During 2016–2020, a longitudinal bark canker was observed on walnut branches in some of the provinces of Iran. The symptoms appeared on one side of the branches. No visible symptoms were observed on the sapwood after removal of the bark using a blade. In order to detect a potential agent of these symptoms on walnut trees, collected samples were transferred to the laboratory for further investigation. After isolation and purification based on standard methods, a fungus was frequently isolated from symptomatic tissues. Morphological and molecular assays indicated that the responsible agent of this disease was Alternaria malorum, moreover, a pathogenicity test confirmed that A. malorum was pathogenic on walnut trees. To the best of our knowledge, this study represents the first attempt to identify A. malorum as a new causative agent of bark canker on walnut trees in the world.

Salinity is one of the most significant constraints to crop production in dry parts of the world. This research emphasizes the beneficial effects of plant growth-promoting rhizobacterial isolates (PGPR) on the physiological responses of maize and wheat in a saline (NaCl) environment. Soil samples for the study were collected from a maize field in Baddi, Himachal Pradesh, India. Isolated bacterial strains were screened for salt (NaCl) tolerance and plant growth-promoting characters (i.e., indole acetic acid (IAA) production, siderophore production, amino cyclopropane-1-carboxylic acid (ACC) deaminase activity, hydrogen cyanide (HCN) production, and mineral phosphate solubilization). Screened bacterial isolates were further tested in pot experiments to examine their effects on wheat and maize growth. The treatments included five levels of bacterial inoculation (P0: control, P1: ACC deaminase positive + siderophore producer + NaCl tolerant bacteria, P2: mineral phosphate solubilizer + HCN producer + NaCl tolerant bacteria, P3: IAA producer + ACC deaminase positive + NaCl tolerant bacteria, P4: bacterial consortium, P5: Phosphomax commercial biofertilizer) and salt stress at 6 dS/m. Research findings found that exposure to a bacterial consortium led to the highest growth parameter in maize, including shoot length, root length, shoot and root dry weight followed by P2, P3, and P5 treatments at 6 dS/m salinity levels. However, P2 showed the best results for wheat at the same salinity levels, followed by P3, P4 and P5 treatments. P1 treatment did not show a significant result compared to control at 6dS/m salt level for both crops. The maximum proline content in maize and wheat was observed in P4 (23.28 μmol · g−1) and P2 (15.52 μmol · g−1) treatments, respectively, followed by P5 with Phosphomax biofertilizer. Therefore, the study proposed the application of growth-promoting bacterial isolates as efficient biofertilizers in the Baddi region of Himachal Pradesh, India.

Solanum elaeagnifolium Cav. is known to be one of the most invasive species worldwide. In this study, laboratory and greenhouse experiments were carried out to investigate the allelopathic properties of S. elaeagnifolium vegetative parts, root parts, fruit mucilage, and exudate extracts on plant communities and soil properties. In addition, the extract profiles of allelochemicals were quantified and their influence on soil properties and microorganisms was determined. Overall, the allelopathic performance of S. elaeagnifolium was established depending on the extract types, used concentrations, and target species. The doseresponse activity indicated that vegetative parts extract showed the greatest allelopathic potential followed by root parts extract. Subsequently, mucilage extract had a moderate inhibitory potential, while root exudates showed the least activity. The same trend with slight response was detected in soil properties of pH and EC properties. Polyphenols, in the range of 5.70–0.211 mg · g–1 and flavonols, in the range of 2.392–0.00 mg · g–1, were found in the analyzed samples extracted by ethyl acetate using LC-DAD-MS. The total phenol amount was 1.67 to 1.89 in the rhizosphere and 0.53 to 087 mg · g–1 in non-rhizosphere soils. Solanum elaeagnifolium exhibited a greater significant suppression of fungi count in both high and low-density areas than in rhizosphere bacteria. In conclusion, the strong and broadspectrum allelopathic potentials may enhance the ability of S. elaeagnifolium to impact seed germination and seedling growth of neighboring species. These biochemical weapons may play a critical role to facilitate their invasion and establishment in new agroecosystems.

Fall armyworm ( Spodoptera frugiperda) (FAW) is an important invasive pest of maize. The young FAW larva disrupts the photosynthetic system by feeding on the leaves. The older caterpillar interferes with pollination and fertilization processes, destroying the tassel and silks, or it bores into the maize cob, reducing harvest quality and predisposing the cob to secondary infections. The infested plant responds by channeling or converting the primary metabolites into secondary metabolites for plant defense, further reducing crop yield. The devastating feeding effect on maize becomes even more severe when maize plants are exposed to prolonged drought, during which the production of secondary metabolites is optimum. These secondary metabolites are food for herbivorous insects like the fall armyworm. Naturally, plants possess several adaptive features which enable them to cope and survive herbivorous insect attacks without compensating yield for plant defense. Such features include: thickening of the leaf cuticle of the epidermal cell walls, production of certain allelochemicals, defense proteins and the toxic chemical compound, favone glycoside (silk maysin). This review attempts to critically appraise the physiological implications of fall armyworm damage on developmental processes and maize yield. Understanding the mechanisms of various adaptive traits that confer resistance to maize against herbivorous insect damage would assist greatly in crop improvement processes.

The perspective direction in the biological regulation of insect pest populations is the combined use of different products of organic origin including fungal biological control agents. Therefore, the present study was aimed to evaluate the efficacy of products of natural origin (Aminogreen 24, Nitrogreen, Foliamin and Naturalis − strain ATCC 74040 of entomopathogenic fungus Beauveria bassiana) and one synthetic insecticide − standard (deltamethrin + thiacloprid), applied alone and in a mixture in the control of Acyrthosiphon pisum in forage pea. The study was conducted in a field experiment during the period 2017 − 2020. Infestation by leaf aphids was estimated by calculating the cumulative insect- -days ( CID). It was found that the combination of Aminogreen 24 + Naturalis had the most pronounced decrease in CID among products over the years from 2017 to 2020 and the average for the period. The greatest, significant reduction in the number of aphids occurred on day 5 (F8.5 = 15.244; p < 0.033) and day 7 (F8.5 = 33.087; p < 0.037) after treatment. On the 14th day, the decrease in CID (57.4% decrease) statistically exceeded the Proteus 110 OD standard (55.3% decrease) (F8.5 = 49.841; p < 0.049). Good protection against A. pisum was also found with Naturalis and Nitrogreen + Naturalis. There was an additive effect between Naturalis and Aminogreen 24 throughout the entire study period. The ratio of chlorophyll a (Chl a) to chlorophyll b (Chl b) and the ratio of green pigments (Chl a + + Chl b) to carotenoids determined that plants treated with Aminogreen 24 + Naturalis and Naturalis had the best physiological state. The combination of Aminogreen 24 and Naturalis gave the largest, significant, increase in stem height, followed by Nitrogreen + Naturalis. The use of Naturalis, alone and in a combination with Aminogreen 24 and Nitrogreen can be a successful alternative to conventional chemical control.

Determination of interference periods, competitive ability and economic threshold level ( ETL) are important tools for integrated weed management (IWM) in barley. The objective of the work was to determine the periods of interference, the competitive ability and the ETL of weeds in barley ( Hordeum vulgare). Two field experiments were carried out, in a randomized block design, with four replications. In this study, the periods of coexistence and control for ryegrass ( Lolium multiflorum) and turnip ( Raphanus raphanistrum) infesting barley cultivar, cv. ANA 01 were evaluated. The coexistence periods and/or control were: 0, 7, 14, 21, 28, 35, 42 and 120 days after barley emergence (DAE). In experiment 2the treatments for determination of ETLs were composed by barley cultivars (BRS Suábia, ANA 01, BRS Korbel, BRS Manduri, BRS Cauê and BRS Greta), and turnip densities, from zero (0) to maximum densities of 816, 788, 948, 394, 584 and 618 plants · m−2, in competition with each cultivar. Control of turnip and ryegrass should be adopted in barley in the period between 12 to 22 DAE, which is described as a critical control period. The rectangular hyperbola adequately estimates losses in grain yield due to turnip infestation. There is an effect on the competitive ability of the cultivars in relation to turnip, which resulted in ETLs that ranged from 0.27 to 1.99 plants · m−2. The cultivars BRS Greta, BRS Suábia, ANA 01 and BRS Manduri were the most competitive in the presence of turnip.

The fumigant pesticide methyl bromide (MB) is no longer used in most countries due to its carcinogenic effects. It is followed by carbon bisulfide and chloropicrin which are the most effective liquid synthetic chemicals in pesticide formulations. They are converted to gas to penetrate soil particles and eliminate plant pests such as insects, weeds, and causal plant diseases of viruses, bacteria, fungi, and nematodes under greenhouse, field and storage conditions. These fumigants are non specific pesticides and highly hazardous to humans, environmental resources, and deplete the ozone layers. Furthermore, increasing the cost of crop production by inceasing the amount of pesticides treatments was increased the cost of research on the alternatives of green pesticides from eco-friendly agents, natural organic soil amendments of organic wastes, green manure, biofumigation crops, compost, and essential oils, as well as formulations, are examples of this. Organic fumigants that are non toxic, non-residual, highly degradable and decomposable are available as eco-friendly alternatives to chemical pesticides to manage soil borne pests and diseases of plants. This article summarizes the development of applicable eco-friendly formulations which use natural organic materials to disinfest soil in order to reduce plant diseases caused by soil- -borne pathogens.