Late-season plastic covering delays the occurrence of severe water stress and improves intrinsic water use efficiency and fruit quality in kiwifruit vines

Limited water supply in the Mediterranean region is a major problem in irrigated agriculture. Grafting may enhance drought resistance, plant water use efficiency, and plant growth. An experiment was conducted in two consecutive growing seasons to determine yield, plant growth, fruit quality, leaf gas exchange, water relations, macroelements content in fruits and leaves, and water use efficiency of mini-watermelon plants [Citrullus lanatus (Thunb.) Matsum. and Nakai cv. Ingrid], either ungrafted or grafted onto the commercial rootstock ‘PS 1313’ (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne), under open field conditions. Irrigation treatments were 1.0, 0.75, and 0.5 evapotranspiration rates. In both years (2006 and 2007), marketable yield decreased linearly in response to an increase in water stress. When averaged over year and irrigation rate, the total and marketable yields were higher by 115% and 61% in grafted than in ungrafted plants, respectively. The fruit quality parameters of grafted mini-watermelons such as fruit dry matter and total soluble solids content were similar in comparison with those of ungrafted plants, whereas titratable acidity, K, and Mg concentrations improved significantly. In both grafting combinations, yield water use efficiency (WUEy) increased under water stress conditions with higher WUE values recorded in grafted than ungrafted plants. The concentration of N, K, and Mg in leaves was higher by 7.4%, 25.6%, and 38.8%, respectively, in grafted than in ungrafted plants. The net assimilation of CO2, stomatal conductance, relative water content, leaf, and osmotic potential decreased under water stress conditions. The sensitivity to water stress was similar between grafted and ungrafted plants, and the higher marketable yield from grafted plants was mainly the result of an improvement in nutritional status and higher CO2 assimilation and water uptake from the soil.

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Influences of severe water stress on photosynthesis, water use efficiency and proline content of almond cultivars

Journal of Applied Horticulture ◽

10.37855/jah.2012.v14i01.06 ◽

2012 ◽

Vol 14 (01) ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

Kazem Barzegar ◽

Abbas Yadollahi ◽

Ali Imani ◽

Noorollah Ahmadi

Keyword(s):

Water Stress ◽

Water Use Efficiency ◽

Water Use ◽

Proline Content ◽

Severe Water Stress ◽

Use Efficiency

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Multidecadal records of intrinsic water-use efficiency in the desert shrubEncelia farinosareveal strong responses to climate change

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2008345117 ◽

2020 ◽

Vol 117 (31) ◽

pp. 18161-18168 ◽

Cited By ~ 2

Author(s):

Avery W. Driscoll ◽

Nicholas Q. Bitter ◽

Darren R. Sandquist ◽

James R. Ehleringer

Keyword(s):

Water Stress ◽

Water Use Efficiency ◽

Carbon Isotope ◽

Water Use ◽

Isotope Ratios ◽

Entire Study ◽

Carbon Isotope Ratios ◽

Population Mean ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency

While tree rings have enabled interannual examination of the influence of climate on trees, this is not possible for most shrubs. Here, we leverage a multidecadal record of annual foliar carbon isotope ratio collections coupled with 39 y of survey data from two populations of the drought-deciduous desert shrubEncelia farinosato provide insight into water-use dynamics and climate. This carbon isotope record provides a unique opportunity to examine the response of desert shrubs to increasing temperature and water stress in a region where climate is changing rapidly. Population mean carbon isotope ratios fluctuated predictably in response to interannual variations in temperature, vapor pressure deficit, and precipitation, and responses were similar among individuals. We leveraged the well-established relationships between leaf carbon isotope ratios and the ratio of intracellular to ambient CO2concentrations to calculate intrinsic water-use efficiency (iWUE) of the plants and to quantify plant responses to long-term environmental change. The population mean iWUE value increased by 53 to 58% over the study period, much more than the 20 to 30% increase that has been measured in forests [J. Peñuelas, J. G. Canadell, R. Ogaya,Glob. Ecol. Biogeogr.20, 597–608 (2011)]. Changes were associated with both increased CO2concentration and increased water stress. Individuals whose lifetimes spanned the entire study period exhibited increases in iWUE that were very similar to the population mean, suggesting that there was significant plasticity within individuals rather than selection at the population scale.

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