Transcript RLO Nutrient Management in Grape Nursery

Introduction
• Proper nutrition at nursery stage is important for desired growth
and berry production in grapevine.
• There are 13 mineral nutrients found essential for the growth of
grape vines.
• The macro-nutrients, needed in concentrations of more than
1000 ppm are nitrogen, phosphorus potassium, calcium,
magnesium, and sulphur.
• The micro-nutrients, needed in concentrations of less than 100
ppm are iron, manganese, zinc, copper, chlorine, boron and
molybdenum.
Nutrient and Soil pH Relation
• Availability of inorganic nutrients to plant has relation soil PH. Vis
a vis acidity or alkalinity of the soil.
• Slightly acidic soils with pH 5.5 to 6.5 are most suitable for crop
production in agriculture as all essential nutrients are readily
available in this pH range.
•
In alkaline soils, some mineral ions such as iron, manganese and
copper precipitate and become unavailable to the plants.
• Aluminium toxicity occurs at pH less than 4.5, and manganese
toxicity occurs at pH less than 5.5, depending on other
environmental factors.
Plant Tissue Analysis
• Plant tissue analysis is a foolproof method of analyzing the
nutritional requirements of grape vines.
• Leaf petioles or leaf blades are used for tissue analysis, as they
are sensitive indicators of nitrogen (N), phosphorus (P) and
potassium (K) status. Stalked leaves opposite to the basal
bunches are harvested randomly for analysis.
• Approximately 200 petioles are required for a sample. The petioles
are washed, surface dried and then analyzed.
• Older leaves are used to analyze mobile nutrients while growing
tips of shoots are required for immobile nutrients.
Nutrient supply through Fertilizers
• Recommendations from the manufacturers must be considered
for quantity of doses and method of application.
• Sandy soils are more prone to leaching and need fertilization
more often than loamy or clay soils.
• Light soils require frequent applications of small amounts of
soluble form of nutrient like nitrogen.
• Vine roots are concentrated under the drip irrigation supply line,
making it convenient to supply fertilizer through the drip water
which is called Fertigation.( Fertilization through Irrigation)
Nitrogen
• Excessive application of Nitrogen (N) in grapes causes excess
vegetative growth. N fertilizers should be apply in 2-3 split doses
to avoid leaching of mineral nitrogen.
• Right choice of a nitrogen fertilizer is particularly important for
drip-irrigated nursery to avoid acidification
• Ammonium Sulphate is the most acidifying nitrogen fertilizer,
followed by urea, ammonium nitrate, di-ammonium phosphate
(DAP) and mono-ammonium phosphate (MAP).
• Calcium Ammonium Nitrate (CAN) and Potassium Nitrate
fertilizers are free from acidity causing effects.
Phosphorus
• Soluble forms of Liquid and solid state phosphorus (P), such as
MAP or phosphoric acid, are applied through drip irrigation and
allow Phosphorus readily available to vines.
Potassium
• Potassium (K) can be applied by broadcasting or banding the
soil surface, in a furrow, or by Fertigation with drip irrigation.
• K based fertilizers commonly used are Potassium Nitrate,
Muriate of Potash (Potassium Chloride) and Sulfate of Potash.
• High levels of Potassium can adversely affect the quality of wine
grape varieties.
Calcium and Sulphur
• Calcium and Sulphur are normally not usually applied but are
supplied indirectly through Gypsum, Lime and Super Phosphate.
• Sulphur is applied to foliage as colloidal sulphur for prevention of
powdery mildew and for mite control.
• Sulphur is also received from use of sulfate of potash, when used
to improve soil potassium levels in some soils.
Magnesium
• Magnesium
fertilizers
include
Epsom
salts
(Magnesium
Sulphate) and Potassium Magnesium Sulphate.
• These fertilizers can be broadcasted or applied through drip
irrigation.
•
Dolomite lime (Calcium Magnesium Carbonate) used for raising
soil pH in highly acidic soil,also contribute magnesium to the soil.
Foliar Application of Nutrients
• Nutrients required can also be applied via foliar sprays. Micronutrients are commonly applied by this method.
• Boron (B) is applied in the form of borax (Solubar or Bortrac).
• Zinc (Zn) is applied in the form of Zinc Sulphate or Zinc Oxide.
• Manganese (Mn) is applied in the form of Manganese Sulphate
with Zinc sprays.
• Mancozeb fungicide will supply Mn as it breaks down, and is
absorbed by the plants.
• Copper-based fungicide sprays will break down and supply Cu to
the plants.
Nutrients through Organic Matter
• Compost is a rich source of organic matter containing almost
all the essential nutrients, can be applied in poly bags for
planting rootstocks.
• The compost should have a carbon to nitrogen ratio of less
than 20:1 to reduce the risk of N draw down.
• Organic mulch is low in Nitrogen, However,
it contains
sufficient amount of Calcium and Potassium that is readily
available to vines in the early growth stages.