scholarly journals Comparing efficiency of different sampling schemes to estimate yield and quality parameters in fruit orchards

2017 ◽  
Vol 8 (2) ◽  
pp. 471-476 ◽  
Author(s):  
J. Arnó ◽  
J.A. Martínez-Casasnovas ◽  
A. Uribeetxebarria ◽  
A. Escolà ◽  
J.R. Rosell-Polo
Keyword(s):  
Auxiliary Information ◽  
Simple Random Sampling ◽  
Quality Parameters ◽  
Sampling Strategies ◽  
Sampling Schemes ◽  
Plot Sampling ◽  
Yield And Quality ◽  
Tree Fruit ◽  
Fruit Orchards ◽  
Peach Orchard

Different sampling schemes were tested to estimate yield (kg/tree), fruit firmness (kg) and the refractometric index (°Baumé) in a peach orchard. In contrast to simple random sampling (SRS), the use of auxiliary information (NDVI and apparent electrical conductivity, ECa) allowed sampling points to be stratified according to two or three classes (strata) within the plot. Sampling schemes were compared in terms of accuracy and efficiency. Stratification of samples improved efficiency compared to SRS. However, yield and quality parameters may require different sampling strategies. While yield was better estimated using stratified samples based on the ECa, fruit quality (firmness and °Baumé) showed better results when stratifying by NDVI.

scholarly journals Two-stage sector sampling for estimating small woodlot attributes

2011 ◽  
Vol 41 (9) ◽  
pp. 1819-1826 ◽  
Author(s):  
Piermaria Corona ◽  
Lorenzo Fattorini ◽  
Sara Franceschi
Keyword(s):  
Large Scale ◽  
Sampling Strategy ◽  
Sampling Variance ◽  
Sampling Strategies ◽  
Fixed Size ◽  
Two Stage ◽  
Sampling Schemes ◽  
Second Stage ◽  
Forest Inventories ◽  
Plot Sampling

A two-stage sampling strategy is proposed to assess small woodlots outside the forests scattered on extensive territories. The first stage is performed to select a sample of small woodlots using fixed-size sampling schemes, and the second stage is performed to sample trees within woodlots selected at first stage. Usually, fixed- or variable-area plots are adopted to sample trees. However, the use of plot sampling in small patches such as woodlots is likely to induce a relevant amount of bias owing to edge effects. In this framework, sector sampling proves to be particularly effective. The present paper investigates the statistical properties of two-stage sampling strategies for estimating forest attributes of woodlot populations when sector sampling is adopted at the second stage. A two-stage estimator of population totals is derived together with a conservative estimator of its sampling variance. By means of a simulation study, the performance of the proposed estimator is checked and compared with that achieved using traditional plot sampling with edge corrections. Simulation results prove the adequacy of sector sampling and provide some guidelines for the effective planning of the strategy. In some countries, the proposed strategy can be performed with few modifications within the framework of large-scale forest inventories.

scholarly journals Accuracy of Subsampling for Height Measurements in Loblolly Pine Plots

2009 ◽  
Vol 33 (3) ◽  
pp. 145-149 ◽  
Author(s):  
Colleen A. Carlson ◽  
Thomas R. Fox ◽  
Harold E. Burkhart ◽  
H. Lee Allen ◽  
Timothy J. Albaugh
Keyword(s):  
Loblolly Pine ◽  
Random Sampling ◽  
Southeastern United States ◽  
Simple Random Sampling ◽  
Stratified Sampling ◽  
The Other ◽  
Diameter Distribution ◽  
Systematic Sampling ◽  
Sampling Strategies ◽  
Sampling Schemes

Abstract Estimating heights in research and inventory plots is costly. We examined the feasibility of subsampling tree heights as opposed to measuring all trees. Four sampling intensities (75, 50, 25, and 10%) and four sampling strategies (systematic sampling, simple random sampling without replacement, stratified sampling across the diameter distribution, and sampling the first trees in each plot) were investigated. Data from 600 loblolly pine plots in fertilizer trials in the southeastern United States were used. The application of a height–dbh regression to predict the heights of unmeasured trees was also investigated. Sampling the first trees generally resulted in poorer estimates than the other sampling schemes. Systematic and simple random sampling performed similarly. A 50% sampling intensity with either systematic or simple random sampling and a height–dbh regression predicting the heights of unmeasured trees estimated more than 90% of plots to within 2.2% of the observed plot height and more than 94% of plots to within 2.5% of the observed volume, and they were more accurate than the stratified sampling at the same intensity. Systematic sampling is easy to implement, requiring no prior plot knowledge. We conclude that a 50% systematic sampling combined with a height–dbh regression will reduce costs without compromising accuracy.

Effect of Integrated Nutrient Management on Yield and Quality of Garlic cv. Yamuna Safed-3

2020 ◽  
Vol 7 (04) ◽  
Author(s):  
A B Priyanshu ◽  
M K Singh ◽  
Mukesh Kumar ◽  
Vipin Kumar ◽  
Sunil Malik ◽  
...  
Keyword(s):  
Nutrient Management ◽  
Block Design ◽  
Quality Parameters ◽  
Organic Fertilizers ◽  
Research Centre ◽  
Yield And Quality ◽  
Randomized Block Design ◽  
The Impact ◽  
Horticultural Research

An experiment was conducted at Horticultural Research Centre, SVP University of Agriculture and Technology, Meerut (UP) during Rabi season of 2018-19 to assess the impact of different INM doses on yield and quality parameters of garlic. A total of ten treatments consisting of combinations of inorganic fertilizers, organic fertilizers and bio-fertilizers like T1- (Control), T2RDF (100:50:50 kg NPK ha-1), T3-RDF + 20 kg sulphur + FYM 20 ton ha-1, T4- RDF + 20 kg sulphur + VC 4 ton ha-1, T5- 75% RDF + 40 kg sulphur + 5 ton FYM ha-1+ PSB 5 kg ha-1, T6-75% RDF + 40 kg sulphur + 2 ton VC + Azotobacter 5 kg ha-1, T7- 75% RDF + 40 kg sulphur + FYM 3 ton + VC 1 ton+ PSB 5 kg + Azotobacter 5kg ha-1, T8- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg ha-1, T9- 50% RDF + 40 kg sulphur + FYM5 ton + VC 2 ton+ Azotobacter 5 kg ha-1and T10- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg + Azotobacter 5 kg ha-1 were used in Randomized Block Design and replicated thrice. Out of these an application of T7 (75% RDF + 40 kg sulphur + FYM3 ton + VC 1 ton ha-1 + PSB 5 kg + Azotobacter 5 kg ha-1) was found to be significantly superior in term of yield and attributing parameters of garlic.

scholarly journals The Effects of Management (Tillage, Fertilization, Plant Density) on Soybean Yield and Quality in a Three-Year Experiment under Transylvanian Plain Climate Conditions

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 200
Author(s):  
Felicia Chețan ◽  
Cornel Chețan ◽  
Ileana Bogdan ◽  
Adrian Ioan Pop ◽  
Paula Ioana Moraru ◽  
...  
Keyword(s):  
Plant Density ◽  
Conventional Tillage ◽  
Quality Parameters ◽  
Soil Tillage ◽  
Reduced Tillage ◽  
Seeding Rate ◽  
Soybean Yield ◽  
Climate Conditions ◽  
Yield And Quality ◽  
Tillage System

The regional agroecological conditions, specific to the Transylvanian Plain, are favorable to soybean crops, but microclimate changes related to global warming have imposed the need for agrotechnical adaptive measures in order to maintain the level of soybean yield. In this study, we consider the effect of two soil tillage systems, the seeding rate, as well as the fertilizer dosage and time of application on the yield and quality of soybean crops. A multifactorial experiment was carried out through the A × B × C × D − R: 3 × 2 × 3 × 3 − 2 formula, where A represents the year (a1, 2017; a2, 2018; and a3, 2019); B represents the soil tillage system (b1, conventional tillage with mouldboard plough; b2, reduced tillage with chisel cultivator); C represents the fertilizer variants (c1, unfertilized; c2, one single rate of fertilization: 40 kg ha−1 of nitrogen + 40 kg ha−1 of phosphorus; and c3, two rates of fertilization: 40 kg ha−1 of nitrogen + 40 kg ha−1 of phosphorus (at sowing) + 46 kg ha−1 of nitrogen at V3 stage); D represents the seeding rate (1 = 45 germinating grains (gg) m−2; d2 = 55 gg m−2; and d3 = 65 gg m−2); and R represents the replicates (r1 = the first and r2 = the second). Tillage had no effect, the climate specific of the years and fertilization affected the yield and the quality parameters. Regarding the soybean yield, it reacted favorably to a higher seeding rate (55–65 gg m−2) and two rates of fertilization. The qualitative characteristics of soybeans are affected by the fertilization rates applied to the crop, which influence the protein and fiber content in the soybean grains. Higher values of protein content were recorded with a reduced tillage system, i.e., 38.90 g kg−1 DM in the variant with one single rate of fertilization at a seeding rate of 45 gg per m−2 and 38.72 g kg−1 DM in the variant with two fertilizations at a seeding rate of 65 gg m−2.

scholarly journals Evaluation of Minimum Preparation Sampling Strategies for Sugarcane Quality Prediction by vis-NIR Spectroscopy

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2195
Author(s):  
Lucas de Paula Corrêdo ◽  
Leonardo Felipe Maldaner ◽  
Helizani Couto Bazame ◽  
José Paulo Molin
Keyword(s):  
Sample Preparation ◽  
Prediction Models ◽  
Spectral Response ◽  
Nir Spectroscopy ◽  
Quality Parameters ◽  
Partial Least Square ◽  
Least Square ◽  
Sample Type ◽  
Sampling Strategies ◽  
Significant Difference

Proximal sensing for assessing sugarcane quality information during harvest can be affected by various factors, including the type of sample preparation. The objective of this study was to determine the best sugarcane sample type and analyze the spectral response for the prediction of quality parameters of sugarcane from visible and near-infrared (vis-NIR) spectroscopy. The sampling and spectral data acquisition were performed during the analysis of samples by conventional methods in a sugar mill laboratory. Samples of billets were collected and four modes of scanning and sample preparation were evaluated: outer-surface (‘skin’) (SS), cross-sectional scanning (CSS), defibrated cane (DF), and raw juice (RJ) to analyze the parameters soluble solids content (Brix), saccharose (Pol), fibre, pol of cane and total recoverable sugars (TRS). Predictive models based on Partial Least Square Regression (PLSR) were built with the vis-NIR spectral measurements. There was no significant difference (p-value > 0.05) between the accuracy SS and CSS samples compared to DF and RJ samples for all prediction models. However, DF samples presented the best predictive performance values for the main sugarcane quality parameters, and required only minimal sample preparation. The results contribute to advancing the development of on-board quality monitoring in sugarcane, indicating better sampling strategies.

scholarly journals Bayesian Analysis of Finite Populations under Simple Random Sampling

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 318
Author(s):  
Manuel Mendoza ◽  
Alberto Contreras-Cristán ◽  
Eduardo Gutiérrez-Peña
Keyword(s):  
Bayesian Analysis ◽  
Random Sampling ◽  
Simple Random Sampling ◽  
Survey Sampling ◽  
Finite Populations ◽  
Population Means ◽  
Sampling Schemes ◽  
Nonparametric Approach ◽  
Conventional Procedure ◽  
Continuous And Discrete Variables

Statistical methods to produce inferences based on samples from finite populations have been available for at least 70 years. Topics such as Survey Sampling and Sampling Theory have become part of the mainstream of the statistical methodology. A wide variety of sampling schemes as well as estimators are now part of the statistical folklore. On the other hand, while the Bayesian approach is now a well-established paradigm with implications in almost every field of the statistical arena, there does not seem to exist a conventional procedure—able to deal with both continuous and discrete variables—that can be used as a kind of default for Bayesian survey sampling, even in the simple random sampling case. In this paper, the Bayesian analysis of samples from finite populations is discussed, its relationship with the notion of superpopulation is reviewed, and a nonparametric approach is proposed. Our proposal can produce inferences for population quantiles and similar quantities of interest in the same way as for population means and totals. Moreover, it can provide results relatively quickly, which may prove crucial in certain contexts such as the analysis of quick counts in electoral settings.

scholarly journals Use of New BTH Derivative as Supplement or Substitute of Standard Fungicidal Program in Strawberry Cultivation

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1031
Author(s):  
Maciej Spychalski ◽  
Rafal Kukawka ◽  
Włodzimierz Krzesiński ◽  
Tomasz Spiżewski ◽  
Monika Michalecka ◽  
...  
Keyword(s):  
Plant Resistance ◽  
Positive Impact ◽  
Quality Parameters ◽  
Nutritional Composition ◽  
Matter Content ◽  
Dry Matter Content ◽  
Yield And Quality ◽  
Amide Derivative ◽  
Combined Use ◽  
The Impact

Triggering the plant resistance induction phenomenon by chemical compounds, for example acibenzolar-S-methyl ester, has been known and described in scientific literature. Other benzothadiazole derivatives have been also described; however, their properties have not been sufficiently studied. The tested substance, N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), is an amide derivative of benzothiadiazole, showing a stimulating effect on plant growth, apart from its plant resistance inducing activity. This article presents the impact of BTHWA, used solo and in the program with fungicides, on the strawberry plants development, fruits health, yield, and quality parameters of the crop. The results show that the combined use of BTHWA and fungicides had a positive impact on the plants health and fruit health and nutraceutical and nutritional composition of compounds when compared to the results obtained when strawberries were treated only with the BTHWA or the fungicide. As a result of BTHWA use, the partitioning of assimilates has changed, which directly translated into the results of the conducted experiments. A reduction in the respiration of the fruit during storage was also observed, possibly due to a reduced disease infestation and a lower dry matter content in the fruit. A correlation between the parameters determined during the experiment was found. The BTHWA mode of action was evidenced to be beneficial to strawberry plants and fruit.

scholarly journals Border Habitat Effects on Captures of Halyomorpha halys (Hemiptera: Pentatomidae) in Pheromone Traps and Fruit Injury at Harvest in Apple and Peach Orchards in the Mid-Atlantic, USA

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 419
Author(s):  
James Christopher Bergh ◽  
William R. Morrison ◽  
Jon W. Stallrich ◽  
Brent D. Short ◽  
John P. Cullum ◽  
...  
Keyword(s):  
Economic Losses ◽  
Halyomorpha Halys ◽  
Pheromone Traps ◽  
Alternative Management ◽  
Crop Fields ◽  
Field Crops ◽  
Crop Injury ◽  
Tree Fruit ◽  
Management Approaches ◽  
Fruit Orchards

The invasive Halyomorpha halys invades crop fields from various bordering habitats, and its feeding on crops has caused significant economic losses. Thus, H. halys is considered a perimeter-driven threat, and research on alternative management tactics against it has focused on intervention at crop edges. Woodlands adjacent to crop fields contain many hosts of H. halys and are therefore considered “riskiest” in terms of pest pressure and crop injury. However, tree fruit orchards in the Mid-Atlantic, USA, are often bordered on one or more sides by woodlands and other habitats, including other tree fruit blocks, and field crops. Monitoring H. halys using pheromone traps has most often focused on the crop–woodland interface, but the relative effects of woodlands and other habitats bordering orchards on pest pressure and crop injury have not been examined. A two-year study comparing seasonal captures of H. halys and fruit injury among different habitats bordering commercial apple and peach orchards in the Mid-Atlantic revealed that while woodland borders often posed the greatest risk, other border habitats also contributed significantly to captures and injury in numerous instances. The relevance of these findings to refining and optimizing perimeter-based monitoring and management approaches for H. halys is discussed.

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