversity. However, soybean yields in relay systems tend to be less than a full‐season monocrop. We hypothesized that improved soybean selection and seeding date for relay cropping could minimize this yield gap, thus increasing agricultural land use productivity. A 2‐year field study was conducted to determine the effects of soybean maturity and seeding date (SD) on winter camelina and soybean yields and land use productivity. Three soybean genotypes differing in maturity (MG) were relayed into winter camelina at rosette (SD1), bolting (SD2), and first flowering (SD3) growth stages. The soybean MGs were MG0.2, MG1.1, and MG1.7 representing early, standard, and late maturity, respectively, for the study region. The MG1.1 sown at SD2 was grown as sole crop check using conventional practices (CP). Results demonstrated that SD3 decreased camelina seed yield compared with SD1 and SD2. Soybean yield in the relay system was greatest for the MG1.7 genotype, and averaged across SD1 and SD2, was just 11.6% less than the sole crop CP check. Relaying soybean MG1.7 at SD2 produced 43% greater total (camelina +soybean) oil yield and greatly improved land use efficiency compared with CP. Appropriate soybean genotype selection can enhance winter camelina–soybean relay system productivity and land use efficiency.

Phytochemical and morpho-physiological changes of hyssop in response to chitosan-spraying under different levels of irrigation

Hyssop [Hyssopus officinalis L. subsp. angustifolius (Bieb.)] well-known for bearing essential oil-producing glands is a medicinal and aromatic plant with valuable properties for pharmaceutical, aromatic, and flavoring. The volatile oil from the aerial parts of hyssop harvested at flowering stage of growth is broadly applied in the cosmetics, pharmaceutical, and food industries In order to improve the growth, yield, and secondary metabolites production or active substances in hyssop, the experiment was done with factorial arrangement in randomized complete block design during two years (2016 and 2017). The Experimental treatments were three levels of the foliar spraying of chitosan at 0.0, 2.5, and 5.0 g/L under three levels of irrigation frequencies (6, 8, and 10 every days based on irrigation at 80–85% field capacity or F.C., 65–70% F.C., and 45–50% F.C., respectively). Results indicated that the chitosan-spraying at 2.5 g/L meaningfully raised the values of the canopy diameter, plant height, inflorescence height, numbers of auxiliary and flowering branches, dry herbal weight, and the concentrations of photosynthesis pigments (Chl a, and Chl b) under different levels of irrigation frequencies. Increasing interval irrigation decreased some physiological characteristics such as biomass and photosynthesis pigments, however, the amounts of proline and carotenoid in both experimental years increased when the hyssop plants irrigated under reduced irrigation treatment. The highest values of the volatile oil content and yield were obtained from chitosan-spraying in reduced irrigation condition. The major constituents of the hyssop volatile oils analyzed by GC-FID and GC/MS were cis-pinocamphone, β-pinene, trans-pinocamphone, myrtenol, bornyl acetate, β-caryophyllene, and germacrene D, which the elicitation of hyssop with chitosan had positive impacts on the percentage of (cis- and trans-) pinocamphone, as the predominant compounds of the hyssop volatile oil, under reduced irrigation condition. In final, it can be concluded that the applied of chitosan decrease the negative effects of water shortages and improve the quantity and quality yield of H. officinalis under reduced irrigation condition.

Proteome changes and associated physiological roles in chickpea (Cicer arietinum) tolerance to heat stress under field conditions.

Interrogative proteome analyses are used to identify and quantify the expression of proteins involved in heat tolerance and to identify associated physiological processes in heat-stressed plants. The objectives of the study were to identify and quantify the expression of proteins involved in heat tolerance and to identify associated physiological processes in chickpea (Cicer arietinum L.) heat-tolerant (Acc#7) and sensitive genotype (Acc#8) from a field study. Proteomic and gene ontological analyses showed an upregulation in proteins related to protein synthesis, intracellular traffic, defence and transport in the heat-tolerant genotype compared to the susceptible one at the warmer site. Results from KEGG analyses indicate the involvement of probable sucrose-phosphate synthase (EC 2.4.1.14) and sucrose-phosphate phosphatase (EC 3.1.3.24) proteins, that were upregulated in the heat-tolerant genotype at the warmer site, in the starch and sucrose pathway. The presence of these differentially regulated proteins including HSP70, ribulose bisphosphate carboxylase/oxygenase activase, plastocyanin and protoporphyrinogen oxidase suggests their potential role in heat tolerance, at flowering growth stage, in field-grown chickpea. This observation supports unaltered physiological and biochemical performance of the heat-tolerant genotypes (Acc#7) relative to the susceptible genotype (Acc#8) in related studies (Makonya et al. 2019). Characterisation of the candidate proteins identified in the current study as well as their specific roles in the tolerance to heat stress in chickpea are integral to further crop improvement initiatives.

Acropetal and basipetal cardenolide transport in Erysimum cheiranthoides (wormseed wallflower)

Plant specialized metabolites are often subject to within-plant transport and have tissue-specific distribution patterns. Among plants in the Brassicaceae, the genus Erysimum is unique in producing not only glucosinolates but also cardenolides. Ten cardenolides were detected with varying abundance in different tissues of Erysimum cheiranthoides L (Brassicaceae; wormseed wallflower). As is predicted by the optimal defense theory, cardenolides were most abundant in young leaves and reproductive tissues. The lowest concentrations were observed in senescing leaves and roots. Crosses between wildtype E. cheiranthoides and a mutant line with an altered cardenolide profile showed that the seed cardenolide phenotype is determined entirely by the maternal genotype. Prior to the development of the first true leaves, seedling cotyledons also had the maternal cardenolide profile. Hypocotyl grafting experiments showed that the root cardenolide profile is determined entirely by the aboveground plant genotype. In further grafting experiments, there was no evidence of cardenolide transport into the leaves, but a mixed cardenolide profile was observed in the stems and inflorescences of plants that had been grafted at vegetative and flowering growth stages, respectively. Together, these results indicate that E. cheiranthoides leaves are a site of cardenolide biosynthesis.

Impact of mid‐season sugarcane aphid infestation from blooming to harvest on forage sorghum yield and silage nutritive value

AbstractForage sorghum (Sorghum bicolorL.) grown for silage production is frequently infested by the sugarcane aphid (SCA;Melanaphis sacchari[Zehntner] [Hemiptera: Aphididae]). The objective of this study was to establish first‐time action thresholds for SCA infestation, leaf feeding, honeydew, and/or dead leaves. In this 2‐yr Texas High Plains study, we quantified the impact of varying densities of SCA and subsequent damage beginning at boot stage to yields and silage nutritive value of a susceptible forage sorghum hybrid (Pioneer 841F) by using untreated controls and different insecticide treatments (lambda cyhalothrin, chlorpyrifos, malathion, and flupyradifurone). Aphid damage occurred from boot to flowering growth stages. Damaging infestations continued until harvest in 2017, but SCA densities declined sharply after peaking at the beginning milk growth stage (BMS) in 2019. Damage levels were significantly correlated to increases in aphid densities at BMS (R2 = .91) in 2017 and at 50% bloom (R2 = .83) and BMS (R2 = .86) in 2019. Yield losses increased with increasing damage at the BMS in 2017 (R2 = .82) and 2019 (R2 = .42). Reductions in nutritive value were correlated to yield reductions. Results indicate that SCA infestations should be controlled when ≥20% of the leaf area is infested and damaged at BMS to prevent yield and nutritive value losses in the fresh and ensiled forage. Based on this work, an action threshold for forage sorghums to minimize losses to yield, nutritive value, and economic returns is presented.

Particle composition and morphology over urban environment (New Delhi): Plausible effects on wheat leaves

Particulate matter (PM) deposition on leaves adversely affects physical, chemical and biological nature of agricultural crops resulting in their loss of productivity and yield. Wheat being a staple food in major parts of Northern India and around the World, has been selected for research purpose by designing a study to explore the probable effects of PM deposition on wheat leaves and wheat crops to ensure the food security. PM5 (Particulate matter with aerodynamic diameter <5 μm) and Dry Deposited Particulate Matter (DDPM) on wheat leaves (Leaf_DDPM) were collected from the wheat crop field in Indian Agriculture Research Institute (IARI), New Delhi for growing and harvesting season of wheat crops (i.e. December 2014 to April 2015). The EDS (Energy Dispersive Spectroscopy) analysis was used for this study and the individual particle analysis revealed the presence of both acidic and alkaline components like C, Al, Si, Fe, Ca, K, S and Mg. The offline characterization tool i.e. SEM (Scanning Electron Microscope) was utilized for obtaining the micrographs which clearly showed the presence of some angular, sharp-edged and spherical particles consisting of both smooth and rough texture. Apart from that, prevalence of slightly non-spherical particles with aspect ratio of range (>1.20–1.40) and CIR (>0.70–0.80) for both PM5 and leaf_DDPM were observed. The size distribution of individual particles for both PM5(#194 particles) and Leaf_DDPM(#657 particles) revealed that Surface Equivalent Radius (SER) and Volume Equivalent Radius (VER) of particles observed to be 0.40–0.80 μm while surface area to be 0–1 μm2. These particles may easily block stomatal openings (with typical diameter range: 42–51 μm) of wheat leaves and damage internal leaf tissues while particle VER determines the interaction of incoming solar radiation with leaf surfaces. Average PM5 concentrations ± Standard deviations (μg/m3) were reported to be 231.05 ± 113.03. The XRF (X-Ray Fluorescence) spectrometer analysis of bulk PM5 revealed the concentrations of non-carbonaceous elements (μg/m3) as N (67.34 ± 16.09), Si (27.44 ± 11.01), Al (7.79 ± 3.37), S (3.88 ± 2.24), Na (2.29 ± 0.94), Mg (1.65 ± 0.62), K (0.51 ± 0.26), Ca (0.60 ± 0.26), Fe (0.54 ± 0.26), Cr (1.10 ± 0.70), Zn (0.05 ± 0.03), P (0.10 ± 0.03), Cu (0.07 ± 0.06). The dominant elemental oxides were calculated as SiO2, Al2O3, SO42−, Na2O, MgO, K2O, CaO, Fe2O3, Cr2O3, ZnO, P2O5, Cu2O with variable concentrations. In high humid conditions, with relative humidity (~85%) during the vegetative and flowering growth stages of wheat crops, presence of C and S rich acidic and hygroscopic particles may cause the corrosion of wheat leaves that ultimately affect the wheat crops.