Abstract A tomato field experiment under deficit irrigation treatments was established to assess the feasibility of nonlinear mixed models to predict the change in the canopy Normalized Difference Vegetation Index ( N D V I ) along the growing season. The irrigation doses were 50, 70, 85, and 100 % of the actual evapotranspiration (ETc). The experiment was performed in the Peruvian Arid Coastal Region (13.10 S, 76.37 W). On-ground destructive plant measurements (7 times) allowed to obtain the leaf area index ( L A I ) and the canopy equivalent water thickness ( E W T c a n o p y ) to validate the experiment. Similarly, volumetric soil moisture was monitored at three hours interval using time-domain reflectometry. High-resolution multispectral imagery was acquired along the growing season (10 times) using an unmanned aerial vehicle. N D V I at plant level was obtained based on oversegmented imagery. The canopy N D V I growth curves were obtained in relation to the irrigation treatments and growing degree days ( G D D ) using a nonlinear mixed model. Deficit irrigation doses (50, 70 and 85 % ETc) induced lower biomass accumulation and greatly affected L A I and E W T c a n o p y , attaining lower values ( p L A I and E W T c a n o p y values, 70 % ETc was not significantly different from 50 % ETc ( p E W T c a n o p y and L A I compared to the other deficit irrigation treatments ( p N D V I compared to the control. Notwithstanding 50 % ETc obtained lower N D V I values than 70 % ETc, differences were not significant. Volumetric soil moisture was consistent with the irrigation treatments, resulting in a decreased trend with decreasing water application along the growing season. A three-parameter logistic mixed model was found to be well-suited to fit the tomato canopy N D V I growth curves in function of the irrigation treatments (i.e. fixed effects) considering the plant-specific variability (i.e. random effects). At maturity stage, significant differences of the deficit irrigation treatments from the control were obtained ( p N D V I reached asymptotic behavior. During the vegetative stage, the inflection point marked the fastest N D V I growth rate for the 100 % ETc treatment whereas the lowest for the 50 % ETc ( p N D V I .

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一种评估灌溉处理下基于冠层 NDVI 的番茄动态的方法学方法

摘要 建立了亏缺灌溉处理下的番茄田间试验，以评估非线性混合模型预测冠层归一化植被指数（NDVI）随生长季节变化的可行性。灌溉剂量为实际蒸散量 (ETc) 的 50%、70%、85% 和 100%。实验在秘鲁干旱沿海地区 (13.10 S, 76.37 W) 进行。地面破坏性植物测量（7 次）允许获得叶面积指数（LAI）和冠层等效水厚度（EWT 冠层）以验证实验。类似地，使用时域反射计以三小时为间隔监测体积土壤水分。使用无人机沿生长季节（10 次）获取高分辨率多光谱图像。植物级别的 NDVI 是基于过度分割的图像获得的。使用非线性混合模型获得了与灌溉处理和生长期（GDD）相关的冠层NDVI生长曲线。不足灌溉剂量（50、70和85 % ETc）导致较低的生物量积累并极大地影响了LAI和EWT冠层，达到了较低的值（p LAI和EWT冠层值，70 % ETc与50 % ETc没有显着差异（ p EWT 冠层）和 LAI 与其他亏缺灌溉处理相比（ p NDVI 与对照相比。尽管 50 % ETc 获得的 NDVI 值低于 70 % ETc，但差异不显着。土壤体积水分与灌溉处理一致，导致下降趋势随着生长季节用水量的减少。考虑到植物特定的可变性（即随机效应），发现三参数逻辑混合模型非常适合以灌溉处理（即固定效应）为函数拟合番茄冠层 NDVI 生长曲线。在成熟阶段，亏缺灌溉处理与对照有显着差异（p NDVI 达到渐近行为。在营养阶段，拐点标志着100 % ETc 处理的NDVI 增长最快，而50 % 的处理最低。 ETc (p NDVI .