Fertilization of apricots in Spain

Soil type: light to medium, good drainage, pH 6-8.
Annual irrigation rate: ~6,000 m3/ha.
Plant Population: 400-600 trees/ha.
Expected yield: 35 t/ha.

Fertigation: Recommended rates of nutrients and fertilizers

Month	Crop requirements (kg/ha)				Recommended Fertilizers (kg/ha)
Month	N	P₂O₅	K₂O	MgO	Multi-K	MAP	AN	Magnisal
March	5	10	5	0	11	16	5	0
April	15	15	30	5	65	25	0	32
May	20	15	40	5	87	25	7	32
June	27	10	50	15	110	16	0	95
July	30	5	60	15	130	8	5	95
August	30	5	50	10	105	8	25	63
September	6	5	5	5	11	8	0	31
Total annual	133	65	240	55	520	106	42	348

Multi K – Potassium nitrate (13-0-46)
MAP – mono-ammonium phosphate (0-61-0)
Amm. Nit – Ammonium Nitrate (34-0-0)
Magnisal – Magnesium nitrate (10.8-0-0-15.8)

A general guideline for splitting K application in fertigation programs for apricots

Growth stage	Share of K₂O at stage (%)	Recommended rate (kg/ha of K₂O)
Leaf emergence	15	23
Flowering	20	30
Fruit-set	25	37
Fruit growth	25	37
Fruit maturation	15	23
Total	100	150

Macro elements removed by 1 ton marketable product

Source: Kinoch: VOLHOUBARE LANDBOU, RSA. Processed by Frans Lourens, Haifa ,RSA May, 1999.

Recommended rates of major nutrients (% of dry weight)*

N	P	K	Mg	Mn
3.2-3.5	0.12-0.15	1.8-2.2	.050	40-60ppm

Rating of K levels in apricot leaves (% in DM) in mid-July, Hungary*

Very low	Low	Medium	Favorable	Optimum
>1.2	1.21 – 1.60	1.61 – 2.00	2.01 – 2.60	2.61 – 3.2

Potassium deficiency symptoms*
Leaves are: yellow-greenish in color, smaller, fewer, folded up along the main leaf-vein boat-like. In extreme situations leaf edges show necrosis.
*Source: Several papers by Szucs E. (i.e. Acta Horticulturae, 192, 1985, pp. 137-141).

In South Africa

Average yield of apricot - 25 tons/ha.

Regular foliar applications of Multi-K have increased yield to 60 tons/ha.

Timing of application	Multi-K, side dressing (kg/ha)	Multi-K, foliar application
8 weeks before harvest	100	-
4 weeks before harvest	100	-
2 weeks before harvest	-	1%

Special treatments to increase fruit size in South Africa

Timing of Application	Multi-K, side dressing (kg/ha)	Multi-K, foliar application
8 weeks before harvest	100	-
4 weeks before harvest	100	-
2 weeks before harvest	-	1%

Foliar feeding

Fall is an excellent season to prepare the tree to next season requirements in N, K and Fe. As long as foliage is green and active it will readily absorb these nutrients applied by foliar sprays.

Plant analysis guide

Nutrient sufficiency ranges (source: A & L, Agronomy Handbook, Ankerman & Large Eds.)

Apricots	N	S	P	K	Mg	Ca	Na	B	Zn	Mn	Fe	Cu
Apricots	------------------ % -------------------							---------- ppm -----------
From	2.00	0.15	0.20	2.50	0.60	3.00	0.01	25	20	35	100	6
To	3.00	0.30	0.40	3.50	0.90	4.50	0.10	50	60	100	200	30