Maize Leaf Area Research Articles

Organic manure input improves soil water and nutrients use for sustainable maize (Zea mays. L) productivity on the Loess Plateau.

Long-term chemical fertilizer input causes soil organic matter losses, structural compaction, and changes in soil water and nutrient availability, which have been subdued in the most of dry farmland in China. The concept of “more efficiency with less fertilizer input” has been proposed and is urgently needed in current agriculture. Application of chemical fertilizer combined with organic manure (OM) could be a solution for soil protection and sustainable production of dry-land maize (Zea mays. L). Field research over three consecutive years on the Loess Plateau of China was conducted to evaluate the integrated effects of chemical fertilizer strategies and additional OM input on soil nutrients availability and water use in maize. The results showed that, after harvest, soil bulk density decreased significantly with OM application, concomitant with 11.9, 18.7 and 97.8% increases in topsoil total nitrogen, organic matter, and available phosphorus contents, respectively, compared with those under equal chemical NPK input. Water use in the 1.0–1.5 m soil profile was improved, therefore, the soil conditions were better for maize root growth, leaf area and shoot biomass of individual maize plants increased significantly with OM application. Optimized NPK strategies increased grain yield and water use efficiency by 18.5 and 20.6%, respectively, compared to only chemical NP input. Furthermore, additional OM input promoted yield and water use efficiency by 8.9 and 5.8%, respectively. Addition of OM promotes sustainable soil and maize grain productivity as well as friendly soil environmental management of dry land farming.

Bacteria from tropical semiarid temporary ponds promote maize growth under hydric stress

World climate change has triggered soil water stress and imposed limitations on agricultural production. Plant growth-promoting bacteria (PGPBs) have been an efficient strategy to improve the biological supply and growth of plants under distinct abiotic stress conditions. We hypothesized that the soils from a temporary pond may harbor PGPBs with potential strains which increase maize tolerance to water deficit. We studied rhizosphere and bulk soil of Mimosa bimucronata in a temporary pond from semiarid Northeast Brazil to access strains with characteristics to promote plant growth and mitigate abiotic stress for maize crop. We isolated 355 bacterial isolates, from which 96 were selected based on the morphophysiological characterization to assess IAA production (42 % produced over 50 μg mL-1 of IAA), calcium phosphate solubilization (with one isolate achieving medium IS), biofilm and exopolysaccharides production (66 % and 98 % of isolates, respectively). Based on these mechanisms, the 30 most promising bacterial isolates were selected to assess biological nitrogen fixation (74 % of the isolates showed nitrogenase activity greater than 20 C2H4.h-1.mg-1), ACC deaminase activity (80 % of isolates) and growth in medium with reduced water activity (8 % of isolates grew in medium with water activity (Aw) of 0.844). We sequenced the 16S rRNA gene from the seven most promising isolates in in vitro and in vivo assays, which were identified as Staphylococcus edaphicus, Bacillus wiedmannii, Micrococcus yunnanensis, Streptomyces alboflavus, Streptomyces alboflavus, Bacillus wiedmanni and Bacillus cereus. In vivo, eleven isolates and three bacterial consortia did not differ from the control with nutrient solution, for total leaf area and root dry mass of maize. S. alboflavus (BS43) had the best in vivo results, not differing from the control with nutrient solution. We highlight the unpublished potential of Staphylococcus edaphicus and Streptomyces alboflavus in promoting the growth of plants under water stress. In addition, it is the first report of bacteria isolated from a temporary pond in the Brazilian semiarid which promoting plant growth attributes and development.

Estimation of maize plant height and leaf area index dynamics using an unmanned aerial vehicle with oblique and nadir photography.

High-throughput phenotyping is a limitation in plant genetics and breeding due to large-scale experiments in the field. Unmanned aerial vehicles (UAVs) can help to extract plant phenotypic traits rapidly and non-destructively with high efficiency. The general aim of this study is to estimate the dynamic plant height and leaf area index (LAI) by nadir and oblique photography with a UAV, and to compare the integrity of the established three-dimensional (3-D) canopy by these two methods. Images were captured by a high-resolution digital RGB camera mounted on a UAV at five stages with nadir and oblique photography, and processed by Agisoft Metashape to generate point clouds, orthomosaic maps and digital surface models. Individual plots were segmented according to their positions in the experimental design layout. The plant height of each inbred line was calculated automatically by a reference ground method. The LAI was calculated by the 3-D voxel method. The reconstructed canopy was sliced into different layers to compare leaf area density obtained from oblique and nadir photography. Good agreements were found for plant height between nadir photography, oblique photography and manual measurement during the whole growing season. The estimated LAI by oblique photography correlated better with measured LAI (slope = 0.87, R2 = 0.67), compared with that of nadir photography (slope = 0.74, R2 = 0.56). The total number of point clouds obtained by oblique photography was about 2.7-3.1 times than those by nadir photography. Leaf area density calculated by nadir photography was much less than that obtained by oblique photography, especially near the plant base. Plant height and LAI can be extracted automatically and efficiently by both photography methods. Oblique photography can provide intensive point clouds and relatively complete canopy information at low cost. The reconstructed 3-D profile of the plant canopy can be easily recognized by oblique photography.

Direct Estimation of Maize Leaf Area Index as Influenced by Organic and Inorganic Fertilizer Rates in Guinea Savanna

Leaf area index (LAI) plays an important role in radiation capture, crop growth and yield formation. However, there is limited quantitative data on the influence of poultry manure (PM) and NPK fertilizer rate (NPK) on LAI, as estimated directly. Using a split-plot design with three replications, a field experiment was conducted to determine the effects of three PM rate (0, 2 and 4 t/ha) as main plot and three NPK rate (0:0:0, 60:30:30 and 120:60:60 kg N P2O5 K2O/ha) as sub plot, on LAI and maize grain yield. The maize was planted at a density of 106,666 plants/ha; two rows on a ridge, one plant per stand at 75 × 25 cm. Linear regression was used to establish predictive equations among correlated variables and to describe the degree of associations. The application of PM in maize increased (p < 0.05) number of leaves/plant (NL) at 8 and 10 weeks after sowing maize (WASM). NL, leaf area constant at 6 and 10 WASM, leaf area (LA) and LAI were significantly affected by NPK. LAI correlated positively with NL, LA and grain yield. The coefficient of determination between actual and estimated LA was in the range of 0.85-0.97. The PM × NPK interaction was significant on maize grain yield. The results suggest that small-scale maize farmers faced with challenges in obtaining and transporting large quantities of poultry manure can use 2 t PM/ha with either 60:30:30 kg N P2O5 K2O/ha or 120:60:60 kg N P2O5 K2O/ha to increase grain yield of maize.

Delayed maize leaf senescence increases the land equivalent ratio of maize soybean relay intercropping system

Abstract Different planting pattern affects the leaf senescence of maize under intercropping systems, which regulate the grain yield of maize plants. In this study, we observed that a narrow-wide-row planting pattern in maize soybean relay intercropping system (MS) improved the leaf greenness and green leaf area, delayed the leaf senescence process in maize and increased the photosynthetic rate of maize leaves during the reproductive stages of maize in MS. In a three-year field experiment, soybean was relay-intercropped with maize under different planting patterns (1M1S, “50 cm + 50 cm” 1-row of maize and 1-row of soybean with an equal row distance of 50 cm; and 2M2S, “40 cm + 160 cm” narrow-wide-row planting pattern, where 2-rows of maize were planted in narrow rows, and 2-rows of soybean were planted in wide rows, and 60 cm distance was maintained between the rows of maize and soybean) of MS, and both planting patterns of MS were compared with sole cropping systems of maize and soybean. Compared with 1M1S, planting pattern 2M2S significantly increased the number of green leaves (by 36%), leaf greenness (by 17%), and leaf nitrogen content (by 13%) at the dent stage (R5). The improved leaf nitrogen content in 2M2S at R5 significantly increased the green leaf area (by 16%, from 4170 cm2 plant−1 in 1M1S to 4960 cm2 plant−1 in 2M2S) of maize, indicating that leaf senescence of maize plants was delayed, which in turn significantly enhanced the photosynthetic rate of maize leaves at R5 by 57% in 2017, 75% in 2018 and 49% in 2019 than 1M1S. Overall, in 1M1S and 2M2S, relay-cropped maize produced 100%, and 89% of sole maize yield and relay-cropped soybean produced 27% and 66% of sole soybean yield, respectively. Importantly, compared to 1M1S, the decline of maize yield by 11% in 2M2S was compensated by a substantial increase in soybean yield by 147%, and 2M2S achieved the highest land equivalent ratio value of 1.54 compared to the land equivalent ratio value of 1.27 in 1M1S. Our results suggest that by selecting the appropriate planting pattern or stay-green maize hybrids, we can improve the land equivalent ratio of maize soybean relay intercropping system.

Maize (Zea mays L.) Growth and Yield Response to Tillage Methods and Fertilizer Combinations in the Midland Agro-ecological Zones of Kenya

The trials were set up in Busia, Embu and Kirinyaga Counties to assess the effect of tillage methods and application of different fertilizer combinations on maize productivity in the lower and upper midland agro-ecological zones of Kenya. Tillage methods were no-tillage (NT) with crop residue retention as mulch (+CR) (NT+CR) and conventional tillage (CT) without crop residue retention on farm surface (-CR) (CT-CR) while fertilizer combinations were NK, NP, PK, NPK, and NPK+CaMgZnBS. The N, P, K, Ca, Mg, Zn, B and S nutrients were applied at the rates of 120, 40, 40, 10, 10, 5 and 26.3 kg ha-1, respectively. The trials were laid in a randomized complete block design with a split-plot arrangement and replicated three times. The results showed that maize leaf area index, plant height, aboveground biomass, crop growth rate, and grain yield were significantly higher under CT-CR than under NT+CR in most of the sites. The CT-CR system out-yielded NT+CR system by 0.3 t ha-1 and 0.6 t ha-1 maize grain in Alupe and Kirinyaga, respectively. However, NT+CR system out-yielded CT-CR system by 0.4 t ha -1 maize grain at Embu. Across all the sites, application of PK and NPK+ZnBMgCaS fertilizer combinations resulted, respectively, in lowest and highest maize shoot biomass, leaf area indices, crop growth rates, plant heights, and grain yields. Based on this result alone, the potential of conservation agriculture in improving yields compared to conventional tillage could not be conclusive despite consistently recording higher soil moisture content across all sites and better yields in Embu. Again, application of a wide range of nutrients may be beneficial to maize production in the study areas as evidenced in the study. Therefore, we recommend multi-season and multi-location trials to comprehensively assess the impact of tillage methods and fertilizer management, particularly in relation to micronutrients.

AGRONOMIC PERFORMANCE AND PHOTOSYNTHETICALLY ACTIVE RADIATION INTERCEPTED BY MAIZE INTERCROPPED WITH BRACHIARIA

Maize and soybean are the main crops used for crop yield on Brazilian Cerrado biome. The off-season maize intercropped with ruzigrass [Urochloa ruziziensis (R. Germ. & C.M. Evrard) Crins (Syn. Brachiaria ruziziensis Germ. & Evrard)] increases soil cover and yield for crops in succession. However, the benefits on maize yield depend on the distribution and radiation-use efficiency (RUE) and its conversion to biomass. This study aimed to evaluate maize and ruzigrass yield in different cultivation systems. The experiment was carried out at Embrapa Agropecuária Oeste, in Dourados, MS, Brazil. The experiment design was randomized blocks, with seven treatments constituted by the combination of spacing between maize rows, single and intercropped, with ruzigrass in distribution methods. Photosynthetically active radiation, chlorophyll, leaf temperature, morphological characteristics and maize mass yield were evaluated in maize at the flowering stage (R1). Maize and ruzigrass yield were evaluated during maize maturation. The reduced spacing in single maize has a higher yield and lower radiation incidence in the ear. Maize intercropped with ruzigrass sown by broadcasting showed higher leaf temperature, lower plant height and lower maize leaf area. Morphological and physiological characteristics and maize grain yield were more influenced by planting methods than the presence of ruzigrass. The highest yield of dry matter and maize grain occurred in reduced spacing in maize, either alone or intercropped with ruzigrass.

Hormonal regulation and redox reaction of maize under partial root drying irrigation

How three different irrigation regimes, conventional irrigation (CI), partial root drying (PRD), and deficit irrigation (DI), on endogenous hormonal abscisic acid (ABA) and zeatin-riboside (ZR) changes, stomatal conductance (gs), reactive oxygen species (ROS), antioxidant enzyme activities, and metabolism of non-enzymatic compounds was assessed. This investigation revealed that the root-sourced chemical signals induced by PRD irrigation reduced the gs without any altered relative water content (RWC) in leaves, and further analysis found that stress-triggered ABA could induce stomatal closure; however, ZR exhibited antagonistic effects on the accumulation and stomatal regulation of ABA. Thus, in the current study, gs was more responsive to the combined ABA/ZR signal than ABA signal solely. Both PRD and DI treatments increased the production rate of superoxide anion ( $$ {\text{O}}_{2}^{ \bullet - } $$ ) as well as hydrogen peroxide (H2O2) concentration in root and leaf tissues under stress conditions; however, the superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities significantly increased under PRD irrigation. Moreover, compared with DI regime, PRD irrigation caused less proline and malondialdehyde (MDA) accumulation in stressed root and leaf tissues, suggesting that PRD irrigation technique alleviated the stress-induced physiological damage. Consequently, compared to CI, the leaf area and whole-plant dry weight in maize were unchanged under PRD irrigation but reduced significantly under DI treatment.

Comparison of inversion method of maize leaf area index based on UAV hyperspectral remote sensing

The current inversion method of maize leaf area index has the problems of long time-consuming inversion, high energy consumption, and low fitting coefficient between the prediction result and the actual result. For these problems, an inversion method of maize leaf area index based on UAV hyperspectral remote sensing is proposed in this paper. Acquisition of spectral image of maize leaf using ASD Field SpecPro FR Field Hyperspectral instrument and CCD Array detector in UAV remote Sensing system. Denoising and segmentation of corn leaf images using stationary wavelets, improved Snake and PSO methods.. The improved Snake model is used to achieve coarse convergence of target image contour after denoising. Through particle swarm optimization iterative algorithm, the optimal image segmentation point is found and the image segmentation is achieved. Based on the results of image denoising segmentation, the expressions of modified chlorophyll absorption ratio, normalized difference spectral index, and ratio-type spectral index are obtained. The correlation between the three indices and the maize leaf area index was analyzed. Finally, the maize leaf area index was obtained by using ratio-type spectral index. Experiments show that the proposed method has a comprehensive performance, and has a strong advantage over the current method.

English

Recurrent droughts are often associated with crop failure and therefore food insecurity especially in semi-arid areas of Kenya. A study was conducted in Machakos County in the long rain and short rain seasons of 2014 to determine the effect of soil moisture variability on crop performances and yields along the toposequence of a terraced vertisol. The crops were grown as either sole maize, sole beans or maize-bean intercrop. An experiment was laid in a randomized complete block design (RCBD) and each treatment replicated three times. Data collected included maize height and leaf area index at 9th leaf and tassel stage, maize and bean yield and soil moisture content. The results showed significant variations (p<0.05) in soil moisture content, maize height, above ground maize biomass yield and maize and bean grain yield at different slope positions. The lower slope position recorded significantly (p<0.05) higher mean soil moisture content (20.6%) compared to the middle (16.1%) and upper (16.3%) slope positions. The lower slope position recorded significantly (p<0.05) higher mean biomass yield of 4.94 ton/ha compared to the middle and upper (4.30 and 4.12 ton/ha, respectively). Results of this study indicate that terracing has an effect on soil moisture content variability and that farmers can benefit from low-cost technology using soil and water conservation structures to increase yields. Key words: Soil moisture variability, terrace embankment, slope position, toposequence, vertisols, crop yields.

AKURASI PENGGUNAAN METODE PANJANG KALI LEBAR UNTUK PENGUKURAN LUAS DAUN JAGUNG (Zea mays L.) DAN KEDELAI (Glycine max L.)

The purpose of this study was to determine the accuracy of the method of long width method for measurement of corn leaf area ( Zea mays L.) and soybean ( Glycine max L) compared to method of leaf area meter. This study use designed by comparing the two methods, then the statistical test was done with the t-test. The result of this study showeed that correction factor (k) of leaf area length method obtained with Agustina (1988) version is not significantly different from Sitompul and Guritno version (1995). The k values used in the calculation of the leaf area with the long-width method of Sitompul &amp; Guritno's (1995) version can be used at any age of observation on both corn and soybean crops, for Agustina (1988) the k value on corn leaves can be used every age of observation, but in soybean crop needs to be made a new k value at the age of the plant further (eg 5 MST) with the number of leaves more. The accuracy of the long-width method for measuring leaf area in maize compared with LAM method is quite high, Sitompul &amp; Guritno (1995) version reaches 100% and Agustina's version is slightly lower that is 75%. The accuracy of Sitompul &amp; Guritno (1995) and Agustina (1988) long-range method for measuring leaf area on soybean crops compared with very low LAM method is 25%. The accuracy of the method of length method times compared to LAM method toward measurement of corn leaf area is higher than in soybean crop Keywords: Leaf area, of corn and soybean leaf, Length method times width, Leaves

Retrieval of Maize Leaf Area Index Using Hyperspectral and Multispectral Data

Field spectra acquired from a handheld spectroradiometer and Sentinel-2 images spectra were used to investigate the applicability of hyperspectral and multispectral data in retrieving the maize leaf area index in low-input crop systems, with high spatial and intra-annual variability, and low yield, in southern Mozambique, during three years. Seventeen vegetation indices, comprising two and three band indices, and nine machine learning regression algorithms (MLRA) were tested for the statistical approach while five cost functions were tested in the look-up-table (LUT) inversion approach. The three band vegetation indices were selected, specifically the modified difference index (mDId: 725; 715; 565) for the hyperspectral dataset and the modified simple ratio (mSRc: 740; 705; 865) for the multispectral dataset of field spectra and the three band spectral index (TBSIb: 665; 865; 783) for the Sentinel-2 dataset. The relevant vector machine was the selected MLRA for the two datasets of field spectra (multispectral and hyperspectral) while the support vector machine was selected for the Sentinel-2 data. When using the LUT inversion technique, the minimum contrast estimation and the Bhattacharyya divergence cost functions were the best performing. The vegetation indices outperformed the other two approaches, with the TBSIb as the most accurate index (RMSE = 0.35). At the field scale, spectral data from Sentinel-2 can accurately retrieve the maize leaf area index in the study area.

Variability examination of photosynthetic pigment content and specific leaf area in individual maize (Zea mays L.) plants

Currently, maize is one of the most important crops (Zea mays L.) both globally and in Hungary. We compared physiological parameters of a maize genotype – p9903 – at two different experimental sites in a field experiment. Furthermore, we examined these parameters’ variability in individual plants on the leaves with different ages. Absolute chlorophyll content of the leaves were analysed, separately that of chlorophyll a and chlorophyll b. We also measured the absolute carotenoid contents of leaves. Furthermore, we calculated these photosynthetic pigments’ content ratio. Specific leaf area (SLA) and dry matter weight were also measured in order to characterise plant production. The results obviously reflect the decreasing in the efficiency of photosynthetic apparatus on the low yield site. Otherwise, we identify significant differences only in certain cases of leaves.

Testing a bell-shaped function for estimation of fully expanded leaf area in modern maize under potential production conditions

Accurate leaf area simulation is critical for the performance of crop growth models. Area of fully expanded individual leaves of maize hybrids released before 1995 (defined as old hybrids) has been simulated using a bell-shaped function (BSF) and the relationship between its parameters and total leaf number (TLNO). However, modern high-yielding maize hybrids show different canopy architectures. The function parameters calibrated for old hybrids will not accurately represent modern hybrids. In this study, we evaluated these functions using a dataset including old and modern hybrids that have been widely planted in China in recent years. Maximum individual leaf area (Y0) and corresponding leaf position (X0) were not predicted well by TLNO (R2 = 0.56 and R2 = 0.70) for modern hybrids. Using recalibrated shape parameters a and b with values of Y0 and X0 for modern hybrids, the BSF accurately predicted individual leaf area (R2 = 0.95–0.99) and total leaf area of modern hybrids (R2 = 0.98). The results show that the BSF is still a robust way to predict the fully expanded leaf area of maize when parameters a and b are modified and Y0 and X0 are fitted. Breeding programs have led to increases in TLNO of maize but have not altered Y0 and X0, reducing the correlation between Y0, X0, and TLNO. For modern hybrids, the values of Y0 and X0 are hybrid-specific. Modern hybrids tend to have less-negative values of parameter a and more-positive values of parameter b in the leaf profile. Growth conditions, such as plant density and environmental conditions, also affect the fully expanded leaf area but were not considered in the original published equations. Thus, further research is needed to accurately estimate values of Y0 and X0 of individual modern hybrids to improve simulation of maize leaf area in crop growth models.

Sequence of Changes in Maize Responding to Soil Water Deficit and Related Critical Thresholds.

The sequence of changes in crop responding to soil water deficit and related critical thresholds are essential for better drought damage classification and drought monitoring indicators. This study was aimed to investigate the critical thresholds of maize growth and physiological characteristics responding to changing soil water and to reveal the sequence of changes in maize responding to soil water deficit both in seedling and jointing stages based on 2-year’s maize field experiment responding to six initial soil water statuses conducted in 2013 and 2014. Normal distribution tolerance limits were newly adopted to identify critical thresholds of maize growth and physiological characteristics to a wide range of soil water status. The results showed that in both stages maize growth characteristics related to plant water status [stem moisture content (SMC) and leaf moisture content (LMC)], leaf gas exchange [net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs)], and leaf area were sensitive to soil water deficit, while biomass-related characteristics were less sensitive. Under the concurrent weather conditions and agronomic managements, the critical soil water thresholds in terms of relative soil moisture of 0–30 cm depth (RSM) of maize SMC, LMC, net Pn, Tr, Gs, and leaf area were 72, 65, 62, 60, 58, and 46%, respectively, in seedling stage, and 64, 64, 51, 53, 48, and 46%, respectively, in jointing stage. It indicated that there is a sequence of changes in maize responding to soil water deficit, i.e., their response sequences as soil water deficit intensified: SMC ≥ LMC > leaf gas exchange > leaf area in both stages. This sequence of changes in maize responding to soil water deficit and related critical thresholds may be better indicators of damage classification and drought monitoring.

Soil water transformation regularity of farmland for typical crop in Beijing-Tianjin-Hebei region: Experimental and simulating analyses

The transformation process of soil water plays an important role in the hydrological cycle, and is a link to other water processes. Study on the regularity of soil water transformation under agricultural plantation is favorable to understanding the influence of human activities on soil water conversion. Typical crop was selected in Beijing-Tianjin-Hebei(BTH) region and the study on regularity of field-scale soil water transformation was carried out by means of crop-soil water field experimental observation combined with model simulation. In the field experiment, testing and observation of irrigated and rainfed maize were simultaneously carried out in the adjacent fields respectively to form a comparative experimental study. The experimental observation data were used to establish the soil water model, which is calibrated in many aspects, such as field water content change during the maize growth period, the soil profile water content distribution at different moments, maize leaf area index and plant height. The results show that this model has an efficient simulation effect. Quantitative study on field evapotranspiration regularity, field soil water flux under irrigated and rainfed modes, impact mechanism of soil water deep seepage during maize growth period was achieved through the simulation of soil water process, and related reference conclusions were also proposed for water resources management and conservation in BTH.

Effects of Previous Wheat Straw on the Yield of Maize in the Oasis Irrigation Region

The surface mulch effects on maize (Zea mays L.) production are not well studied. Higher yield depends on coordinated development among the yield components of crops. The purpose of this study was to determine whether plastic film combined with four straw management systems (no tillage with straw standing [NTSS]; no tillage with straw covering [NTS]; tillage with straw incorporation [TIS]; and conventional tillage without straw retention [CT]) could boost grain yield of maize via increasing leaf area index and yield components. This study was conducted in a wheat (Triticum aestivum L.)–maize rotation system from 2009 to 2012 in northwestern China. Plastic film combined with straw retention boosted grain yield by 4.5 to 17.5%, especially, NTS had the highest increasing effect, boosted grain yield by 13.7 to 17.5%, and improved harvest index by 5.4 to 8.4%, compared to CT. Plastic film combined with straw retention significantly increased yield components of maize. Among the three straw retention treatments, NTS increased the maize ear number (EN) by 18.1 to 21.0%, increased the kernel number per ear (KNE) by 63.7 to 67.8%, increased the thousand‐kernel weight (TKW) by 8.7 to 9.6%, compared to CT. Straw retention decreased the maize leaf area index (LAI) before the silking stage and increased the LAI after the silking stage, which effectively regulated the growth and development of maize at early and late stages of development, NTS had the best regulating effect. Path analysis indicated that the integrated system with plastic film combined with straw retention increased the maize grain yield by improving the KNE. We conclude that plastic film combined with previous straw covering can be an effective system for boosting crop productivity by improving the yield components and optimizing LAI dynamics under limited resources in arid environments.

Potential impacts of increasing atmospheric carbon dioxide on yield and plant growth of rice (Oryza sativa) and maize (Zea mays) crops

Free air carbon dioxide enrichment (FACE) facility was used to conduct the experiments during 2011-12 and 2012-13 cropping seasons for assessing the growth and yield attributes of rice (Oryza sativa L) and maize (Zea mays L). The concentration of CO2 was kept 550± 30 ppm in enriched condition. The concentration of ambient condition was 395±30. Recommended doses of NPK fertilizers were given to both the crops. Plant growth and yield parameters were measured and analyzed for both the conditions. Assessment revealed that the plant height of rice and maize did not change significantly. A significant (F= 9.800; P&lt;0.02) change was noticed in the post-harvest index of rice. However, there no change was noticed in the post-harvest percentage of maize. Leaf area of rice (P&lt;0.01) and maize (P&lt;0.005) increased significantly at flowering stage of plants under enriched CO2 environment over the ambient. Under elevated CO2 condition, biological yields of rice and maize were improved by 14.3% and 17.2% respectively. Carbon dioxide enrichment exposure improved the grain yield by16. 2% (P&lt;0.02) and 13.8% ( P&lt;0.02) for rice and maize respectively.

QTL mapping for leaf area in maize (Zea mays L.) under multi-environments

Leaves are the main organs of photosynthesis in green plants. Leaf area plays a vital role in dry matter accumulation and grain yield in maize (Zea mays L.). Thus, investigating the genetic basis of leaf area will aid efforts to breed maize with high yield. In this study, a total of 150 F7 recombinant inbred lines (RILs) derived from a cross between the maize lines Xu 178 and K12 were used to evaluate three ear-leaves area (TELA) under multi-environments. Inclusive composite interval mapping (ICIM) was used to identify quantitative trait loci (QTLs) for TELA under a single environment and estimated breeding value (EBV). A total of eight QTLs were detected under a single environmental condition, and four QTLs were identified for EBV which also can be detected in single environment. This indicated that the EBV-detected QTLs have high genetic stability. A major QTL (qTELA_2-9) located in chromosome bin 2.04/2.05 could be detected in four environments and has a high phenotypic contribution rate (ranging from 10.79 to 16.51%) that making it a good target for molecular breeding. In addition, joint analysis was used to reveal the genetic basis of leaf area in six environments. In total, six QTL×environment interactions and nine epistatic interactions were identified. Our results reveal that the genetic basis of the leaf area is not only mainly determined by additive effects, but also affected by epistatic effects environmental interaction effects.

河北固城夏玉米比叶面积对水分梯度的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 河北固城夏玉米比叶面积对水分梯度的响应 DOI: 10.5846/stxb201701130104 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家行业专项（GYHY201306038） Response of specific leaf area of summer maize to water gradient in Hebei Gucheng Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于河北固城农试站2013-2015年夏玉米田间水分控制试验，研究了夏玉米比叶面积（SLA）随发育期的变化趋势，并分主要发育时段探讨了SLA与水分梯度的定量关系。结果表明，从七叶期开始夏玉米SLA随发育进程的推进总体呈下降趋势，七叶期至成熟期SLA变化范围平均为14.6-34.9m2/kg。尽管干旱胁迫会明显降低夏玉米地上绿叶面积和干重，但却使SLA表现出"补偿性"增大，用于弥补干旱胁迫导致光合产物不足引起的叶片扩张乏力。夏玉米出苗-拔节期、抽雄-成熟期土壤相对湿度（θ）每降低1%，SLA分别上升0.45m2/kg和0.07m2/kg，表明出苗-拔节期夏玉米对干旱的"适应"能力更强；而拔节-抽雄期SLA与θ的关系较为复杂，表现为先增大后减小的抛物线型。 Abstract:Specific leaf area (SLA), the ratio of green leaf area to its dry weight, is one of the most important parameters of leaf function evaluation, which could reflect resource utilization ability and adaptability to different environments of plants. Recently, many preliminary conclusions have been reported about the variation trend of maize SLA under drought stress, but most of them were qualitative descriptions and lacked quantitative analysis. In this study, based on water-control field experiments in Hebei Gucheng, China from 2013 to 2015, the variation trends of summer maize SLA on major developmental stages were investigated, and the quantitative relationships between SLA and soil moisture on different developmental stages were also established. As the experiment designed, 3 major developmental stages of summer maize (emergence to jointing, jointing to tasseling, tasseling to maturity), as well as[(emergence to jointing) + (jointing to tasseling)],[(emergence to jointing) + (tasseling to maturity)], and[(jointing to tasseling) + (tasseling to maturity)], were all water controlled in turn. The experiment was set with 4 water-control treatments and 1 contrast treatment, in which the soil relative moisture θ was ≤ 40% (T1), 40%-60% (T2), 60%-80% (T3), >80% (T4), and natural precipitation (T5), respectively. Results showed that the summer maize SLA presented a declining trend during the entire growing season, with an averaged variation range of 14.6-34.9m2/kg. Specifically, the SLA reached maximum value at seven-leaf stage (34.9m2/kg), declined rapidly at jointing stage (23.4m2/kg), decreased slightly at the tasseling stage (18.1-18.8m2/kg), and was the lowest at the maturity stage with an average of 14.6m2/kg. Experimental data showed that drought stress could significantly decrease the leaf area and dry weight of summer maize, but the SLA showed a "compensatory" larger value in order to compensate for the leaf expansion fatigue caused by insufficient photosynthates. The summer maize SLA had a significant linear negative correlation with soil moisture from the emergence to jointing and tasseling to maturity stages, with increase of 0.45m2/kg (emergence to jointing stage) and 0.07m2/kg (tasseling to maturity stage) when the soil relative moisture decreased by 1%, indicating that the summer maize had more adaptation to drought during emergence to jointing stage. However, the relationship between SLA and soil moisture on the jointing to tasseling stage was more complex; it first increased and then decreased with a parabola shape. 参考文献 相似文献 引证文献