Relationships between Leaf Area Index and Evapotranspiration and Crop Coefficient of Hilly Apple Orchard in the Loess Plateau

Jia, Qingxuan; Wang, Yanping

doi:10.3390/w13141957

Cited by 12 publications

(5 citation statements)

References 62 publications

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“…Moreover, FAO 56 employs factors such as the crop coefficient Kc, the ratio between the actual crop evapotranspiration and the reference evapotranspiration, an essential input for evaluating crop evapotranspiration. Kc is related to leaf area [8,9] and changes during the growing season according to leaf area, the solar radiation intercepted by the canopy, and crop phenology [10]. These components are strictly related to the plant's genetics.…”

Section: Introductionmentioning

confidence: 99%

A Novel Technique Using Planar Area and Ground Shadows Calculated from UAV RGB Imagery to Estimate Pistachio Tree (Pistacia vera L.) Canopy Volume

et al. 2022

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Interest in pistachios has increased in recent years due to their healthy nutritional profile and high profitability. In pistachio trees, as in other woody crops, the volume of the canopy is a key factor that affects the pistachio crop load, water requirements, and quality. However, canopy/crown monitoring is time-consuming and labor-intensive, as it is traditionally carried out by measuring tree dimensions in the field. Therefore, methods for rapid tree canopy characterization are needed for providing accurate information that can be used for management decisions. The present study focuses on developing a new, fast, and low-cost technique, based on two main steps, for estimating the canopy volume in pistachio trees. The first step is based on adequately planning the UAV (unmanned aerial vehicle) flight according to light conditions and segmenting the RGB (Red, Green, Blue) imagery using machine learning methods. The second step is based on measuring vegetation planar area and ground shadows using two methodological approaches: a pixel-based classification approach and an OBIA (object-based image analysis) approach. The results show statistically significant linear relationships (p < 0.05) between the ground-truth data and the estimated volume of pistachio tree crowns, with R2 > 0.8 (pixel-based classification) and R2 > 0.9 (OBIA). The proposed methodologies show potential benefits for accurately monitoring the vegetation of the trees. Moreover, the method is compatible with other remote sensing techniques, usually performed at solar noon, so UAV operators can plan a flexible working day. Further research is needed to verify whether these results can be extrapolated to other woody crops.

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Section: Introductionmentioning

confidence: 99%

A Novel Technique Using Planar Area and Ground Shadows Calculated from UAV RGB Imagery to Estimate Pistachio Tree (Pistacia vera L.) Canopy Volume

et al. 2022

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“…H. v. rimpaui and H. v. nigricans, as representatives of ancient cereals, have not undergone any improvement and are characterized by a higher LAI, especially hooded barley. However, under less favorable weather conditions (as in 2022 in our study), blackseeded barley does not develop a significantly larger leaf area (LAI), which in drought stress allows for reducing evapotranspiration [38].…”

Section: Discussionmentioning

confidence: 58%

Physiological and Agronomic Characteristics of Alternative Black Barley Genotypes (Hordeum vulgare var. nigricans and H. v. var. rimpaui) under Different Hydrothermal Conditions of the Growing Seasons

Szczepanek,

Nowak,

Błaszczyk

2023

Agriculture

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Black-seeded barley can be a valuable raw material for functional food. However, its restoration to cropping should be preceded by the identification of the characteristics determining productivity. The field study was conducted to identify specific parameters of the black-seeded barley genotypes (Hordeum vulgare var. nigricans and H. v. var. rimpaui) and compare them with common barley (H. vulgare) under the different hydrothermal conditions of the two growing seasons of 2021 and 2022. Our research has shown that each genotype has a set of specific characteristics that best describe it at a given developmental stage. H. v. rimpaui was well characterized by chlorophyll fluorescence parameters such as FV/FM, FV/F0, and PIABS at the seedling stage and H. v. nigricans by FV/FM and FV/F0 at the flag leaf stage. Moreover, H. v. var. rimpaui was distinguished by a high biomass of shoot (726 g m−2) and straw yield (5.04 t ha−1) but H. v. var. nigricans by a high number of sterile generative tillers (103 m−2 in the dry year 2022). Further research should focus on the response of black-seeded barley genotypes to abiotic stresses, while in agronomic practice, efforts should be made to increase the number of grains per ear and 1000-grain weight.

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“…Existing research results indicate that precipitation, temperature, and solar radiation are the climatic factors that have the greatest impact on the LAI [57][58][59][60]. In general, temperature exerts a significant impact on high-latitude and high-altitude areas, whereas precipitation plays a noticeable role in arid and semi-arid regions, and solar radiation is a crucial source for plant growth.…”

Section: Sensitivity Analysis and Contribution Rate Calculationmentioning

confidence: 99%

Identifying and Predicting the Responses of Multi-Altitude Vegetation to Climate Change in the Alpine Zone

Chen,

Guan,

Zhang

et al. 2024

Forests

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Global climate change has affected vegetation cover in alpine areas. In this paper, we analyzed the correlation between Leaf Area Index (LAI) and climate factors of the Yarlung Tsangpo River basin, and identified their contributions using the quantitative analysis method. The results show that the vegetation cover in the study area generally exhibited an increasing trend. Grassland in the middle- and high-altitude areas was the main contributing area. Temperature is the dominant climatic factor affecting the change, the effect of which increases with the rise in elevation. The influences of precipitation and radiation had obvious seasonality and regionality. The vegetation illustrated a lag response to climate drivers. With the change in the elevation band, the response time to precipitation was significantly less than that to air temperature in the low-elevation area, while the opposite trend was observed in the high-elevation area. In the future, the LAI of the watershed will show different characteristics at different time points, with the increases in the LAI in autumn and winter becoming the main factors for the future increase in the LAI. This provides a crucial basis upon which to explore hydrological and ecological processes as important components of the Third Pole region.

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Relationships between Leaf Area Index and Evapotranspiration and Crop Coefficient of Hilly Apple Orchard in the Loess Plateau

Cited by 12 publications

References 62 publications

A Novel Technique Using Planar Area and Ground Shadows Calculated from UAV RGB Imagery to Estimate Pistachio Tree (Pistacia vera L.) Canopy Volume

A Novel Technique Using Planar Area and Ground Shadows Calculated from UAV RGB Imagery to Estimate Pistachio Tree (Pistacia vera L.) Canopy Volume

Physiological and Agronomic Characteristics of Alternative Black Barley Genotypes (Hordeum vulgare var. nigricans and H. v. var. rimpaui) under Different Hydrothermal Conditions of the Growing Seasons

Identifying and Predicting the Responses of Multi-Altitude Vegetation to Climate Change in the Alpine Zone

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