(i) Iron deficiency:
It is a plant disorder also known as lime induced chlorosis. A deficiency in the soil is rare but iron can be unavailable for absorption if soil PH is not between 5 and 6.5. A common problem is when the soil is too alkaline. Also, iron deficiency can develop if the soil is too waterlogged or has been overfertilised. Iron is needed to produce chlorophyll, hence its deficiency causes chlorosis.
Symptoms:
Leaves turning yellow or brown in the margins between the veins which may remain green, while young leaves may appear to be bleached. Fruit would be of poor quality.
Treatment:
By choosing appropriate soil for the growing conditions or by adding well-rooted manure or compost.
(2) Potassium deficiency:
Plants require potassium ions for protein synthesis and for the opening and closing of stomata, which is regulated by proton pumps to make surrounding guard cells either turgid or flaccid. A deficiency of potassium ions can impair a plant’* ability to maintain these processes.
Symptoms:
Brown scorching and curling of leaf tips and yellowing of leaf veins. Purple spots may appear on the leaf undersides.
Prevention and cure:
Feeding with homemade comfrey liquid, adding seaweed meal, composted bracken or other organic potassium-rich fertilizer. Adding plants of well rotted compost.
(3) Calcium deficiency:
Caused by insufficient calcium in the growing medium, but is more frequently a product of a compromised nutrient mobility system in the plant.
Symptoms:
Stunted plant growth, necrotic leaf margins on young leaves or curling of the leaves and eventual ***** of terminal buds and root tips.
Treatment:
Adding agricultural lime to acid soils, aiming at a P H of 6.5. Adding organic matter to the soil to improve its moisture retaining capacity.
(4) Nitrogen deficiency:
Occurs when woody material such as sawdust is added to the soil. Soil organisms will utilise any nitrogen in order to break this down; thus making it temporarily unavailable to growing plants.
Symptoms:
Poor plant growth, leaves are pale green or yellow in case of brassicas. Leaves are said to be etiolated with reduced chlorophyll. Following and fruiting are delayed.
Prevention and control: using grass movings as a mulch, or foliar feeding with manure and building up levels of organic matter in the soil, Leguminous green manures will fix additional nitrogen from the atmosphere.
(5) Manganese deficiency:
Most common in poorly drained soils also where organic matter levels are high. Symptoms: yellowing of leaves with smallest leaf veins remaining green to produce a chequered effect. Brown spots appear on leaf surfaces and severely affected leaves turn brown and wither.
