Does water stress exacerbate the impacts of heat stress on berry development of Vitis vinifera cv. Semillon vines grown in controlled environment conditions?

Author(s):  
Dennis H. Greer ◽  
Mark M. Weedon
2009 ◽  
Vol 36 (7) ◽  
pp. 645 ◽  
Author(s):  
Dennis H. Greer ◽  
Sylvie M. Sicard

Assessing the impacts of environmental stresses on plant growth and productivity requires an understanding of the growth processes and the carbon economy that underpins this growth. Potted grapevines of the Vitis vinifera L. cv. Semillon were grown in a controlled environment and canopy growth; leaf, bunch and stem extension and net photosynthesis were routinely measured from budbreak to harvest. Allometric relationships enabled dry matter to be determined and, with net photosynthesis, used to determine the shoot carbon economy. Stems, leaves and bunches all followed a sigmoid growth pattern with leaves and stems allocated similar amounts of biomass and carbon while bunches had twice as much. Rates of carbon sequestered as biomass exceeded rates of carbon acquisition through net photosynthesis for over 25 days after budbreak. Despite the high demand for biomass in bunch growth, rates of carbon sequestration actually declined and overall, the vines maintained a positive carbon balance throughout the period of bunch growth. The Semillon shoots relied on carbon reserves to commence growth then produced a 53% carbon surplus after leaf (9%), stem (10%) and bunch (28%) growth demands were satisfied. This suggests these vines also allocated carbon to reserves to sustain the next season’s growth.


2020 ◽  
Author(s):  
Iman Haqiqi ◽  
Danielle S. Grogan ◽  
Thomas W. Hertel ◽  
Wolfram Schlenker

Abstract. Agricultural production and food prices are affected by hydroclimatic extremes. There has been a large literature measuring the impacts of individual extreme events (heat stress or water stress) on agricultural and human systems. Yet, we lack a comprehensive understanding of the significance and the magnitude of the impacts of compound extremes. Here, we combine a high-resolution weather product with fine-scale outputs of a hydrological model to construct functional indicators of compound hydroclimatic extremes for agriculture. Then, we measure the impacts of individual and compound extremes on crop yields focusing on the United States during the 1981–2015 period. Supported by statistical evidence, we confirm that wet heat is more damaging than dry heat for crops. We show that the average damage from heat stress has been up to four times more severe when combined with water stress; and the value of water experiences a four-fold increase on hot days. In a robust framework with only a few parameters of compound extremes, this paper also improves our understanding of the conditional marginal value (or damage) of water in crop production. This value is critically important for irrigation water demand and farmer decision-making – particularly in the context of supplemental irrigation and sub-surface drainage.


Crop Science ◽  
2020 ◽  
Vol 60 (6) ◽  
pp. 3344-3361
Author(s):  
Florence Breuillin‐Sessoms ◽  
Eric Watkins

Plant Science ◽  
2010 ◽  
Vol 179 (5) ◽  
pp. 510-519 ◽  
Author(s):  
Danielle Costenaro-da-Silva ◽  
Gisele Passaia ◽  
João A.P. Henriques ◽  
Rogério Margis ◽  
Giancarlo Pasquali ◽  
...  

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