avocado GB by jlhd32


More Info
									                 Sulphate of Potash
                and Avocado Production

                                                    (150-200 ppm) in the soil before planting,
         Mineral nutrition                          while maintaining a balance with calcium and

The avocado is a tropical to subtropical tree,      Ideally, potassium should represent between
with severe cold being the most limiting factor     0.7 and 2.4 % of the leaf dry matter. In a potassium
to its successful cultivation. It can be grown on   deficient tree, the leaves are small and narrow
a wide range of soil types, but requires good       and necrotic spots appear on the older leaves.
drainage as it cannot tolerate flooding. A soil     A high level of potassium in the soil and leaves
pH from 6 to 6.5 is preferable.                     reduces the development of both vascular
                                                    browning and pulpy spots in the fruit.
 Mineral requirements for different avocado
      cultivars (kg/ton of production)
                               N      P2O5   K2O
Hass                          3.60    0.55   6.10
Fuerte                        1.30    0.39   2.35
Lula                          2.80    0.80   5.46

In the past, the avocado was thought to need
few mineral nutrients. Deficient trees may not
show the symptoms immediately, so mineral
nutrition should be monitored through regular
leaf and soil analysis.

                                                         Potassium deficiency in avocado leaves

                                                            Potassium sulphate
                                                            for higher yield

                                                    The avocado tree does not tolerate high levels
                                                    of chloride, either in the soil or in irrigation
                                                    water, with a toxicity threshold considered to
                                                    be 0.25% chloride in the leaf dry matter.

                                                    Consequently, chloride-based fertilizers such
                                                    as MOP (potassium chloride) should be avoided.
                                                    The main symptom of chloride toxicity is a
         Potassium, the key nutrient                light grey-brown scorch on the tips and edges
                                                    of the older leaves, which spreads back along
                                                    them in an irregular pattern.
Potassium is an important factor for a high
level of avocado production. Its role in sugar      Opposite is an example of a fertilization programme
synthesis and translocation of assimilates is       based on potassium sulphate (SOP), single super
essential for the quality of the fruit. Potassium   phosphate (SSP) and calcium nitrate (CaN).
should be adjusted to an adequate level             Calcium is an important element to increase
          the resistance of the roots to disease and the
          storage life of the avocado fruit.

              Canopy            CaN         SSP       SOP
           diameter (m)

             2                    50        200       50
             4                   175        300      200
             6                   350        400      400
             8                   650        600      750
            10                  1000       1000      900
            12                  1500       1200     1600
                                                                     Sulphur in avocado
          The experiment below compares different
          methods of applying 200kg K2O/ha to Hass
                                                               Sulphur (S) is an important nutrient for plant
          avocados grown in the state of Michoacan in
                                                               growth, playing a key role in amino acid
          Mexico. These are fertigation and soil application
                                                               synthesis. However, sulphur deficiency is
          with and without foliar sprays after flowering.
                                                               becoming increasingly frequent.

           Cumulated 2004-2006 production according            The optimum range for the sulphur content in
                    to application method                      the avocado leaf dry matter is between 0.2 to
                                                               0.6%. Potassium sulphate also contains 18%
                                                               S which covers the plant's sulphur requirements.
                                                               In addition, sulphur is helpful in pest and
                                                               disease control.

          Source : inifap Mexique (2006)

          Results show the benefit of foliar application in
          enhancing root absorption and, consequently,
          on fruit production.

                                                                    Sulphur deficiency in avocado leaves

                                                               Thanks to the effect of its combination of
                                                               potassium and sulphur, sulphate of potash is
                                                               recommended for high avocado yields, as well
                                                               as high quality fruit.
                Different forms of SOP available
                from Tessenderlo Group

            Standard:         for direct application or for use in the
                              manufacture of compound fertilizers.

            GranuPotasse®: a granular form ideal for bulk blending or for
                              direct application with an even distribution
                              on the soil.

            SoluPotasse®: a highly soluble form for fertigation or
                              foliar application.

                            Imported and distributed by:

                    Tessenderlo Group Fertilizers
                               giving nature a helping hand

                                           Tessenderlo Group
                                             Troonstraat 130
                                      B-1050 Brussels, Belgium
                              Tel: +32 2 639 1811 Fax: +32 2 639 1940

To top