scholarly journals Impact of post-infiltration soil aeration at different growth stages of sub-surface trickle-irrigated tomato plants

2016 ◽  
Vol 30 (3) ◽  
pp. 331-337 ◽  
Author(s):  
Yuan Li ◽  
Zong-xia Jia ◽  
Wen-Quan Niu ◽  
Jing-wei Wang

Abstract Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

Author(s):  
Amanullah , ◽  
Inamullah , ◽  
Zahir Shah ◽  
Shad Khan Khalil

Leaf area index (LAI) is a measure of leafiness per unit ground area and denotes the extent of photosynthetic machinery is an important growth and yield-determining factor because it is a major determinant of light interception and transpiration. Phosphorus (P) and zinc (Zn) and rate are the most important factors affecting leaf area index (LAI) of rice(<em>Oryza sativa</em> L.). A field experiment was conducted to assess the impact of phosphorus (0, 40, 80, 120 kg P ha<sup>-1</sup>) and zinc levels (0, 5, 10, 15 kg Zn ha<sup>-1</sup>) on LAI of rice (<em>Oryza sativa</em> L.) genotypes [fine (Basmati-385) and coarse (Fakhr-e-Malakand &amp; Pukhraj)]. The experiment was conducted on farmer field at Batkhela, Malakadnd in Northwest Pakistan during summer 2011 and 2012. When combined over the two years, the data revealed that the highest LAI at three different growth stages (tillering, heading and physiological maturity) was obtained with application of the highest P level (120 kg ha<sup>-1</sup>) being at par with 80 kg P ha<sup>-1</sup>, while the lowest LAI was recorded when P was not applied. Similarly, the highest LAI was obtained with application of the two higher Zn levels (10 and 15 kg Zn ha<sup>-1</sup>), while the lowest LAI was recorded when Zn was not applied. In case of rice genotypes, the highest LAI was obtained from Pukhraj than other two genotypes at all growth stages. The other two rice genotypes (Fakher-e-Malakand and Basmati-385) produced statistically similar LAI at different growth stages. The higher LAI of Pukhraj was attributed to its long and wider leaves that resulted in higher mean single leaf area, leaf area per tiller, per hill and per square meter. The LAI was highest at heading stages than at early (tillering) and later (physiological maturity) growth stages. The increase in LAI was attributed to the increase in tillers number and leaf area hill<sup>-1</sup>. The increase in LAI showed positive impact on crop growth rate, dry matter accumulationand yield. Application of 120 kg P + 10 kg Zn ha<sup>-1</sup> to rice genotype Pukhraj was more beneficial in terms of higher LAI and productivity in the study area.


2020 ◽  
Vol 12 (3) ◽  
pp. 397 ◽  
Author(s):  
Sadeed Hussain ◽  
Kaixiu Gao ◽  
Mairaj Din ◽  
Yongkang Gao ◽  
Zhihua Shi ◽  
...  

Unmanned aerial vehicles (UAVs) equipped with spectral sensors have become useful in the fast and non-destructive assessment of crop growth, endurance and resource dynamics. This study is intended to inspect the capabilities of UAV-onboard multispectral sensors for non-destructive phenotype variables, including leaf area index (LAI), leaf mass per area (LMA) and specific leaf area (SLA) of rapeseed oil at different growth stages. In addition, the raw image data with high ground resolution (20 cm) were resampled to 30, 50 and 100 cm to determine the influence of resolution on the estimation of phenotype variables by using vegetation indices (VIs). Quadratic polynomial regression was applied to the quantitative analysis at different resolutions and growth stages. The coefficient of determination (R2) and root mean square error results indicated the significant accuracy of the LAI estimation, wherein the highest R2 values were attained by RVI = 0.93 and MTVI2 = 0.89 at the elongation stage. The noise equivalent of sensitivity and uncertainty analyses at the different growth stages accounted for the sensitivity of VIs, which revealed the optimal VIs of RVI, MTVI2 and MSAVI in the LAI estimation. LMA and SLA, which showed significant accuracies at (R2 = 0.85, 0.81) and (R2 = 0.85, 0.71), were estimated on the basis of the predicted leaf dry weight and LAI at the elongation and flowering stages, respectively. No significant variations were observed in the measured regression coefficients using different resolution images. Results demonstrated the significant potential of UAV-onboard multispectral sensor and empirical method for the non-destructive retrieval of crop canopy variables.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1971
Author(s):  
Xingyang Song ◽  
Guangsheng Zhou ◽  
Qijin He ◽  
Huailin Zhou

Drought stress has adverse effects on crop growth and yield, and its identification and monitoring play vital roles in precision crop water management. Accurately evaluating the effect of drought stress on crop photosynthetic capacity can provide a basis for decisions related to crop drought stress identification and monitoring as well as drought stress resistance and avoidance. In this study, the effects of different degrees of persistent drought in different growth stages (3rd leaf stage, 7th leaf stage and jointing stage) on the maximum carboxylation rate at a reference temperature of 25 °C (Vcmax25) of the first fully expanded leaf and its relationship to the leaf water content (LWC) were studied in a field experiment from 2013 to 2015. The results indicated that the LWC decreased continuously as drought stress continued and that the LWC decreased faster in the treatment with more irrigation. Vcmax25 showed a decreasing trend as the drought progressed but had no clear relationship to the growth stage in which the persistent drought occurred. Vcmax25 showed a significantly parabolic relationship (R2 = 0.701, p < 0.001) with the LWC, but the different degrees of persistent drought stress occurring in different growth stages had no distinct effect on the LWC values when Vcmax25 reached its maximum value or zero. The findings of this study also suggested that the LWC was 82.5 ± 0.5% when Vcmax25 reached its maximum value (42.6 ± 3.6 μmol m−2 s−1) and 67.6 ± 1.2% (extreme drought) when Vcmax25 reached zero. These findings will help to improve crop drought management and will be an important reference for crop drought identification, classification and monitoring as well as for the development of drought monitoring and early warning systems for other crops or maize varieties.


2021 ◽  
Vol 25 (8) ◽  
pp. 1513-1518
Author(s):  
A.S. Gunu ◽  
M. Musa

Field trial was carried out during the 2019 rainy season (June to October) at the Dryland Teaching and Research Farm of the Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto to determine the growth and yield of sorghum varieties in the study area. The treatments consisted of five (5) sorghum varieties (Samsorg 45, Samsorg 46, Janjari, Yartawa and Jardawa), the treatments were laid out in a Randomized Complete Block Design (RCBD) replicated three (3) times. Data were collected on the growth and yield of the crop. Janjari and Jardawa varieties were higher in plant height. Jardawa and Yartawa varieties were higher in number of leaves. Janjari and Yartawa varieties were higher in total dry weight. Janjari, Jardawa and Yartawa varieties were higher in harvest index. Yartawa variety was higher in leaf area, leaf area index and 1000-grain weight. Jardawa variety was higher in panicle length. Janjari variety was early in number of days to heading, flowering, and maturity and was higher in dry stalk weight. The grain yield (249 – 1506kg ha-1 ) was higher in Janjari and Yartawa varieties (1268 – 1506 kg ha-1). Based on the findings of this research, it could be concluded that Janjari and Yartawa varieties performed better than other varieties in the study area.


1991 ◽  
Vol 27 (4) ◽  
pp. 397-405 ◽  
Author(s):  
I. A. M. Yunusa ◽  
N. A. Gworgwor

SUMMARYTwo tropical and one temperate genotypes of maize were grown during the cool dry winter seasons in northern Nigeria. The tall tropical genotypes produced a greater leaf area index and more above-ground dry matter, and so had a higher crop growth rate, than the dwarf temperate genotype. However, the early flowering temperate genotype yielded more grain than the late flowering tropical genotypes. Although the initial low winter temperatures prolonged the preflowering growth period in the tropical genotypes, the terminal high temperatures hastened maturity and were associated with poor grain filling.Maíz de temporada seca en Nigeria


Author(s):  
Fei Huang ◽  
Xiao-Hui Wen ◽  
Yi-Xia Cai ◽  
Kun-Zheng Cai

Silicon (Si) plays important roles in alleviating heavy metal stress in rice plants. Here we investigated the physiological response of rice at different growth stages under the silicon-induced mitigation of cadmium (Cd) and zinc (Zn) toxicity. Si treatment increased the dry weight of shoots and roots and reduced the Cd and Zn concentrations in roots, stems, leaves and grains. Under the stress of exposure to Cd and Zn, photosynthetic parameters including the chlorophyll content and chlorophyll fluorescence decreased, while the membrane permeability and malondialdehyde (MDA) increased. Catalase (CAT) and peroxidase (POD) activities increased under heavy metals stress, but superoxide dismutase (SOD) activities decreased. The magnitude of these Cd- and Zn-induced changes was mitigated by Si-addition at different growth stages. The available Cd concentration increased in the soil but significantly decreased in the shoots, which suggested that Si treatment prevents Cd accumulation through internal mechanisms by limiting Cd2+ uptake by the roots. Overall, the phenomena of Si-mediated alleviation of Cd and excess Zn toxicity in two rice cultivars could be due to the limitation of metal uptake and transport, resulting in an improvement in cell membrane integrity, photosynthetic performance and anti-oxidative enzyme activities after Si treatment.


2019 ◽  
Vol 42 (10) ◽  
pp. 1133-1141 ◽  
Author(s):  
Hasnain Waheed ◽  
Muhammad Mansoor Javaid ◽  
Adeel Shahid ◽  
Hafiz Haider Ali ◽  
Javaria Nargis ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 453
Author(s):  
Haidong Lu ◽  
Zhenqing Xia ◽  
Yafang Fu ◽  
Qi Wang ◽  
Jiquan Xue ◽  
...  

Adaptive highly efficient mulching technologies for use on dryland agricultural ecosystems are crucial to improving crop productivity and water-use efficiency (WUE) under climate change. Little information is available on the effect of using different types of mulch on soil water thermal conditions, or on root/shoot trait, leaf area index (LAI), leaf area duration (LAD), yield, and WUE of spring maize. Hence, in this study, white transparent plastic film (WF), black plastic film (BF), and maize straw (MS) was used, and the results were compared with a non-mulched control (CK). The results showed that the mean soil temperature throughout the whole growth period of maize at the 5–15 cm depth under WF and BF was higher than under MS and CK, but under BF, it was 0.6 °C lower than WF. Compared with CK, the average soil water storage (0–200 cm) over the whole growth period of maize was significantly increased under WF, BF, and MS. WF and BF increased the soil water and temperature during the early growth stages of maize and significantly increased root/shoot biomass, root volume, LAI, LAD, and yield compared with MS. Higher soil temperatures under WF obviously reduced the duration of maize reproductive growth and accelerated root and leaf senescence, leading to small root/shoot biomass accumulation post-tasseling and to losses in yield compared with BF


2018 ◽  
Vol 81 (9) ◽  
pp. 1557-1564
Author(s):  
LINLIN JIANG ◽  
JIANLONG ZHANG ◽  
JINXIU TANG ◽  
MENG LI ◽  
XIAOYU ZHAO ◽  
...  

ABSTRACT The aim of the present study was to analyze the aerosol concentrations and microbial community structures in closed cage broiler houses at different broiler growth stages to assess the dynamic pattern of microbial aerosols in closed cage systems. Our results revealed that the total concentration of bacterial aerosols gradually increased during the growth cycle of broilers. High-throughput sequencing of 16S rDNA revealed that microbial compositions differed tremendously during different growth stages, although Firmicutes and Proteobacteria were the dominant taxa in samples from all broiler growth stages. At the genus level, dominant phylotypes displayed great variation during different growth stages. Escherichia and Shigella were the most dominant taxa throughout the growth cycle, increasing from 4.3 to 12.4% as the broilers grew. The alpha index revealed that the microbial diversity displayed significant differences between the different growth stages and that the bacterial community had the highest diversity when broilers were 22 days old. High-throughput sequencing analyses revealed that environmental microbes and opportunistic pathogens had relatively high abundances during the winter growth period. The data revealed the composition and aerodynamic diameters of microbial aerosols in closed cage broiler houses at different broiler growth stages in winter. The results also enabled us to elucidate the dynamic pattern of microbial aerosols in broiler houses in response to bacterial communities. Our results may provide a basis for developing technologies for air quality control in caged poultry houses.


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