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Evapotranspiration (ET) is a major hydrologic flux used in water resources planning and irrigation management. While recent advances in remote sensing (RS) have enabled availability of high spatial and temporal resolution ET data, a lack of information related to error in the estimations has made it challenging to use this data for on-farm irrigation management decision making. In this study, three commonly used single-source RS ET models (pySEBAL-a new version of Surface Energy Balance Algorithm for Land; SEBS-Surface Energy Balance System algorithm; and METRIC -Mapping Evapotranspiration at High Resolution with Internalized Calibration) were used to estimate daily actual evapotranspiration (ET a ) for almond, processing tomato, and maize in the Central Valley of California. Model evaluation wasconducted by comparing the predicted ET a from RS with in-situ measured ET a using surface renewal. Results indicated that the RS-based ET a estimations for all three models were within acceptable levels of uncertainty and agreed well with surface renewal estimates except for the underestimation by pySEBAL and METRIC during early season growth stages of processing tomatoes. This underestimation was attributed to the lack of accuracy when using single source ET models under lower vegetation cover condition (when ET is dominated by soil evaporation). Better estimates of ET a with pySEBAL and METRIC were detected at full cover, which explains the applicability of these two models to irrigation management during peak crop water demand. SEBS performed the best among the three RS-based models for daily ET a estimation for all crops. This suggests that SEBS-based ET a estimates can be adopted in operational irrigation management programs for farms that have not installed in field ET sensors such as Tule Sensors (Tule Technologies Inc.). In addition, RS based ET is spatially distributed which can help to identity spatial variability between different irrigation zones.

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Membrane microdomains are nano-scale domains (10–200 nm) enriched in sterols and sphingolipids. They have many important biological functions, including vesicle transport, endocytosis, and pathogen invasion. A previous study reported that the membrane microdomain-associated protein Flotillin1 (Flot1) was involved in plant development in Arabidopsis thaliana; however, whether sterols affect the plant immunity conveyed by Flot1 is unknown. Here, we showed that the root length in sterol-deficient cyclopropylsterol isomerase 1 (cpi1-1) mutants expressing Flot1 was significantly shorter than in control seedlings. The cotyledon epidermal cells in cpi1-1 mutants expressing Flot1 were smaller than in controls. Moreover, variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) and single-particle tracking (SPT) analysis demonstrated that the long-distance Flot1-GFP movement was decreased significantly in cpi1-1 mutants compared with the control seedlings. Meanwhile, the value of the diffusion coefficient Ĝ was dramatically decreased in cpi1-1 mutants after flagelin22 (flg22) treatment compared with the control seedlings, indicating that sterols affect the lateral mobility of Flot1-GFP within the plasma membrane. Importantly, using confocal microscopy, we determined that the endocytosis of Flot1-GFP was decreased in cpi1-1 mutants, which was confirmed by fluorescence cross spectroscopy (FCS) analysis. Hence, these results demonstrate that sterol composition plays a critical role in the plant defense responses of Flot1.

To evaluate the irrigation distribution uniformity and optimize the suitable combination of irrigation technical parameters for alternate furrow irrigation (AFI) and conventional furrow irrigation (CFI), field experiments on maize were conducted during 2010 and 2012 at the Shiyanghe Experimental Station in the arid area of north‐west China. A surface irrigation simulation model (SIRMOD) was used to optimize the combination of irrigation technical parameters such as field slope, furrow length and inflow rate. From the distribution uniformity (DU) results calculated from measured data in field experiments, under the same kind of soil texture, using the AFI method in the field could improve irrigation distribution uniformity for 9.67, 3.16 and 3.44% under a slope 1.5, 2.0 and 3.0‰ respectively; the relative error of DU between the simulation value from SIRMOD and the calculated value from field experiment was 4.25%, which was in an acceptable range. On the other hand, combinations of irrigation technical parameters of the CFI and AFI methods were simulated using SIRMOD with the distribution uniformity being the evaluation index. For the irrigation technical parameters, field slope ranging from 0 to 3.0‰, inflow rate from 1.0 to 8.0 l s−1 and furrow length from 25 to 300 m were chosen in this paper. Copyright © 2017 John Wiley & Sons, Ltd.