scholarly journals Estimation of Plant Height and Aboveground Biomass of Toona sinensis under Drought Stress Using RGB-D Imaging

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1747
Author(s):  
Wenjian Liu ◽  
Yanjie Li ◽  
Jun Liu ◽  
Jingmin Jiang

Rapid and accurate plant growth and biomass estimation is essential for formulating and implementing targeted forest cultivation measures. In this study, RGB-D imaging technology was used to obtain the RGB and depth imaging data for a Toona sinensis seedling canopy to estimate plant growth and aboveground biomass (AGB). Three hundred T. sinensis seedlings from 20 varieties were planted under five different drought stress treatments. The U-Net model was applied first to achieve highly accurate segmentation of plants from complex backgrounds. Simple linear regression (SLR) was used for plant height prediction, and the other three models, including multivariate linear (ML), random forest (RF) and multilayer perceptron (MLP) regression, were applied to predict the AGB and compared for optimal model selection. The results showed that the SLR model yields promising and reliable results for the prediction of plant height, with R2 and RMSE values of 0.72 and 1.89 cm, respectively. All three regression methods perform well in the prediction of AGB estimation. MLP yields the highest accuracy in predicting dry and fresh aboveground biomass compared to the other two regression models, with R2 values of 0.77 and 0.83, respectively. The combination of Gray, Green minus red (GMR) and Excess green index (ExG) was identified as the key predictor by RReliefF for predicting dry AGB. GMR was the most important in predicting fresh AGB. This study demonstrated that the merits of RGB-D and machine learning models are effective phenotyping techniques for plant height and AGB prediction, and can be used to assist dynamic responses to drought stress for breeding selection.

2021 ◽  
Vol 22 (9) ◽  
pp. 4337
Author(s):  
Kai Huang ◽  
Tao Wu ◽  
Ziming Ma ◽  
Zhao Li ◽  
Haoyuan Chen ◽  
...  

WRKY transcription factors (TFs) have been reported to respond to biotic and abiotic stresses and regulate plant growth and development. However, the molecular mechanisms of WRKY TFs involved in drought stress and regulating plant height in rice remain largely unknown. In this study, we found that transgenic rice lines overexpressing OsWRKY55 (OsWRKY55-OE) exhibited reduced drought resistance. The OsWRKY55-OE lines showed faster water loss and greater accumulation of hydrogen peroxide (H2O2) and superoxide radical (O2−·) compared to wild-type (WT) plants under drought conditions. OsWRKY55 was expressed in various tissues and was induced by drought and abscisic acid (ABA) treatments. Through yeast two-hybrid assays, we found that OsWRKY55 interacted with four mitogen-activated protein kinases (MAPKs) that could be induced by drought, including OsMPK7, OsMPK9, OsMPK20-1, and OsMPK20-4. The activation effects of the four OsMPKs on OsWRKY55 transcriptional activity were demonstrated by a GAL4-dependent chimeric transactivation assay in rice protoplasts. Furthermore, OsWRKY55 was able to reduce plant height under normal conditions by decreasing the cell size. In addition, based on a dual luciferase reporter assay, OsWRKY55 was shown to bind to the promoter of OsAP2-39 through a yeast one-hybrid assay and positively regulate OsAP2-39 expression. These results suggest that OsWRKY55 plays a critical role in responses to drought stress and the regulation of plant height in rice, further providing valuable information for crop improvement.


2016 ◽  
Vol 7 (1) ◽  
pp. 154 ◽  
Author(s):  
Marcia Eugenia Amaral Carvalho ◽  
Paulo Roberto de Camargo e Castro ◽  
Marcos Vinicius de Castro Ferraz Junior ◽  
Ana Carolina Cabrera Machado Mendes

One of the major disadvantages of sunflower cultivation is the increased plant height, making it prone to the lodging. The use of plant growth retardants can be an alternative strategy to reduce plant height; however, these compounds may affect productivity. The aim of this study was to evaluate the effects of plant growth retardants on sunflower development and yield. Four treatments were studied: 1- control; 2- gibberellic acid (GA) 10 mg L−1; 3- trinexapac-ethyl (TE) 5 mL L−1, and 4- maleic hidrazide (MH) 8 mL L−1. TE and MH decreased plant height (16.9 and 35.9%, respectively); however, only TE positively influenced capitulim diameter and dry mass (46.7 and 311%, when compared to control) at 60 days after planting (DAP). At 81 DAP, dry mass of capitulum did not differ among control and TE-treated plants. On the other hand, MH impaired diameter and dry mass of capitulum (92.9 and 74.7%, respectively). It can be concluded that the application of TE is a potential strategy to decrease lodging probability without affecting sunflower yield. Furthermore, although MH negatively affected sunflower development, its use on the crop cannot be excluded since other doses, frequencies and moment of application can be studied.


2020 ◽  
Vol 8 (6) ◽  
pp. 823 ◽  
Author(s):  
Andres Moreno-Galván ◽  
Felipe A. Romero-Perdomo ◽  
German Estrada-Bonilla ◽  
Carlos Henrique Salvino Gadelha Meneses ◽  
Ruth R. Bonilla

Drought is a global problem for crop productivity. Therefore, the objective of this research was to evaluate five dry-Caribbean Bacillus spp. strains in drought stress amelioration in maize plants. Maize seeds were single-strain inoculated and sown in pots under greenhouse conditions. After 12 days, plants were subjected to 33 days of drought conditions, i.e., 30% of soil field capacity, and then collected to measure leaf and root dry biomass, plant height, antioxidant enzymes, proline accumulation, and P+, Ca2+, and K+ uptake. Results correlated drought stress amelioration with the inoculation of Bacillus spp. strains XT13, XT38 and XT110. Inoculated plants showed increases in dry biomass, plant height, and K+ and P+ uptake. The overall maize antioxidant response to bacterial inoculation under drought stress showed dependence on proline accumulation and decreases in ascorbate peroxidase and glutathione reductase activities. Moreover, results suggest that this stress amelioration is driven by a specific plant-strain correlation observed in antioxidant response changes in inoculated plants under stress. Also, there is a complex integration of several mechanisms, including plant growth-promotion traits and nutrient uptake. Hence, the use of dry-Caribbean plant growth-promoting Bacillus strains represents an important biotechnological approach to enhance crop productivity in arid and semi-arid environments.


2014 ◽  
Vol 16 (1) ◽  
pp. 25
Author(s):  
Panut Sahari ◽  
Eddy Tri Haryanto ◽  
Lutfi Dwi Syahrizal

<p>Peanut productivity has decreased significantly caused by low fertilizer use. This study aimed to obtain optimum combination of dolomite and organic fertilizer in order to get high yield productivity of peanut. This study was conducted in the Field Laboratory of Faculty of Agriculture, Sebelas Maret University. The experiment was conducted by using a Randomized Completely Block Design (RCBD) with two factors, namely dolomite and organic fertilizer. The results showed that there was interaction in the application of dolomite and organic fertilizer on plant growth. The use of 100 kgha-1of dolomite and 10 tons ha-1of organic fertilizer provided higher yield than the other treatments on plant height, number of branches, number of pods per plant and weight of 1000 seeds.</p>


Nematology ◽  
2006 ◽  
Vol 8 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Inge Van den Bergh ◽  
Nguyen Thi Tuyet ◽  
Duong Thi Minh Nguyet ◽  
Dirk De Waele ◽  
Ho Huu Nhi

AbstractThe objective of the presented study was to look at the effect of Pratylenchus coffeae and Meloidogyne spp., the two major nematode species associated with banana ( Musa spp.) in North Vietnam, on the plant growth and yield of cv. Grand Naine (AAA) and four local banana cultivars, Ngu Tien (AA), Hot (BB), Ben Tre (AAA) and Tay Tia (ABB). Inoculated plants were compared with nematode-free control plants in terms of plant growth, crop cycle duration and yield under field conditions in Hanoi, North Vietnam. Infection with P. coffeae did not affect the crop cycle duration or the plant height, the pseudostem girth or the number of standing leaves at harvest of any of the cultivars, but did significantly reduce the bunch weight of cv. Ngu Tien from 6.6 to 5.3 kg (20% reduction), the bunch weight of cv. Tay Tia from 7.3 to 5.9 kg (19% reduction) and the bunch weight of cv. Grand Naine from 6.9 to 6.0 kg (13% reduction). The bunch weight of cvs Hot and Ben Tre was not significantly affected. The number of hands of the inoculated and the control plants did not differ for any of the cultivars but infection with P. coffeae resulted in a 34% reduction in the number of fingers of cv. Grand Naine (from 67 to 44 fingers). The number of fingers of the other cultivars were not affected by inoculation with P. coffeae. Infection with Meloidogyne spp. did not affect the time from planting to harvest for any of the cultivars, but the time from planting to shooting was increased from 367 to 387 days for cv. Ngu Tien. The plant height and the pseudostem girth at harvest of cv. Grand Naine were significantly reduced by 27% and 18%, respectively. The number of standing leaves as well as the plant height and the pseudostem girth at harvest of the other cultivars were unaffected. Infection with Meloidogyne spp. significantly reduced the bunch weight of cv. Ngu Tien from 6.6 to 5.1 kg (23% reduction) and the bunch weight of cv. Grand Naine from 6.9 to 5.6 kg (19% reduction). The bunch weight of cv. Hot was unaffected. Infection with Meloidogyne spp. reduced the number of hands of cv. Ngu Tien by 14% (from 6.2 to 5.4 hands) the number of fingers of cv. Grand Naine by 25% (from 67 to 50 fingers). The number of hands and fingers of the other cultivars were not affected. The results indicate that in areas where the burrowing nematode, Radopholus similis, is not present, other nematodes, especially Meloidogyne spp., may become more important in terms of damage and yield loss.


HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 565-569 ◽  
Author(s):  
Peter Alem ◽  
Paul A. Thomas ◽  
Marc W. van Iersel

Production of poinsettias (Euphorbia pulcherrima) often involves intensive use of plant growth retardants (PGRs) to regulate height. Height control is necessary for visual appeal and postharvest handling. Since PGRs do not always provide consistent height control and can have unwanted side effects, there is interest in alternative methods of height control. Since turgor potential drives cell expansion, and thus stem elongation, drought stress has potential for regulating plant height. Through soil moisture sensor-controlled irrigation, the severity of drought stress can be both monitored and controlled. The objective of our study was to compare poinsettia ‘Classic Red’ height control using PGRs (spray, mixture of daminozide and chlormequat at 1000 mg·L−1 each and drench, 0.25 mg·L−1 paclobutrazol) with the use of controlled water deficit (WD). Graphical tracking of plant height, using a final target height of 43.5 cm, was used to determine when to apply PGR or controlled WD. In the WD treatment, substrate volumetric water content (θ) was reduced from 0.40 to 0.20 m3·m−3 when actual height exceeded the expected height. PGR applications (spray or drench) reduced poinsettia height to 39 cm, below the final target level of 43.5 cm. WD resulted in a height of 44.5 cm, closest to the target height, while control plants were taller (49.4 cm). There was no effect of PGR drenches or WD on bract size, while spraying PGR reduced bract size by ≈ 40%. Bract chroma was unaffected by WD or PGR treatments. There was no difference in shoot dry weight between PGR- and WD-treated plants. Lateral growth was reduced by the PGR treatments, but not by WD. These results indicate that controlled WD can be used to regulate poinsettia height.


1998 ◽  
Vol 63 ◽  
Author(s):  
P. Smiris ◽  
F. Maris ◽  
K. Vitoris ◽  
N. Stamou ◽  
P. Ganatsas

This  study deals with the biomass estimation of the understory species of Pinus halepensis    forests in the Kassandra peninsula, Chalkidiki (North Greece). These  species are: Quercus    coccifera, Quercus ilex, Phillyrea media, Pistacia lentiscus, Arbutus  unedo, Erica arborea, Erica    manipuliflora, Smilax aspera, Cistus incanus, Cistus monspeliensis,  Fraxinus ornus. A sample of    30 shrubs per species was taken and the dry and fresh weights and the  moisture content of    every component of each species were measured, all of which were processed  for aboveground    biomass data. Then several regression equations were examined to determine  the key words.


2008 ◽  
Vol 54 (10) ◽  
pp. 861-867 ◽  
Author(s):  
Kanchalee Jetiyanon ◽  
Sakchai Wittaya-Areekul ◽  
Pinyupa Plianbangchang

The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P ≤ 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.


2021 ◽  
Vol 13 (8) ◽  
pp. 1595
Author(s):  
Chunhua Li ◽  
Lizhi Zhou ◽  
Wenbin Xu

Wetland vegetation aboveground biomass (AGB) directly indicates wetland ecosystem health and is critical for water purification, carbon cycle, and biodiversity conservation. Accurate AGB estimation is essential for the monitoring and supervision of ecosystems, especially in seasonal floodplain wetlands. This paper explored the capability of spectral and texture features from the Sentinel-2 Multispectral Instrument (MSI) for modeling grassland AGB using random forest (RF) and extreme gradient boosting (XGBoost) algorithms in Shengjin Lake wetland (a Ramsar site). We use five-fold cross-validation to verify the model effectiveness. The results indicated that the RF and XGBoost models had a robust and efficient performance (with root mean square error (RMSE) of 126.571 g·m−2 and R2 of 0.844 for RF, RMSE of 112.425 g·m−2 and R2 of 0.869 for XGBoost), and the XGBoost models, by contrast, performed better. Both traditional and red-edge vegetation indices (VIs) obtained satisfactory results of AGB estimation (RMSE = 127.936 g·m−2, RMSE = 125.879 g·m−2 in XGBoost models, respectively), with the red-edge VIs contributed more to the AGB models. Moreover, we selected eight gray-level co-occurrence matrix (GLCM) textures calculated by four processing window sizes using the mean value of four offsets, and further analyzed the results of three analysis sets. Textures derived from traditional and red-edge bands using a 7 × 7 window size performed better in biomass estimation. This finding suggested that textures derived from the traditional bands were as important as the red-edge bands. The introduction of textures moderately improved the accuracy of modeling AGB, whereas the use of textures alo ne was not satisfactory. This research demonstrated that using the Sentinel-2 MSI and the two ensemble algorithms is an effective method for long-term dynamic monitoring and assessment of grass AGB in seasonal floodplain wetlands, which can support sustainable management and carbon accounting of wetland ecosystems.


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