/l/ Classified as: high = symptoms seldom occur outside the stated pH; medium = symptoms occur most commonly within 

 the stated pH; low = syn^itoms occur at all pH values, /s/ Species most sensitive to a deficiency state, and there- 

 fore exhibiting syn^itomB of deficiency of the element in a short period of time. /}/ Data refer to the role of 

 aluminum In producing blue pigments in hydrangea flowers, /k/ Reported to be 5.5-6.5 with flax growing on certain 

 waterlogged soils. /5/ Reported to be 5.5 on very acid sandy soils which have been treated with magnesium lime- 

 stone. /6/ Reported to be 7 for citrus crops, /j/ Sodium is utilized by certain higher plants and is considered 

 an essential element for beets. 



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