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During the year 2022-23, the extension department of the Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh undertook a study to analyse the adoption pattern of ANGRAU recommended direct seeded rice (DSR) production technology among farmers in the Guntur district, Andhra Pradesh. The study sampled one hundred DSR farmers and found that a great majority were adhering to recommendations concerning soil management, sowing method, harvesting and water management. However, significant gaps were identified in the adoption of other practices. Specifically, the majority of the farmers were not following recommended practices for weed management (92.00%), fertilizer management (86.00%), seed rate (82.00%), pest management (77.00%), disease management (74.00%) and main field preparation (68.00%). Farmers' perception of DSR highlighted its benefits, particularly the reduction in water, labour and fertilizer usage, which facilitated the timely completion of crop activities. The study identified that extension contact and training sessions attended by the farmers had a highly significant relationship with adoption at 1 per cent level of significance. Despite the advantages, several constraints were noted by the farmers practicing DSR cultivation. These included severe weed incidence, rat damage, yield loss due to lodging and increased harvesting costs due to lodging. These challenges pointed out at the clear extension gaps in the adoption of DSR technology. To enhance the adoption of DSR technology, it is crucial to address these extension gaps. This involves focusing on improved weed and pest management strategies, proper fertilizer application, appropriate seed rate and better field preparation techniques. By addressing these areas, farmers can achieve higher net return and contribute to a more sustainable agricultural environment. [ABSTRACT FROM AUTHOR]

The Yasmina variety is a new, highly productive spring fodder barley. It was created at the Institute of Agriculture in Karnobat by means of a combinatorial selection method. The biological and economic traits of the variety were tested in the Institute's competitive variety trials and the IASAS system during 2019-2020. The aim of this study was to present the biological and economic traits of the new recognized spring six-row barley variety Yasmina. In the ecological network regions, it demonstrated high productivity. The mean yield from the new variety obtained in 4 Bulgarian regions was proven higher than the one from the standard variety Venera by 22.0%. During the testing period, the variety realized a yield of up to 6500 kg/a. With high protein content of 13.51%, it is ideally suited for fodder.The variety has good lodging resistance. Yasmina was recognized as an original cultivar with Order No RD-12-4/10 Mar 2021 by the Minister of Agriculture, Food and Forestry and was approved for entry in List A of the Official Variety List of the Republic of Bulgaria. [ABSTRACT FROM AUTHOR]

By studying the changes of yield and three factors of Xinmai 35 in different years, the purpose was to reveal the potential of high and stable yield of Xinmai 35, and to provide theoretical basis for its production and popularization in the south of Huang-Huai area. The yield performance and yield increasing point of Xinmai 35 were statistically analyzed by using the method of comparing multi-point test data for many years. The results showed that the yield of Xinmai 35 was more than 5. 00% higher than that of the control, with a maximum of 8. 77%, which had obvious potential for yield increase. In 2014-2018, the yield of Xinmai 35 increased by 95. 5%, 90. 0%, 95. 5% and 100%, respectively, in the statistical stations participating in the regional test and the national production test, showing strong adaptability and stability in the southern Huang-Huai area. According to the field statistics, the plant height of Xinmai 35 was 75. 5 cm and had no lodging in 22 experimental sites, which provided a guarantee for the safety of grain production. The experiment showed that Xinmai 35 was a wheat variety with high yield potential, strong regional adaptability and high lodging resistance, which was suitable for popularization and application in the south of Huang-Huai area. [ABSTRACT FROM AUTHOR]

The key to high-yielding peanut cultivation is the optimization of agricultural production practices. Regulating single-seed precise sowing (SSPS) density and paclobutrazol (Pbz) application concentration are effective practices that increase peanut yield by improving plant architecture, lodging resistance, and photosynthetic characteristics. Therefore, we conducted a two-factor field optimization experiment for the sowing density (D1: 1.95 × 105 plants ha-1, D2: 2.40 × 105 plants ha-1, D3: 2.85 × 105 plants ha-1, and D4: 3.30 × 105 plants ha-1) and Pbz application concentration (P0: 0 mg L-1 and P1: 100 mg L-1). The objective was to optimize agricultural production practices and provide a theoretical basis for highyielding peanut cultivation by evaluating the effects of sowing density and Pbz application on plant architecture, lodging resistance, photosynthetic characteristics, and yield. The results showed that at the same Pbz application concentration, increasing sowing density increased lodging percentage and reduced leaf photosynthetic capacity. At the same sowing density, Pbz application reduced lodging percentage by decreasing plant height (PH), improving lignin biosynthesis-related enzyme activities, and enhancing stem puncture strength (SPS) and breaking strength (SBS). The paclobutrazol-induced alterations in plant architecture and lodging resistance improved light transmission at the middle and bottom leaf strata, resulting in the increase in relative chlorophyll content and net photosynthetic rate (Pn) of leaves. Furthermore, D3P1 treatment had the highest peanut yield among all treatments. In summary, the production strategy combining the sowing density of 2.85 × 105 plants ha-1 with the application of 100 mg L-1 Pbz was found to be the optimal agricultural production practice for giving full play to production potential and achieving higher peanut yield. [ABSTRACT FROM AUTHOR]

Lodging is a critical constraint to yield increase. There appear to be tradeoffs between yield formation and lodging resistance in maize. Hypothetically, it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments. A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018-2020. Lodging-susceptible (LS) cultivars on average yielded more than lodging-resistant (LR) cultivars when lodging was not present. The yield components kernel number per ear (KN) and thousand-kernel weight (TKW) were both negatively correlated with lodging resistance traits (stalk bending strength, rind penetration strength, and dry matter weight per internode length). Before silking, the LR cultivar Lishou 1 (LS1) transported more assimilates to the basal stem, resulting in a thicker basal stem, which reduced dry matter allocation to the ear and in turn KN. The lower KN of LS1 was also due partly to the lower plant height (PH), which increased lodging resistance but limited plant dry matter production. In contrast, the LS cultivars Xianyu 335 (XY335) and Xundan 20 (XD20) produced and allocated more photoassimilates to ears, but limited dry matter allocation to stems. After silking, LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear. The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height (EH). High-yielding and high-LR traits of Fumin (FM985) were related to optimized EH and stem anatomical structure, higher leaf productivity, low assimilate demand for kernel formation, and assimilate partitioning to ear. A high presilking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength. Post-silking temperature influences lodging resistance and yield more than other environmental factors. These results will be useful in understanding the tradeoffs between KN, KW, and LR in maize and environmental influences on these tradeoffs. [ABSTRACT FROM AUTHOR]

[Objective] This study analyzed the relationships between brace root traits and lodging resistance of maize to provide basis for lodging resistance breeding. [Method] A total of 190 maize inbred lines were used to investigate brace root angle and brace root number inserted soil and their correlation with lodging grades was analyzed by contingency analysis method. The brace root angle, brace root number inserted soil, brace root diameter and brace root depth of two groups with different lodging resistances were also compared. [Result] The Chi-square values of correlation test in contingency analysis of brace root angle and brace root number with lodging grades were χ² = 23.261 and χ² = 13.023, reaching extremely significant and significant levels, respectively. Wider brace root angle and more brace number led to stronger lodging resistance. In the same environment, brace root angles of all lodging-resistant inbred lines were wider than those of lodging-sensitive ones and the differences among the two groups were significant except for inbred lines R1 and S3. Both brace root number of the first layer and total of the lodging-resistant inbred lines were generally larger than the lodging-sensitive ones. The average diameter and depth of brace roots of lodging-resistant maize inbred lines were larger than lodging-sensitive ones without significant difference. [Conclusion] There were closely positive correlations of brace root angle and brace root number with lodging resistance. Thus, it is suggested to select maize inbred lines or crosses with wider brace root angle and more brace root number and consider brace root diameter and brace root depth for effective selection of breed lodging resistant varieties. [ABSTRACT FROM AUTHOR]

Core Ideas: Increasing the seeding rate by 10,000 seeds acre–1 increased root lodging incidence by 14%.Greensnap incidence did not change with an increased seeding rate.Yield loss from root lodging was evident at seeding rates above 36,000 seeds acre–1.Yield loss from greensnap was evident at 24,000 to 36,000 seeds acre–1. [ABSTRACT FROM AUTHOR]

The use of bast fiber film can improve rice seedling quality, and nano-silicon fertilizer can increase rice yields. This study aimed to compare the effects of using bast fiber film, nano-silicon fertilizer, and both treatments on rice yield and lodging resistance. A 2-year field experiment was conducted in 2017 and 2018, in Liaoning, China. The experiment comprised a control (no-bast fiber film, no nano-silicon fertilizer; CK), and three treatments: seedlings cultivated with bast film (FM), single nano-silicon fertilization (SF), and bast fiber film seedlings + nano-silicon fertilization (FM + SF). The japonica rice (Oryza sativa L.) cultivar Liaojing 371 was used. Compared with the plants in CK, those in the FM treatment showed greater average root diameter, root volume and root dry weight. The SF treatment increased the single stem flexural strength, increased the contents of silicon, lignin, and cellulose in the rice plant stalk, and reduced the lodging index, thereby increasing lodging resistance. The SF treatment resulted in increased leaf chlorophyll content at late growth stage and a higher net photosynthetic rate, which increased plant dry matter accumulation. In the FM + SF treatment, plant growth was enhanced during the whole growth period, which resulted in an increased number of effective panicles and an increased grain yield. The results show that the combination of FM and SF synergistically improves rice lodging resistance and grain yield. This low-cost, high-efficiency system is of great significance for improving the stability and lodging resistance of rice plants, thereby increasing yields. [ABSTRACT FROM AUTHOR]

In dry lands, small millets such as kodo millet contribute to regional food security to some extent. It is normally harvested using paddy combine harvester due to labour scarcity. However, the current varieties are not amenable for mechanized harvesting as they lodge at grain filling and maturity stages, thus resulting in heavy grain loss in terms of quality and quantity. In this context, we studied the anatomical features of culm and elemental composition in relation to lodging behaviour in kodo millet (Paspalum scrobiculatum L.), which is one of the important yield limiting factors in this crop. The strong culm genotype, Adari had higher culm thickness, thicker mechanical tissue, more lignin deposition and more number of vascular bundles per cross section when compared to the weaker counterpart, Aamo10. However, not all the genotypes with thicker culm were lodging resistant. Sel21 which recorded the highest culm thickness (1283.4 µm) among the genotypes lodged heavily as higher culm thickness in Sel21 was not supported by an increased number of vascular bundles. Interestingly, TNPsc183 which had a moderate culm thickness of 782.82 μm exhibited a low degree of lodging and had more number of vascular bundles per cross section than Sel21. Hence, 'number of vascular bundles per unit area' appears to be an important trait in contributing lodging resistance in kodo millet. SEM-EDX studies for silicon and potassium contents in culm implicated the role of silicon, but not potassium in imparting culm strength in kodo millet. However, more potassium content in parenchymatous cell wall suggests its role in imparting strength to the non-lignified cells of the culm. [ABSTRACT FROM AUTHOR]

Traits related to plant lodging and architecture are important determinants of plant productivity in intensive maize cultivation systems. Motivated by the identification of genomic associations with the leaf angle, plant height (PH), ear height (EH) and the EH/PH ratio, we characterized approximately 7,800 haplotypes from a set of high-quality single nucleotide polymorphisms (SNPs), in an association panel consisting of tropical maize inbred lines. The proportion of the phenotypic variations explained by the individual SNPs varied between 7%, for the SNP S1_285330124 (located on chromosome 9 and associated with the EH/PH ratio), and 22%, for the SNP S1_317085830 (located on chromosome 6 and associated with the leaf angle). A total of 40 haplotype blocks were significantly associated with the traits of interest, explaining up to 29% of the phenotypic variation for the leaf angle, corresponding to the haplotype hapLA4.04, which was stable over two growing seasons. Overall, the associations for PH, EH and the EH/PH ratio were environment-specific, which was confirmed by performing a model comparison analysis using the information criteria of Akaike and Schwarz. In addition, five stable haplotypes (83%) and 15 SNPs (75%) were identified for the leaf angle. Finally, approximately 62% of the associated haplotypes (25/40) did not contain SNPs detected in the association study using individual SNP markers. This result confirms the advantage of haplotype-based genome-wide association studies for examining genomic regions that control the determining traits for architecture and lodging in maize plants. [ABSTRACT FROM AUTHOR]

Highlights • The influence of lodging on flax fiber performances is explored. • Flax gravitropic response is investigated at key stages of plant development. • Fibers from the pulling side of tilted stems show changes in mechanical properties. • Only slight dissimilarities in fiber performances remain at plant maturity. • Fiber properties stay adequate for composite reinforcement in case of lodging. Abstract Flax fibers (Linum Usitatissimum L.) are currently used for textile applications and composite reinforcement. Due to its industrial importance, flax is the subject of a varietal selection work in view of obtaining varieties with higher fiber yields, but also exhibiting a greater lodging resistance. Indeed, lodging sometimes happens within flax fields, complicating plant harvest and compromising yields. Interestingly, it sometimes occurs that flax stems restore from lodging through a gravitropic reaction. Depending on the time of lodging, variations in elementary fiber mechanical performances, monitored by tensile tests appeared to be more or less pronounced, being greater in the earliest stage of the experiment, and also depend on the studied side of the stem curvature. Namely, the pulling of the stems provides fibers with the most emphasized changes, in terms of strength at break, filling rate (presence of a fiber lumen) as well as cell wall tangent modulus. Finally, differences between tilted and control fibers diminish as the plant maturity progresses, with only slight remaining dissimilarities at plant maturity. Thus, flax fibers are involved in the plant gravitropic reaction and maintain their efficient mechanical characteristic despite lodging, through the adjustability of their cell wall performances over fiber thickening, which is a major result for fiber suppliers and composite manufacturers. [ABSTRACT FROM AUTHOR]

Winter rapeseed is an important oilseed crop in the Yangtze River Basin. To optimize its cultivation in this area and improve its production efficiency, a split-plot experiment with various planting dates (25 September and 10 October), nitrogen applications (120, 240 and 360 kg ha −1 ) and planting densities (3.0 × 10 5 , 4.5 × 10 5 and 6.0 × 10 5 plants ha −1 ) was performed to investigate their effects and interactions on the seed yield of rapeseed, its lodging index and weed occurrence in farmland. Our results indicated that (1) Delay in planting led to the decrease in the net photosynthetic rate ( Pn ) of leaf, nitrogen seed production efficiency (NUE), pod number per plant and yield, but aggravated weed occurrence. The increase in nitrogen fertilization resulted in reduced NUE, elevated Pn of leaves, improved pod number per plant and yield, and facilitated weed growth. The increase of planting density elevated NUE, reduced Pn and yield per plant because of the lowered number of pods per plant, but enhanced the population yield and substantially inhibited weed growth. (2) Delayed planting inhibited rapeseed growth, showing significant reductions in plant height, rhizome diameter, root dry weight, aboveground dry weight and root/shoot ratio, and resulted in lower snapping resistance but a higher lodging index. Although higher nitrogen application improved root dry weight, rhizome diameter and snapping resistance, it resulted in the increase of plant height and aboveground dry weight, which led to a reduced root/shoot ratio and a greater lodging index. The increase in planting density lowered the rhizome diameter, root dry weight and snapping resistance, significantly reduced the plant height and aboveground dry weight, hence increasing the root/shoot ratio, which further decreased the lodging index. A linear relationship was observed between the seed oil content and lodging index (2013–2014, R 2  = 0.3783**; 2014–2015, R 2  = 0.5641**). Oil content was reduced while the lodging index increased, indicating that lodging index was a key factor determining oil content under various planting dates, nitrogen amounts, densities and their interactions. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The field experiment was conducted to evaluate how row intercropping of the lentil with naked oats as a supporting plant impacts macro- and micronutrient content of two lentil varieties 'Tina' and 'Anita' as well as a mixture of these two varieties. Additionally, amino acid content and fatty acid composition of lentil seeds were determined. Lentil was sown at a row spacing of 20 and 25 cm. In var. 'Tina' seeds, a higher content of K, Ca, Mg, Mn and B was determined than in var. 'Anita'. 'Anita' seeds, in turn, were characterized by a higher content of fat, N, P, Cu, Zn and Fe. Lentil seeds sown at a spacing of 20 cm had a higher content of P, K, Ca, Cu, Zn and B compared to a spacing of 25 cm, but they contained less nitrogen. The presence of oats as a supporting crop deteriorated the quality of lentil seeds by contributing to a reduced content of N, P, K, Cu, Zn, Mn, Fe and B compared to sole cropped lentil. A higher content of C18:0, C18:2, C18:3, C20:0, OMEGA 3, and OMEGA 6 acids was determined in 'Anita' seeds. Var. 'Tina', in turn, contained more C16:0, C18:1 acids. In 'Anita' seeds, the content of most evaluated amino acids was determined to be significantly higher than in 'Tina' seeds. [ABSTRACT FROM AUTHOR]

Summary: Plant lodging resistance is an important integrative agronomic trait of grain yield and quality in crops. Although extensin proteins are tightly associated with plant cell growth and cell wall construction, little has yet been reported about their impacts on plant lodging resistance. In this study, we isolated a novel extensin‐like (OsEXTL) gene in rice, and selected transgenic rice plants that expressed OsEXTL under driven with two distinct promoters. Despite different OsEXTL expression levels, two‐promoter‐driven OsEXTL‐transgenic plants, compared to a rice cultivar and an empty vector, exhibited significantly reduced cell elongation in stem internodes, leading to relatively shorter plant heights by 7%–10%. Meanwhile, the OsEXTL‐transgenic plants showed remarkably thickened secondary cell walls with higher cellulose levels in the mature plants, resulting in significantly increased detectable mechanical strength (extension and pushing forces) in the mature transgenic plants. Due to reduced plant height and increased plant mechanical strength, the OsEXTL‐transgenic plants were detected with largely enhanced lodging resistances in 3 years field experiments, compared to those of the rice cultivar ZH11. In addition, despite relatively short plant heights, the OsEXTL‐transgenic plants maintain normal grain yields and biomass production, owing to their increased cellulose levels and thickened cell walls. Hence, this study demonstrates a largely improved lodging resistance in the OsEXTL‐transgenic rice plants, and provides insights into novel extensin functions in plant cell growth and development, cell wall network construction and wall structural remodelling. [ABSTRACT FROM AUTHOR]

Background and aims: Root lodging is a structural failure of the root-soil anchorage system in a plant that adversely affects its yield. It is a complex phenomenon that depends strongly on both crop genetics and environmental factors. An accurate biomechanical model to predict root lodging would disentangle the component factors and improve development of lodging resistant plants, thereby reducing the constraint of root lodging on crop yields.Methods: We developed a biomechanical model that employs an engineering safety factor approach to quantify root lodging resistance as the ratio of anchorage supply and wind demand. We also conducted field experiments to parametrize the model for a sensitivity analysis and validate the model for predictive accuracy.Results: The sensitivity analysis revealed primary, secondary, and tertiary factors for root lodging. The primary factors consisted of root angle, structural rooting depth, soil strength, and wind speed. The secondary factors were plant height, ear height, leaf area, stalk taper, ear mass, and leaf drag. Tertiary factors were stalk diameter and leaf number. The validation analysis found the model predictions compared well with data collected from three natural lodging events, with a goodness-of-fit of 0.58.Conclusions: The model effectively described a collection of natural lodging events, giving confidence in its predictive accuracy as well as the relative phenotypic and envirotypic influence factors determined in the sensitivity analysis. There are significant opportunities for model improvement, perhaps most significantly in the phenomenological understanding of the physical process. [ABSTRACT FROM AUTHOR]

Non-oilseed sunflower plants can be exposed to lodging in some production regions due to higher plant height and larger heads, which is further exacerbated by heavily rainfall and strong winds. In this context, plant growth regulators such as mepiquat chloride (MC) can be considered as an alternative approach in reducing plant height and lodging. This study was conducted to determine the effect of MC application on the growth, yield, and yield components of non-oilseed sunflowers at different growth stages (V4, R1, R2, and R3) and rates (0, 30, 60, and 90 g a.i. ha-1) in Erzurum Province, eastern Anatolia, Turkey, in the 2012 and 2013 growing seasons. In general, the MC applications had significant effects on the plant parameters investigated. In comparison with the control treatment, the MC application of 60 g a.i. ha-1 decreased plant height by 5.38% and increased stem diameter, head diameter, seed filling percentage, ratio of dehulled/hulled seed weight, 1000-achene weight, and seed yield by 14.01%, 3.78%, 1.61%, 4.20%, 5.94%, and 5.26%, respectively. Similarly, the applications of MC at different growth stages also significantly affected seed yield and other characteristics such as plant height, stem diameter, and head diameter. The application of MC at the early growth stage (V4) was more effective compared to the later growth stages (R1, R2, and R3). The results of this study suggest that the mepiquat application rate of 60 g a.i. ha-1 in the early growth stage (V4) was more effective on the plant characteristics and that MC application could be effectively used as a means of reducing plant height and the risk of lodging in non-oilseed sunflower production. [ABSTRACT FROM AUTHOR]

Copyright of Society & Leisure / Loisir & Société is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soybean lodging can result in serious yield reduction. Detecting the quantitative trait loci ( QTL) associated with lodging tolerance for their further application in marker-assisted selection ( MAS) has the potential to enhance soybean breeding efficiency. In this study, a genome-wide association analysis ( GWAS) was performed to identify soybean accessions that could potentially be used to produce lodging-tolerant varieties, based on the comprehensive evaluation of lodging scores ( LS) obtained for the parental cultivar 'Tokachi nagaha' and its 137 derived cultivars. Results showed that genotype, environment and genotype × environment interaction significantly influenced LS. Of the 31 significant SNPs identified, 22 were consistently detected in two or more environments and 27 SNPs were located in or close to agronomically important QTL mapped by linkage analysis. Best linear unbiased predictors ( BLUPs) of LS tend to decrease with the elite alleles contained by accessions increasing. Some excellent accessions, with lower BLUPs and D i (stability coefficients) values and more elite alleles, were selected. This study contributed to understand the genetic mechanism of lodging, providing genetic and phenotypic information for MAS. [ABSTRACT FROM AUTHOR]

Stalk lodging resistance is a particularly important trait on maize, especially in terms of mechanized harvesting of the crop. Stalk lodging represents a major problem of corn with yield losses. Because of this reason, it takes a special attention on the breeding process. The purpose of this research was the study of maize stalk lodging resistance before the harvest time and finding the best breeding lines for this type of resistance. We used 7 breeding lines (TE 229, TE 202B, TA 452, TE 330A, TD 364, TE 317 and TE 335) as maternal lines and another 3 (TD 268, TC 385A and TC 399) as testers. Lines were tested in 2011 and 2012, in compared cultures with 24 variants, where 21 of them were the experimental hybrids between tested lines and testers and the other 3 were the control hybrids Turda 201, Turda Favorit and PR39D81. Variance analysis was performed according to the classical model of a two-factor system. Genic effects were calculated after 2nd North Carolina model. Regarding the results, the highest percentage of unbroken plants was on TD 268 tester (80.7%) and the lowest on TD 364 tested line (70.2%). Tested lines that was noted for the general combining ability of lodging resistance were TA 452 and TE 335. Crossings that marked high values for non-additive effects were TA 452 x TC 385A, TE 202B x TC 399 and TE 202B x TD 268. Effects values for general combining ability were between -4.72% and +4.49% on tested lines, -1.68% and +5.78% on testers; effects values for specific combining ability were between -11.25% and +7.58%. Regarding the tested lines was noted TA 452 inbred line and regarding the testers was noted TD 268 inbred line. On this issue, we can state that in the selection process of maize hybrids must be chosen only those hybrid combinations with stalk-lodging resistance because of the similar contribution of additive and non-additive genic effects to resistant genotypes. [ABSTRACT FROM AUTHOR]

Height, an important agronomic trait, relates to lodging resistance, harvest index, and yield potential. Height is also a major issue in developmental biology. Systematic identification and characterization of dwarf plants that show defects in height have basic and applied significance. In previous research, we analyzed the agronomic and physiological features of the dominant maize dwarf plant Dwarf11 ( D11). However, transcriptomic specialization of D11 remains largely unknown. Here, we combined RNA-seq and co-expression analysis to survey the transcriptome dynamics of D11. A total of 306 significantly differentially expressed genes (DEGs) were identified, including 171 upregulated and 135 downregulated DEGs. Functional annotation, gene ontology (GO), and pathway enrichment analysis indicated that roles of DEGs were diversified, from organ size control, cell wall character, vascular tissue development, leaf morphology, chlorophyll metabolism, chloroplast function to sugar homeostasis. Functional associations of DEGs were further revealed by the co-expression analysis. Results presented here are informative for the elucidation of D11-involved regulatory network, and lay a foundation for candidate gene prioritization and D11 gene cloning. [ABSTRACT FROM AUTHOR]

Key message: Identification and characterization of a semi-dwarfing gene ds-3 encoding a mutant DELLA protein regulating plant height through gibberellin signaling pathway. Abstract: Lodging is one of the most important factors causing severe yield loss in oilseed rape. Utilization of semi-dwarf varieties has been proved the most effective way to increase lodging resistance and yield in many crops. To develop semi-dwarf germplasm in oilseed rape, we identified a semi-dwarf mutant ds-3 which showed a reduced response to phytohormones gibberellins (GAs). Genetic analysis indicated the dwarfism was controlled by a single semi-dominant gene, ds-3. The DS-3 gene was mapped to a genomic region on chromosome C07, which is syntenic to the region of a previously identified semi-dwarf gene ds-1 ( BnaA06.RGA). In this region, DS-3 ( BnaC07.RGA) gene was identified to encode a DELLA protein that functions as a repressor in GA signaling pathway. A substitution of proline to leucine was identified in ds-3 in the conserved VHYNP motif, which is essential for GA-dependent interaction between gibberellin receptor GID1 and DELLA proteins. Segregation analysis in the F population derived from the cross between ds-1 and ds-3 demonstrated that BnaA06.RGA displayed a stronger effect on plant height than BnaC07.RGA, indicating that different RGA genes may play different roles in stem elongation. In addition to BnaA06.RGA and BnaC07.RGA, two more RGA genes ( BnaA09.RGA and BnaC09.RGA) were identified in the Brassica napus ( B. napus) genome. Reverse-transcription polymerase chain reaction (RT-PCR) and yeast two-hybrid (Y2H) assays suggest that both BnaA09.RGA and BnaC09.RGA are transcribed in leaves and stems and can mediate GA signaling in vivo. These genes represent potential targets for screening ideal semi-dwarfing alleles for oilseed rape breeding. [ABSTRACT FROM AUTHOR]

Because edible canna is approximately 3-m tall in its latter growth stage, strong winds such as by typhoons can induce plant lodging and cause severe damage to it. To improve our previous estimations that the 1-m dwarfing of a plant mitigated 10–20% by strong wind (external force) and 50% by own weight (internal force), respectively, we re-examined these parameters in relation to rhizome yield for field-grown plants. From early middle growth stage (July–August) of edible canna, the perpendicularly projected area of above-ground biomass increased rapidly due to rapid shoot elongation. After the middle growth stage (September), the stock base radius increased and shoot inclination angle decreased until the latter growth stage (November) gradually, indicating a disturbed architecture and easy lodging. Throughout the growth period, we observed no radial, directional difference in the leaf area distribution. Increase in the distance between the ground surface and the center of gravity of shoot weight and decrease in the shoot inclination increased the components of the internal force. The easiness to fall down (percentage own-weight invasion moment) of plant became maximal in the latter growth stage. We conclude that approximately 50-cm dwarfing of the plant with minimal loss of rhizome yield (as low as approximately 20%) and the maintenance of lodging tolerance is optimal. In such a situation, both external and internal forces are mitigated by approximately 30%. [ABSTRACT FROM PUBLISHER]

A liquid silicon fertilizer [Si(OH) 4 ] was root sprayed at various concentrations during the seedling stage (T1) and early bud stage (T2) using the rapeseed varieties ( Brassica napus L.) Huayouza 62 and Fengyou 520. The lodging- and yield-related index, silique shatter were evaluated. Our results indicated that the lodging resistance, silique shatter resistance, and yield all increased significantly in the two rapeseed varieties after the application of silicon fertilizer in both stages. The seed number per silique was reduced after silicon application, but the silique number per plant and 1000-grain weight were increased, especially the silique number on the branches, thereby improving the overall yield, where the most obvious effect on the yield increase occurred at the T2 stage with 0.96 mM silicon. At the T1 and T2 stages, the higher concentration of silicon fertilizer increased the root diameter, as well as the stem SiO 2 content and breaking strength, but reduced the plant height and lodging index. There were also increases in the expression levels of the key genes related to stem lignin biosynthesis (phenylalanine ammonia lyase ( PAL ) and 4-coumarate: CoA ligases), the lignin content, thereby increasing the resistance to lodging. At stages T1 and T2, the higher concentration of silicon fertilizer increased the expression of the PAL , which induced the accumulation of lignin. There was a significant correlation between the silique dry weight and silique shatter index. The silique SiO 2 content and dry weight also increased, thereby improving the shatter resistance. Considering the yield and mechanical harvesting properties, the results of the present study show that the optimum effect of the liquid silicon fertilizer on both rapeseed varieties occurred during the early bud stage (bolting height of 8–12 cm) with a monosilicic acid content was 0.96 mM. [ABSTRACT FROM AUTHOR]

In this study were characterized various aspects of the plants lodging and weeds of wheat and barley as compared with the normal state, through image analysis. Observations were made in stages BBCH 73 Development of fruit and BBCH 93 - Senescence at wheat crops, respectively BBCH 87 (Ripening) and BBCH 93 (Senescence) at barley crops. From the analysis of the terrestrial and aerial images (drone DJI Phantom series) spectral data were obtained in the RGB system, based on which were calculated normalized values (rgb). The data obtained were analyzed in two ways in relation to the studied aspects: plants lodging (6 variants - V1 to V6) and weeds (8 variants - V7 to V14). With respect to the lodging of wheat and barley plants, the cluster analysis method facilitated the grouping of the data into two clusters, CIL and CIIL, statistical safe, Cophenetic coefficient having the value of 0.774. The analysis has made the classification, both in relation to the two categories of crops (wheat and barley), as well as compared with the normal plants and lodging plants identified. In the situation of the second category of cases studied, was analyzed the presence of weeds in wheat and barley crops, compared to the normal status of the crops, in advanced stages of the growing season. The analysis grouped the 8 variants studied in two in clusters (CIW - V12, V13 and V14; CIIW- V7, V8, V9, V10) and a independent position (V11), in the average conditions of statistical certainty, the Cophenetic coefficient being 0.689. Regarding to the level of statistical certainty of results, it would have been higher if the analysis should have been done on each individual crop, but in the case of complex approach, the interaction of the phenomenon (plant lodging or weed, and crops), made that the safety level have lower values. [ABSTRACT FROM AUTHOR]

Lodging of cabbage plants ( Brassica oleracea var. capitata ) can reduce crop efficiency and yield during machine harvesting, and this is a problem in Japan in the context of growing demand for cabbage crops from the food processing and retail industries. We have previously described a method, involving transplantation of plug-grown seedlings at increased depth, which addresses these problems, but the reasons for this result were unclear. We therefore sought to determine the underlying mechanism by a further study assessing the distribution and anchorage of roots in cabbages transplanted at different depths. Cabbage plug seedlings were transplanted with the top of the plug-soil positioned either 5 mm above (shallow planting) or 20 mm below (deep planting) the surface of the planting soil. The number and diameter of the roots were determined during the head-filling stage. After removal of the cabbage head and leaves, the stem was artificially pushed downwards, in order to assess the type and resistance of root anchorage. The shallow-planted cabbages showed a few thick roots near the soil surface, in contrast with the deep-planted cabbages, which had grown many fine roots at a depth of 3–5 cm. Artificial lodging caused the roots and surrounding soil to rotate to an extent that was dependent on the angle of the stem from the vertical. An angle of 30° from the vertical would appear to be critical for cabbage lodging. The deep-planted cabbages showed high resistance to lodging and improved anchorage resistance. The higher anchorage resistance, probably resulting from deeper root development, could be a contributory factor in the lower susceptibility to lodging of cabbages grown from deep planting of plug seedlings. [ABSTRACT FROM AUTHOR]

Using the rapeseed Huayouza 62 as experimental material, yield and lodging related traits were evaluated under various nitrogen applications [120,240 and 360 kg ha −1 (N1–N3, respectively)] and planting densities [15 × 10 4 , 30 × 10 4 and 45 × 10 4 plants ha −1 (D1–D3, respectively)]. Results showed: (1) the increase of nitrogen fertilizer elevated the leaf (and silique) area index (LAI) and light interception rate (LIR), significantly affecting the bud stage. In addition, the radiation use efficiency (RUE) for different growth stages and biomass accumulation were increased, which improved yield by facilitating formation of siliques in both single plants and populations. The increase of planting density significantly elevated the population LAI and LIR in seedlings, and the RUE in various growth stages, increased population biomass accumulation, which may have also improved yield by promoting the formation of siliques in the population. The correlation between LIR/LAI and yield was the highest at the bud stage, while the strongest correlation between RUE and yield was at silique development. (2) More nitrogen increased the lodging angle, base lodging index (LIL) and the upper lodging index (LIU), resulting in elevated whole plant lodging risk. With increases in nitrogen fertilizer, expression of phenylalanine ammonia-lyase ( PAL ) of lignin biosynthesis decreased in the upper stem, leading to lower lignin content and lodging resistance. However, higher plant density reduced the lodging angle and LIU, but increased LIL. The increase in planting density induced the expression of PAL , cinnamoyl-CoA reductase 1 ( CCR1 ), 4-coumarate: CoA ligase (4CL) in the stem, which showed their highest expression in the N2D3 treatment, leading to higher lignin content and lodging resistance. (3) In this study, N2D3 achieved relative high yield and the lowest lodging index, which will meet the requirements for mechanized harvest. [ABSTRACT FROM AUTHOR]

A methodology to estimate wind and rain effects on the four main growth crops in the United Kingdom is presented. The method is based on simulated weather scenarios acting on synthetic plants over a period of thirty years. The environmental data is generated with the UKCP09 Weather Generator considering future climate scenarios whereas plants are modelled as simple oscillators characterised by their mass, stiffness and damping. The joint probability of occurrence of wind and rain are estimated together with the conditions in which lodging would occur. The paper shows that the dynamic response of plants varies with season being the first three months of the year the most critical whilst the plants’ performances define crop failure velocities ranging between 4 ms −1 and 23 ms −1 and associated failure rates of 50% and 5% per unitary velocity. [ABSTRACT FROM AUTHOR]

Late-season drought is a major limiting factor worldwide for rainfed sorghum [ Sorghum bicolor (L.) Moench] production. Field screening of genotypes against post-anthesis drought is challenging as the stress is unpredictable and, when it happens, is often confounded with stalk diseases and lodging. In this study, we report on the results of tests on the use of desiccants in simulating post-anthesis drought effects in sorghum as aid in selection for late-season drought tolerance. First, we tested the efficacies of three desiccants KI, NaClO 3 and KClO 3 . Each desiccant was applied at three concentrations: 0.4% w/v, 0.6% w/v and 1% w/v, and on three genotypes P89001, P898012 and TX7078, known for their drought responses. Genotypic grain yield (GY) and seed weight (SWT) differed significantly under each of these desiccants. Genotype P898012, tolerant to post-anthesis drought, had the highest GY and SWT, while TX7078 and P89001, known for their post-anthesis drought susceptibility, had the lowest values following treatment with desiccants. The desiccants had significantly different effects, with NaClO 3 inducing the most severe effect on GY and SWT while KI had the least effect. Observed genotypic differences were greater at 0.4% w/v for NaClO 3 and KClO 3 , while KI had greater marked effect both at 0.6% w/v and 1% w/v. In the second experiment, we assessed the sensitivity of 18 diverse sorghum genotypes to KI (0.6% w/v). All genotypes tolerant to late-season drought had lower grain yield reduction (GYR), seed weight reduction (SWR) and stress susceptibility index (SSI), but a higher stress tolerance index (STI) than the susceptible genotypes. Remobilized total nonstructural carbohydrate was associated positively with STI’s but negatively with SSI’s. Results from this study suggested that desiccants simulated the effect of post-season drought stress, and that this technique could be used in assisting sorghum breeders to rapidly screen for post-anthesis drought tolerance under drought free environments. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is an important crop in the midsouthern United States. However, some high-yielding cultivars are highly susceptible to lodging. Th e plant growth regulator, trinexapacethyl (TE), has been shown to decrease lodging in upland cereal crops, but data are scarce that demonstrate rice response to TE. The objective of this study was to determine the effect of TE on rice plant height, lodging, and grain yield. Experiments were established at multiple locations during the 2012 and 2013 growing seasons in Mississippi. Trinexapac-ethyl was applied to a lodging-susceptible rice cultivar at 12, 24, and 48 g a.i. ha-1 at two timings: panicle differentiation (R1) and R1 + 14 d. Rice response to TE was determined for rice that received 100% of N applied at V3 and rice that received a two-way split N strategy (75% N at V3 and 25% at R1). On both clay and silt-loam soils all rates of TE reduced plant height and lodging compared to nontreated rice. Th e effect of TE on rice grain yield was variable. On silt-loam soils 12 g a.i. ha-1 TE resulted in rice grain yield similar to nontreated rice when applied at R1, but decreased grain yield when applied to rice at R1+ 14 d. Th e 48 kg a.i. ha-1 rate decreased rice grain yield on both soil textures. The results of this study indicate that trinexapac-ethyl may be a useful tool to manage lodging, but further research is needed refine TE use guidelines in rice. [ABSTRACT FROM AUTHOR]

Stem lodging is the most important constraint for soybean at seedling stage in maize–soybean intercropping in China. This study was conducted to determine whether cellulose accumulation and lodging resistance of soybean was affected by different cropping systems and soybean varieties with different shading tolerance at seedling stage. Three soybean varieties – Nandou 032-4 (shade susceptible), Jiuyuehuang (moderately shade tolerant) and Nandou 12 (shade tolerant) – were used to investigate the effect of intercropping on soybean lodging behavior and cellulose accumulation in stems and its relationship to lodging resistance. Shading by maize significantly reduced cellulose accumulation and the stem breaking strength of the soybean, which were significantly negatively correlated with the lodging rate. In the maize–soybean intercropping system, shading inhibited sucrose transportation and degradation into cellulose in the soybean stem. Less content of cellulose in soybean stem at the seedling stage resulted in lodging in the intercropping system. Compared with shade susceptible varieties, Nandou 12 had higher cellulose accumulation and related enzyme activities in the stem, and thus the stem breaking strength and lodging resistance of the basal stem increased. The higher activities of sucrose phosphate synthase and sucrose synthetase in the stem were associated with shade tolerance and lodging resistance. Thus, we concluded that the high physical strength and high cellulose contents of the stem of shade tolerant soybean reduced the rate of lodging in the maize–soybean intercropping system. [ABSTRACT FROM AUTHOR]

In-crop nitrogen (N) application is used widely in rainfed winter wheat production to reduce lodging risk; however, uncertainty exists as to its ability to reduce lodging risk in subtropical irrigated wheat production without simultaneously reducing yield potential. The objective of this study was therefore to determine whether in-crop N application reduces lodging risk without reducing yield of irrigated spring wheat in a subtropical environment. Irrigated small-plot experiments were conducted to compare the effect of alternative N timing on lodging and yield in two cultivars. Variable N regimes were imposed during the vegetative growth phase, after which additional N was applied to ensure that total season N application was uniform across N-timing treatments. Treatments with low N at sowing had significantly less lodging and were the highest yielding, exhibiting yield increases of up to 0.8 t ha–1 compared to treatments with high N at sowing. Increased leaf area index, biomass and tiller count at the end of the vegetative growth phase were correlated with increased lodging in both cultivars, although the strength of the correlation varied with cultivar and season. We conclude that canopy-management techniques can be used to simultaneously increase yield and decrease lodging in irrigated spring wheat in the subtropics, but require different implementation from techniques used in temperate regions of Australia. [ABSTRACT FROM AUTHOR]

Stem lodging causes significant losses in crops of cereals and oilseeds. The aim of the present study was to identify the anatomical causes that generate differences in response to stem lodging in sunflower. Two sunflower hybrids (Stay-Green, resistant to stem lodging; Zenit, susceptible to stem lodging) were grown at three crop population densities and artificially lodged at two advanced ontogeny stages (R7 and R8), which were preceded by ethephon application near the flower button stage (R1). Measurements included stem failure moment of force (Bs), thickness of primary and secondary structures in the stem lodging zone (t), diameter of the stem lodging zone (di), sclerenchyma packages area (sp), secondary xylem tissue area (xt) and yield. Stay-Green had significantly higher values for Bs, t, di, sp and xt. At higher crop densities and more advanced ontogeny stages these parameters were reduced, favouring stem lodging, although the effects were ameliorated by ethephon application through anatomical modifications. Zenit exhibited the greatest responses to ethephon application. The present study is the first field study identifying anatomical changes causing stem lodging and intraspecific variability in sunflowers. The information provided can be used by geneticists in selection programs for stem lodging tolerance in the context of increasing crop population densities to improve sunflower yield. [ABSTRACT FROM AUTHOR]

The barley ( Hordeum vulgare L.) mutant erectoides-k.32 ( ert-k.32) was isolated in 1947 from an X-ray-mutant population of cultivar 'Bonus'. The mutant was released as a cultivar in 1958 with the name 'Pallas' - one of the first cereal crop cultivars developed from induced mutants. 'Pallas' is a semi-dwarf barley cultivar known for its culm stability and resistance to lodging. In total, eight allelic ert-k mutants are known that show different phenotypic strength concerning culm length and spike architecture. They represent alternatives to the widely used, but pleiotropic 'Green Revolution' alleles of the Sdw1 ( semidwarf1/denso) and Uzu1 ( semi-brachytic1) genes in breeding of robust elite barley cultivars. In the present study, we locate Ert-k to a 15.7- cM region in the centromeric region of chromosome 6H. Although the interval is estimated to contain approximately 700 genes, the work provides a solid foundation for the identification of the underlying mutations causing the ert-k lodging-resistant phenotype. In addition, the linked markers could be used to follow the ert-k mutant genotype in marker-assisted selection of new lodging-resistant barley cultivars. [ABSTRACT FROM AUTHOR]

Strong wind and heavy rain remain the two most important causes of large acreage wheat (Triticum aestivum L.) lodging in China. For research the influence of wind speed and rainfall—separately as well as together—on the extent and degree of lodging, five levels of the severity of lodging were defined based on a combination of the lodging area and the degree of tilting. Detailed meteorological information was studied on 52 instances of large-scale lodging that occurred from 2007 to 2014. The results showed that strong wind’s lodging accounted for 8% of the instances studied, continuous rainfall’s lodging accounted for 19% and strong winds-heavy rainfall’s accounted for 73%. The minimum instantaneous wind speed that could cause large-scale lodging was closely related to rainfall. Without rainfall, the wind speed that resulted in lodging ranging in severity from slight to severe (Level 2 to Level 5) was 14.9 m/s, 19.3 m/s, 21.5 m/s, and 26.5 m/s, respectively; when accompanied by rainfall, the wind speed that resulted in lodging of the same severity decreased linearly with the increase of rainfall. These results will be particularly useful in preventing and alleviating wheat lodging as well screening wheat varieties with good lodging resistance. [ABSTRACT FROM AUTHOR]

Late-season stalk lodging in maize (Zea mays L.) is a major agronomic problem that has farreaching economic ramifications. More rapid advances in lodging resistance could be achieved through development of selective breeding tools that are not confounded by environmental factors. It was hypothesized that measurements of stalk flexural stiffness (a mechanical measurement inspired by engineering beam theory) would be a stronger predictor of stalk strength than current technologies. Stalk flexural stiffness, rind penetration resistance and stalk bending strength measurements were acquired for five commercial varieties of dent corn grown at five planting densities and two locations. Correlation analyses revealed that stalk flexural stiffness predicted 81% of the variation in stalk strength, whereas rind penetration resistance only accounted for 18% of the variation in stalk strength. Strength predictions based on measurements of stalk flexural stiffness were not confounded by hybrid type, planting density, or planting location. Strength predictions based on rind penetration resistance were moderately to severely confounded by such factors. Results indicate that stalk flexural stiffness is a good predictor of stalk strength and that it may outperform rind penetration resistance as a selective breeding tool to improve lodging resistance of future varieties of maize. [ABSTRACT FROM AUTHOR]

The plant growth regulator trinexapac-ethyl (TE) is widely used to increase seed yield by reducing lodging in many grass species, including perennial ryegrass (Lolium perenneL.) and tall fescue (Festuca arundinaceaSchreb.). However, the seed yield responses of annual ryegrass (Lolium multiflorumLam.) to TE has not been widely investigated. In four field experiments, different rates of TE (between 0 and 800 g ha−1) were applied and the plant response measured. Seed yield was significantly (P < 0.05) increased above the control by all TE treatments with an average response of 51% and 65% for the 200 g and 400 g TE ha−1treatments, respectively. The seed yield response was associated with reduced lodging and shorter stems contributing to 1.1 more seeds per spikelet attaining saleable weight resulting in 72% more seeds m−2. The plant growth regulator TE can improve seed yield in well-managed stands of annual ryegrass. [ABSTRACT FROM PUBLISHER]

Tef [Eragrostis tef (Zucc.) Trotter] and finger millet [Eleusine coracana Gaertn] are staple cereal crops in Africa and Asia with several desirable agronomic and nutritional properties. Tef is becoming a life-style crop as it is gluten-free while finger millet has a low glycemic index which makes it an ideal food for diabetic patients. However, both tef and finger millet have extremely low grain yields mainly due to moisture scarcity and susceptibility of the plants to lodging. In this study, the effects of gibberellic acid (GA) inhibitors particularly paclobutrazol (PBZ) on diverse physiological and yield-related parameters were investigated and compared to GA mutants in rice (Oryza sativa L.). The application of PBZ to tef and finger millet significantly reduced the plant height and increased lodging tolerance. Remarkably, PBZ also enhanced the tolerance of both tef and finger millet to moisture deficit. Under moisture scarcity, tef plants treated with PBZ did not exhibit drought-related symptoms and their stomatal conductance was unaltered, leading to higher shoot biomass and grain yield. Semi-dwarf rice mutants altered in GA biosynthesis, were also shown to have improved tolerance to dehydration. The combination of traits (drought tolerance, lodging tolerance and increased yield) that we found in plants with altered GA pathway is of importance to breeders who would otherwise rely on extensive crossing to introgress each trait individually. The key role played by PBZ in the tolerance to both lodging and drought calls for further studies using mutants in the GA biosynthesis pathway in order to obtain candidate lines which can be incorporated into crop-breeding programs to create lodging tolerant and climate-smart crops. [ABSTRACT FROM AUTHOR]

Growth, biomass yield, fiber content and lodging resistance were studied, during a six month growth period, for eight varieties of Cenchrus purpureus , intended as energy crop, in Veracruz, Mexico. Then, only yield at day 182 was assessed for two additional years. The varieties were: CT115 (CT), African Cane (AC), Taiwan (TAI), King Grass (KG), Vruckwona (VRU), Roxo (RX), OM22 (OM) and Cameroon (CAM). Local weather is warm and sub-humid, historical data for monthly average temperature and annual rainfall were 25.8 °C and 1142 mm, respectively. Height, diameter and light interception were measured monthly from day 65–185. At day 185, biomass yield and tiller density were measured. Number of lying tillers was counted to estimate lodging resistance. Cellulose and hemicellulose content were estimated in leaf and stem. No differences were found for dry matter yield or stem yield at day 185 in the first year. Regarding the next two years, TAI yielded above CT, OM or ROX. Average dry matter yield was higher in the second year than in the establishment cycle (38.6 vs 21.1 Mg ha −1 ), but decreased in the third year (32.2 Mg ha −1 ). In both stem and whole plant, AC and KG showed higher hemicellulose content than RX, OM or CT; while AC and VRU had higher cellulose than RX in stem, or than CT in the whole plant. Furthermore, varieties AC, KG, VRU and TAI were resistant to lodging and had a higher fiber content, so they are recommended as energetic crops. [ABSTRACT FROM AUTHOR]

Limited information is available on the effects of spring-applied N on winter canola (Brassica napus L.) seed yield in seasonally high-rainfall environments. The objective of this study was to investigate spring-applied N effects on four winter canola cultivars: Athena, Baldur, Virginia and Kronos. Trials were conducted over a 3-yr period at Corvallis, OR, with four spring N rates: 0, 56, 112, and 168 kg N ha-1. Lodging severity affected seed yield responses to spring-applied N. Under low or moderate lodging, yield was increased incrementally with spring N rate. When lodging was severe, yields were reduced by 168 kg N ha-1. Spring N increased yield up to 75%, but losses in yield due to N when lodged ranged up to 11%. Seeds m-2 was the main contributor to increased or decreased yields in response to spring N. Seed oil content was reduced by increased N rate, but seed protein was unaffected by spring N. Oil yield was increased by spring N when lodging was low or moderate but not when severe. Seed yield varied among cultivars with a different cultivar producing the highest yield each year. Athena, Baldur, and Virginia averaged 2800 kg ha-1, while Kronos yielded the lowest at 2550 kg ha-1. Expression of yield by cultivars was governed by a combination of seed number and seed weight. The best spring N rate for winter canola was 112 kg N ha-1 because it provided high potential yield while minimizing yield losses associated with lodging. [ABSTRACT FROM AUTHOR]

Close planting often increases the lodging rate of maize, but the cause is unclear. Close planting reduces light intensity within the canopy; therefore, we hypothesized that light intensity may be the main factor affecting maize lodging. To test this hypothesis, three field experiments involving plant density, shading and defoliation were designed to explore how the light environment in a maize canopy affects stalk strength formation and lodging rate. The results showed that close planting and artificial shading treatments both reduced light intensity in the lower canopy. This reduced the dry weight per unit length (DWUL) and rind penetration strength (RPS) of the third basal internode and increased the lodging rate. Removal of leaves 10–12 reduced the DWUL and RPS of the third internode and increased lodging rate. This showed that leaves 10–12 play a crucial role both in the formation of RPS of the third basal internode and in lodging resistance. Removal of either all or part of leaf 16 and above not only increased ptotosynthetic active radiation (PAR) at leaves 10–12 but also increased the DWUL and RPS of the third basal internode. This resulted in a decline in lodging. Therefore, we conclude that light intensity is an important factor affecting maize lodging at high plant density. Increasing light intensity at leaves 10–12 can enhance stalk strength and reduce lodging. [ABSTRACT FROM AUTHOR]

Lodging is an important adversity affecting maize yield and quality in the world, especially under dense populations. A field experiment was conducted with two hybrids, Xianyu335 (XY) and Jingdan28 (JD) to study the influence of tillage practices on root system characteristics and their relationships with lodging resistance. The tillage practices included direct seeding of maize into stubble (ST), direct seeding with hilling (STH), rotary tillage before seeding (RT) and rotary tillage with hilling (RTH); the hilling was done at the jointing stage. The RT significantly increased the soil water content, number of nodal roots, root length density, average root diameter, axile root/shoot (RS) ratio and root width, decreased the penetration resistance (PR), centre of gravity height and ear position coefficient of plants, and enhanced vertical root-pulling resistance and tensile force of individual aerial roots. The grain yield was also highest and root lodging rate lowest under TR, followed by ST. Although hilling at the jointing stage tended to increase root number, root length density and average root diameter within the 40 cm depth, the RS ratio, root width and vertical root-pulling resistance decreased markedly, resulting to lower yields and poorer root-lodging resistance. The vertical root-pulling resistance was positively correlated with number of nodal roots and RS ratio, but negatively correlated with centre of gravity height of plants. The root lodging rate had weak positive correlation with PR which had significant negative correlation with number of nodal roots. This suggested that the poor root system of summer maize was the main reason of the weak root lodging-resistance and rotary tillage before seeding and direct seeding into stubble would be suitable practices for maize production while hilling could exacerbate root lodging and should be avoided. The knowledge obtained here will be useful for hybrid selection and improving cultural practices for enhancing the root lodging resistance of maize in rain and wind prone regions. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on the effect of three retardants on the length of the stem, ear internode and successive internodes, as well as on the mechanical properties and geometric features of the stem of winter wheat, i.e. inner and outer stem diameter, as well as stem wall thickness. The following retardants: Antywylegacz Płynny 675 SL, Moddus 250 EC and Cecefon 465 SL, were applied at the recommended rates and at rates reduced by 50 and 67% at the beginning of stem elongation (BBCH 31) or at the 2nd node stage (BBCH 32) of winter wheat. The study showed that the lengths of individual internodes, their outer diameters as well as the diameter and thickness of the 4th internode were most influenced by the growth regulators used at the highest rate. The diameter of the stem gradually decreased from the lower internodes towards the ear. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)