Mechanism by which water flows through xylem
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NO,for capillary action 2 things are of importance 1) the radius of capillary tube[R] ,2)the tension force between molecules at surface of liquid [T] (for water=72.8 dynes/cm= 728 X 10^-6 N)

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height to which the fluid will rise due to cap.effect, H=(2T cosα)÷(ρgR) 

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[ρ=density of liq,here water =1000kg/m³] 

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numer.=constant(for given liq) denomin.=variable R

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so if capillary was in effect for trees 100s of meters tall the deno. wud have to be small while the ρg is a fixed value here for water = 10000 units the R wud have to be impossibly small 


WHAT HAPPENS IS the transpiration of water droplets from the stomata causes a suction as no air can enter to fill in for the water lost the water as to rise up taking more of it from the soil