Non-treated Control Plants Research Articles

Effect of Methyl Jasmonate on the Performance of Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) and Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) on Tomato Plants

Inducible anti-herbivore defenses in plants are predominantly regulated by jasmonic acid (JA). The red spider mite Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) is an invasive pest known for its detrimental impact on tomato plants and other Solanaceae crops. Here, we investigated the extent to which T. evansi and the predatory mite Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) are affected by induced JA-defenses. Initially, we artificially induced the JA-response in tomato plants using exogenous methyl jasmonate (MeJA) and subsequently assessed the effect of JA defenses on spider mite by evaluating mortality and oviposition rates. Our findings revealed a higher mortality and lower oviposition rates on plants treated with MeJA compared to non-treated control plants. Furthermore, we examined the predatory mite's predation rates on spider mite eggs produced on MeJA-treated and non-treated tomato plants. The results showed a reduced predation on T. evansi eggs derived from MeJA-treated plants, indicating a potential negative impact of JA-induced defenses on the predator's performance. Finally, we released five predatory females on T. evansi-infested tomato plants treated and non-treated with MeJA, monitoring the predator population density for three generations. Predator population was not affected, as the abundance of larvae and adults was not significantly different between treatments. These findings underscore the negative impact of JA defenses on herbivores and highlight the trade-off it may pose on natural enemies.

Screening of Bacillus sp. (OQ654027) Mediated Seed Bio-priming Enhance Plant-Growth-Promotion for Sustainable Crop Production of Groundnut and Chickpea

Plant growth-promoting bacteria are valuable microbes that enhance the plant growth, development, and yield. Several seed priming methods are able to improvise seed germination, seedling potency, to overwhelmed abiotic stress and biotic stress management which gets prime attention. Generally, plant-growth promoting bacteria are utilized for biopriming technique that is able to survive under stress environmental conditions. The aims of the present investigation were to screening ofKC9bacterial isolate as PGPB in groundnut and chickpea and study the effects ofKC9 bacterial isolation seed, seedling germination and growth during the development of both seeds. In this study KC9 has been isolated from the soil sample of chickpea crop field at Saurashtra region. Preliminary screening was conducted based on their identification via morphological, biochemical i.e., catalase, starch hydrolysis, sugar utilization, motility, IMViC test, gram’s nature and by 16S rRNA gene nucleotide sequences and identified as Bacillus sp. that has been submitted to the NCBI for Accession number. Further examine the production of indole acetic acid (IAA), Ammonia (NH3), HCN, Siderophore and Phosphate solubilization. KC9 (Bacillus sp.) was recognized as most efficient plant-growth promoting bacteria. For the pot experiment seed biopriming method is employing to coat the seeds of chickpea and groundnut with Bacillus inoculant consider as treated and seeds sown with double distilled water as control. Bacillus coated seed biopriming also minimize the seed germination time period that takes only 3-4 days to proper seed radicle development. By the statistical approach of paired t-test of pot experiment on chickpea and groundnut seeds and seedlings were treated with Bacillus strain exhibited significantly higher levels at of seed germination, seedling growth via root length, shoot length and number of leaves in compared to non-treated control plants. In this present investigation , impact of seedling germination on the inoculated condition with KC9 of groundnut and chickpea, determining remarkable changes in total chlorophyll content (11.81 µg/g and 10.40 µg/g), relative water content(RWC) obtained 86% and 83%., total free amino acids (92.14±0.03µg/ml whereas 37.5±0.02µg/ml), total phenolic acid content (76.28±0.03mg GAE/100g and chickpea is 52.83±0.08 mg GAE/100g) and total flavonoid content increases with the treatment of KC9 (Bacillus sp.) 626±0.05QE/100g is recorded in groundnut seedlings and chickpea is 0.085±0.01QE/100g respectively.

Evaluation of Some Botanical Extracts and Chemical Insecticides against Cabbage Aphids, Brevicoryne brassicae L. (Hemiptera: Aphididae) on Cabbage (Brassicae oleracea) in West Shoa of Oromia, Ethiopia

Cabbage is Ethiopia's second most significant vegetable crop after red pepper (Capsicum spp), although its yield and yield components are influenced by a variety of factors, including cabbage aphids, which are a major pests in most of Ethiopia's cabbage-growing areas. This study was conducted to evaluate a newly introduced chemical insecticide (Kanthion 50% E.C), and locally available botanicals. Each treatment was replicated three times and the entire setup was arranged in a randomized complete block design (RCBD) under field conditions. In the field, among the botanicals tested, N. tabacum, A. sativum, and lemon extract resulted in the highest percentage of nymphs and adult mortality greater than 65% within three days after application. In the field, non-treated control plants showed low yield as compared to the chemical, and botanical insecticide. The highest fresh weight (3.01 kg) was obtained from plants treated with Kanthion 50% E.C. This study indicates that Kanthion 50% E.C, N. tabacum, A. sativum, and Citrus limon could be recommended as an alternative management option against Brevicoryne brassicae (L) under field conditions.

Echinochloa crus-galli seedlings surviving florpyrauxifen-benzyl applications have a greater potential to produce resistant seeds

Abstract Florpyrauxifen-benzyl (FPB) is an important postemergence rice herbicide. This study tested the potential for seed production in an FPB-resistant barnyardgrass population. A barnyardgrass population (NL) collected from a rice field in eastern China was highly resistant to FPB with a GR50 dose (the FPB dose causing a 50% reduction in fresh weight of aboveground parts) of 50.2 g ai ha−1. No significant differences in the percentages of surviving seedlings after treatment with different doses of the herbicide were found between F1 lines collected from F0 plants surviving a 36 g ai ha−1 FPB treatment and those collected from nontreated control F0 plants. Additionally, no significant differences were found in the rate of surviving seedlings after treatment with varying doses of FPB among the F2 lines collected from F1 plants that survived varying doses of FPB. At a constant temperature of 30 C, seeds from different F1 and F2 lines showed germination percentages of 85% to 92.0% and 68.3% to 89.0%, respectively. In the absence of competition, plants from the NL population surviving 0–144 g ai ha−1 FPB showed no significant differences in plant height, dry weight of aboveground parts, effective accumulated temperature (EAT) from sowing to seed maturation, seed production per plant, or 1,000-seed weight. In the susceptible population (HJ), plants surviving 18 g ai ha−1 FPB showed no significant differences compared to the nontreated control plants of the same population for the above variables. This is the first report of FPB-resistant barnyardgrass in China. Barnyardgrass seedlings that survived FPB application showed a higher potential for accumulating in the soil seedbank and negatively affecting rice.

Transcriptional and Metabolic Profiling of Arabidopsis thaliana Transgenic Plants Expressing Histone Acetyltransferase HAC1 upon the Application of Abiotic Stress-Salt and Low Temperature.

Augmented knowledge of plant responses upon application of stress could help improve our understanding of plant tolerance under abiotic stress conditions. Histone acetylation plays an important role in gene expression regulation during plant growth and development and in the response of plants to abiotic stress. The current study examines the level of transcripts and free metabolite content in transgenic Arabidopsis thaliana plants expressing a gene encoding histone acetyltransferase from Medicago truncatula (MtHAC1) after its heterologous expression. Stable transgenic plants with HAC1 gain and loss of function were constructed, and their T5 generation was used. Transgenic lines with HAC1-modified expression showed a deviation in root growth dynamics and leaf area compared to the wild-type control. Transcriptional profiles were evaluated after the application of salinity stress caused by 150 mM NaCl at four different time points (0, 24, 48, and 72 h) in treated and non-treated transgenic and control plants. The content and quantity of free metabolites-amino acids, mono- and dicarbohydrates, organic acids, and fatty acids-were assessed at time points 0 h and 72 h in treated and non-treated transgenic and control plants. The obtained transcript profiles of HAC1 in transgenic plants with modified expression and control were assessed after application of cold stress (low temperature, 4 °C).

Integration of Pseudomonas fluorescens and Rosemarinus officinalis for controlling of potato bacterial wilt

BackgroundBacterial wilt caused by Ralstonia solanacearum is considered one of the most important diseases that cause economic losses to many economic crops and spread in many regions around the world, especially in the subtropical tropics and some warm temperate regions of the world. In this study the aqueous plant extract of Rosemarinus officinalis and Pseudomonas fluorescens for their antagonistic activity against bacterial wilt in vitro, greenhouse and population of R, solanacearum in plants was study.ResultsFollowing intensive screening studies, aqueous plant extract of R. officinalis and P. fluorescens was selected to study their effectiveness against bacterial wilt of potato plants and their antimicrobial activity or induction of systemic resistance in plants. In greenhouse, all soil drenching treatments on potato plants significantly reduced disease incidence of potato bacterial wilt than infected control. R. officinalis, P. fluorescens mixture between plant extract and endophytic bacteria and streptomycin reduced profoundly the disease severity by 75.51, 65.0 77.9 and 81.00%, respectively, than the infected control (83.71%). The plant extract and microorganism significantly increased fresh and dry weight of potato plants (g) per plant compared to non-treated control plants. R. officinalis, P. fluorescens mixture between plant extract and endophytic bacterium and streptomycin increased fresh weight from 100.1 to 169.9 compared to infected control also increased dry weight from 68.4 in streptomycin to 170.4% in mixture of plant extract and endophytic bacterium. The populations of bacterial pathogen R. solanacearum were lowest in stem of potato plants treated with plant extracts than in inoculated control plants (50%). In general, the total phenols increased in both inoculated and non-inoculated potato plants.ConclusionsRalstonia officinalis and P. fluorescens showed a strong in vitro activity in relation growth limitation of R. solanacearum as well as limiting the development of bacterial wilt disease on potato plants under greenhouse conditions.

Priming of Vigna mungo (Black Gram) Seeds with Magnetic Hematite Nano-Particle Ameliorates Salinity and Drought Stress via Modulation of Physiochemical Attributes

Vigna mungo (black gram) is a leguminous crop often cultivated in many areas of tropics, for protein-rich edible seeds. Drought and salinity are the major abiotic stress which hampers the growth, development and yield of crop plants including black gram. The present study aimed to investigate the efficacy of magnetic hematite nanoparticles on the stress tolerance potential of Vigna mungo against salinity and drought stress. We found that the treatment of magnetic hematite nanoparticles (Fe2 O3 ) helped to improve black gram tolerance to salt and drought stress under in-vitro as well as in-vivo conditions. The treated plants showed better phenotypic performance in terms of biomass accumulation imposed stress. Moreover, the photosynthetic performance was also higher in treated plants which include total chlorophyll content, stomatal conductance, and maximum photochemical efficiency of PSII as compared to the NNP (non-nanoparticle control) group grown under invivo conditions. In agreement with the results of the increased antioxidant enzyme activity, the V. mungo plants treated with nanoparticles had much less membrane damage, electrolyte leakage, and a greater relative water content and proline content. Further experiments revealed that under imposed stress, the treated V. mungo plants had significantly lower Na+ and higher K+ content which correspond to the higher K+ /Na+ ratio than the non-treated stressed control plants.

Nicotiana benthamiana as a model plant host for Xylella fastidiosa: Control of infections by transient expression and endotherapy with a bifunctional peptide.

Transient expression of genes encoding peptides BP134 and BP178 by means of a Potato virus X (PVX) based-vector system, and treatment with synthetic peptides by endotherapy, were evaluated in the control of Xylella fastidiosa infections, in the model plant Nicotiana benthamiana. Transient production of BP178 significantly decreased disease severity compared to PVX and non-treated control (NTC) plants, without adverse effects. Plants treated with synthetic BP134 and BP178 showed consistently lower levels of disease than NTC plants. However, the coinfection with PVX-BP134 and X. fastidiosa caused detrimental effects resulting in plant death. The levels of X. fastidiosa in three zones sampled, upwards and downwards of the inoculation/treatment point, significantly decreased compared to the NTC plants, after the treatment with BP178, but not when BP178 was produced transiently. The effect of treatment and transient production of BP178 in the induction of defense-related genes was also studied. Synthetic BP178 applied by endotherapy induced the expression of ERF1, PR1a, PAL, PALII and WRKY25, while the transient expression of BP178 overexpressed the Cath, Cyc, PR4a, 9-LOX and Endochitinase B genes. Both treatments upregulated the expression of PR1, PR3, PR4 and CycT9299 genes compared to the NTC or PVX plants. It was concluded that the effect of BP178, either by endotherapy or by transient expression, on the control of the X. fastidiosa infections in N. benthamiana, was due in part to the induction of the plant defense system in addition to its bactericidal activity reported in previous studies. However, the protection observed when BP178 was transiently produced seems mainly mediated by the induction of plant defense, because the levels of X. fastidiosa were not significantly affected.

Enhancement of Rose Scented Geranium Plant Growth, Secondary Metabolites, and Essential Oil Components through Foliar Applications of Iron (Nano, Sulfur and Chelate) in Alkaline Soils

Iron (Fe) deficiency exists as a widespread nutritional disorder in alkaline and calcareous soils; therefore, Fe-enriching strategies may be used to overcome this issue. Field experiments were conducted with a randomized complete design with three replicates for evaluating the effectiveness of iron oxide nanoparticles (Fe-NPs) against traditional Fe compounds (sulfate or chelate), which have various shortcomings on Rose-scented geranium (RSG) herb in terms of plant growth, phytopharmaceuticales, essential oil (EO), and its constituents. Supplementation of Fe-sources considerably improved RSG plant growth and EO yield in the 1st and 2nd cut throughout the two seasons over non-treated control plants. A total of 11 compounds of RSG-EO were identified; the main constituents were citronellol, geraniol, and eugenol. The results indicate that EO composition was significantly affected by Fe-sources. Amendments of Fe-sources considerably augmented photosynthetic pigments, total carbohydrates, nitrogen, phosphorous, potassium, iron, manganese, zinc, phenols, flavonoids, and anthocyanin. Commonly, Fe-NPs with humic acid (Fe-NPs-HA) supplementation was superior to that of traditional sources. The highest values were recorded with spraying Fe-NPs-HA at 10 mg L−1 followed by 5 mg L−1, meanwhile, the lowest values were recorded in untreated control plants. Current findings support the effectiveness of nanoparticle treatment over Fe-sources for improving growth and yield while also being environmentally preferred in alkaline soil. These modifications possibly will be applicable to EO quality and its utilization in definite food and in medical applications.

Significance to the Horticulture Industry

Significance to the Horticulture Industry

Hazelnut tolerance to basal-directed applications of clopyralid and quinclorac

AbstractField studies were conducted to determine hazelnut tolerance to quinclorac and clopyralid and control efficacy of Canada thistle and field bindweed at three commercial orchards in western Oregon. Hazelnut cultivars evaluated included ‘Jefferson’, ‘Wepster’, and ‘McDonald’. Clopyralid at 278, 547, and 1,090 g ae ha−1, and quinclorac at 420, 840, and 1,680 g ai ha−1 were applied once a year as basal-directed applications to trees that were 1, 2, and 5 yr old. Treatments were imposed in the early spring of 2019 and reapplied in 2020. In both years, treatments covered hazelnut suckers. Hazelnut injury from clopyralid and quinclorac was consistently between 0% and 13% and not different from nontreated control plants (P > 0.05) between 14 d and 455 d after initial treatment. Similarly, there was no treatment effect on plant canopy index, leaf chlorophyll content, trunk cross-sectional area, internode length, or yield among treatments, even at the highest rates of clopyralid and quinclorac. In separate efficacy studies, clopyralid (278 g ae ha−1) resulted in 68% Canada thistle control and did not differ when clopyralid was mixed with carfentrazone (278 + 35 g ai ha−1) or glufosinate (278 + 1,148 g ai ha−1). Clopyralid-containing herbicide treatments suppressed field bindweed growth but did not kill plants even when mixed with carfentrazone or glufosinate. Quinclorac (420 g ha−1) alone provided 80% control of field bindweed and 93% and 98% control when combined with rimsulfuron (35 g ai ha−1) or carfentrazone (35 g ai ha−1), respectively. Still, all herbicide treatments resulted in similar field bindweed biomass. Results indicate that clopyralid and quinclorac are effective tools to help manage Canada thistle and field bindweed and that hazelnut can tolerate clopyralid and quinclorac at rates equivalent to 4-fold commercial-use rates not affecting plant growth and yield.

The Multifarious Endophytic Actinobacterial Isolate, Streptomyces tubercidicus UAE1, Combined With the Seaweed Biostimulant Further Promotes Growth of Avicennia marina

Mangrove (Avicennia marina) is a “green lung” tree growing along the Arabian Gulf coastline in the United Arab Emirates. Here, we aimed to determine the impact of the application of a commercial seaweed extract (SWE) biostimulant and endophytic actinobacterial isolates on growth performance and endogenous hormonal levels of mangroves. Therefore, we isolated endophytic plant growth-promoting (PGP) actinobacteria (PGPA) from mangrove roots and evaluated their potential as biological inoculants on mangrove seedlings under greenhouse and open-field nursery conditions. Seven salt-tolerant isolates had the ability to produce different levels ofin vitroplant growth regulators (PGRs) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) and to solubilize phosphorus. Accordingly, only one isolate,Streptomyces tubercidicusUAE1 (St), was selected based on its relative superiority in displaying multiple modes of action and in successfully colonizing mangrove tissues for 15 weeks. In the greenhouse experiments, plants treated withStand SWE significantly (p< 0.05) improved dry biomass by 40.2% and 55.1% in roots and 42.2% and 55.4% in shoots, respectively, compared to seawater-irrigated non-treated mangrove plants (control). However,St+SWE caused a greater significant (p< 0.05) increase in dry weight of roots (67.6%) and shoots (65.7%) than did control plants. Following the combined treatment ofSt+SWE,in plantaPGR levels were found to be greatly enhanced over the non-treated control plants grown in non-SWE supplemented sediments, or plants inoculated with onlySt without the supplementation with SWE,or with non-inoculated plants grown in sediments supplied with SWE only. This was evident from the significant (p< 0.05) increases in the photosynthetic pigments and production of PGRs, as well as the reduction in the endogenous ACC levels of plant tissues compared to those in other treatments. Tissue nutrient contents of seedlings also increased by at least two-fold inSt+SWE treatment as compared to control. Similar effects were observed on all growth parameters under natural open-field nursery conditions. CombiningStwith SWE not only stimulates plant growth but also potentially has additive effects on mangrove ecosystem productivity in nutrient-impoverished soils in the Arabian coastal areas. This report is the first in the field of marine agriculture that uses SWE as a nutrient base for actinobacteria capable of producing PGRs and ACCD.

Gibberellic Acid 4+7 Influences Shoot Growth of Seedling Pecan and Bitternut Hickory

Abstract Shoot development of seedling hickories is slow, limiting their success as viable crops using standard growing techniques. Because hickories are predominantly propagated by seed, we questioned whether gibberellic acid (GA) could be used on seedlings to overcome slow shoot development during juvenility. Treatments of one-year-old seedlings of bitternut hickory [Carya cordiformis (Wangenh.) K. Koch], pignut hickory [C. glabra (Mill.) Sweet], pecan [C. illinoinensis (Wangenh.) K. Koch], kingnut hickory [C. laciniosa (F. Michx.) Loud.], shagbark hickory [C. ovata (Mill.) K. Koch], and mockernut hickory [C. tomentosa (Lam.) Nutt.] began at bud break by applying a solution of 500 ppm GA4+7 dissolved in 95% ethanol directly to apical buds or stem tissue at three-day intervals for 27 days. After 160 days, neither treatment affected caliper of any taxon, although species differences were observed. Compared to nontreated control plants, treatment of buds resulted in a 234% and 144% increase in shoot height of bitternut hickory and pecan, respectively. In a second experiment, the same treatments were implemented on seedlings of bitternut hickory shortly after germination. Only shoot height and dry weight were affected (increased) by application of GA4+7. This study indicates plant growth regulators could be effective at increasing shoot extension of some hickories. Chemicals used in this study: Gibberellic acid 4+7 (GA4+7). Species used in this study: bitternut hickory [Carya cordiformis (Wangenh.) K. Koch]; pignut hickory [C. glabra (Mill.) Sweet]; pecan [C. illinoinensis (Wangenh.) K. Koch]; kingnut hickory [C. laciniosa (F. Michx.) Loudon]; shagbark hickory [C. ovata (Mill.) K. Koch]; and mockernut hickory [C. tomentosa (Lam.) Nutt.].

Timing and Rate of Foliar Potassium Application to Improve Yield, Fruit Size and Quality Attributes of Pomegranate: Based on Data Generated in Field Experiments Conducted in Iran and Egypt

ABSTRACT It is proven that potassium (K) plays a key regulatory role in many physiological processes of plant growth and that K fertilization can improve the yield and quality attributes in fruit crops. This study was carried out to evaluate the effect of timing and various concentrations of foliar sprays of potassium sulfate, during fruit growth and maturation, on yield and quality of pomegranate fruit in Iran and Egypt, which have different pomegranate production systems. In Iran one, two or three sprays of 1% or 2% K-Leaf® (a high grade foliar potash booster) was used, and in Egypt a single spray of either 10 or 20 kg/ha, and two sprays of 10 and 20 kg/ha K-Leaf® were applied. Results showed that in both experiments in Iran and Egypt, foliar K treatments increased total and marketable yield of pomegranates, as well as fruit weight and size, flavor index (the ratio of total soluble solids/total acid). The treatments also improved the fruit’s peel and aril color compared to the non-treated control plants. Results also demonstrated that multiple potassium sprays (two or three applications) were more effective than applying higher concentrations; as in many cases, there were no significant differences between 1 and 2% concentrations of K fertilizer in treatments with same number of applications (one, two or three sprays). Although three sprays of 2% K-Leaf® were the most effective treatments, it can be concluded that three sprays of 1% K-Leaf®) is probably more economically sound for use in pomegranate orchards.

Characterization of Endophytic Fungi, Acremonium sp., from Lilium davidii and Analysis of Its Antifungal and Plant Growth-Promoting Effects.

The present study was aimed at isolating endophytic fungi from the Asian culinary and medicinal plant Lilium davidii and analyzing its antifungal and plant growth-promoting effects. In this study, the fungal endophyte Acremonium sp. Ld-03 was isolated from the bulbs of L. davidii and identified through morphological and molecular analysis. The molecular and morphological analysis confirmed the endophytic fungal strain as Acremonium sp. Ld-03. Antifungal effects of Ld-03 were observed against Fusarium oxysporum, Botrytis cinerea, Botryosphaeria dothidea, and Fusarium fujikuroi. The highest growth inhibition, i.e., 78.39 ± 4.21%, was observed for B. dothidea followed by 56.68 ± 4.38%, 43.62 ± 3.81%, and 20.12 ± 2.45% for B. cinerea, F. fujikuroi, and F. oxysporum, respectively. Analysis of the ethyl acetate fraction through UHPLC-LTQ-IT-MS/MS revealed putative secondary metabolites which included xanthurenic acid, valyl aspartic acid, gancidin W, peptides, and cyclic dipeptides such as valylarginine, cyclo-[L-(4-hydroxy-Pro)-L-leu], cyclo(Pro-Phe), and (3S,6S)-3-benzyl-6-(4-hydroxybenzyl)piperazine-2,5-dione. Other metabolites included (S)-3-(4-hydroxyphenyl)-2-((S)-pyrrolidine-2-carboxamido)propanoic acid, dibutyl phthalate (DBP), 9-octadecenamide, D-erythro-C18-Sphingosine, N-palmitoyl sphinganine, and hydroxypalmitoyl sphinganine. The strain Ld-03 showed indole acetic acid (IAA) production with or without the application of exogenous tryptophan. The IAA ranged from 53.12 ± 3.20 μg ml−1 to 167.71 ± 7.12 μg ml−1 under different tryptophan concentrations. The strain was able to produce siderophore, and its production was significantly decreased with increasing Fe(III) citrate concentrations in the medium. The endophytic fungal strain also showed production of organic acids and phosphate solubilization activity. Plant growth-promoting effects of the strain were evaluated on in vitro seedling growth of Allium tuberosum. Application of 40% culture dilution resulted in a significant increase in root and shoot length, i.e., 24.03 ± 2.71 mm and 37.27 ± 1.86 mm, respectively, compared to nontreated control plants. The fungal endophyte Ld-03 demonstrated the potential of conferring disease resistance and plant growth promotion. Therefore, we conclude that the isolated Acremonium sp. Ld-03 should be further investigated before utilization as a biocontrol agent and plant growth stimulator.

Evaluation of Chemical Control Methods of Fountain Grass

Fountain grass (Pennisetum alopecuroides) is a common ornamental grass because of its glossy foliage and showy inflorescence. However, there have been reports of populations growing outside of cultivation and demonstrating invasive tendencies. There is limited research of the chemical control of fountain grass in natural areas. The objective of this experiment was to evaluate the impact of glyphosate, sethoxydim, and fluazifop on fountain grass. Treatments consisted of 2250 and 4500 g⋅ha–1 glyphosate, 262.5 and 525 g⋅ha–1 sethoxydim, and 200 and 400 g⋅ha–1 fluazifop; a nontreated control group was also included. The percent herbicide injury was determined visually 1, 3, 4, 6, and 10 weeks after treatment (WAT). Both rates of glyphosate resulted in 100% of the foliage injured by 3 WAT. The application of flauzifop and sethoxydim led to intermediate results ranging from 15% to 23% injury by 6 WAT, with no significant difference between active ingredients or rates. Nontreated control plants exhibited little to no injury throughout the study. Flauzifop, sethoxydim, and glyphosate all caused visible injury to fountain grass. For complete, fast-acting control, glyphosate is recommended. Herbicide control coupled with restorative plantings of native plants can help reduce invasive plant pressure and improve biodiversity of natural areas.

Effects of sunn hemp (Crotalaria juncea) and Mexican sunflower (Tithonia diversifolia) leaf extracts on the development of Meloidogyne incognita on African indigenous vegetables

The effects of sunn hemp and Mexican sunflower extracts were evaluated on the development of Meloidogyne incognita on two vegetables, Amaranthus cruentus and Solanum macrocarpon in the screenhouse in 2017. Seedlings of each vegetable were inoculated with 3000 eggs of M. incognita per pot. There were five treatments; sunn hemp and Mexican sunflower extracts at 20 and 40 g leaf tissues/L water for each and a non-treated control. The treatments were laid out in a randomized complete block design in four replications. Data were collected on nematode counts, egg masses, developmental stages and gall-index. Extracts of sunn hemp and Mexican sunflower at 40 g leaf tissues/L water, significantly reduce nematode number, egg mass and gall-index in comparison with plants treated at 20 g leaf tissue/L water and non-treated control plants. Plants treated at lower rate were not different from the non-treated control plants in all parameters measured. The results showed that sunn hemp or Mexican sunflower at 40 g leaf tissue/L could be used in managing nematode pest.

Seed Biopriming With Trichoderma Strains Isolated From Tree Bark Improves Plant Growth, Antioxidative Defense System in Rice and Enhance Straw Degradation Capacity.

This study is a unique report of the utilization of Trichoderma strains collected from even tree barks for rice plant growth, its health management, and paddy straw degradation. Seven different spp. of Trichoderma were characterized according to morphological and molecular tools. Two of the isolated strains, namely Trichoderma hebeiensis and Trichoderma erinaceum, outperformed the other strains. Both of the strains controlled four important rice pathogens, i.e., Rhizoctonia solani (100%), Sclerotium oryzae (84.17%), Sclerotium rolfsii (66.67%), and Sclerotium delphinii (76.25%). Seed bio-priming with respective Trichoderma strains reduced the mean germination time, enhanced the seedling vigor and total chlorophyll content which could be related to the higher yield observed in two rice varieties; Annapurna and Satabdi. All the seven strains accelerated the decomposition of rice straw by producing higher straw degrading enzymes like total cellulase (0.97–2.59 IU/mL), endoglucanase (0.53–0.75 IU/mL), xylanase (145.35–201.35 nkat/mL), and laccase (2.48–12.60 IU/mL). They also produced higher quantities of indole acetic acid (19.19–46.28 μg/mL), soluble phosphate (297.49–435.42 μg/mL), and prussic acid (0.01–0.37 μg/mL) which are responsible for plant growth promotion and the inhibition of rice pathogen populations. Higher expression of defense enzymes like catalase (≥250% both in shoot and root), peroxidase (≥150% in root and ≥100% in shoot), superoxide dismutase (≥ 150% in root and ≥100% in shoot), polyphenol oxidase (≥160% in shoot and ≥120% in shoot), and total phenolics (≥200% in root and ≥250% in shoot) as compared to the control indicates stress tolerance ability to rice crop. The expression of the aforementioned enzymes were confirmed by the expression of corresponding defense genes like PAL (>3-fold), DEFENSIN (>1-fold), POX (>1.5-fold), LOX (>1-fold), and PR-3 (>2-fold) as compared to the non-treated control plants. This investigation demonstrates that Trichoderma strains obtained from tree bark could be considered to be utilized for the sustainable health management of rice crop.

Impact of root-associated\xa0strains of three Paraburkholderia species on primary and secondary metabolism of Brassica oleracea

Several root-colonizing bacterial species can simultaneously promote plant growth and induce systemic resistance. How these rhizobacteria modulate plant metabolism to accommodate the carbon and energy demand from these two competing processes is largely unknown. Here, we show that strains of three Paraburkholderia species, P. graminis PHS1 (Pbg), P. hospita mHSR1 (Pbh), and P. terricola mHS1 (Pbt), upon colonization of the roots of two Broccoli cultivars led to cultivar-dependent increases in biomass, changes in primary and secondary metabolism and induced resistance against the bacterial leaf pathogen Xanthomonas campestris. Strains that promoted growth led to greater accumulation of soluble sugars in the shoot and particularly fructose levels showed an increase of up to 280-fold relative to the non-treated control plants. Similarly, a number of secondary metabolites constituting chemical and structural defense, including flavonoids, hydroxycinnamates, stilbenoids, coumarins and lignins, showed greater accumulation while other resource-competing metabolite pathways were depleted. High soluble sugar generation, efficient sugar utilization, and suppression or remobilization of resource-competing metabolites potentially contributed to curb the tradeoff between the carbon and energy demanding processes induced by Paraburkholderia-Broccoli interaction. Collectively, our results provide a comprehensive and integrated view of the temporal changes in plant metabolome associated with rhizobacteria-mediated plant growth promotion and induced resistance.

Saccharin Provides Protection and Activates Defense Mechanisms in Wheat Against the Hemibiotrophic Pathogen Zymoseptoria tritici.

Plant resistance inducers are among the most promising alternatives to develop sustainable crop protection. Here, we examined the ability of saccharin, a metabolite derived from probenazole, to protect wheat against Zymoseptoria tritici, the most frequently occurring and damaging foliar pathogen on this crop. The experiments were performed in the greenhouse by treating seedlings of the wheat cultivar 'Alixan' with 15 mM of saccharin 2 days before challenge inoculation with the Z. tritici pathogenic strain T02596. Foliar application of saccharin resulted in 77% lower disease severity than in nontreated control plants. In vitro and in planta assays showed that saccharin did not exhibit any direct antifungal effect on spore germination or hyphal growth. Molecular investigations from 2 to 7 days posttreatment (dpt) revealed that saccharin treatment upregulates the expression of genes encoding for lipoxygenase (LOX) at all sampled time points and pathogenesis-related protein 1 (PR1) at 7 dpt, in both noninfectious and infectious contexts, as well as peroxidase (POX2) in noninfectious conditions. However, saccharin did not induce significant change in the expression of PAL gene encoding for phenylalanine ammonia-lyase. Our findings report for the first time the potential of saccharin to confer protection in wheat against Z. tritici through an elicitation and priming of LOX and PR gene-related defense pathways. Additional investigations would provide a better deciphering of defense mechanisms activated by this molecule in wheat against Z. tritici.