Growing Avocado
Crop Nutrition Advice

General Aspects:

Nitrogen

Nitrate is readily dissolved in the soil solution, so it is drawn passively into the plant roots, saving on plant’s energy, and enjoying fast assimilation and nutritional effect. While most soil ammonium is attached to soil clays, making it more difficult to take up. Unlike the situation with ammonium, nitrate uptake by the tree’s roots, does not deprive them of their sugars, so roots’ energy supply is not impaired.It also, Promotes high yields and ensures vegetative growth of the crop, plays a key role in synthesis of proteins, which are directly involved in growth and yield.

Phosphorus

Phosphorus is a central part of nucleic acids (RNA and DNA), it is used in storage and transfer of energy (ATP and ADP). P fertilizer stimulates early growth and root formation, used for nutrient uptake, cell division, metabolism. Generally sufficient in most California soils. Least response by plants takes place in the summer with extensive root systems. Taken up by avocado trees mainly by mycorrhizae.  Promotes development of a good root system. A prerequisite for flowering and hence- number and maintenance of fruits. Essential for appropriate energy management in the plant. Enhances cell division.

Potassium

The potassium cation, K+, is the most abundant cation in plant cell’s chloroplasts and cytosol (the liquid matrix surrounding the cell’s organelles), it is very mobile in the plant at all levels: within the cells, within tissues, and in long-distance transport, via the xylem and phloem. It is not located in any specific organ. High K concentrations balance the negative charge of all kinds of organic and inorganic anions, thus, stabilizing and buffering the cytosol’s pH at 7–8, which is the optimum for most enzymatic reactions.
Additionally, K+ and its accompanying anions are a major factor, determining the osmotic potential of the plant’s cells and tissues. Potassium’s high mobility across the plants enables it to become a multi-functional factor in plant metabolism.

Calcium and Magnesium

In subtropical growth conditions, approximately 50% of the total fruit nutrient uptake for Mg occurs during the first year, and 50% gets accumulated during the second growing season. However, in contrast to other nutrients, fruit Ca content follows a single sigmoid curve, i.e.- increasing during the first 5 post-bloom months, and then remains constant until fruit harvest, whenever it takes place.

Nutrients requirements

Nutrients removal by 10 MT of avocado fruit

Nutrient		Kg		Nutrient		g
N		11 - 41		B		401
K		20 - 61		Fe		47 - 212
Mg		4 - 8		Zn		45 -156
S		4 - 8		Cu		10 - 58
P		2 - 10		Mn		9 - 47
Ca		2 - 7

*(Calculated on fresh weight basis)