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There are different climate classes in Iran where about 85% of the agricultural lands are located in arid and semi-arid regions. To mitigate or compensate effects of drought stress and increase crop fitting and yield, effects of micronutrient application have been studied by several researchers. Field experiments were conducted during the 2021–2022 and 2022–2023 crop seasons to investigate the effect of micronutrients on quantitative and qualitative characteristics of canola cultivars under late-season drought stress conditions. The experiments were arranged in a factorial split-plot design, with two irrigation treatments – normal irrigation (control) or restricted irrigation at flowering stage – and four foliar applications of Zn and Mn after rosette stage (F1: Water, F2: ZnSO4, F3: MnSO4 and F4: ZnSO4 + MnSO4) as the main factor. Winter canola cultivars, including Okapy, Hyola401 and Hyola308, as sub-factor. The results showed that limited irrigation at flowering reduced seed yield, oil percentage and fatty acids content in different canola cultivars. Most of the canola oil is composed of unsaturated fatty acids, and the occurrence of drought stress at the reproductive stage reduced oil quality. By contrast, the minimum yield loss was obtained from Hylon401 cultivar, an early mature cultivar. Overall, it is recommended Hylon401 cultivar for normal irrigation and Hylon308 cultivar for a drought environment when considered the acceptable seed yield in canola. In general, it is suggested that a suitable performance of canola seeds is achieved by foliar application of manganese and zinc. [ABSTRACT FROM AUTHOR]

The cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae), is one of the important pests of cruciferous plants throughout the world including Iran. In the present study, we grew cultivated canola plants under different fertilizers or distilled water and sprayed them with 100 µM abscisic acid (ABA) or a control solution (NaOH dissolved in water) to study (i) the antibiosis parameters of B. brassicae on these plants; (ii) the antixenosis of B. brassicae adults on these plants; (iii) the plant's peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activity; and (iv) the plant's total phenolic and glucosinolate content. The results of antibiosis experiments showed that ABA and fertilizers have a profound and negative effect on the performance of B. brassicae. In the antixenosis experiment, control plants attracted a significantly higher number of adult females in comparison to treated plants. Also, B. brassicae had lower performance and preference when they were reared on the ABA-treated fertilized plants with higher levels of phenolic and glucosinolate content. These results prompted us to hypothesize that fertilizers enable canola plants to trigger a higher level of secondary metabolites. Our findings reveal that the type and level of nutrient availability may have different impacts on how the plant regulates its defense mechanisms. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the efficacy of different fertilizer management systems such as organic, chemical and integrated fertilizer systems in increasing total quality and quantity yields of canola and wheat in two rotations included canola–soybean–wheat and canola-wheat. In this experiment, the effects of zeolite incorporation with different organic and chemical fertilizers were investigated on the improvement of yield components, crop yield and nutrient uptake of canola and wheat in Iran during 2014–2018. Two crop rotations of canola-soybean-wheat and canola-wheat provided the whole-plot treatments with nine fertilization management (F1: urea, F2: urea + zeolite, F3: composted manure, F4: composted manure + zeolite, F5: urea + composted manure, F6: urea+ composted manure + zeolite, F7: urea+ azocompost, F8: urea+ azocompost + zeolite and F9: Control) providing the sub-plots. The highest yield of canola and wheat were observed under F6 and F8. Embedding soybean in the rotation was not significantly efficacious in increasing canola and wheat yields. Also, soybean did not reduce wheat and canola yield, it could fulfill its own requirements. Elemental composition of seeds in crops was affected by the treatments. Principal component analysis (PCA) perfectly displayed that organic fertilizers, especially composted manure accompanied with the application of 8 ton ha−1 zeolite and urea (F6) had the most predominant effect on yield and yield components in both wheat and canola. Crop rotation in the short-term programs might not produce desirable results, but it is expected to see the efficacy of crop rotation in long-term farming practices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nineteen non plant pathogenic pseudomonads strains were isolated for first time. • All strains were pathogenic to eggs and larvae of Ephestia keuhniella. • The strains cause 73.2 to 90.1% mortalities of this pest. • Females Habrabracon hebetor avoided the infection of the treated larvae by the strains. Pseudomonas bacteria include a variety of species with distinct characteristics. Some species within this genus are known for their ability to stimulate plant growth. Recently, the potential of these bacteria in controlling insect pests has been documented. In this study, 58 bacterial isolates were purified from rhizospheres of wheat, broad bean and canola that were collected from different fields of Khuzestan province in south-west of Iran. With biochemical tests 19 non plant pathogenic pseudomonads strains were detected and their lethal effects on the eggs and larvae of Ephestia keuhniella as an important pest that infests stored products, were evaluated under laboratory conditions. For the bioassays, two concentrations of each strain were administered, and the 5th instar larvae and eggs of the pest were subjected to treatment. Mortality rates were recorded after 24 h. The results showed that all isolated Pseudomonad strains of this study had insecticidal effects against eggs and larvae of E. keuhniella. The strains AWI1, AWI2, AWI7, ABI12, ABI15 and ABI16 displayed the highest mortality rate (91.1 %, 86.2 %, 82.3 %, 84.2, 90.5 % and 90.5 %, respectively). Molecular identification and phylogeny tree according to 16 s rRNA sequencing clarified that AWI1, AWI2 belong to P. plecoglossicida , AWI5 belongs to P. lini , ABI12, ABI15 and ABI16 belong to P. taiwanensis. Moreover, the bacterial efficacy at a suspension concentration of 0.5 OD (80 %) was significantly greater than that at a concentration of 0.2 OD (63.33 %). No significant difference was detected in the response of the pest larvae or eggs to the different strains. Furthermore, olfactory trials revealed that the female parasitoid wasp Habrabracon hebetor actively avoided the infection of the treated larvae by the strains. These findings have practical implications for the development of microbiological pest control strategies. [ABSTRACT FROM AUTHOR]

Optimum use of nitrogen (N) fertilizers is necessary to achieve maximum profitability by farmers and to minimize the risks of environmental pollution. In this study, we used three statistical models to predict the grain yield response of wheat, safflower, and canola to N fertilizer based on combined data from 38 field experiments. Meanwhile, based on the yield response functions and fertilizer-to-product price ratios, the economic optimum N fertilizer rate for each crop for 2009 (before targeting subsidies) and 2015 (after targeting subsidies) was estimated. According to quadratic, exponential, and square root models, 82.5, 90, and 76 kg N ha−1 was estimated to be required for maximum agronomic yield of safflower. More than 300 kg N ha−1 was estimated by all three models to obtain the maximum agronomic yield of canola. In contrast with the government policies for reducing N fertilizer application rates by farmers, due to low fertilizer-to-product price ratios, all application rates of N fertilizer were economic for wheat production even after targeting subsidies. According to the results, to achieve the optimum use of N fertilizers, a proper ratio of the fertilizer cost to the product value should be considered in fertilizer subsidy programs. [ABSTRACT FROM AUTHOR]

Blackleg, caused by a complex of Leptosphaeria species (L. maculans and L. biglobosa), is a fungal disease on Brassica species, especially important in canola (Brassica napus). Since the first report of L. biglobosa in Iran in 2007 and L. maculans in 2008, both species are now of major importance in Iran affecting 10 provinces and 30 regions, with a higher prevalence in the northern provinces of Mazandaran and Golestan. Despite the rapid progression of the disease and the emergence of new Leptosphaeria races in Iran, the research into this pathogen has not progressed at the same rate and is limited to phenotypic characterization studies, pathogenicity research, and to a lesser extent, disease management research. Given the rapid increase in canola cultivation in Iran and changes in the genetic diversity of the pathogen populations, it is likely that blackleg disease will increasingly become a severe threat to Iran's canola production. Therefore, systematic and prospective studies, along with fundamental research on the pathogen's biology, epidemiology, and genetic diversity, would provide critical information for the development of disease management strategies. Here, we review the research that has been carried out to date on blackleg disease in Iran and describe the extent of progress towards disease control, especially in disease‐prone regions. [ABSTRACT FROM AUTHOR]

The pod drop and seed losses in rapeseed is one of the most important problems in the cultivation of this plant and determining the most appropriate harvesting time can greatly prevent this problem and subsequently reduce the grain yield reduction. Thus, the present research was conducted as a split-plot in time in the form of a randomized complete block design with three replications during the crop year of 2019-2020 in the Research Station of the Rice Research Institute of Iran in Rasht. The main factor was rapeseed genotypes at 22 levels and the subfactor was harvesting time at three levels (including the amount of moisture between 30-40, 20-30, and 10-20% in the third grade of the lower stage of the original stem). The results of analysis of variance showed that in addition to the significance of yield-related traits in rapeseed lines, the interaction of lines in time was also significant, which shows the effect of harvesting time on rapeseed lines is different. In most of the lines, the highest and lowest grain yields were related to the first and second harvesting time, respectively. The highest grain yield was found for SRL-98-17 with a mean of 3662 kg ha-1. Number of siliques per line due to loss of pods decreased from the first to the third harvesting time. However, SRL98-9, SR-98-19, SRL-98-1 and SRL-98-11 had the lowest loss of grains. According to these results, it seems that the first harvesting time results in the highest grain yield, hastens the harvest of rapeseed by one week, and potentiates it as a suitable choice for inclusion in the rotation after a rice crop. [ABSTRACT FROM AUTHOR]