Using plant water status to define threshold values for irrigation management of vegetable crops using soil moisture sensors

Six-year-old loblolly pine seedlings were subjected to root severing treatments varying from 0 to 100% of first-order lateral roots. Separate treatments severed surface-oriented or deep-oriented roots. Plant water status was monitored periodically for several months. After all measurements were taken, gross root system structure was determined by excavation. Treatment responses were evident on all dates of measurement. Relationships between percentage of root system cut and leaf conductance or water potential were stronger when surface-oriented roots were cut than when deep-oriented roots were cut. Severing surface-oriented first-order lateral (SOFOL) roots probably resulted in greater impact on plant water status than severing deep-oriented first-order lateral (DOFOL) roots because (i) SOFOL roots had both surface-oriented and deep-oriented second-order lateral roots that could tap both surface and subsurface soil horizons for soil moisture, and (ii) the deep-oriented second-order roots (originating from the SOFOL roots) were spatially distributed over a much larger area than the DOFOL roots and thus would have access to soil water in a larger volume of soil. For SOFOL roots the relationship between percentage cut and leaf conductance or transpiration was strongly negative; for DOFOL roots, no relationship between these variables was observed. Initially water potential decreased with the percentage of roots cut in both groups; in later measurements, water potential was affected more by severing SOFOL than DOFOL roots. Calculation of soil moisture depletion by depth indicated that both surface- and deep-oriented second-order lateral roots were important for water uptake. Severing SOFOL roots significantly decreased nitrogen, phosphorus, and potassium levels in needles of the first growth flush of the year. Levels of these elements in terminal buds were not affected by severing SOFOL roots, but were significantly reduced by severing DOFOL roots. Secondary xylem production was reduced proportionately to the amount of root system cross-sectional area severed.

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Assessing plant water status from infrared thermography for irrigation management

10.21611/qirt.2018.050 ◽

2018 ◽

Author(s):

M. Zovka ◽

I. Boras ◽

S. Švaić

Keyword(s):

Infrared Thermography ◽

Water Status ◽

Irrigation Management ◽

Plant Water Status ◽

Plant Water

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Growth of Rice (Oryza SativaL.) Cultivars Under Upland Conditions With Different Levels of Water Supply3. Root System Development, Soil Moisture Changeand Plant Water Status

Plant Production Science ◽

10.1626/pps.10.3 ◽

2007 ◽

Vol 10 (1) ◽

pp. 3-13 ◽

Cited By ~ 28

Author(s):

Yoichiro Kato ◽

Akihiko Kamoshita ◽

Junko Yamagishi ◽

Hiromi Imoto ◽

Jun Abe

Keyword(s):

Soil Moisture ◽

Root System ◽

System Development ◽

Water Status ◽

Plant Water Status ◽

Plant Water ◽

Root System Development ◽

Upland Conditions ◽

Different Levels

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The relationship of grain yield to vegetative growth and post-flowering leaf area in the wheat crop under conditions of limited soil moisture

Australian Journal of Agricultural Research ◽

10.1071/ar9660281 ◽

1966 ◽

Vol 17 (3) ◽

pp. 281 ◽

Cited By ~ 71

Author(s):

RA Fischer ◽

GD Kohn

Keyword(s):

Soil Moisture ◽

Grain Yield ◽

Leaf Area ◽

Vegetative Growth ◽

Water Status ◽

Plant Water Status ◽

Flowering Plant ◽

Wheat Crop ◽

Plant Water ◽

Relative Differences

Trials were conducted in 1961 and 1962 at Wagga Wagga in southern New South Wales to investigate the yield physiology of the wheat crop. Various cultural treatments were applied to a single variety (Heron). This paper covers aspects directly related to grain yield. In the rate of sowing and fertilizer trials relative differences in grain yield were invariably less than relative differences in total dry weight at or before flowering. In some cases increased vegetative growth depressed grain yield. These results appear to be mainly the consequence of increased post-flowering competition for limited soil moisture in denser crops. High soil nitrogen had an additional detrimental effect. When as a result of later sowing flowering was delayed, both vegetative growth and post-flowering plant water status decreased; as a consequence grain yield decreased with successively later sowings. For the 1962 crops, grain yield was closely correlated (r = 0.969**) with leaf area duration after flowering, which in turn was related to leaf area index at flowering and to the rate of senescence of photosynthetic tissue. Increased rates of senescence were usually associated with reduced post-flowering plant water status, as indicated by the relative turgidity of the leaves. These results are discussed in relation to the importance of numerical components of grain yield and to improvement of grain yield in the wheat crop.

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The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

Beccariana Botanical Research Bulletin ◽

10.30862/bbrp.v7i1.274 ◽

2010 ◽

Vol 7 (1) ◽

Author(s):

Saraswati Prabawardani

Keyword(s):

Water Content ◽

Sweet Potato ◽

Relative Water Content ◽

Water Status ◽

Plant Water Status ◽

Equilibration Time ◽

Plant Water ◽

Font Size ◽

Potato Leaf ◽

Relative Water

The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.

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Plant Water Status in Relation to Clouds 1

Agronomy Journal ◽

10.2134/agronj1973.00021962006500040045x ◽

1973 ◽

Vol 65 (4) ◽

pp. 677-678 ◽

Cited By ~ 15

Author(s):

J. R. Stansell ◽

Betty Klepper ◽

V. Douglas Browning ◽

H. M. Taylor

Keyword(s):

Water Status ◽

Plant Water Status ◽

Plant Water

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White Clover Seed Production: II. Soil and Plant Water Status on Yield and Yield Components

Crop Science ◽

10.2135/cropsci1994.0011183x003400030030x ◽

1994 ◽

Vol 34 (3) ◽

pp. 768-774 ◽

Cited By ~ 10

Author(s):

R. N. Oliva ◽

J. J. Steiner ◽

W. C. Young

Keyword(s):

Seed Production ◽

White Clover ◽

Yield Components ◽

Water Status ◽

Plant Water Status ◽

Plant Water ◽

Yield And Yield Components ◽

Clover Seed

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Remote Sensing for Plant Water Content Monitoring: A Review

Remote Sensing ◽

10.3390/rs13112088 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2088

Author(s):

Carlos Quemada ◽

José M. Pérez-Escudero ◽

Ramón Gonzalo ◽

Iñigo Ederra ◽

Luis G. Santesteban ◽

...

Keyword(s):

Remote Sensing ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Continuous Wave ◽

Technological Development ◽

Water Status ◽

Irrigation Management ◽

Coefficient Of Determination ◽

Plant Water ◽

Monitoring Methods

This paper reviews the different remote sensing techniques found in the literature to monitor plant water status, allowing farmers to control the irrigation management and to avoid unnecessary periods of water shortage and a needless waste of valuable water. The scope of this paper covers a broad range of 77 references published between the years 1981 and 2021 and collected from different search web sites, especially Scopus. Among them, 74 references are research papers and the remaining three are review papers. The different collected approaches have been categorized according to the part of the plant subjected to measurement, that is, soil (12.2%), canopy (33.8%), leaves (35.1%) or trunk (18.9%). In addition to a brief summary of each study, the main monitoring technologies have been analyzed in this review. Concerning the presentation of the data, different results have been obtained. According to the year of publication, the number of published papers has increased exponentially over time, mainly due to the technological development over the last decades. The most common sensor is the radiometer, which is employed in 15 papers (20.3%), followed by continuous-wave (CW) spectroscopy (12.2%), camera (10.8%) and THz time-domain spectroscopy (TDS) (10.8%). Excluding two studies, the minimum coefficient of determination (R2) obtained in the references of this review is 0.64. This indicates the high degree of correlation between the estimated and measured data for the different technologies and monitoring methods. The five most frequent water indicators of this study are: normalized difference vegetation index (NDVI) (12.2%), backscattering coefficients (10.8%), spectral reflectance (8.1%), reflection coefficient (8.1%) and dielectric constant (8.1%).

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Visual estimation of plant water status in cereals

The Journal of Agricultural Science ◽

10.1017/s0021859600060524 ◽

1979 ◽

Vol 92 (1) ◽

pp. 83-89 ◽

Cited By ~ 13

Author(s):

H. G. Jones

Keyword(s):

Spring Wheat ◽

Water Status ◽

Plant Morphology ◽

Leaf Water ◽

Plant Water Status ◽

Plant Water ◽

Visual Estimation ◽

Leaf Water Status ◽

Visual Scoring ◽

Breeding Programmes

SummaryThe potential offered for plant breeding programmes by visual scoring techniques for plant water status was investigated in rice and spring wheat. It was found that differing plant morphology could seriously bias visual estimates of leaf water potential, particularly in spring wheat. In spite of this problem, it was found that at least for rice, this type of approach may have potential in future breeding programmes where an estimate of leaf water status is required, such as those for drought tolerance, so long as a high intensity of selection is not necessary.

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