This is a follow-on from the previous article on banana plant nutritional requirements. To reiterate, in order to produce healthy, disease resistant plants that produce large bunches of tasty fruit the nutritional requirements must be met. Nutrients can be classified as macronutrients (primary and secondary) and micronutrients - a shortage of any of these will have a limiting effect on the plant. However, the most limiting effect is water and this is crucial for fruit-fill.
Nitrogen (N) Sulfur (S)
Phosphorus (P) Chlorine (Cl)
Potassium (K) Iron (Fe)
Calcium (Ca) Boron (B)
Magnesium (Mg) Manganese (Mn)
N has the greatest limiting factor when undersupplied. However, when oversupplied the result is rapid growth leading to a weak pseudostem causing buckling or easy toppling of plants. N drives plant growth (along with Mg, Mn, Fe) via chlorophyll production which leads to sugar production and from that all other substances are synthesised that plants require. It is also important for yield and fruit quality. Symptoms of deficiency are a yellowing of the older leaves which can spread to the younger leaves. Eventually the leaves take on a yellow/orange colour (can be confused with potassium deficiency) while in young plants wings of the petioles can have a red or pink colour. N is taken up by the plant in the form of ammonium or nitrate, however it is interesting to note that a corn plant can expend up to 16% of its energy converting the nitrate into amino acids and proteins when 80% of its N is supplied as nitrate.
While all this may sound complex I think the best way of ensuring adequate N is to use plenty of compost along with well rotted animal manures, especially from cows or chickens. This will also have the added benefit of providing the rest of the nutrients you require with good amounts of N being supplied by the soil life in the forms of amino acids and proteins. Otherwise a well balanced compound fertiliser such as Yara Mila can be used. It is important not foget the requirement for calcium and it must be supplied in liberal quantities throughout the year. More on that next time.
Posted: Thu 16 Sep 2021