Excess- too high at night , poor flowering
- growth poor as food used faster than made
- leaves fall prematurely
Minimal – water & nutrients absorbed slowly
- yellow foliage & poor development control – can survive short spells if assisted
- reduce or increase temp differential, misting, shading, humidity, air movement, heating
NUTRIENT DEFICIENCIES
ph - the acidity, i.e. low ph – below 7 or alkalinity , high ph – i.e. above 7 affects the uptake of nutrients
- ideal usually between 5 & 6.5 – there are some exceptions
- organic mediums generally self regulating so ph not so important unless pebble culture, hydroculture used
- problems with nutrient uptake if water excessively acid or alkaline
nitrogen (N) - for leaf growth and shoot development
- deficient : stunted growth and mature too early old leaves turn yellow and drop
phosphorus (P) -as a catalyst for flower production and root development
- deficient – stunted growth dark green leaves/ purple tinge
potassium (K) – for control of flower and fruit development
- deficient – dwarfing & edges of leaves scorched & dead
calcium (Ca) – for building cell walls & cell metabolism
- deficient – new growths stunted & distorted
magnesium (Mg) – part of chlorophyll & food manufacture
- deficient – yellowing between veins, plants don’t thrive
sulphur (S) – an ingredient of proteins
- deficient – may stunt root growth
manganese (Mn) – for cell activities
- deficient – poor growth ( trace element)
trace elements – other chemicals Cu, Mb, B, Zn required only in minute amounts
- generally available in organic media & as impurities in water & fertilizers
Excess – poisonous to plants, loss of new growths,& chemical burn of mature parts
Deficiency – rare but generally poor growth
