Lodging In Wheat Research Articles

Non-uniform wheat population distribution enhances wheat yield and lodging resistance synchronously

Film mulching ridge-furrow planting (RF) planting is an important dry farming mode for wheat but it usually causes lodging, which depends on lignin accumulation in the stems. Previous research has generally speculated that lignin synthesis is influenced by the light environment, which can be modified by regulating the population distribution. However, whether light is the main factor affecting lignin accumulation has yet to be determined. Meanwhile, the impact of light-based regulation on lodging suppression and the specific mechanism involved are still unclear, especially under RF conditions. Thus, we investigated the effects of regulating the population distribution on the occurrence of lodging in wheat to clarify the mechanism associated with lodging resistance and to develop approaches for improving lodging resistance under RF. This three-year field experiment investigated the effects of four treatments on lodging occurrence in wheat: traditional flat planting treatment (TF, row spacing of 20 cm), RF + uniform wheat population distribution (RF20, row spacing of 20 cm:20 cm:20 cm), and RF + non-uniform population distribution (RF25, row spacing: 25 cm:10 cm:25 cm; RF30, row spacing: 15 cm:30 cm:15 cm). Compared with TF, RF20 significantly increased the occurrence of lodging, whereas RF25 and RF30 could effectively reduce the occurrence of lodging and increase wheat yield, in which the effect of RF30 was optimal. The photosynthetically active radiation (PAR) in the middle–lower layers of the canopy was significantly reduced under RF20, whereas RF25 and RF30 effectively improved PAR. Mechanical stem parameters comprising the filling degree, section modulus, breaking strength, and lodging resistance index were significantly lower under RF20 than TF, whereas these parameters improved significantly under RF25 and RF30. In addition, lignin accumulation and the activities of lignin biosynthesis enzymes and related gene expression levels were significantly lower under RF20 compared with TF, whereas these parameters were significantly higher under RF25 and RF30. Correlation and path analyses showed that the canopy light environment was related to lignin biosynthesis in the stems, and thus lodging resistance. The canopy light environment was undesirable under RF with a uniform population distribution, where it significantly reduced the mechanical properties of the stems and lodging resistance. Regulating the population distribution can enhance the mechanical properties of the stems by improving the canopy light environment to promote the synthesis and accumulation of lignin in the stems to reduce lodging in wheat. These findings may provide a theoretical basis for understanding the lower stem strength in wheat under RF and help the development of suitable measures for enhancing lodging resistance.

Wheat Lodging Direction Detection for Combine Harvesters Based on Improved K-Means and Bag of Visual Words

For the inconsistent lodging of wheat with dense growth and overlapped organs, it is difficult to detect lodging direction accurately and quickly using vehicle vision for harvesters. Therefore, in this paper, the k-means algorithm is improved by designing a validity evaluation function, selecting initial clustering centers by distance, constructing a multidimensional feature vector, and simplifying calculations using triangle inequality. An adaptive image grid division method based on perspective mapping and inverse perspective mapping with a corrected basic equation is proposed for constructing a dataset of wheat lodging directions. The improved k-means algorithm and direction dataset are used to construct a bag of visual words. Based on scale-invariant feature transform, pyramid word frequency, histogram intersection kernel, and support vector machine, the wheat lodging directions were detected in the grid. The proposed method was verified through experiments with images acquired on an intelligent combine harvester. Compared with single-level word frequencies with existing and improved k-means, the mean accuracy of wheat lodging direction detection by pyramid word frequencies with improved k-means increased by 6.71% and 1.11%, respectively. The average time of detection using the proposed method was 1.16 s. The proposed method can accurately and rapidly detect wheat lodging direction for combine harvesters and further realize closed-loop control of intelligent harvesting operations.

Relationship between canopy coverage at the initiation of stem elongation and lodging in wheat

While lodging in wheat appears to correlate with the ratio of canopy coverage at the initiation of stem elongation (CC30), a mechanistic understanding of the relationship between lodging index and CC30 is lacking. The objective of this study was to examine more closely the relationship between lodging and CC30 and to identify the most effective sowing densities and/or planting patterns in reducing lodging. The CC30 was adjusted by varying the sowing density and planting pattern, i.e., wide vs narrow-spaced rows and altering the seed spacing within the row and by spread sowing. We found that CC30 was positively correlated with the lodging degree at maturity and was negatively correlated with internode dry weight per unit length. The CC30 for a sowing density of 3 g m−2 (which is about half the conventional sowing density in Japan) was low at a range of 28–75 %. In these treatments, CC30 was lowest under spread sowing where the spacing between plants was greatest. The yield of the 3 g m−2 spread-seed treatments was more than 500 g m−2. This yield is comparable to that of the other treatments even though the sowing density was much lower. The aboveground N accumulation at maturity of the 3 g m−2 spread-seed treatments was similar to that of the other treatments. As found in the spread-seed treatments, our results suggest that lowering CC30 by reducing the sowing density and/or by changing the planting pattern, increased the spacing between seedlings and thus helped to prevent lodging while still retaining high yields.

RETRACTED: Theoretical research on rice and wheat lodging detection based on artificial intelligence technology and a template matching algorithm

AbstractTraditional detection of lodging in rice (Oryza sativa L.) and wheat (Triticum aestivum L.) mostly uses statistical methods or routine ground surveys. These methods have a low degree of automation and poor accuracy. In order to improve the detection of rice and wheat lodging, this study combined artificial intelligence technology and a template matching algorithm to construct a rice and wheat lodging detection system. Moreover, this study used perceptual hash technology for image matching processing, built an intelligent recognition model on the basis of improved algorithms, and combined this with camera technology to build the system's functional framework. The constructed system could perform image matching for rice and wheat, and detected rice and wheat lodging on the basis of image matching. Finally, this study analyzed the system's function structure based on the actual situation of rice and wheat lodging, and designed experiments to verify the effect of the system. The experimental research results showed that the system constructed in this study can play an effective role in the detection of rice and wheat lodging.

Rapid in situ nondestructive evaluation of lodging risk in dryland agronomic wheat research

AbstractThe natural occurrence of lodging in wheat (Triticum aestivum L.) in small‐plot research aiming to record visual ratings is unpredictable highly dependent on environmental conditions, and does not differentiate between root and shoot lodging. Detailed plant characteristics can be used to indicate lodging risk; however, such measurements are destructive and time‐consuming for projects that are not focused solely on evaluating lodging. The Stalker, a push force meter, can be used nondestructively to rapidly indicate stem strength and elasticity, which may be useful for measuring lodging risk in small‐plot research to indicate both root and shoot lodging. The objective of this study was to evaluate the ability of the Stalker to detect agronomic management practices that are known to reduce lodging risk (reduced plant density, split nitrogen applications, and plant growth regulator applications). Stalk strength (resisting force) and elasticity (spike displacement, energy, and power) measurements were taken at anthesis and physiological maturity in a small‐plot agronomic research trial. The Stalker was able to identify practices with high and low lodging risk. Lower plant density led to increased stem strength (measured by resisting force) and stem flexibility (measured by spike displacement) compared with high plant densities, indicating a decreased risk of both stem and root lodging when low plant densities were used. Overall, the Stalker is a new tool for rapid and nondestructive measurements of lodging risk in small‐plot agronomic research trials and can indicate both stem and root lodging risk by measuring indicators of both stem strength and elasticity.

Late sowing enhances lodging resistance of wheat plants by improving the biosynthesis and accumulation of lignin and cellulose

Delayed sowing mitigates lodging in wheat. However, the mechanism underlying the enhanced lodging resistance in wheat has yet to be fully elucidated. Field experiments were conducted to investigate the effects of sowing date on lignin and cellulose metabolism, stem morphological characteristics, lodging resistance, and grain yield. Seeds of Tainong 18, a winter wheat variety, were sown on October 8 (normal sowing) and October 22 (late sowing) during both of the 2015–2016 and 2016–2017 growing seasons. The results showed that late sowing enhanced the lodging resistance of wheat by improving the biosynthesis and accumulation of lignin and cellulose. Under late sowing, the expression levels of key genes (TaPAL, TaCCR, TaCOMT, TaCAD, and TaCesA1, 3, 4, 7, and 8) and enzyme activities (TaPAL and TaCAD) related to lignin and cellulose biosynthesis peaked 4–12 days earlier, and except for the TaPAL, TaCCR, and TaCesA1 genes and TaPAL, in most cases they were significantly higher than under normal sowing. As a result, lignin and cellulose accumulated quickly during the stem elongation stage. The mean and maximum accumulation rates of lignin and cellulose increased, the maximum accumulation contents of lignin and cellulose were higher, and the cellulose accumulation duration was prolonged. Consequently, the lignin/cellulose ratio and lignin content were increased from 0 day and the cellulose content was increased from 11 days after jointing onward. Our main finding is that the improved biosynthesis and accumulation of lignin and cellulose were responsible for increasing the stem-filling degree, breaking strength, and lodging resistance. The major functional genes enhancing lodging resistance in wheat that are induced by delayed sowing need to be determined.

Identification of QTL for Stem Traits in Wheat (Triticum aestivum L.).

Lodging in wheat (Triticum aestivum L.) is a complicated phenomenon that is influenced by physiological, genetics, and external factors. It causes a great yield loss and reduces grain quality and mechanical harvesting efficiency. Lodging resistance is contributed by various traits, including increased stem strength. The aim of this study was to map quantitative trait loci (QTL) controlling stem strength-related features (the number of big vascular bundles, stem diameter, stem wall thickness) using a doubled haploid (DH) population derived from a cross between Baiqimai and Neixiang 5. Field experiments were conducted during 2020–2022, and glasshouse experiments were conducted during 2021–2022. Significant genetic variations were observed for all measured traits, and they were all highly heritable. Fifteen QTL for stem strength-related traits were identified on chromosomes 2D, 3A, 3B, 3D, 4B, 5A, 6B, 7A, and 7D, respectively, and 7 QTL for grain yield-related traits were identified on chromosomes 2B, 2D, 3D, 4B, 7A, and 7B, respectively. The superior allele of the major QTL for the number of big vascular bundle (VB) was independent of plant height (PH), making it possible to improve stem strength without a trade-off of PH, thus improving lodging resistance. VB also showed positive correlations with some of the yield components. The result will be useful for molecular marker-assisted selection (MAS) for high stem strength and high yield potential.

Genetic techniques for plant breeding

Genetic techniques for plant breeding

Perceptions of extension field staff regarding coping with the climatic impacts on wheat crop in rural areas of Punjab

Climate change is a global phenomenon and it has changed the landscape of global agriculture. Wheat is a globally acknowledged crop that is also influenced by climate change around the world. Wheat is a staple crop for Pakistan and recent development confirms that wheat is under huge pressure due to climate change. In this study, an attempt is made to consolidate the perceptions of the extension field staff about the impacts of climate change on wheat crops in district Sargodha of Punjab. Total 80, agriculture officers (AOs) and Field Assistants (FAs) working in public sector extension were chosen and interviewed face to face on a structured questionnaire. Findings indicate that lodging in wheat (x̅=2.26), increase in pests (x̅=2.202) and diseases (x̅=2.02) were the major impact of climate change on wheat crop. Increase precipitation (100%) and increase in temperature (77.5%) were the leading climatic indicators posing threats to the wheat crop. Aphids (95%) and yellow rust (87.5%) caused a reduction in yield as the result of climatic changes. All respondents (100%) suggested the adoption of raised bed plantations of wheat to cope with climate change. Farmers should be connected with the weather updated and public and private sector extension should diffuse the wheat production technology among farmers considering the climatic changes.

Genome-Wide Association Analysis for Stem Cross Section Properties, Height and Heading Date in a Collection of Spanish Durum Wheat Landraces.

Durum wheat landraces have a high potential for breeding but they remain underexploited due to several factors, including the insufficient evaluation of these plant materials and the lack of efficient selection tools for transferring target traits into elite backgrounds. In this work, we characterized 150 accessions of the Spanish durum wheat collection for stem cross section, height and heading date. Continuous variation and high heritabilities were recorded for the stem area, pith area, pith diameter, culm wall thickness, height and heading date. The accessions were genotyped with DArTSeq markers, which were aligned to the durum wheat ‘Svevo’ genome. The markers corresponding to genes, with a minor allele frequency above 5% and less than 10% of missing data, were used for genome-wide association scan analysis. Twenty-nine marker-trait associations (MTAs) were identified and compared with the positions of previously known QTLs. MTAs for height and heading date co-localized with the QTLs for these traits. In addition, all the MTAs for stem traits in chromosome 2B were located in the corresponding synteny regions of the markers associated with lodging in bread wheat. Finally, several MTAs for stem traits co-located with the QTL for wheat stem sawfly (WSS) resistance. The results presented herein reveal the same genomic regions in chromosome 2B are involved in the genetic control of stem traits and lodging tolerance in both durum and bread wheat. In addition, these results suggest the importance of stem traits for WSS resistance and the potential of these landraces as donors for lodging tolerance and WSS resistance enhancement. In this context, the MTAs for stem-related traits identified in this work can serve as a reference for further development of markers for the introgression of target traits into elite material.

Mapping of wheat lodging susceptibility with synthetic aperture radar data

Crop lodging reduces yield quantity and grain quality of cereal crops. Understanding seasonal variation in crop lodging susceptibility enables lodging risk assessments and predictions of associated crop yield losses. We demonstrate a novel remote sensing-based approach, using sparse field observations and widely available synthetic aperture radar (SAR) satellite imagery, to map a safety factor against root lodging (SFA) in wheat. SFA quantifies the ability of the rooting system to support the self-weight moment of the whole plant and can be used as an indicator of in-season root lodging susceptibility. SAR satellite images, from Sentinel-1 and RADARSAT-2, were acquired synchronously with field measurements in Jolanda di Savoia, Ferrara, Italy during the 2018 winter wheat growing season. The field data included measurements from non-lodged (healthy) wheat such as plant height, height at the centre of gravity, self-weight moment of the whole plant, soil anchorage strength, SFA and those from lodged wheat such as crop angle of inclination, lodged area and the point of plant failure (stem or root). Field measurements confirmed that SFA decreased progressively through the season and was consistent with the observed lodging. Strong and significant correlations through the season were observed between SFA and SAR satellite image metrics. The validated regression models showed a strong relationship between field-measured SFA and the metrics from RADARSAT-2 (R2CV = 0.84, RMSECV = 0.54) and Sentinel-1 data (R2CV = 0.73, RMSECV = 0.59). However, it is possible that the relationship between SFA and SAR parameters is confounded by the variations in crop biomass, which is highly correlated with SFA (r = −0.71, p < 0.0001). Our study, for the first time, demonstrates the use of remote sensing SAR data for lodging susceptibility assessment. Current and planned satellite platforms have the potential for large scale, operational assessment of lodging susceptibility in cereal crops.

Enhancing wheat (Triticum aestivum L.) grain yield and quality by managing lodging with growth regulators under different nutrition levels

This study was conducted to determine the effect of different nutrient levels [No nutrients absolute control, RDF (recommended dose of fertilizer) (N:P:K 150:26.22), 150%RDF (225:39.33), 150%RDF + FYM (Farm Yard Manure) (225:39:33 + 15 t ha−1), & 200%RDF (300:52.44 NPK kg ha−1) and application of growth regulators, i.e., water spray, CCC (chlormequat chloride) 0.2%, tebuconazole (0.1%), and tank-mixed application of chlormequat chloride + tebuconazole at first node and flag leaf stage on growth, lodging, yield, and quality of wheat with three replications. Application of 150%RDF + FYM and 200%RDF recorded significantly higher plant height, dry matter accumulation, and tiller density. Lodging percent and score recorded in 150%RDF + FYM was similar to 200%RDF, but sіgnіfіcаntly higher than оthеr levels. The application of chlormequat chloride + tebuconazole recorded the lowest plant height, lodging percent and lodging score. Application of chlormequat chloride + tebuconazole recorded higher 1000-grain weight and grain yield than control, chlormequat chloride, and tebuconazole. In RDF (N:P:K 150:26.22), exogenous application of chlormequat chloride alone was sufficient to reduce lodging. However, at higher nutrient level of 150%RDF or 150%RDF + FYM, both chlormequat chloride + tebuconazole were most promising for reducing lodging and enhancing the wheat productivity.

Assessment of the Influence of Various Agro-Technological Methods on the Development of Diseases, Pests, as Well as on the Lodging of Spring Wheat of the Ulyanovskaya 105 Variety in the Conditions of Predkamye of the Republic of Tatarstan

The article is devoted to the question of the influence of various agro-technological methods on the development of diseases, pests, as well as on the lodging of spring wheat. Over the years of research (2019–2020) on spring wheat crops, the effect of calculated doses of fertilizers at different rates of sowing seeds on plant damage by latent pests and leaf rust damage, as well as the resistance of spring wheat plants to lodging was studied. On the basis of the results obtained, it was possible to establish that at strongly reduced seeding rates, regardless of the nutritional background, the number of damaged plants by the fruit fly, as well as damage by leaf rust, increased sharply. At the same time, excessive thickening of crops did not contribute to a significant further decrease in damage and susceptibility, as well as to lodging of plants.

Effect of precise levelling and crop establishment options for wheat based systems on soil quality, system- and water productivity in scarce irrigated areas

ABSTRACT In scarce-irrigated areas of India, pearl millet-wheat cropping system is depleting soil quality, system productivity and resources. The objective of study was to restore soil quality and sustain productivity. It was considered necessary to diversify cereal through legume-based wheat system and shift of traditional to conservation technologies. A field experiment was assessed the rainy season cereal crop pearl millet (PM) and three legumes- pigeon pea (PP), green gram (GG) and cluster bean (CB)-based winter wheat (W) systems under two land levelling methods viz. traditional (TLL) and precision laser assisted (PLL), and three establishment methods- traditional tillage (TT), zero tillage (ZT) and permanent broad bed- furrow (PBBF) on various parameters. Results of PLL and PBBF crop establishment was significantly enhanced the soil quality parameters, growth characters, less plant mortality of rainy season crops and lodging of wheat compared with traditional practices. Overall improvement in soil quality, system- and water productivity (WP) and net returns were in ordered: PP-W > CB-W > GG-W > PM-W and PBBF > ZT > TT. Results indicated that PBBF crop establishment in PLL conditions can be made more sustainable productive, economic profitable, ameliorate soil quality and save resources in scarce/canal support irrigation system.

Understanding wheat lodging using multi-temporal Sentinel-1 and Sentinel-2 data

Crop lodging assessment is essential for evaluating yield damage and informing crop management decisions for sustainable agricultural production. While a few studies have demonstrated the potential of optical and SAR data for crop lodging assessment, large-scale crop lodging assessment has been hampered by the unavailability of dense satellite time series data. The unprecedented availability of free Sentinel-1 and Sentinel-2 data may provide a basis for operational detection and monitoring of crop lodging. In this context, this study aims to understand the effect of lodging on backscatter/coherence and spectral reflectance derived from Sentinel-1 and Sentinel-2 data and to detect lodging incidence in wheat using time-series analysis. Crop biophysical parameters were measured in the field for both healthy and lodged plots from March to June 2018 in a study site in Ferrara, Italy, and the corresponding Sentinel images were downloaded and processed. The lodged plots were further categorised into different lodging severity classes (moderate, severe and very severe). Temporal profiles of backscatter, coherence, reflectance and continuum removed spectra were studied for healthy and lodging severity classes throughout the stem elongation to ripening growth stages. The Kruskal Wallis and posthoc Tukey tests were used to test for significant differences between different classes. Our results for Sentinel-2 showed that red edge (740 nm) and NIR (865 nm) bands could best distinguish healthy from lodged wheat (particularly healthy and very severe). For Sentinel-1, the analysis revealed the potential of VH backscatter and the complementarity of VV and VH/VV backscatter in distinguishing a maximum number of classes. Our findings demonstrate the potential of Sentinel data for near real-time detection of the incidence and severity of lodging in wheat. To the best of our knowledge, there is no study that has contributed to this application.

Winter Wheat Crop Height Estimation Using Small Unmanned Aerial System (sUAS)

Deploying the small Unmanned Aerial System (sUAS) for data collection of high-resolution images is a big potential in determining crop physiological parameters. The advantage of using sUAS technology is the ability to acquire a high-resolution orthophoto and a 3D Model which is highly suitable for plant height monitoring. Plant height estimation has a big impact in the growth and development of wheat because it is essential for obtaining biomass, which is a factor for higher crop yield. Plant height is an indicator of high yield estimation and it correlates to biomass, nitrogen content, and other plant growth parameters. The study is aimed to determine an accurate height of wheat using the sUAS generated Digital Surface Model (DSM). A high-resolution imagery between 1.0 - 1.2 cm/pixel was obtained from a 35 m altitude with area coverage of 1.01 hectares. The DSM and orthophoto were generated from the sUAS, and the computed wheat heights were derived from the difference of Digital Elevation Model (DEM) and DSM data. Field measurement using steel tape was done for ground truth. The sUAS-based wheat height data were evaluated using the ground truth of 66 wheat-rows by applying correlation and linear regression analysis. Datasets were collected from three different flight campaigns (March 2018-May 2018). The sUAS-based wheat height data were significantly correlated, obtaining the result of R2 = 0.988, R2 = 0.996 and R2 = 0.944 for the month of March, April and May 2018 respectively. The significance of linear regression results was also validated by computing for the p-value. The p-value results were 0.00064, 0.0000824 and 0.0058 respectively. The main concern is the lodging of winter wheat, especially during the month of April which affects the recording of the plant’s height. Because some of the wheat plants are now lying on the ground, so measurements are done vertically. Nonetheless, the results showed that sUAS technology is highly suitable for many agricultural applications.

Can intercropping or mixed cropping of two genotypes enhance wheat lodging resistance?

Lodging negatively affects wheat production worldwide. However, little is known about the potential of intercropping (different genotypes of wheat are planted in alternating rows) and mixed cropping of different genotypes to enhance the lodging resistance of wheat populations. In this study, a field experiment was conducted with two cultivars, ‘Shannong8355’ (SN8355, a lodging-resistant cultivar) and ‘Shannong15’ (SN15, a lodging-susceptible cultivar), to investigate the effect of these planting patterns on the occurrence of lodging in wheat and analyze the mechanism through which lodging resistance may be enhanced. Intercropping and mixed cropping of SN8355 with SN15 was shown to effectively reduce the occurrence of lodging in SN15, through SN8355 plants supporting SN15 plants and thereby inhibiting lodging of the composite population; the effect of mixed cropping was strongest. Furthermore, compared with the sole cropping and intercropping treatments, the mixed cropping of SN8355 and SN15 significantly improved the yield stability of wheat population. These results suggested that mixed cropping could inhibit the occurrence of lodging completely via lodging-resistant wheat cultivars providing both lateral and longitudinal support for lodging-susceptible cultivars, thus significantly enhancing the lodging resistance and yield stability of composite populations. The conclusion of this study could provide a theoretical basis to improve regulatory techniques for effectively inhibiting the occurrence of wheat lodging.

High-Throughput Phenotyping Enabled Genetic Dissection of Crop Lodging in Wheat.

Novel high-throughput phenotyping (HTP) approaches are needed to advance the understanding of genotype-to-phenotype and accelerate plant breeding. The first generation of HTP has examined simple spectral reflectance traits from images and sensors but is limited in advancing our understanding of crop development and architecture. Lodging is a complex trait that significantly impacts yield and quality in many crops including wheat. Conventional visual assessment methods for lodging are time-consuming, relatively low-throughput, and subjective, limiting phenotyping accuracy and population sizes in breeding and genetics studies. Here, we demonstrate the considerable power of unmanned aerial systems (UAS) or drone-based phenotyping as a high-throughput alternative to visual assessments for the complex phenological trait of lodging, which significantly impacts yield and quality in many crops including wheat. We tested and validated quantitative assessment of lodging on 2,640 wheat breeding plots over the course of 2 years using differential digital elevation models from UAS. High correlations of digital measures of lodging to visual estimates and equivalent broad-sense heritability demonstrate this approach is amenable for reproducible assessment of lodging in large breeding nurseries. Using these high-throughput measures to assess the underlying genetic architecture of lodging in wheat, we applied genome-wide association analysis and identified a key genomic region on chromosome 2A, consistent across digital and visual scores of lodging. However, these associations accounted for a very minor portion of the total phenotypic variance. We therefore investigated whole genome prediction models and found high prediction accuracies across populations and environments. This adequately accounted for the highly polygenic genetic architecture of numerous small effect loci, consistent with the previously described complex genetic architecture of lodging in wheat. Our study provides a proof-of-concept application of UAS-based phenomics that is scalable to tens-of-thousands of plots in breeding and genetic studies as will be needed to uncover the genetic factors and increase the rate of gain for complex traits in crop breeding.

Study of the relationship between field lodging and stem quality traits of winter wheat in the north China plain

Winter wheat (Triticum aestivum L.) production in the North China Plain (NCP) is threatened by wheat lodging. Therefore, enhancing plant lodging resistance by improving stem quality traits is crucial to maintaining high stable yields of winter wheat. A consecutive 7-year field experiment was conducted to study the effects of stem traits on lodging resistance and the yield of four winter wheat cultivars (Bainong 418, Aikang 58, Wenmai 6 and Zhoumai 18). The results indicated that rainfall is often accompanied by strong winds that can cause lodging in the field. Stalk bending strength and wall thickness of the second internode showed significant negative correlations with lodging index, and a higher lodging index indicated increased lodging risk, which, in turn, could seriously affect the grain yield of wheat. Significant regression relationships were observed between lodging index and population lodging resistance strength, as measured using a crop lodging resistance electronic measuring device. Statistical analysis revealed that yield components and the grain yield of Bainong 418 were higher than those of the other cultivars; there was no significant difference between Bainong 418 and Aikang 58 in lodging index, stalk bending strength or single-stalk and population lodging resistance strengths at anthesis and the middle filling stages, but the mean plant height of Bainong 418 was significantly higher than that of Aikang 58. These results provide a new and reliable method for assessing lodging resistance capacity and indicate that greater lodging resistance, as determined by simultaneously considering plant height and basal stem strength, is an important way to achieve high, stable yield in winter wheat.

Mechanistic understanding of lodging in spring wheat (Triticum aestivum): An Indian perspective

Lodging in modern spring wheat (Triticum aestivum L.) varieties is largely overlooked in India. There is scanty information available in literature for Indian condition regarding the extent, distribution, direct and indirect losses caused by the lodging. Little work has been done on this problem post green revolution period in India. Introduction of dwarfing genes and development of semi-dwarf varieties has resulted in quantum yield gains during 1970-80.After this period till recent years the progress in yield gains are slowed down mainly due to plant architecture of modern varieties not supporting heavier heads inducing lodging. Therefore, the higher potential of genotypes could not be realized to full extent at field level and varieties promising consistent yield level of six tonnes /ha or more are lacking. The complex phenotyping strategies and models designed by the workers working on the problem elsewhere are further impeding the progress as these are not much helpful at field level under Indian conditions. The current paper takes into the consideration the mechanistic approach to understand the problem and correlate the facts andfindings of universal nature to design the strategies to manage the lodging through different approaches much suited to Indian conditions.