A Second Lease on Life for Technological Forecasting

According to the metaphor of the business seasons developed by T. Modis in his book "Conquering Uncertainty" the Journal (TF&SC), which is celebrating its 30th anniversary this year, is traversing a "fall" season. In fall seeds are put in the ground for the next season's crop. A promising such “seed” for a new generation of technological-forecasting activities is biology-related studies.

Temporal Dynamics and Severity of Cucurbit Downy Mildew Epidemics as Affected by Chemical Control and Cucurbit Host Type

Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis is an important disease that affects members of Cucurbitaceae family globally. However, temporal dynamics of the disease have not been characterized at the field scale to understand how control strategies influence disease epidemics. Disease severity was assessed visually on cucumber and summer squash treated with weekly alternation of chlorothalonil with either cymoxanil, fluopicolide or propamocarb, during the 2018 spring season and 2019 and 2020 fall seasons in North Carolina, and the 2018 and 2020 fall seasons in South Carolina. Disease onset was observed around mid-June during the spring season and early September during the fall season, followed by a rapid increase in severity until mid-July in the spring season and late September or mid-October in the fall season, typical of polycyclic epidemics. The Gompertz, logistic and monomolecular growth models were fitted to disease severity using linear regression and parameter estimates used to compare the effects of fungicide treatment and cucurbit host type on disease progress. The Gompertz and logistic models were more appropriate than the monomolecular model in describing temporal dynamics of cucurbit downy mildew, with the Gompertz model providing the best description for 34 of the 44 epidemics examined. Fungicide treatment and host type significantly (P < 0.0001) affected standardized area under disease progress curve (sAUDPC), final disease severity (Final DS) and weighted mean absolute rates of disease progress (ρ), with these variables, in most cases, being significantly (P < 0.05) lower in fungicide treated plots than in untreated control plots. Except in a few cases, sAUDPC, Final DS and ρ were lower in cases where chlorothalonil was alternated with fluopicolide or propamocarb than in cases where chlorothalonil alternated with cymoxanil or when chlorothalonil was applied alone. These results characterized the temporal progress of cucurbit downy mildew and provided an improved understanding of the dynamics of the disease at the field level. Parameters of disease progress obtained from this study could serve as inputs in simulation studies to assess the efficacy of fungicide alternation in managing fungicide resistance in this pathosystem.

Effect of Spraying with Water Hyacinth and Silverleaf Extractson Growth and Yield of Sunflower (Helianthus annuus L.)

A field experiment was carried out in one of the special fields Al-Jazirah - Al-Budhiyab located at latitude 38.28° north and longitude 43.19° east, to find out the effect of different concentrations of the extract of the Water hyacinth and silverleaf plants in three varieties of sun flower. The experiment was applied using a split-plate arrangement within an RCBD design with three replications. The main plots were represented by the varieties Ishaqi, Sakha, and Iqmar, and the sub plots included the spray concentrations 0, 5, 15 and 25 mg L-1. The results showed that the Iqmar variety was superior in plant height (179.73 cm) in the spring season, and the cultivar Ishaqi (175.50 cm) in the fall season. The variety also outperforms generously in leaf area (307.4 cm2) in the fall season. As for the extracts, the water hyacinth outperformed the plant height (177.74 and 175.11 cm) in both seasons, respectively. And in the stem diameter (20.45 mm) in the spring season and in the dry weight of the weeds (0.045 and 0.053 g m2) in both seasons respectively. While silverleaf herb extract exceeded the leaf area (213.9 and 271.1 cm2) in both seasons sequentially and the stem diameter (20.86 mm) in the fall season, the silverleaf herb extract reduced the dry weight of the weeds (0.032 and 0.043 g m2) in both seasons respectively. He increased the weight of 1000 seeds (59.25 and 67.20 grams) in both seasons and the total yield (3.26 ton ha-1) in the fall season. The 15 mg L-1 concentration also increased plant height (180.02 cm) and leaf area (208.9 cm2) in the spring season, disc diameter (22.39 cm) in the fall season and the number of seeds (924 seeds per disc-1). While the concentration increased plant height (176.19 cm) and leaf area (276.8 cm2) in the fall season. The concentration outperformed 5 mg L-1 in stem diameter (19.65 and 20.32 mm) in both seasons and increased the weight of 1000 seeds (59.57 and 67.94 g) in both seasons sequentially and the overall yield (4.35 and 3.18 ton ha-1) in both seasons. Sequentially. We conclude that there is a fluctuation in the behavior of the same crop varieties due to the overlap of study factors and in different directions, so it is recommended to individualize the factors in their influence on the varieties to know the behavior of those varieties more accurately.

Assessment of Macrophyte Biological Index for Rivers, and evaluation of physicochemical parameters in the Sakarya River Basin of Turkey

In this study, the Macrophyte Biological Index for Rivers (IBMR) method and physicochemical measurements were used to assess the trophic status of the Sakarya River Basin in Turkey. The most abundant macrophytes were Phragmites australis, Thypa latifolia, Juncus sp., and Paspalum distichum. The IBMR values varied between 6.00 and 13.00 in spring, and between 6.714 and 14.40 in the fall season. The sampling stations, which are under the influence of agricultural runoffs, domestic effluents, and industrial discharges, had hypoxia accompanied by eutrophic and/or hypertrophic conditions at least in one season. The individual trophy levels of the sampling sites in the basin have been assessed as mesotrophic to eutrophic. However, considering the average IBMR value of all stations, the general trophy level of the basin was close to eutrophic. The results indicate that the physicochemical parameters are affected by various effluents discharged to the basin as observed during field studies, and the obtained data would be useful to apply conservation measures.

First report of cucurbit yellow stunting disorder virus and cucurbit chlorotic yellows virus in cucurbit crops in Alabama

During the summer and fall of 2020, foliar yellowing symptoms, including leaf mottle and interveinal yellowing with green veins were observed on several melon, squash, and cucumber plants in commercial fields in Alabama, USA. These foliar symptoms were similar to those caused by the whitefly-transmitted yellowing viruses, cucurbit chlorotic yellows virus (CCYV) and cucurbit yellow stunting disorder virus (CYSDV) (both genus Crinivirus, Closteroviridae). A total of 231 leaf samples showing yellowing, interveinal chlorosis, and mottling (e-Xtra 1, 2) were collected from individual plants from 25 commercial fields in Alabama (70 watermelon, 52 melon, 34 pumpkin, 50 squash, and 25 cucumber) during two sampling periods, June (spring/summer season) and October (fall season) 2020. Total RNA, extracted as described in Tamang et al. (2021), was used in reverse transcription polymerase chain reaction (RT-PCR) with primer sets designed to amplify portions of the CCYV and CYSDV RNA-dependent RNA polymerase (RdRp) genes encoded on RNA1 of these viruses (Mondal et al. 2021, submitted; Kavalappara et al., 2021). Single infections of either CYSDV or CCYV were found in 53 of 57 infected cucurbit samples (of 231 total plants), whereas both viruses were detected in four samples, all squash. In June 2020 near the end of the spring season, CYSDV was identified from 20 of 114 total cucurbit plants tested (17.5%), but CCYV was not identified from any plants. During the fall season, 37 of 117 plants (32%) tested positive for the presence of one or both criniviruses. Of the 37 virus-positive samples from the fall season, 26 were singly infected with CCYV (70%), seven were singly infected with CYSDV (19%), and four were infected with both CYSDV and CCYV (11%). The RdRp amplicon was sequenced from three CCYV-infected plants (2 squash; GenBank Accession No. MZ073347, MZ073348; 1 cucumber, MZ073349) and one CYSDV-infected plant (melon, MZ073350); the 857 nt sequenced portion of the CCYV RdRp gene was found to share 99% identity with the same sequence of CCYV RNA1 isolates from Israel (MH477611.1) and California (MW680157), whereas the 494 nt CYSDV amplicon shared 100% sequence identity with the comparable sequence from RNA1 of a CYSDV isolate from Arizona (EF547827.1). In addition, all of the CYSDV and CCYV infections were confirmed using a second set of primers that amplified 394 and 372 nt sections of the coat protein gene of each virus, respectively (Wintermantel et al., 2009; 2019), encoded on RNA2 of each viral genome. Furthermore, a recently developed multiplex RT-qPCR method (Mondal et al. 2021, submitted) was used to confirm four representative CYSDV and CCYV infections each. This is the first report of CYSDV and CCYV in cucurbit crops from Alabama. Surprisingly, CYSDV was only found in melon plants (20 of 52, 38%), whereas CCYV was only found in squash, pumpkin, and cucumber (26 of 109, 24%); no watermelon plants were infected with either virus, even though watermelon is a known host of both viruses. The identification of CCYV and CYSDV in Alabama, along with a recent report of both criniviruses from nearby Georgia (Kavalappara et al., 2021) illustrates the need for a more thorough sampling of cucurbit crops, further monitoring of the whitefly vector, Bemisia tabaci, and the identification of alternate hosts of these viruses to better understand the epidemiology of these viruses in Alabama and throughout the Gulf Coast region.

Seasonal Spectral Separation of Western Snowberry and Wolfwillow in Grasslands with Field Spectroradiometer and Simulated Multispectral Bands

Woody plant encroachment (WPE), the expansion of native and non-native trees and shrubs into grasslands, has led to degradation worldwide. In the Canadian prairies, western snowberry and wolfwillow shrubs are common encroachers, whose cover is currently unknown. As the use of remote sensing in grassland monitoring increases, opportunities to detect and map these woody species are enhanced. Therefore, the purpose of this study is to identify the optimal season for detection of the two shrubs, to determine the sensitive wavelengths and bands that allow for their separation, and to investigate differences in separability potential between a hyperspectral and broadband multispectral approach. We do this by using spring, summer, and fall field-based spectra of both shrubs for the calculation of spectral separability metrics and for the simulation of broadband spectra. Our results show that the summer offers higher discrimination between the two species, especially when using the red and blue spectral regions and to a lesser extent the green region. The fall season fails to provide significant spectral separation along the wavelength spectrum. Moreover, there is no significant difference in the results from the hyperspectral or broadband approach. Nevertheless, cross-validation with satellite imagery is needed to confirm the current results.

Budget of nitrous acid (HONO) and its impacts on atmospheric oxidation capacity at an urban site in the fall season of Guangzhou, China

Nitrous acid (HONO) can produce hydroxyl radicals (OH) by photolysis and plays an important role in atmospheric photochemistry. Over the years, high concentrations of HONO have been observed in the Pearl River Delta region (PRD) of China, which may be one reason for the elevated atmospheric oxidation capacity. A comprehensive atmospheric observation campaign was conducted at an urban site in Guangzhou from 27 September to 9 November 2018. During the period, HONO was measured from 0.02 to 4.43 ppbv with an average of 0.74 ± 0.70 ppbv. The emission ratios (HONO/NOx) of 0.9 ± 0.4 % were derived from 11 fresh plumes. The primary emission rates of HONO at night were calculated to be between 0.04 ± 0.02 ppbv h−1 and 0.30 ± 0.15 ppbv h−1 based on a high-resolution emission inventory. The HONO formation rate by the homogeneous reaction of OH + NO at night was 0.26 ± 0.08 ppbv h−1, which can be seen as secondary results from primary emission. They were both much higher than the increase rate of HONO (0.02 ppbv h−1) during night. Soil emission rate of HONO at night was calculated to be 0.019 ± 0.001 ppbv h−1. Assuming dry deposition as the dominant removal process of HONO at night, and a deposition velocity of at least ~2.5 cm s−1 is required to balance the direct emissions and OH + NO reaction. Correlation analysis shows that NH3 and relative humidity (RH) may participate in the heterogeneous transformation from NO2 to HONO at night. In the daytime, the average primary emission Pemis was 0.12 ± 0.01 ppbv h−1, and the homogeneous reaction POH + NO was 0.79 ± 0.61 ppbv h−1, larger than the unknown sources PUnknown (0.65 ± 0.46 ppbv h−1). These results suggest primary emissions as a key factor affecting HONO at our site, both during daytime and nighttime. Similar to previous studies, the daytime unknown source of HONO, PUnknown, appeared to be related to the photo-enhanced conversion of NO2. The daytime average OH production rates by photolysis of HONO was 3.7 × 106 cm−3 s−1, lower than that from O1D + H2O at 4.9 × 106 cm−3 s−1. Simulations of OH and O3 with the Master Chemical Mechanism (MCM) box model suggested strong enhancement effect of HONO on OH and O3 by 59 % and 68.8 %, respectively, showing a remarkable contribution of HONO to the atmospheric oxidation in the fall season of Guangzhou.

Iodine Biofortification Counters Micronutrient Deficiency and Improve Functional Quality of Open Field Grown Curly Endive

Human iodine (I) shortage disorders are documented as an imperative world-wide health issue for a great number of people. The World Health Organization (WHO) recommends I consumption through ingestion of seafood and biofortified food such as vegetables. The current work was carried out to appraise the effects of different I concentrations (0, 50, 250, and 500 mg L−1), supplied via foliar spray on curly endive grown in the fall or spring–summer season. Head fresh weight, stem diameter, head height, and soluble solid content (SSC) were negatively correlated to I dosage. The highest head dry matter content was recorded in plants supplied with 250 mg I L−1, both in the fall and spring–summer season, and in those cultivated in the fall season and supplied with 50 mg I L−1. The highest ascorbic acid concentration was recorded in plants cultivated in the spring–summer season and biofortified with the highest I dosage. The highest fructose and glucose concentrations in leaf tissues were obtained in plants cultivated in the spring–summer season and treated with 250 mg I L−1. Plants sprayed with 250 mg I L−1 and cultivated in the fall season had the highest I leaf concentration. Overall, our results evidently suggested that an I application of 250 mg L−1 in both growing seasons effectively enhanced plant quality and functional parameters in curly endive plants.

Ubiquity of quasi-aerosol layers in the free troposphere over the Indian region: Results from multiyear satellite observations

&lt;p&gt;Vertical distribution of aerosols and their composition in the lower troposphere is critically important for assessing the Earth&amp;#8217;s radiation budget and their impact on monsoon circulation. We combine the extinction coefficient, particulate depolarization ratio obtained&amp;#160;from CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) for period of 11 years (2008-2018) over the Indian region to provide an unprecedented climatological overview of the physical and optical characteristics of quasi-aerosol&amp;#160;layers and their source and formation mechanism&lt;strong&gt; &lt;/strong&gt;throughout its annual life cycle in the free troposphere. The key findings includes: i)The quasi aerosol layer over the Indian region are found to be persistent between 4-6 km during all seasons and occasionally reach above 6 km and exhibited strong seasonal and regional dependency, ii) Layer thickness varies between 2.0 -3.0 km corresponds to primary peak are more frequent of about 80-90 % of cases over all six regions and while&amp;#160; secondary layer occasionally forms (10-20 %), iii) The aerosol layer thickness increases by about 36.7 and 25% during summer and fall season compared to that of spring, and winter, iv) Layer-AOT showed year-to-year variations of up to a factor of two with a relative variability of about 15-23% (1&amp;#963;), v) Trend in layer AOT is not very conspicuous and showed oscillatory pattern, vi) Depolarization ratios generally increase with height suggesting that the irregularity of aerosol shape increases with altitude, vii) The polluted dust and smoke are the major aerosol components of the observed quasi aerosol layer&amp;#160; between 4 to 6 km for spring and fall season while these are the polluted dust during winter and summer.&lt;/p&gt;