Plant Micronutrient Functions (part 1)

Boron

The function of boron is for the wall formation, so boron-deficient plants may be stunted. Sugar transport in plants, flower retention and pollen formation and germination also are affected by boron.Insufficient of boron intake result in reduction of  seed and grain production . Boron-deficiency symptoms first appear at the growing stage. This results in a stunted appearance (resetting), barren ears due to poor pollination, hollow stems and fruit (hollow heart) and brittle, discoloured  leaves and loss of fruiting bodies.

Boron deficiencies are easily detected  in acid, sandy soils in regions of high rainfall, and those with low soil organic matter. Borate ions are mobile in soil and can be leached from the root zone. Boron deficiencies are more prominient during dry periods when root activity is restricted.

Copper

Copper is needed for carbohydrate and nitrogen metabolism and, inadequate copper results in stunting of plants. Copper also is required for lignin synthesis which is needed for cell wall strength and prevention of wilting. The sign of deficiency  in copper are dieback of stems and twigs, yellowing of leaves, stunted growth and pale green leaves that wither easily.

Copper deficiencies are mainly happened  on sandy soils which are low in organic matter. Copper uptake decreases as soil pH increases. Increased phosphorus and iron availability in soils decreases copper uptake by plants

Iron

Iron is involved in the production of chlorophyll, and iron chlorosis is easily recognized on iron-sensitive crops growing on calcareous soils. Iron also is a component of many enzymes associated with energy transfer, nitrogen reduction and fixation, and lignin formation. Iron is associated with sulphur  in plants to form compounds that catalyse other reactions. Iron deficiencies are mainly manifested by yellow leaves due to low levels of chlorophyll. Leaf yellowing first appears on the younger upper leaves in inte veinal tissues. Severe iron deficiencies cause leaves to turn completely yellow or almost white, and then brown as leaves die.

Iron deficiencies occured on high pH soils, although some acid, sandy soils that is low in organic matter also may be iron-deficient. Cool, wet weather enhances iron deficiencies, especially on soils with marginal levels of available iron. Poorly aerated or compacted soils also reduce iron uptake by plants. Uptake of iron decreases with increased of  soil pH, and is adversely affected by high levels of available phosphorus, manganese and zinc in soils.