Dispersing Rice-Associated Arthropods Ignore a Phantom Ultrasonic Insect Chorus

A within-season approach for detecting early growth stages in corn and soybean using high temporal and spatial resolution imagery

Microdochium nivale and various Fusarium spp. cause severe diseases at all cereal growth stages. To investigate the successive colonization of the basal parts of winter rye in the field, 12 inbred lines were inoculated artificially with M. nivale and 11 with F. culmorum at one location across 2 yr for each pathogen. Arbitrarily sampled shoot or stem bases were assessed for fungal protein content in the host tissue by indirect enzymelinked immunosorbent assay (ELISA) at seven growth stages from the beginning of tillering (EC 21) to full maturity (EC 91). Foot rot lesions were rated on a 1 to 9 scale at milk ripening. For M. nivale, the highest protein content and best genotypic differentiation were found in EC 21 shortly after snow melt. During further growth of the plants, M. nivale protein content decreased substantially and increased again between anthesis and full maturity. In contrast, Fusarium spp. showed a continuous increase in host tissue colonization from tillering to full maturity. In the early growth stages, fungal protein content was highly variable between years. Genotypic differentiation for resistance was significant at the earliest (EC 21) and a late (EC 75) host growth stage for M. nivale and at all growth stages tested for Fusarium spp. Heritability estimates reached the highest value at EC 21 for the M. nivale ELISA (h 2 = 0.59) and at milk ripening for the Fusarium spp. ELISA (h 2 = 0.91). Microdochium nivale and Fusarium spp. all caused foot rot symptoms at milk ripening leading to a mean foot rot rating of 3.3 and 3.8, respectively. No significant correlation existed between the resistance at early and adult-plant growth stages. For resistance to Fusarium spp., moderate to high genotypic correlations (r = 0.64-0.86) were found only among the adult-plant heading, anthesis, and milk ripening stages. Selection for adult plant resistance to Fusarium foot rot is not feasible during early host growth stages due to strong host genotype-growth stage interactions. Accordingly, resistance to M. nivale at early host growth stages (EC 21 and EC 25) cannot be used to predict resistance to M. nivale foot rot at milk ripening

Wheat powdery mildew (Blumeria graminis Dc.speer) is one of the most devastating crop diseases in the globe. Thinking of economic effective and environmental protection value, early detection of the severity of wheat powdery mildew can provide important information and technical support for disease prevention. In this study, the wheat leaves infected powdery mildew were chosen as observation objects, the obtained hyperspectral imagery data was pre-processed by reflectance calculation and noise elimination. After the disease-infected samples with different severities were divided into three-levels, four-levels, and five-levels, the effects of samples classification on identification of the disease were explored. Subsequently, the Relief-F algorithm was used to screen the sensitive bands of the disease in the early and mid-late growth stages, to observe the wavelengths change of disease identification in different developmental periods. The results showed that the sensitive bands of disease detection respectively locate at 700 nm and 680 nm for the early and mid-late growth stages, and the position of sensitive wavelength moves toward the short-wave direction as the disease worsens. On the basis, Calculating the powdery mildew disease index (PMDI) and nine kinds of common vegetation indexes, to compare their effects on disease identification, the study found that when the samples were divided into four levels, the determination coefficientR2 of PMDI is the highest. For the early and mid-late infection stages, theR2 are respectively 0.763 and 0.766. Furthermore, the corresponding SVM models were established in the different developmental periods, the classification accuracy is 90.63% at the early growth stage, while that one is the 84.62% at mid-late developmental period. The above results show that PMDI calculated by the sensitive band screening has good effective on identifying the severity of the disease, especially there is a good potential at the early growth stage.

Aluminum has great application in the machinery, transportation, aviation and military and other fields, because of its light weight, rich in resources, good comprehensive properties. Structure determines the properties, in order to obtain good properties, the key is to get the fine and uniform equiaxed grain. In order to obtain the high quality aluminum alloy of fine and uniform equiaxed grain, we must control the growth of grain in the casting process. This paper mainly discusses the effect of magnesium doped on microstructure and properties of aluminum alloy under ultrasonic vibration. Adding Mg of different content for 1wt%, 3wt%, 5wt%, 7wt%, 9wt%, 15wt% in pure aluminum, respectively, then solidifying under ultrasonic vibration. The effect of different solute content on the microstructure of aluminum alloy under ultrasonic vibration is studied. The result shows that aluminum alloy containing 9wt.% magnesium can achieve the best effect of grain refinement under ultrasonic vibration.

Nitrogen (N) deposition is a key global change factor that is increasing and affecting the structure and function of many ecosystems. To determine the influence of N deposition on specific systems, however, it is crucial to understand the temporal and spatial patterns of deposition as well as the response to that deposition. Response of the receiving plant communities may depend on the life stage-specific performance of individual species. We focus on the California oak savanna because N deposition to this system is complex—characterized by hotspots on the landscape and seasonal pulses. In a greenhouse experiment, we investigated the relative influence of N deposition on plant performance during early growth, peak biomass, and senescent life stages across different soil types, light, and community compositions. To represent the community we used three grass species—a native, naturalized exotic, and invasive exotic. At early growth and peak biomass stages performance was measured as height, and shoot and root biomass, and at the senescent stage as seed production. Simulated N deposition 1) increased shoot biomass and height of the native and, even more so, the naturalized exotic during early growth, 2) positively affected root biomass in all species during peak biomass, and 3) had no influence on seed production at the senescent stage. Alone, N deposition was not a strong driver of plant performance; however, small differences in performance among species in response to N deposition could affect community composition in future years. In particular, if there is a pulse of N deposition during the early growth stage, the naturalized exotic may have a competitive advantage that could result in its spread. Including spatial and temporal heterogeneity in a complex, manipulative experiment provides a clearer picture of not only where N management efforts should be targeted on the landscape, but also when.

BackgroundSalinity is one of the major limiting abiotic stresses that decrease crop production worldwide. To recommend genotypes for cultivation under saline stress conditions, a comprehensive understanding of the genetic basis and plant responses to this stress is needed. In the present study, a total of 20 barley genotypes were investigated to identify potential salt-tolerant genotypes, both at the early growth stage using a hydroponic system, and in adult plants under field conditions. For these purposes, the multi-trait genotype-ideotype distance index (MGIDI) was used to identify salt-tolerant barley genotypes at the seedling stage, and the weighted average of absolute scores (WAASB) index was used to identify the high-yielding and stable genotypes in adult plant stage. At the early growth stage, barley seedlings were treated with two salinity levels: 0 mM NaCl (as control conditions) and 200 mM NaCl (as stress conditions) for 30 days, and during this period different growth and physiological traits were measured. Besides, the yield performance and stability of the investigated barley genotypes were evaluated across five environments during the 2018–2020 cropping seasons.ResultsSalinity stress significantly decreased growth and physiological traits in all seedling plants; however, some salt-tolerant genotypes showed minimal reduction in the measured traits. Multivariate analysis grouped the measured traits and genotypes into different clusters. In the early growth stage, the G12, G14, G6, G7, and G16 were selected as the most salt-tolerant genotypes using MGIDI index. In the multi-environment trials experiment, AMMI analysis showed that grain yields of the tested barley genotypes were influenced by the environment (E), genotype (G), and GE interaction. Based on the weighted average of absolute scores of the genotype index (WAASB) and other stability statistics, G7, G8, G14, and G16 were selected as superior genotypes.ConclusionTogether the MGIDI and WAASB indices revealed that three genotypes—G7, G14 and G16—can be recommended as new genetic resources for improving and stabilizing grain yield in barley programs for the moderate climate and saline regions of Iran. Our results suggest that using the MGIDI index in the early growth stage can accelerate screening nurseries in barley breeding programs. Besides, the WAASB index can be used as a useful stability measurement for identify high-yielding and stable genotypes in multi-environment trials.

Effect of Application Timing on Rhizome Johnsongrass (<i>Sorghum halepense</i>) Control with DPX-V9360

Sweet sorghum (Sorghum bicolor) is a C4 drought resistant species with a huge potential for bioenergy. Accentuated reductions in water availability for crop production and altered rainfall distribution patterns, however, will have direct impact on its physiological attributes, metabolic functions and plant growth. The objective of this study was to evaluate the effects of drought and re-watering on the photosynthetic efficiency of sweet sorghum. Durable or short transient drought stress periods were imposed at early and late growth stages and compared with well-watered plants. In spite of very similar drought levels at early and late growth stages (Ψsoil = -1.6 and -1.7 MPa), the decrements in maximum quantum yield (ϕPo ) and performance index (PI) were about twice at late than at early growth stages. All the PI components, that is, density of active reaction centers (RCs), excitation energy trapping and conversion of excitation energy into electron flow followed a similar decreasing pattern. Upon re-watering and regardless the duration and growth stage of the drought period, all the photosynthetic functions, and particularly those of photosystem II (PSII), fully recovered. Such effective self-regulating functional activity by PSII photochemistry likely contributes to both high drought resistance and photosynthetic recovery capacity of sweet sorghum. At vegetative growth stages, the down regulation of the photochemistry seems to be the main photoprotective/regulative mechanisms, while at late growth stages, the accumulation of compatible solutes likely has a more preponderant role. The observed sugar concentration increments likely contributed to prevent permanent photo-oxidative destruction of the PSII RCs of mature droughted sweet sorghum plants.

Accurate and timely monitoring of leaf nitrogen concentration (LNC) in rice is crucial to optimize nitrogen fertilizer management and reduce environmental pollution. Existing vegetation indices (VIs) often perform well for high canopy cover conditions, but their performance becomes poor at early growth stages due to the significant exposure of background materials and the induced spectral mixing effect. This study proposed a novel approach to estimate the LNC at early and middle growth stages of paddy rice by using abundance adjusted VIs (AAVIs) from unmanned aerial vehicle (UAV) multispectral imagery. An AAVI was constructed by combining the traditional VI and the rice abundant from linear spectral mixture analysis of UAV imagery. Subsequently, the performance of AAVIs was evaluated in comparison with traditional VIs derived from all pixels or green pixels for individual growth stages or multiple stages. The results demonstrated that AAVIs exhibited better performance in LNC estimation, regardless of individual stages or across the entire early season. Specially, AACI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">red-edge</sub> showed the best performance among the AAVIs evaluated for LNC estimation. For universal modeling across early stages, the combination of AACI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">red-edge</sub> and AAEVI yielded the highest accuracy (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.78, RMSE = 0.26%, and rRMSE = 10.4%) performed remarkably better than the traditional VIs from all pixels or green pixels (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> <;0.40). These findings illustrated that the AAVIs have great potential in monitoring nitrogen status at early growth stages with high-resolution aerial or satellite images in the context of precision crop management.

We isolated a cold sensitive virescent1 (csv1) mutant from a rice (Oryza sativa L.) population mutagenized by carbon ion irradiation. The mutant exhibited chlorotic leaves during the early growth stages, and produced normal green leaves as it grew. The growth of csv1 plants displayed sensitivity to low temperatures. In addition, the mutant plants that were transferred to low temperatures at the fifth leaf stage produced chlorotic leaves subsequently. Genetic and molecular analyses revealed translocation of a 13-kb genomic fragment that disrupted the causative gene (CSV1; LOC_Os05g34040). CSV1 encodes a plastid-targeted oxidoreductase-like protein conserved among land plants, green algae, and cyanobacteria. Furthermore, CSV1 transcripts were more abundant in immature than in mature leaves, and they did not markedly increase or decrease with temperature. Taken together, our results indicate that CSV1 supports chloroplast development under cold stress conditions, in both the early growth and tillering stages in rice.

Roots play an important role in improving crop yield by affecting the amount of water uptake and nutrient acquisition. The objective of this study was to characterize variability in root and above-ground characteristics among three diverse semi-dwarf spring wheat cultivars, ‘Vida‘, ‘Oneal‘ and ‘Duclair‘ and a wild-type cultivar, ‘Scholar‘ at early and late growth stages in a greenhouse. Plants were grown in 45-cm long tree pots in a greenhouse under optimal growth conditions. As soil-less media, a mixture of peat (70%) and perlite (30%) was used. Plants were harvested at tillering (GS25-26) with 5-6 tillers, booting (GS43-45), and maturity (GS92). Root and shoot traits indicated significant variability among wild-type and semi-dwarf spring wheat cultivars at those growth stages. The study results showed that root mass per plant at tillering, booting, and maturity ranged from 0.10 to 0.14 g, 0.47 to 0.9 g, and 0.55 to 0.85 g, respectively, while shoot mass per plant varied from 1.7 to 2.5 g, 6.5 to 10.7 g, and 21.2 to 24.5 g, respectively. From booting to maturity, root mass was relatively constant, however, shoot mass increased considerably. Moreover, the average root mass of semi-dwarf spring wheat cultivars was 37% lower at booting and 30% lower at maturity compared to the wild-type cultivar, even though there was no significant variation among the cultivars at the early growth stage. Based on the results of the variability identified in this research, wild-type cultivar, Scholar can be evaluated for the improvement of genotypes with superior root system in breeding programs.

Simple SummaryThe gut microbiota are involved in the metabolism of nutrients, and the growth and development of pig is strongly influenced by the gut microbiome. To maintain the integrity of the intestinal barrier and promote the digestion and absorption of nutrients and other physiological activities, it is beneficial if the host has a stable gut microbial community. The composition of the gut microbiota is influenced by many factors, such as genetic and environmental factors, and it changes with age. Throughout pig growth and development, the porcine gut microbiota constantly changes in composition. This study investigated the regulation of growth and development of body weight and body size index. We further examined changes in gut microbiota during early and finishing growth stages in Duroc, Landrace and Yorkshire pigs. Results showed that the microbiota of Landrace and Yorkshire pigs were more similar compared with Duroc pigs. There were significant differences in gut microbiota in the early and late growth stages. This study underlines the longitudinal variation in breed and lateral variation in age in gut microbiota.The gut microbiota affects the metabolism, health and growth rate of pigs. Understanding the characteristics of gut microbiota of different pig breeds at each growth stage will enable the design of individualized feeding strategies. The present study aimed to compare the growth curves and development patterns of pigs of three different breeds (Duroc, Landrace and Yorkshire) using the mathematical models Gompertz, Logistic, Von Bertalanffy and Richards. For Duroc pigs, the Gompertz model showed the highest prediction accuracy (R2 = 0.9974). In contrast, the best models for Landrace and Yorkshire pigs were Richards (R2 = 0.9986) and Von Bertalanffy (R2 = 0.9977), respectively. Path analysis showed that body length (path coefficient = 0.507) and chest circumference (path coefficient = 0.532) contributed more significantly to the body weight of pigs at the early growth stage, while hip circumference (path coefficient = 0.312) had a greater influence on pig body weight in the late growth stage. Moreover, the composition of the gut microbiota of pigs at two growth stages (60 kg of body weight in the early growth stage and 120 kg in the finishing stage) was studied using 16S rRNA sequencing technology. Variations in gut microbiota composition of pigs at different growth stages were observed. KEGG pathway enrichment analysis of annotated metagenomes revealed that protein synthesis and amino acid metabolism pathways were significantly enriched in pigs at the early growth stage, which may be related to nutritional requirements of pigs during this stage. This study confirmed longitudinal variation in the gut microbiota of pigs pertaining to age as well as lateral variation related to pig breed. The present findings expand the current understanding of the variations in swine gut microbiota during production stages.

Water and nitrogen( N) are two primary factors controlling plant growth in desert ecosystems. Most studies have focused on water stress resulting from the low rainfall and high evaporation rates in arid areas. However,irrigation has become the main strategy for vegetation recovery in the southern rim of Tarim Basin. Many studies have shown that irrigation is most effective when nutrients are not limited,and fertilization is most effective when plants are not water-stressed. In addition,N not only affects drought tolerance through changing dry matter partitioning,but also plays an important role in ecosystem functioning and vegetation succession. Therefore,the combined effects of water and N on vegetation recovery and reconstruction in this area should be evaluated. We conducted a pot experiment to study characteristics of N allocation,use, and resorption,and growth of Calligonum caput-medusae Schrenk seedlings under different irrigation treatments( 4.6,6.1, 7.7,9.2,13.0 kg / plant per irrigation event). The results showed that the amounts of both N and dry matter per whole plant significantly increased with increasing amounts of irrigation. However,C. caput-medusae Schrenk seedlings were infected with powdery mildew at the high irrigation level( 13.0 kg / plant). During the early growth stage,irrigation promoted drymatter accumulation in and N allocation to,assimilating branches. On average,these assimilating branches accounted for 39.5% of whole-plant dry matter accumulation and 66.1% of whole-plant N-allocation. During the late growth stage,stems and older branches became the main organs for dry matter and N accumulation,on average accounting for 54.7% and 47.8% of whole-plant dry matter accumulation and N accumulation,respectively. The dry matter accumulation in and N allocation to stems and older branches was positively affected by irrigation at the end of the growing season. The plants allocated more dry matter and N into assimilating branches in their early growth stage to obtain more photosynthates,and to stems and older branches at the late growth stage to accumulate more energy for plant growth the following year. The root / shoot ratio of C. caput-medusae Schrenk seedlings was markedly higher under dry conditions than under irrigated conditions. The mean value of N resorption efficiency( NRE) at the early and late growth stages was 64.4% and 58.1%,respectively. The NRE was positively affected by irrigation at the early growth stage,but negatively affected by irrigation at the late growth stage( at the end of the growing season). There was a clear seasonal variation in N use efficiency( NUE),with a low mean value( 120.5 g / g) at the early growth stage and a high mean value( 235.8 g / g) at the late growth stage. Irrigation significantly enhanced the NUE of assimilating branches,stems,and older branches,and roots at the late growth stage. Although the whole-plant NUE increased significantly under higher irrigation levels,excessive irrigation did not increase the NUE. These findings suggested that both N and biomass could be distributed to the most appropriate organ of C. caput-medusae Schrenk at different growth stages to adapt to the arid and barren natural environment. Since plant growth and N use could be limited by over-irrigation and water stress,medium irrigation levels( 7.7—9.2 kg / plant) were appropriate for establishing C. caputmedusae Schrenk seedlings in this area.

Plant vigor is an important trait of field crops at early growth stages, influencing weed suppression, nutrient and water use efficiency and plant growth. High-throughput techniques for its evaluation are required and are promising for nutrient management in early growth stages and for detecting promising breeding material in plant phenotyping. However, spectral sensing for assessing early plant vigor in crops is limited by the strong soil background reflection. Digital imaging may provide a low-cost, easy-to-use alternative. Therefore, image segmentation for retrieving canopy cover was applied in a trial with three cultivars of winter wheat (Triticum aestivum L.) grown under two nitrogen regimes and in three sowing densities during four early plant growth stages (Zadok’s stages 14–32) in 2017. Imaging-based canopy cover was tested in correlation analysis for estimating dry weight, nitrogen uptake and nitrogen content. An active Greenseeker sensor and various established and newly developed vegetation indices and spectral unmixing from a passive hyperspectral spectrometer were used as alternative approaches and additionally tested for retrieving canopy cover. Before tillering (until Zadok’s stage 20), correlation coefficients for dry weight and nitrogen uptake with canopy cover strongly exceeded all other methods and remained on higher levels (R² > 0.60***) than from the Greenseeker measurements until tillering. From early tillering on, red edge based indices such as the NDRE and a newly extracted normalized difference index (736 nm; ~794 nm) were identified as best spectral methods for both traits whereas the Greenseeker and spectral unmixing correlated best with canopy cover. RGB-segmentation could be used as simple low-cost approach for very early growth stages until early tillering whereas the application of multispectral sensors should consider red edge bands for subsequent stages.

The intensification of cropping systems in the salt-affected coastal zones of the Ganges Delta can boost food security in the region. The scarcity of fresh water, coupled with varying degrees of soil and water salinity are however limiting factors for the expansion of irrigated cropping in that area. In this study, we assessed the potential of growing sunflowers using combinations of low and medium saline water for irrigation. The experiments were conducted at two locations with six irrigation treatments in 2016–2017 and 2017–2018. The treatments were: T1—two irrigations at early vegetative (25–30 days after sowing; DAS) and flowering stages (60–65 DAS) with low salinity water (LSW, electric conductivity, ECw &lt; 2 dS m−1); T2—two irrigations, one at the vegetative stage with LSW and one at the flowering stage with medium salinity water (MSW, 2 &lt; ECw &lt; 5dS m−1); T3—two irrigations, one at the vegetative stage with LSW and one at seed development stage (75–80 DAS) with MSW; T4—three irrigations at the vegetative, flowering and seed development stages with LSW; T5—three irrigations, at vegetative stage with LSW, and flowering and seed development stages with MSW; and T6—three irrigations, two at the vegetative and flowering stages with LSW and one at the seed development stage with MSW. Irrigation with LSW at early growth stages and MSW at later growth stages did not significantly (p &lt; 0.05) affect the yield compared to the LSW irrigation at early and later growth stages. Crop water productivity and irrigation water productivity of sunflowers (p &lt; 0.001) increased substantially with the decreasing amount of irrigation water with an average of 1.18 kg m−3 and 2.22 kg m−3 in 2017 and 0.92 kg m−3 and 1.29 kg m−3 in 2018, respectively. Grain yield was significantly correlated with root zone solute potential. The flowering and seed development stages of sunflowers in February–March were sensitive to both low and medium saline water irrigation for seed yield. Overall, the results show that irrigation with LSW (ECw &lt; 2dS m−1) at early growth stages and MSW (2 &lt; ECw &lt; 5dS m−1) at later growth stages could be an option for dry-season sunflowers in the coastal zones of the Ganges Delta which would allow double cropping in this area.