How to maximize the yield of gerberas grown in greenhouse

The nutrition recommendations, using Haifa's fertilizers, also help to fight magnesium and iron deficiencies in gerbera

 

Growing conditions: Greenhouse
Plant density: Plants/Ha

 

Nutrition Recommendations
Fertigation:
Soil type: Clay

 

 

Growth stage

Nutrients Demand (kg/day/ha)

Fertilizers recommendations (kg/ha/day)

N

P2O5

K2O

Multi-K

MAP

AS

Establishment

1.5

0.75

1.5

3.2

1.2

5.4

Vegetative development

3

1

3

6.4

1.6

9.5

Flower initiation - cutting

3

1

4.5

9.5

1.6

8.75

 

 

Soil type: sandy
Proportional application (ppm in irrigation water)*

 

 

 

 

Growth stage Nutrients Demand (g/m3) Fertilizers recommendations (g/m3)

N

P2O5

K2O

Multi-K

MAP

AS

Establishment

80

40

80

170

60

350

Vegetative development

150 

65

150

330

110

660

Flower initiation - cutting

200

90

200

430

150

880

 

 

Multi-K = Potassium nitrate (13% Nitrogen, 46% K2O)
Haifa MAP = Mono-ammonium Phosphate (12% Nitrogen, 61% P2O5 )
AS = Ammonium sulfate (21-0-0)

 

* Based on irrigation rate of 20-30 m3/ha/day

 

 

 

Nutrition database for gerberas

 

Parameter

Concentration

Rockwool

Rockwool (reuse drainage)

Plant – dry matter (13-15%)

Nutrient Solution

Root Environ.

Nutrient Solution

Root Environ.

Guiding Range

Deficient

Excessive

EC (mS/cm)

1.7 

2.2

1.1

2.2      
 

(mg/l)

(mg/l)

(%)

NH4

27.0

9.0

13.5

9.0

     
N- NH4

21.0

6.9

10.4

6.9

     
K-sap        

0.59–0.74

   
K

215.1

234.6

176.0

234.6

3.91–5.00

1.96

 
Ca

120.3

200.5

64.2

200.5

1.00–2.41

 

 
Mg

24.3

48.6

9.7

48.6

0.24–0.63

   
N, total        

2.52–4.90

   
NO3

697.5

806.0

449.5

806.0

     
N- NO3

157.4

181.9

101.5

181.9

     
S, total        

 

   
SO4

120.1

240.3

67.3

240.3

     
P        

 

0.25-0.62

 
H2PO4

121.3

97.0

58.2

97.0

     
         

mg/Kg (ppm)

Fe

1.955

2.234

1.396

2.234

55.9-111.7

 

> 558.5**

Mn

0.275

0.165

0.275

0.165

38.5-48.3

 

> 219.7*

Zn

0.262

0.327

0.196

0.327

32.7-52.3

   
B

0.324

0.432

0.216

0.432

30.2-40.0

   
Cu

0.048

0.064

0.032

0.064

3.8-12.7

   
Mo

0.048

-

0.048

-

     

 

 

* Dependent on the cultivar
** In petals
Important note: The a/m database was prepared to fit Dutch conditions (low transpiration and low EC of the water). Considerable and proportional reduction in the concentration of the macronutrients should be required to offset for lower quality water prevailing in other conditions.

 

 

 

sources:

  • N. Straver. Nutrient solutions for vegetables and flowers grown in water or substrates. 10th Ed. 1994.
  • C. de Kreij, Sonneveld C., Warmenhoven M.G. and Straver N.A. Guide values for nutrient element contents of vegetables and flowers under glass. 3rd Ed. 1992.

 

 

 

Combating Mn & Fe deficiencies in Gerbera

Source: FlowerTech 1999, vol. 2/ no. 2, p.30.

A deficiency of nutrients such as manganese and iron can affect the size and other floral characteristic of the Gerbera.
Manganese deficiency leads to the younger leaves displaying interveinel chlorosis with small chlorotic patches.
With a severe deficiency, the patches spread and coalesce, resulting in chlorotic mottling. Subsequently the foliage turns yellow leaving the veins green.

 

Iron deficiency initially appears as chlorosis at the basal portion of the leaves and spreads towards the anterior leaf margin, showing yellow-green chlorotic mottling. The chlorotic areas turn brown and show necrosis.
To correct these deficiencies, a combined foliar spray of manganese sulphate and ferrous sulphate each at 200 mg/litre of water twice at an interval of 15 days over the foliage, during April-May will help to increase the size and number of flowers.