Field Growing Conditions Research Articles

Water use characteristics and drought tolerant ability of different winter wheat cultivars assessed under whole growth circle and at seedling stage

Using drought-resistant cultivars is important to increase crop production in water limited regions. Cultivar performance is influenced by genetic, management and environmental factors, and selection good performance cultivars is often a challenge. Five seasons (2016–2021) of field experiments and three seedling growing durations in a greenhouse, both under three water supply levels (serious water deficit, moderate water deficit and normal water supply), were conducted to assess 10 winter wheat cultivars for their water use characteristics and drought tolerance ability based on seven drought resistance indices and agronomic traits. The performance of the cultivars varied seasonally under field growing conditions. Drought resistance screened by a single index or based on the results from a single season was inconsistent. To avoid seasonal changes in cultivar performance, principal component analyses (PCA) and hierarchical cluster analysis (HCA) were conducted based on the seven indices to classify the ten cultivars into four types of drought responses. The drought resistance classification under field growing conditions at the grain yield level was highly consistent with that obtained under greenhouse growing conditions for biomass at the seedling stage. The results showed that the biomass at the seedling growing stage of the winter wheat cultivars could be used to predict the yield performance and water use characteristics when grown in the field under different water supply conditions. Precisely controlled greenhouse pot experiments could amplify the water use characteristics of different wheat cultivars for assessment. The cultivars with strong stomatal control ability had higher drought resistance and biomass production. Under field growing conditions, lower canopy temperature, deep root growth, a high root/shoot ratio and the maintenance of stomatal conductance under water stress were associated with high drought resistance. These findings provide references for selection methods and indicators for assessing drought-resistant winter wheat cultivars under different growing conditions.

Efficiency of bio-agents and green-synthesized silver nanoparticles in controlling purple blotch disease caused by Alternaria porri in onion plants

One of the most fatal diseases that harm Allium species is purple blotch, which is brought on by Alternaria porri. As the disease's severity rises, crop production may decrease. In this study, 12 isolates of A. porri exhibiting purple blotch symptoms have been isolated from diseased onion plants. Sequencing of the internal transcribed spacer region (ITS) allowed for the identification of the isolate that was the most virulent and caused a disease severity of 85.93%. Under greenhouse and field growing conditions, the efficiency of two bio-agents, Trichoderma asperellum T34 and Saccharomyces cerevisiae AUMC 10203, as well as three doses (50, 25, and 12.5 ppm) of their green-synthesized silver nanoparticles (AgNPs) against purple blotch disease was assessed. For avoiding or treating purple blotch disease in onion plants, it has been demonstrated that the T. asperellum T34 spore suspension was the most effective resulting in a 76% reduction in disease severity. The spore suspension of S. cerevisiae and a 50-ppm dosage of AgNPs were the top contenders for T. asperellum. When compared to the control plants, the plants treated with bio-agents and AgNPs showed a significant decline in disease incidence and disease severity. Additionally, improvements were made to the broadness of inflorescences, the number of flowers and seeds, the weight of seeds per inflorescence, and the seed productivity. Therefore, it is recommended in this study to use T. asperellum T34 spore suspension as a potent bio-agent to manage the symptoms of purple blotch on onions.

Ensifer adhaerens strain OV14 seed application enhances Triticum aestivum L. and Brassica napus L. development

Given the challenges imposed by climate change and societal challenges, the European Union established ambitious goals as part of its Farm to Fork (F2F) strategy. Focussed on accelerating the transition to systems of sustainable food production, processing and consumption, a key element of F2F is to reduce the use of fertilisers by at least 20% and plant protection products by up to 50% by 2030. In recent years, a substantial body of research has highlighted the potential impact of microbial-based applications to support crop production practices through both biotic/abiotic stresses via maintaining or even improving yields and reducing reliance on intensive chemical inputs. Here, we have characterised the ability of a new soil-borne free-living bacterium strain Ensifer adhaerens OV14 (EaOV14) to significantly enhance crop vigour index by up to 50% for monocot (wheat, Triticum aestivum L., p < 0.0001) and by up to 40% for dicot (oilseed rape, Brassica napus L., p < 0.0001) species under in-vitro conditions (n = 360 seedlings/treatment). The beneficial effect was further studied under controlled glasshouse growing conditions (n = 60 plants/treatment) where EaOV14 induced significantly increased seed yield of spring oilseed rape compared to the controls (p < 0.0001). Moreover, using bespoke rhizoboxes, enhanced root architecture (density, roots orientation, roots thickness etc.) was observed for spring oilseed rape and winter wheat, with the median number of roots 55% and 33% higher for oilseed rape and wheat respectively, following EaOV14 seed treatment compared to the control. In addition, EaOV14 treatment increased root tip formation and root volume, suggesting the formation of a more robust root system architecture post-seed treatment. However, like other microbial formulations, the trade-offs associated with field translation, such as loss or limited functionality due to inoculum formulation or environmental distress, need further investigation. Moreover, the delivery method requires further optimisation to identify the optimal inoculum formulation that will maximise the expected beneficial impact on yield under field growing conditions.

The Impact of Greenhouse and Field Growth Conditions on Chenopodium quinoa Willd Accessions’ Response to Salt Stress: A Comparative Approach

Quinoa’s exceptional capacity to tolerate high salt levels presents a promising solution to the agricultural challenges posed by salt stress. This study aimed to explore salt stress effects on three quinoa accessions (18 GR, R-132, and DE-1) and to compare the influence of greenhouse and field growing conditions on their salinity tolerance. The plants were irrigated by 50, 100, 150, and 200 mM NaCl concentrations. The results showed that quinoa plants’ response to morphological, physiological, biochemical, and enzymatic parameters was influenced by NaCl concentration, accession, growing conditions, and their interactions. As salinity irrigation increased, aerial part length and leaf area decreased significantly (p &lt; 0.05) for all studied accessions, correlating with plant photosynthetic parameters. Greenhouse conditions promote faster and more vigorous growth with a larger leaf area compared to field cultivation. Furthermore, at 200 mM concentration, the DE-1 accession displayed greater photosynthetic activity, recording values of 195.66 ± 3.56 and 120 ± 1.13 µmol·m−2·s−1 for greenhouse and open field conditions, respectively. NaCl stimulated MDA and H2O2 in both conditions for all accessions, and the DE-1 accession displayed the lowest levels. Proteins, sugars, proline, peroxidase, ascorbate peroxidase, and catalase were stimulated by salt stress, except in the R-132 accession. Field cultivation resulted in a more severe salinity response. Greenhouse conditions may enhance quinoa’s salt tolerance due to the less demanding growth conditions. DE-1 exhibited the highest salt tolerance, while R-132 showed the lowest. This study sets the stage for further research into the genetic basis of salt tolerance in various quinoa accessions, optimizing growth in salty regions through farming practices, and confirming the obtained results in real-world conditions for sustainable agriculture.

Evaluation of selection indices for heat tolerance and their correlation with yield in some chickpea (Cicer Arietinum L.) genotypes of sudan

The major a biotic stresses affecting chickpea production are high and low temperature, drought and salinity. Heat stress is a major a biotic stress factor, constraining chickpea production worldwide. This study was conducted to identifying chickpea genotypes combining heat tolerance and high yield potential and to study correlation among the heat tolerance indices. The genotypes were tested under different field-growing conditions, normal sown (non – heat stress) and late sown (heat stress) at two locations, Merowe and Gezira during winter season 2018/2019. The trials were laid out in alpha lattice design with three replications. Eight heat tolerance indices, which were most frequently used in plant breeding including, geometric mean productivity (GMP), yield index (YI), mean productivity (MP), stress susceptibility index (SSI), stress tolerance index (STI), tolerance index (TOL), sensitivity heat index (SHI) and relative heat index (RHI) were calculated based on seed yield under heat stress (Ys) and non – heat stress (Yp) conditions. Under both environments, the results from combined analysis of variance showed that there were highly significant differences among the genotypes for all traits studies. There were highly significant differences observed among the tested chickpea genotypes response to heat stress. Seed yield in stress (Ys) condition was positive and highly significant correlated with geometric mean productivity, yield index, stress tolerance index and relative heat index. The Ys was negative and highly significant correlated with stress susceptibility index and sensitivity heat index. Seed yield in non-stress (Yp) condition was positive and significant correlated with geometric mean productivity, yield index, stress tolerance index and tolerance index. The results of this research showed that the six indices, GMP, YI, SSI, STI, SHI and RHI can be used as optimal indicators for screening heat tolerant chickpea genotypes. Nine genotypes including four released improved varieties (Shiekh Mohamed, Wad Hamid, Salwa and Hwata) and five genotypes (no. 11, 4, 26, 30 and 34) are most stable chickpea genotypes for heat tolerance and can be further used in breeding program. These genotypes can be used in the chickpea national breeding program to develop varieties with improved heat tolerance in Sudan. Genotype no. 11 (FLIP 08-59 C) was release by Sudan national variety release committee for commercial production under the name Elbarkal in September 2022 to will be grown in Gezira, River Nile and Northern States of Sudan.

Prediction of Corn Yield in the USA Corn Belt Using Satellite Data and Machine Learning: From an Evapotranspiration Perspective

The reliable prediction of corn yield for the United States of America is essential for effective food and energy management of the world. Three satellite-derived variables were selected, namely enhanced vegetation index (EVI), leaf area index (LAI) and land surface temperature (LST). The least absolute shrinkage and selection operator (LASSO) was used for regression, while random forest (RF), support vector regression (SVR) and long short-term memory (LSTM) methods were selected for machine learning. The three variables serve as inputs to these methods, and their efficacy in predicting corn yield was assessed in relation to evapotranspiration (ET). The results confirmed that a high level of performance can be achieved for yield prediction (mean predicted R2 = 0.63) by combining EVI + LAI + LST with the four methods. Among them, the best results were obtained by using LSTM (mean predicted R2 = 0.67). EVI and LST provided extra and unique information in peak and early growth stages for corn yield, respectively, and the usefulness of including LAI was not readily apparent across the whole season, which was consistent with the field growing conditions affecting the ET of corn. The satellite-derived data and the methods used in this study could be used for predicting the yields of other crops in different regions.

On-field phenotypic evaluation of sunflower populations for broad-spectrum resistance to Verticillium leaf mottle and wilt

Sunflower Verticillium Wilt and Leaf Mottle (SVW), caused by Verticillium dahliae (Kleb.; Vd), is a soil-borne disease affecting sunflower worldwide. A single dominant locus, known as V1, was formerly effective in controlling North-American Vd races, whereas races from Argentina, Europe and an emerging race from USA overcome its resistance. This emphasizes the need for identifying broad-spectrum genetic resistance (BSR) sources. Here we characterize two sunflower mapping populations (MPs) for SVW resistance: a biparental MP and the association MP from the National Institute of Agricultural Technology (INTA), under field growing conditions. Nine field-trials (FTs) were conducted in highly infested fields in the most SVW-affected region of Argentina. Several disease descriptors (DDs), including incidence and severity, were scored across four phenological stages. Generalized linear models were fitted according to the nature of each variable, adjusting mean phenotypes for inbred lines across and within FTs. Comparison of these responses allowed the identification of novel BSR sources. Furthermore, we present the first report of SVW resistance heritability, with estimates ranging from 35 to 45% for DDs related to disease incidence and severity, respectively. This study constitutes the largest SVW resistance characterization reported to date in sunflower, identifying valuable genetic resources for BSR-breeding to cope with a pathogen of increasing importance worldwide.

Effects of shading on triterpene saponin accumulation and related gene expression of Aralia elata (Miq.) Seem

Aralia elata (Miq.) Seem is widely used as a medicinal plant and functional food in China. In this study, A. elata plants were exposed to full sunlight (CK), 40% shading (LS), 60% shading (MS), and >80% shading (ES) condition to investigate the effects of shading treatments on growth, stress levels, antioxidant enzymes activity, araloside content and related gene expression. The greatest growth and leaf biomass were achieved in 40% shading, and leaf biomass per plant increased by 16.09% compared to the non-shading treatment. Furthermore, the lowest reactive oxide species (ROS) production and lipid peroxidation resulting from increasing antioxidant enzyme activity were also observed in LS treatment. Overall, shading percentage negatively regulated the expression of key enzymes (squalene synthase, SS; squalene epoxidase, SE and β-amyrin synthase, bAS) involved in the saponin biosynthesis, resulting in the greatest yields of total and four selected aralosides in A. elata leaves were achieved in sunlight group. However, the greatest yield of total saponin in the leaves was observed in the 40% shading group due to higher leaf biomass. The results suggest that optimizing the field growing conditions would be important for obtaining the greatest yield of bioactive components. Total saponin and selected aralosides also have a significant correlation with ROS production and antioxidant enzyme activity, these indicated the increased yield of these saponins may be part of a defense response. The study concludes that the production of saponin was the interaction of oxidative stress and photosynthesis.

Physiological Responses of Onion Varieties to varying Photoperiod and Temperature Regimes

We measured the gas exchange parameters of six onion varieties in two photoperiodic regimes. The photoperiods simulated early (long-day) and late (short-day) onion growing seasons of the high desert regions near Lancaster, California. We used six locally grown onion varieties: RedBull (RB), RedWing (RW), Hybrid Cometa (HC), Granero (YG), Hybrid Valero (HV) and Hybrid SR (HS). For both photoperiod regimes, daylength and temperature were changed weekly to represent the natural progression of field growing conditions. The results show that the onion plants grown under short-daylength (SD) and higher temperature regimes exhibited higher leaf photosynthetic rates and stomatal conductance than onion seedlings grown under the long-day (LD) regime. Onion plants also had different functional leaf traits depending on crop growth environment during the onset of bulbing. The higher photosynthetic rate of the short-day plants coincided with bulb initiation. Onion photosynthesis and stomatal conductance increased at bulb initiation, apparently to provide carbohydrates for growth and storage in the bulb.

Assessing thermal efficiency for berry anthocyanin accumulation in four different sites and field-growing conditions

Assessing thermal efficiency for berry anthocyanin accumulation in four different sites and field-growing conditions

Assessment of genetic and epigenetic changes in virus-free garlic (Allium sativum L.) plants obtained by meristem culture followed by in vitro propagation.

This is the first report assessing epigenetic variation in garlic. High genetic and epigenetic polymorphism during in vitro culture was detected.Sequencing of MSAP fragments revealed homology with ESTs. Garlic (Allium sativum) is a worldwide crop of economic importance susceptible to viral infections that can cause significant yield losses. Meristem tissue culture is the most employed method to sanitize elite cultivars.Often the virus-free garlic plants obtained are multiplied in vitro (micro propagation). However, it was reported that micro-propagation frequently produces somaclonal variation at the phenotypic level, which is an undesirable trait when breeders are seeking to maintain varietal stability. We employed amplification fragment length polymorphism and methylation sensitive amplified polymorphism (MSAP) methodologies to assess genetic and epigenetic modifications in two culture systems: virus-free plants obtained by meristem culture followed by in vitro multiplication and field culture. Our results suggest that garlic exhibits genetic and epigenetic polymorphism under field growing conditions. However, during in vitro culture system both kinds of polymorphisms intensify indicating that this system induces somaclonal variation. Furthermore, while genetic changes accumulated along the time of in vitro culture, epigenetic polymorphism reached the major variation at 6 months and then stabilize, being demethylation and CG methylation the principal conversions.Cloning and sequencing differentially methylated MSAP fragments allowed us to identify coding and unknown sequences of A. sativum, including sequences belonging to LTR Gypsy retrotransposons. Together, our results highlight that main changes occur in the initial 6 months of micro propagation. For the best of our knowledge, this is the first report on epigenetic assessment in garlic.

Integrated Effects of Light Intensity and Fertilization on Growth and Flavonoid Accumulation in Cyclocarya paliurus

Cyclocarya paliurus has been used for drug formulations and ingredients in functional foods in China. Field studies were conducted to examine the relationships between environmental factors and flavonoid accumulation. A split-plot randomized design was used to establish three shading treatments and three fertilization levels, and growth parameters and flavonoid contents were detected. The greatest biomass production was achieved in intermediate shade and fertilization treatment, and leaf production per seedling increased by 139.5% compared to the treatment without shade and fertilization. Overall, shade and fertilization had a significantly negative effect on contents of total flavonoid, kaempferol, quercetin, and isoquercitrin in leaves of C. paliurus. However, the greatest accumulation of total flavonoid in the leaves was observed in intermediate shade and fertilization treatment, achieving 364.4 g/plant. The results suggest that manipulating the field growing conditions and optimizing the silvicultural system would be important for obtaining the greatest yield of targeted health-promoting substances.

Physiological characterization of ‘stay green’ wheat cultivars during the grain filling stage under field growing conditions

Rye (Secale cereale L.) chromosome arm 1RS could delay leaf senescence, and change in H2O2 content is a useful index for weighing the ability to delay the senescence. Two wheat cultivars, Chuannong12 (CN12) and Chuannong 18 (CN18), harboring the wheat–rye 1BL/1RS translocated chromosome were investigated for H2O2 change and physiological index after flowering under field conditions, and MY11, the agronomical parent of both CN12 and CN18, was used as the control. A combined change in the peak value of CdSe/ZnS quantum dot (QD) fluorescence and morphological observation indicated that the H2O2 contents in CN12 and CN18 were generally lower than that in MY11. They both had higher values for net photosynthetic rate (Pn), stomatal conductance (Gs), \( F_{\text{v}} /F_{\text{m}}^{\prime } \)\( F_{\text{v}}^{\prime } /F_{\text{m}}^{\prime } \), and photochemical quenching of PSII (qP) than MY11 only in the late measurement stage. Some small differences were also observed, such as CN12 and CN18 wheat cultivars having higher and longer photosynthetic competence than MY11 during the grain filling stage, which perhaps resulted from a mechanism for removing oxidative species, especially H2O2.

Intermittent Shade Effect on Gas Exchange of Cotton Leaves in the Humid Southeastern USA

AbstractConvective cumulus clouds intermittently shade growing plants on most days during the summer months in the southeastern USA. Previous research indicates a significant delay in the recovery of stomatal conductance (gs) of cotton (Gossypium hirsutum L.) leaves following a period of shade. Our objective was to determine the effect of shade on leaf net CO2 exchange rate (CER) and gs of three cotton cultivars. We monitored CER and gs of greenhouse‐ and field‐grown cotton before, during, and after shading plants for up to 9 min at photosynthetically active radiation (PAR) levels of &lt;300 μmol quanta m−2 s−1. The three cultivars had the same gas exchange response to shade. With the imposition of a 6‐min shade on greenhouse‐grown plants at 7 weeks after planting (WAP) gs of uppermost fully expanded leaves fell 43%. Two weeks later, a 6‐min shade reduced gs of uppermost fully expanded leaves by 97%. Under field conditions, a 9‐min shade reduced gs by 35% early in the cutout period (cessation of vegetative growth) in 1992 and 42% late in the cutout period in 1994. Under both greenhouse and field growing conditions, the low PAR levels with shade reduced CER to near 0 μmol CO2 m−2 s−1. Recovery of CER to preshade levels after the shade was removed coincided with the rate of recovery of gs. In the greenhouse‐grown plants, recovery of CER to preshade levels following 6 min of shade did not occur until 7 min (at 7 WAP) and 10 min (at 9 WAP) after the shade was removed. Field‐grown leaves needed only 4 min to recover to preshade levels of CER and g2 following 9 min of shade. The results suggest that, following a brief shade period, field‐grown cotton leaves reacclimate within 4 min, while leaves on greenhouse‐grown plants may take longer.

Weed Control Strategies for Field Grown Herbaceous Perennials

Abstract Fourteen herbicides or herbicide combinations, wood chip mulch, chipped rubber tire mulch, and newspaper mulch were evaluated for weed control efficacy and phytotoxicity using 12 species of herbaceous perennials under field growing conditions. The effect of herbicide application time was monitored by applying herbicides to dormant and actively growing plants. Herbicide and mulch treatments were compared to weeded and non-weeded controls. Herbicide phytotoxicity was dependent on age and species of herbaceous perennial and time of herbicide application. Herbicide injury was generally greater for young plants compared to established plants and phytotoxicity was usually reduced when herbicides were applied to dormant rather than actively growing plants. Injury was sometimes greater when herbicides were applied in early spring compared to applications made after complete herbaceous perennial emergence. Injury to young shoots that had emerged prior to the earliest possible time that herbicides could be applied in the spring was probably involved. Applying herbicides in the fall may avoid such injury. Mulching field grown perennials with wood chips provided the most effective weed control and often the best quality plants. With the exceptions of Hemerocallis ‘After Dark’ and Phlox maculata ‘Omega’, the herbaceous perennials evaluated were tolerant of most of the herbicides applied. Several herbicides, including Balan 2.5G at 3.36 kg ai/ha (3.0 lb ai/A), Snapshot 80DF at 4.48 kg ai/ha (4.0 lb ai/A), and Stomp 60WDG at 4.48 kg ai/ha (4.0 lb ai/A), demonstrated potential for weed control in herbaceous perennial production systems and landscape plantings. Goal 1.6EC at 1.68 kg ai/ha (1.5 lb ai/A) and Ronstar 50WP at 3.92 kg ai/ha (3.5 lb ai/A) were often phytotoxic when applied to herbaceous perennials.

Weed Control Strategies for Field- and Container-grown Herbaceous Perennials

Fourteen herbicides or herbicide combinations, a wood chip mulch, a chipped rubber tire mulch, and a newspaper mulch were evaluated for weed control efficacy and potential phytotoxicity using 12 species of herbaceous perennials under field-growing conditions. Nineteen herbicides or herbicide combinations were similarly evaluated under container-growing conditions using 11 species of herbaceous perennials. The effect of herbicide application time also was monitored through application of herbicides to dormant and actively growing plants. Herbicides and mulch treatments were compared to weeded and nonweeded controls. Herbicide phytotoxicity effects were dependent on the age and species of the herbaceous perennial and herbicide application timing. Herbicide injury was generally greater for newly established plants compared to established plants. Although injury was usually reduced when herbicides were applied to dormant plants, injury was sometimes greater when herbicides were applied in early spring compared to applications made in late spring after complete herbaceous perennial emergence. This effect resulted in injury to young shoots that had emerged before the earliest possible time that herbicides could be applied in early spring. A wood chip mulch provided the most effective weed control and highest quality plants under field growing conditions. Several of the herbicides evaluated demonstrated potential for weed control in both field and container herbaceous perennial production systems and landscape plantings.

Morphological Studies of Flower Bud Initiation and Development in Bulbous Iris Stored at Various Temperatures1,3

Abstract Flower buds are absent in dormant iris bulbs, but floral initiation occurs after subjecting them to a high temp, heat curing treatment, followed by a holding period at a moderate temp, and then a low temp pre-cooling period. The effects of cultivars, digging dates, ethylene gas treatment, and different storage temp on earliness and uniformity of flowering were studied in microscopic sections of bulb growing points of samples collected at intervals from the different treatment lots. The results indicated that variations in field growing conditions produced bulbs with varying degrees of maturity, of which some would respond properly to curing treatments and others would not. Properly matured bulbs grown in the Pacific Northwest can be heat cured by exposing them to a temp of 32.2°C for 10 days. Holding temp lower than 15.5°C delayed subsequent flower bud initiation. Ethylene gas treatment prior to heat curing appeared to stimulate floral initiation.

Effects of Diets Containing Helminthosporium maydis Blighted Corn on Growth Rate, Feed Conversion, Mortality and Blood Clotting Time of Broilers

THE severe infection of corn by Helminthosporium maydis has resulted in blighted corn of questionable value as the main food ingredient in poultry rations. There are a number of areas involving the blighted corn that need to be studied, but the question of most immediate importance is whether or not blighted corn of otherwise good quality can be incorporated into broiler rations without deleterious effects on growth. The present study was designed to determine if the feeding of diets containing moderately blighted corn (25% of kernels visibly infected with Helminthosporium maydis) would have a deleterious effect on growth rate or feed conversions of broiler chicks under field growing conditions. In addition, its possible effect on coagulation time was studied, since various toxins produced by microorganisms, particularly aflatoxins, (Forgacs et al., 1962) may interfere with blood coagulation and result in a hemorrhagic syndrome-type disease.MATERIALS AND METHODSThe experimental diets (Table)…