A foliage fertiliser has various elements, are all of them absorbed from leaves/stem if so, what is the time taken by each element to get completely absorbed ? what should be the concentration? Should it be a light spray or drenching of the plant and how often it may be repeated.
I use foliar spray more in winter and less in summer. I mostly dissolve 1 tea spoon in 1 litre water and spray each leaf so each leaf is wet. i also spray on stems and twigs ets. These days i am doing it twice a week. But this is for my potted plants. IMO, the absorption by leaves is completed within 24 hours and effect is visible within few days. I Spray my seedlings half the above dose. How much and how frequent depends on your plants and your micro climate. You need to experiment with yours by decreasing and increasing.
But when i feed my plants with DAP dissolved in water, they show excellent growth as compared to foliar sprary.
The subject is not as simple, the net makes it even more confusing. All water soluble salts can be used for foliar feeding. The absorption from leaves is only effective if their advertised commercial product is be added. Nitrogen is absorbed with in 2 hours, Potassium in about 6 hours and Phosphorus takes days. The availability of nutrients is un-blocked where as through roots it is selective. My friend Khabbab, Izhar and some others are very fond of DAP although it has no Potassium and other trace elements. MAIN KITHAY JAVAN, MANJI KITHAY DAVAN?
Experts say that nitrogen does not say in soil for long, it is flushed where as P and K remain in soil for long and plant uses it when needed. Experts also say that one must do the soil analysis to confirm which element is lacking and which is abundant and then apply accordingly. Although the soil sample laboratory is not far from my home, it is near thokar niaz beg(Actually nearer to Brig Sb.) i heard but i never tried that.
Generally speaking, for potted and established plants, I tend to over fertilize. For plants in ground, I fertilize less.
BASED ON COMPOSITION OF PLANTS; plants use 13-19 parts of P or an average of about 16 parts for every 100 parts of N, or 6 times more N than P. Plants use about 45-80 parts of K or an average of about 62 parts for every 100 parts of N, or about 3/5 as much K as N, and so on.,
Nitrogen = 100 Phosphorus = 13-19 Potassium = 45-80 Range of NPK = 10 – 1.3 – 4.5 to 10 – 1.9 - 8
Our favourite DAP has NPK 18-46-0 Scholars please help
After reading all this I am planning to stop foliage fertilizer. Instead i will add 1 granule of DAP and 1 granule of NPK in 7 inch pot for seasonals. 2 each for 10 inch, 3 each for 12 inch and 4 each for 14 inch pot