Measured Plant Height Research Articles

High-precision plant height measurement by drone with RTK-GNSS and single camera for real-time processing

Conventional crop height measurements performed using aerial drone images require 3D reconstruction results of several aerial images obtained through structure from motion. Therefore, they require extensive computation time and their measurement accuracy is not high; if the 3D reconstruction result fails, several aerial photos must be captured again. To overcome these challenges, this study proposes a high-precision measurement method that uses a drone equipped with a monocular camera and real-time kinematic global navigation satellite system (RTK-GNSS) for real-time processing. This method performs high-precision stereo matching based on long-baseline lengths (approximately 1 m) during the flight by linking the RTK-GNSS and aerial image capture points. As the baseline length of a typical stereo camera is fixed, once the camera is calibrated on the ground, it does not need to be calibrated again during the flight. However, the proposed system requires quick calibration in flight because the baseline length is not fixed. A new calibration method that is based on zero-mean normalized cross-correlation and two stages least square method, is proposed to further improve the accuracy and stereo matching speed. The proposed method was compared with two conventional methods in natural world environments. It was observed that error rates reduced by 62.2% and 69.4%, for flight altitudes between 10 and 20 m respectively. Moreover, a depth resolution of 1.6 mm and reduction of 44.4% and 63.0% in the error rates were achieved at an altitude of 4.1 m, and the execution time was 88 ms for images with a size of 5472 × 3468 pixels, which is sufficiently fast for real-time measurement.

NP and 9311 are excellent population parents for screening QTLs of potassium-efficient rice.

High and stable rice yields are critical to global food security, and potassium-deficient soils in East Asia have seriously limited rice production in the regions. It is feasible to screen potassium efficient quantitative trait locus(QTLs) from existing rice varieties to cope with rice production in potassium-deficient areas, and the selection of population parents is the key to locating major QTLs. After a long period of natural selection, potassium efficient rice varieties mainly exist in the region where the soil potassium level is low. The present study chose the representative twelve high-yielding rice varieties in east Asia, firstly, to measure plant height, fresh sheath weight, and fresh blade weight under hydroponic conditions. Based on the difference and consistency of the three parameters, NP as low potassium tolerant, and 9311 as low potassium sensitive rice variety were screened. We further analyzed the relative values of the six parameters of NP and 9311 treated with a culture medium containing different potassium (K+) concentrations and showed that the two varieties significantly differed in multiple low potassium concentrations. Meanwhile, we calculated the coefficient of variation of twelve rice varieties and most of those parameters reached a maximum at 4 mg/L K+, indicating that this concentration was suitable for screening potassium-efficient rice. We also measured the potassium content and the potassium-related traits in NP and 9311 tissues, and found that NP and 9311 significantly differed in potassium translocation. These differences may be responsible for the long-distance transport of potassium from the root to the aboveground part. In conclusion, we identified a pair of parents with significant differences in potassium translocation, which can be used to locate the relevant QTLs with high potassium efficiency to cope with the crisis of soil potassium deficiency in East Asia.

Zonal Application of Plant Growth Regulator in Cotton to Reduce Variability and Increase Yield in a Highly Variable Field

Variable-rate application has great potential to reduce variability and increase yield by spatially optimizing agricultural inputs. In cotton, plant growth regulators (PGRs) control excessive growth and provide suitable plant height for harvest operations. This study evaluates the effect of variable-rate PGR application compared to constant-rate application to reduce yield spatial variability and increase yield. The variable-rate approach was carried out in 2020 based on zonal applications defined by clustering analysis using soil electrical conductivity, vegetation indexes, and yield maps. Application doses and timings were determined by integrating plant height measurements for the whole field in 2019 and by zone in 2020. To compare the two procedures, cultivar and plant populations were kept constant; fertilization and accumulated rain were similar in both seasons. A reduction in yield spatial variability due to the zonal application was observed, with yield coefficient of variation (CV) decreasing from 18% in 2019 to 12% in 2020. Spatial and temporal analysis of Normalized Difference Vegetation Index satellite images showed higher CV values in 2019 (constant-rate) reaching 30% at the end of the season, whereas in 2020 (variable-rate) CV was constant (approximately 10%). Cotton yield increased from 3.5 to 4.3 t ha-1 between 2019 and 2020, which can be partially attributed to the variable-rate approach. The variable-rate approach based on application zones and plant height measurements was a viable strategy for reducing yield spatial variability and likely increasing yield in a highly variable cotton field.

EUCALYPTUS RESPONSE TO THE APPLICATION OF LIMESTONE, GYPSUM, AND LIME MUD IN HUMIC CAMBISOL

Eucalyptus response to limestone, gypsum, and lime mud application in Humic Cambisol. This study aimed to evaluate the development of Eucalyptus dunnii Maiden in Humic Cambisol in the Santa Catarina. Individuals were treated with doses and application forms of dolomitic limestone, gypsum, and lime mud. The experiment was conducted in the field, testing the following treatments: T1 – control; T2 – 3.5 t ha-1 of limestone in total area; T3 – 1.75 t ha-1 of limestone in the planting strip; T4 – 3.5 t ha-1 of limestone in the planting strip; T5 – 3.5 t ha-1 of lime mud in the planting strip; T6 – 3.5 t ha-1 of limestone + 2.75 t ha-1 of gypsum in the planting strip; T7 – 1.75 t ha-1 of limestone in the furrow; T8 – 1.75 t ha-1 of limestone + 1.38 t ha-1 of gypsum in the furrow; T9 – 1.38 t ha-1 of gypsum in the furrow. The treatments were applied in April 2016, six months after the seedlings were planted. In total, four forest inventories were carried out, measuring plant height and diameter, from 2019 to 2022. Soil samples up to a depth of 0.40 meters were collected at 31 and 56 months after application of treatments, determining the relationships Ca/Mg and Mg/K. None of the variables, measured or calculated, of the plants were significantly altered as a function of the treatments. Ca/Mg ratios were higher under lime mud and gypsum, whereas Mg/K ones, under treatments with dolomitic limestone.

Estimation of alfalfa fall dormancy using spaced plant and sward trials across multiple environments

AbstractBackgroundAlfalfa is a globally important forage crop. Cultivars are characterized by fall dormancy (FD). FD affects biomass yield and winter survival and is used to identify appropriate growing regions of cultivars. It has historically been assessed by measuring the natural height of regrowth in autumn of spaced plants in the field. Because commercial alfalfa is normally grown as a solid planted sward, FD could be different if plants were grown under real production conditions. The objective of this experiment was to assess whether FD ratings obtained from swards were similar to those obtained on spaced plants.MethodsWe evaluated 20 alfalfa cultivars in field trials established in 2015 at five locations in the United States. We harvested the trials in early autumn and measured regrowth plant height approximately 3 weeks later in 2015 and 2016.ResultsAutumn plant height responded as expected for the established check cultivars in all locations. Fall dormancy ratings for cultivars under both management systems were highly correlated.ConclusionsEstimating FD from spaced plant height measurements in autumn is very robust, and using height data from sward plots gives equivalent results to that measured in spaced plant nurseries. This finding has many practical advantages.

Application of sentinel-1 SAR-derived vegetation descriptors for soil moisture retrieval and plant height prediction during the wheat growth cycle

ABSTRACT Soil moisture is the crucialparameter impacting the plant growth during its phenological cycle. The Water Cloud Model (WCM) is one of the most widely used semi-empirical models for retrieval of soil moisture of vegetated lands from synthetic aperture radar (SAR) images. The model considers the effect of soil as well as vegetation on the radar backscatter. The study assesses the applicability of Sentinel-1 SAR-derived vegetation descriptors in the WCM for soil moisture retrieval during the wheat growth cycle. Various combinations of vegetation descriptors (V1and V2), viz. VH polarized backscatter coefficient (σ0 VH), Radar Vegetation Index (RVI) and depolarization ratio (χv), were used in the model. The model performed better when different parameters are used as vegetation descriptors (V1≠V2) in the WCM rather than using the same parameter for both the vegetation descriptors (V1= V2). The best results were observed when σ0 VHwas considered as one of the vegetation descriptors (V1) while either χvor RVI were utilized as the other vegetation descriptor (V2) giving a Pearson correlation coefficient (R) of 0.959 and 0.958 and a root mean square error (RMSE) of 0.499 dB and 0.516 dB respectively. The validation of the model-retrieved soil moisture against the in-situ measured values gave an R value of 0.72 and a RMSE of 0.096m3/m3. The plant height was also predicted by the WCM in which the retrieved soil moisture from SAR data was used as a parameter. The predicted plant height was compared to in-situ measured plant height and an R value of 0.76 and RMSE of 0.214 was obtained as the best result. The study demonstrates the capability of SAR-derived parameters as vegetation descriptors in the WCM for soil moisture retrieval.

Competition Study of Cowpea (Vigna unguiculata L. Walp) and Bidens pilosa L. Using Replacement Series Approach

Weeds disturb plants through competition or competition that occurs with cultivated plants. Weed competition can reduce crop production by up to 40%, as well as reduce seed quality. The amount of competition between weeds and plants is determined by the density of weeds, the length of time they grow with cultivated plants, and the type of weeds. Thus, it is necessary to increase productivity by considering the presence of weeds that can reduce production. On this basis, it is necessary to conduct research on the competition between cowpea and weeds using the replacement series method. Replacement series is a method used to evaluate competition between species by studying interspecific and intraspecific interactions of plant combinations. This research was carried out in the greenhouse of SEAMEO BIOTROP July – September 2021. This study used a simple randomized block design with a single factor, namely the composition of weeds with 5 treatment levels, namely: P1: 100% weeds. , P2: 75% weeds + 25% cowpeas, P3: 50% weeds + 50% cowpeas, P4: 25% weeds + 75% cowpeas, and P5: 100% cowpeas. The observation parameters are growth parameters represented by plant height variables and yield parameters are represented by dry weight. The results showed that the increasing proportion of weeds was accompanied by a decrease in the dry weight of cowpea. Vice versa. Then, the results of plant height measurements show that the increasing proportion of weeds and plants will be accompanied by a decrease in the height of their competitors. The results of the analysis of RYT values showed that there was competition between weeds and cowpeas at the P3 treatment level: 50% weeds and 50% cowpeas. Meanwhile, in other proportions there is a negative interaction.

Uji Antagonis Bacillus sp. dan Pseudomonas berfluorescens dari PGPR Akar Bambu Dalam Menekan Penyakit Layu Bakteri Ralstonia solanacearum Pada Tomat

Bacterial wilt disease caused by Ralstonia solanacearum on tomato plants can reduce the quantity and quality, so it is necessary to control this disease. One of the controls that can be used is control using antagonistic agents. Bacteria Bacillus sp. and Pseudomanas fluorescens is an antagonist agent contained in PGPR which has the ability to suppress disease growth, increase plant root uptake of several nutrients and increase plant growth. This study aims to determine the effect of Bacillus sp. and P. fluorescens from bamboo roots in suppressing bacterial wilt disease of R. solanacearus in tomatoes. Using a Completely Randomized Design Method (CRD) consisting of 3 treatments, each treatment consisted of 6 replications so that 18 experimental units were obtained in vivo. Observations were made by measuring plant height, number of fruit, fruit weight and intensity of disease attack. The results obtained in this study indicate that the administration of Bacillus sp. and P. fluorescens were able to control bacterial wilt disease caused by Ralstonia solanacearum bacteria in tomato plants.

Effect of dual inoculation of Rhizobium and Mycorrhiza on the growth of two varieties of Cicer arietinum

The impact of Rhizobium and mycorrhizal fungal spores on two varieties (RVG 202 and Radhey) of Cicer arietinum (Chickpea) was studied in this research. In the research field of the Bipin Bihari College Jhansi, Uttar Pradesh, seeds of chickpea varieties RVG 202 and Radhey were sown. Chickpea seeds were inoculated individually and together with Rhizobium and mycorrhizal spores. After germination, measurements of plant height, plant weight, the number of root nodules and number of pods, amount of chlorophyll, leaf area, and total yield were recorded. The data were measured after 30, 45, 60, 75, 90, and 120 days after sowing. According to the findings of these tests, mycorrhiza and Rhizobium had a good impact on the growth and yield of chickpea plant. When Rhizobium and mycorrhiza are inoculated together, the results are better than when they are inoculated separately.

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“Culantro”, also known as “cilantro” (Eryngium foetidum) is extensively used in seasoning, marinating and garnishing as a culinary condiment. It’s occasionally used as a cover for coriander leaves, but has a much stronger taste. Agro-homoeopathy is one of the newest approaches in husbandry exploration and also is the most chemical free, nontoxic system of growing food and other crops. So, this exploration was carried out with indigenous Culantro using Homoeopathic medicine Magnesium Phosphoricum 6X & 6C potencies at biodynamic farming prospective level. This study was conducted for 90 days to assess initial plant growth in 7 different settings to minimize obscurity. The growth was assessed by measuring plant height, number & size of leaves in millimeters. After study period the compliances shown that, Homoeopathic medicine Magnesium Phosphoricum 6X & Magnesium Phosphoricum 6C is effective in cultivating indigenous Culantro and can be recommended for agrarian field for cultivation of indigenous Culantro (Eryngium foetidum).

Alternative Management Strategies and Impact of the Northern Root-Knot Nematode in Daylily Production

Bare-root production of Hemerocallis spp., daylily, is of major economic importance to Michigan's ornamental industry, but production of clean nursery material is challenging due to plant-parasitic nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most important perennial ornamental pathogen in northern North America; it causes over 20% yield loss in Hemerocallis spp. production and reduces marketability and distribution. A field trial was established in 2018 to 2020 at a Michigan commercial nursery to determine effective and long-term management strategies to reduce nematode population levels. Eleven treatments were tested: a control, four bio-nematicides, two nematicides, a nematicide root dip, and three compost blends. Soil samples were taken three times per year, along with annual root samples and plant height measurements. Results indicated that TerraClean 5.0 (hydrogen peroxide) and Majestene 304 ( Chromobacterium subtsugae) nematicides best controlled M. hapla populations by 49 and 37%, respectively, compared with the control, whereas Indemnify (fluopyram) significantly increased plant biomass and yields by 31%. A greenhouse study was conducted to determine the impact of M. hapla on Hemerocallis spp. production by inoculating daylily with varying nematode inoculation densities. Even at low population levels, plant biomass reductions were observed, and M. hapla was readily able to reproduce on Hemerocallis spp. These experiments highlight the importance of managing M. hapla and provide effective, alternative management methods that can reduce the application of fumigants and prevent yield losses to increase profitability for ornamentals.

Produção de tomate-cereja irrigado utilizando canteiros econômicos com mulching

ABSTRACT Technologies that improve water use efficiency (WUE) and increase crop yields are essential for the development of a responsible and productive agriculture. Therefore, the objective of this study was to evaluate economical planting beds with the use of mulching and application of different irrigation water depths as a water-saving technology, and determine the irrigation water depth that promote the optimal plant development and fruit yield and quality of two cherry tomato cultivars. The experiment was conducted at the Federal Rural University of Pernambuco, Serra Talhada, PE, Brazil. A randomized block experimental design with split-plots (5×2) was used, with plots consisting of five irrigation water depths (25%, 50%, 75%, 100%, and 125% of the crop evapotranspiration - ETc) and subplots consisting of two cherry tomato cultivars (Carolina and Yubi), with four replications, totaling 40 experimental units. The development of tomato plants was evaluated through biometric measurements of stem diameter, plant height, and canopy area. Additionally, the following variables were evaluated during fruit harvest: number of fruits, mean fruit weight, fruit diameter, fruit yield, WUE, titratable acidity, pH, and soluble solids content. The economical planting beds promoted increases in WUE. Irrigation water depths lower than 100% of ETc resulted in better plant development and higher fruit yield, number of fruits, and WUE for the evaluated cherry tomato plants. The cultivar Carolina exhibited higher production performance compared to Yubi.

Effect of Different Types of Fertilizers on Stevia Rebaudiana Production in Rwanda

Fertilizers are recognized as limiting factors for crop growth in Rwanda. The choice of fertilizers to be used for a certain crop in certain soil is crucial for production. The experiment was conducted in Rubona and Ntendezi stations of Rwanda Agriculture and Animal resources Development Board (RAB) during seasons 2021A and 2021B respectively. The objectives were to develop guidelines for stevia production in Rwanda and increase production through promotion and utilization of good quality fertilizers in stevia production. The treatments included four types of organic manures (cow dung, poultry manure, compost and pig manure), three inorganic fertilizers (NPK, DAP and urea) and control or check (without fertilizer Plant sampling was done once a week to measure plant height, number of tillers, internodes and to measure yield at harvest. . The results revealed a significant interaction between treatments and plant height. Poultry manure played more dominant role in increasing plant height (44.51m), cow dung was the second (43.50m) while control treatment showed minimum contribution in increasing number of stevia height (39.76m). Poultry manure also played dominant role in increasing number of tillers (22.76), urea was the second (21.0) while control treatment showed minimum contribution in increasing number of stevia tillers (16.8). The yield of harvested fresh leaves of stevia that resulted from poultry manure has shown at least height yield in comparison with other treatments. Keywords: Fertilizers, Types of fertilizers, Stevia rebaudiana, production

Identifikasi Kandungan dan Pengaruh Lama Fermentasi POC terhadap Pertumbuhan Tanaman Sawi dengan Sistem Hidroponik

One of the plants that has the potential and is easy to cultivate is mustard (Brassica juncea L.) especially in hydroponic systems. This study identified the total N, P and K content in liquid organic fertilizer made from moringa, banana weevil, maja fruit, sugar water, and rice washing water. Next, look at the effect of fermentation time on the growth of mustard plants through a hydroponic system. The study used a randomized block design with 3 treatments and three replications and one control was made using AB Mix fertilizer. The research stages include: preparation of tools and materials, preparation of hydropinic buildings, manufacture of liquid organic fertilizer, seeding and planting, measurement of plant height, number of leaves, leaf length and leaf width, as well as identification of liquid organic fertilizer content and data analysis. The results obtained showed that the highest nitrogen content was found in f liquid organic fertilizer with a fermentation period of 21 days, which was 0.72% and the lowest was found in liquid organic fertilizer with a fermentation time of 7 days. Furthermore, the highest phosphorus content was found in liquid organic fertilizer with a fermentation time of 7 days and 21 days, which contained 0.02% phosphorus. Likewise, the highest potassium content was found in liquid organic fertilizer with a fermentation time of 7 days and 21 days with a potassium content of 0.10%. The results of the research on the effect of fermentation time on plant growth showed that the length of fermentation affected the growth of plant height, leaf width, leaf length, and number of leaves. POC with a fermentation time of 21 gave a better effect on plant growth when compared to POC fermented for 7 days and 14 days. POC fermented for 21 days showed no difference in plant growth when compared to the control.

Genetic Variability Studies in F2 Generations of Determinate High Yield Dry Bean Lines for Seed Yield and Yield Components

Dry bean is the third most important pulse crop which is widely adapted and can improve soil fertility in Türkiye. The genetic variability and association studies help in selection which would increase the yield potential of dry bean. The F2 generation and parents (Kınalı, Alberto, Great, Göynük, Özmen) obtained by diallel hybrid method (5 x 5 and 20 combinations were obtained) were sown in the experimental field of Selçuk University Faculty of Agriculture in 2021.In the research, measurement, counting, weighing and analysis of plant height, pod height, number of seeds per plant, number of seeds per pod, seed yield per plant, hundred-seed weight, protein ratio, protein yield in the plant were made. In the F2 generation, the seed yield values in plant of the hybrids are between 23.63 g/plant (Kınalı x Özmen) and 97.45 g/plant (Alberto x Kinalı). Heterosis values of seed yield in plant range from -50.72% (Kınalı x Özmen) to 93.01% (Kınalı x Göynük), heterobeltiosis values varies from -58.92% (Kınalı x Özmen) to 77.26% (Göynuk x Özmen). The protein ratio of the crosses in the F2 generation ranged from 23.05% (Alberto x G Northern 59) to 29.12% (Özmen x Alberto). Heterosis values of protein ratio are between -18.33% (Alberto x G Northern 59) and 7.23% (Özmen x Alberto), heterobeltiosis values are between -22.27% (Alberto x G Northern 59) and 5.82% (Özmen x Alberto). As a result of this research, a sufficient level of genetic variation was determined in the population, considering the agronomic characteristics examined. Determination of suitable parents and hybrids for green bean breeding in terms of sustainability of calcareous soils, agronomic characteristics and inheritance of these parents and hybrids were determined.

Intra-individual variation in Galium odoratum is affected by experimental drought and shading.

Climate-change induced warmer spring temperatures advance tree leaf-out and result in earlier shading of the forest floor. Climate change also leads to more frequent droughts. Forest understorey herbs may respond to these environmental changes by varying traits at different hierarchical levels of organization. While trait mean variation at the inter-individual level in response to environmental changes is well-studied, little is known about how variation at the intra-individual level responds. We sampled genets of the forest understorey herb Galium odoratum from 21 populations in three regions in Germany, varying in microclimatic conditions. The genets were transplanted into a common garden, where we applied shading and drought treatments. We measured plant height and leaf length and width, and calculated the coefficient of variation (CV) at different hierarchical levels: intra-population, intra-genet, intra-ramet and intra-shoot. Variance partitioning showed that intra-shoot CV represented most of the total variation, followed by intra-ramet CV. We found significant variation in CV of plant height and leaf width among populations of origin, indicating that CV is at least partly genetically based. The soil temperature at populations' origins correlated negatively with CV in plant height, suggesting adaptation to local conditions. Furthermore, we observed that early shade led to increased intra-ramet CV in leaf length, while drought reduced intra-shoot CV in leaf width. Finally, intra-shoot leaf width mean and CV were independent under control conditions but correlated under drought. Our experimental results reveal correlations of intra-individual variation with soil temperature, indicating that intra-individual variation can evolve and may be adaptive. Intra-individual variation responded plastically to drought and shading, suggesting functional changes to improve light capture and reduce evapotranspiration. In conclusion, intra-individual variation makes up the majority of total trait variation in this species and can play a key role in plant adaptation to climatic change.

Rapid Nondestructive Detection of Chlorophyll Content in Muskmelon Leaves under Different Light Quality Treatments

In order to select the light quality suitable for plant growth, a quantitative detection model of chlorophyll content in muskmelon leaves was established to monitor plant growth quickly and accurately. In the paper, muskmelon “Boyang 91” was used as the experimental material, and six different light proportion treatments were set up. Through measuring plant height, stem diameter, number of leaves, nodes, and other growth indicators, in addition to leaf chlorophyll content, the response difference of muskmelon to different light qualities was explored in a plant factory. The hyperspectral imaging technology was used to establish the prediction model for the chlorophyll content of muskmelon. The original spectrum was preprocessed and optimized by five pretreatments, and then the characteristic wavelengths were extracted by six methods. Partial least squares regression (PLSR), least squares support vector machine (LSSVM), and convolutional neural network (CNN) were established for optimal feature wavelength. The results showed that the plant height and stem diameter of the T3 treatment were higher than those of other treatments, and their values were 14.48 (cm) and 5.02 (mm), respectively. The chlorophyll content of the T3 treatment was the highest, and its value was 40.16 (mg/g), which was higher than that of other treatments. Through comprehensive analysis, the T3 treatment (light ratio: 6R/1B/2W, light quantum flux: 360 μmol/(m2·s), photoperiod: 12 h) was optimal. Meanwhile, the average spectral reflectance data of 216 leaf samples were extracted, and the S-G preprocessing method was selected to preprocess the original spectral data (Rc = 0.860, RMSEC = 1.806; Rcv = 0.790, RMSECV = 2.161). By comparing and analyzing the correlation coefficients and root mean square errors of six feature wavelength extraction methods, it was concluded that the variable combination population analysis (VCPA) method had the best model effect for feature wavelength extraction (RP = 0.824, RMSEP = 1.973). Ten characteristic wavelengths ( 396, 409, 457, 518, 532, 565, 687, 691, 701, and 705 nm) extracted by the VCPA method were used to establish the chlorophyll content prediction model, and the chlorophyll content prediction model of S-G-VCPA-CNN had the best performance (Rc = 0.9151, RMSEC = 1.445; Rp = 0.811, RMSEP = 2.055). The results of this study provide data support and a theoretical basis for screening the light ratio of other crops, and also present technical support for online monitoring of crop growth in plant factories.

Estimation of cotton canopy parameters based on unmanned aerial vehicle (UAV) oblique photography.

The technology of cotton defoliation is essential for mechanical cotton harvesting. Agricultural unmanned aerial vehicle (UAV) spraying has the advantages of low cost, high efficiency and no mechanical damage to cotton and has been favored and widely used by cotton planters in China. However, there are also some problems of low cotton defoliation rates and high impurity rates caused by unclear spraying amounts of cotton defoliants. The chemical rate recommendation and application should be based upon crop canopy volume rather than on land area. Plant height and leaf area index (LAI) is directly connected to plant canopy structure. Accurate dynamic monitoring of plant height and LAI provides important information for evaluating cotton growth and production. The traditional method to obtain plant height and LAI was s a time-consuming and labor-intensive task. It is very difficult and unrealistic to use the traditional measurement method to make the temporal and spatial variation map of plant height and LAI of large cotton fields. With the application of UAV in agriculture, remote sensing by UAV is currently regarded as an effective technology for monitoring and estimating plant height and LAI. In this paper, we used UAV RGB photos to build dense point clouds to estimate cotton plant height and LAI following cotton defoliant spraying. The results indicate that the proposed method was able to dynamically monitor the changes in the LAI of cotton at different times. At 3 days after defoliant spraying, the correlation between the plant height estimated based on the constructed dense point cloud and the measured plant height was strong, with [Formula: see text] and RMSE values of 0.962 and 0.913, respectively. At 10 days after defoliant spraying, the correlation became weaker over time, with [Formula: see text] and RMSE values of 0.018 and 0.027, respectively. Comparing the actual manually measured LAI with the estimated LAI based on the dense point cloud, the [Formula: see text] and RMSE were 0.872 and 0.814 and 0.132 and 0.173 at 3 and 10 days after defoliant spraying, respectively. Dense point cloud construction based on UAV remote sensing is a potential alternative to plant height and LAI estimation. The accuracy of LAI estimation can be improved by considering both plant height and planting density.

Morphological and physiologic response of black rice M5 gamma ray irradiation to drought stress

Drought stress is one of the factors that affect plant growth, both in terms of morphology and physiology. Bantul M4 local black rice produces crops that have high proline content and low production. This study aims to examine the response to morphology, physiology and selection of M5 black rice irradiated by gamma rays which are tolerant to drought stress. This research was conducted in the Taman Keceh screen house, Wonogiri Regency at an altitude of 141 masl from June to September 2021. This study used a non-replicated experimental design with drought stress treatment using 50% and 100% water gravimetry. Observation of morphological characters by measuring plant height, number of productive tillers, and flowering age. Observation of physiological characters by measuring stomatal conductance, and transpiration. The results showed that the morphological response decreased plant height, increased the number of productive tillers, and accelerated flowering time. Physiological response to narrow stomatal conductance, transpiration.

Estimation of Density and Height of Winter Wheat Varieties Using Unmanned Aerial Vehicles Images

In order to quickly and accurately obtain density and height information of winter wheat varieties, it is of great practical significance for the growth monitoring of new wheat varieties. In actual production, the plant density and height are mainly obtained by manual measurement, which is inefficient, time-consuming and laborious. Therefore, the winter wheat were extracted coverage based on unmanned aerial vehicles (UAV) images at seedling stage, the relationship between coverage and plant density were investigated. Moreover, the high-definition digital images of winter wheat varieties at 4 growth stages including jointing, booting, flowering and grain filling stages were obtained. The digital orthophoto model (DOM) and digital surface model (DSM) of winter wheat varieties was generated in combination with the ground control points. The estimation model of plant height at the four growing stages were established. Based on the ground measured plant height (H) of new wheat varieties, the plant height of new wheat varieties extracted by DSM was verified. The results showed that the coverage of new wheat varieties extracted from the UAV images at seedling stage was highly correlated with the measured plant density, and the coefficient of determination (R2) was 0.82. The new wheat varieties H extracted by DSM was significantly correlated with the measured H, and the fittedR2and root mean square error (RMSE) of the predicted plant height and the measured value were 0.96 and 6.32 cm, respectively. It indicated that the use of UAV images to predict the plant density and plant height of new wheat varieties has good applicability, and can provide technical reference for the monitoring of wheat phenotypic information in the future.