92. SIGNS OF CHEMICAL ELEMENT DEFICIENCY AND 

 EXCESS: HIGHER PLANTS 



Nutrient 



Deficiency SynrptomB 



Toxicity Symprta 



HL 



HE 



m: 



Boron 



Terminal leaves chlorotic, shed prematurely; inter- 

 nodes of terminal shoots shortened, usually reset- 

 ting; apical meristems blacken and die, general 

 breakdovn of meristematlc tissue; root branches 

 short, stubby. Plant dwarfed and stunted. Flover 

 development auod seed production usually inquired. 



Marginal necrosis in lower leaves, remainder of 

 leaves dark green; death of most plants if present 

 in considerable concentration. 



Calcium 



Leaves chlorotic, ro]J.ed and curled; breakdown of 

 meristematlc tissues in stenis and roots, in acute 

 cases death; roots poorly developed, lack fiber, 

 may appear gelatinous. Symptcins appear near grow- 

 ing points of stems and roots. Little or no frxiit- 

 Ing. 



Chlorosis similar to iron or manganese deficiency.^ 

 Zinc and boron deficiency may be induced when soil 

 reaction, e. g. pH, Is altered. 



Copper 



Wilting of terminal shoots, often followed l^ death; 

 leaf color often faded; carotene formation and pig- 

 mentation reduced. 



Chlorosis similar to iron deficiency; followed by 

 necrosis, permanent wilting of upper leaves; leaves 

 may become wrinkled and necrotic at margins; fibrous 

 roots stubby, poorly developed; brownish at tips; 

 reduced growth; extreme cases death. 



Intervelnal white chlorosis, appearing first on 

 young leaves, tendency for chlorosis of all aerial 

 parts, often becooLlng necrotic; in sane cases leaves 

 may be completely bleached, margins and tips 

 scorched. Usually hats an overall effect. 



Same as phosphorus or manganese deficiency. 



Magnesium 



Mottled chlorosis with veins green aod leaf web 

 tissue yellow or ^rtilte, appearing first on old 

 leaves; severely affected leaves may wilt and shed, 

 or may absciss without the wilting stage; brlttle- 

 ness of leaves common, necrosis often occurs. 



Sane as calcium deficiency. 



Manganese 



Mottled chlorosis with veins green and leaf web tis- 

 sue yellower white, appearing first on young leaves, 

 may spread to old leaves; stems yellowish green, 

 often hard and woody. Carotene development reduced. 



Leaves pale, necrotic, bronzing at margins; similar 

 to iron deficiency. With potato, small black spots 

 on stem. 



Molybdenum 



Leaves have light yellow chlorosis; leaf blade may 

 fall to expand. 



Lower leaves yellow with brown necrotic areas; in 

 severe cases, upper leaves may be stunted, chlorotic 

 and absciss. 



Hltrogen 



In young plants stunted growth and yellowish green 

 leaves; older leaves light green, followed by yel- 

 lowing and drying or shedding, often abundant 

 anthocyanins In veins; shoots short, thin, growth 

 upright and spindly; blossoming reduced; with apple 

 and peach, fruit highly colored, develops slowly, 

 small vhen mature. Usually has an overall effect. 



Leaves dark green, excessive vegetative growth; high 

 transpiration; reduced yield of seed and fruit crops 

 may secure satisfactory yield of leafy vegetables but 

 reduced quality (lack succulence). 



Phosphorus 



Leaves pale green^, often anthocyanins (usxisJly pur- 

 ple) In veins, may beccme necrotic; with potato, 

 meristematlc growth ceases; fruits ripen slowly; 

 plants often dwarfed at maturity. 



Same as Iron deficiency. May induce zinc deficiency 



LC 



Leaves usually dark blue green (sometimes bronzed) 

 with marginal chlorosis and necrosis, appearing 

 first on old leaves; usually wrinkled, corrugated 

 or crinkled between veins. 



Leaves yellowish green; reduced growth; tendency 

 toward calcium and magnesium deficiency. 



U 



Leaves light green to yellow, appearing first along 

 veins of young leaves; stems often slender. 



No evidence except as acidity of root medium is in- 

 fluenced. 



LS 



Leaves chlorotic and necrotic, appearing first on 

 young growth, resetting, premature shedding, 

 whitish chlorotic streaks between veins in older 

 leaves and irtiltening of upper leaves in mono- 

 cotyledons, chlorosis of lower leaves in dicoty- 

 ledons . 5 



Leaves yellow frcm zinc Induced iron chlorosis. 



/l/ Chlorosis due to the physiological unavailability of Iron and manganese or reduced potassium. /2/ With potato and 

 certain other vegetables, leaves dark green. /?/ Young plants showing deficiency symptoms often lose symptoms when 

 roots penetrate the subsoil. 



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