Foliar Nutrition in Macadamia Tree Nut ProductionFoliar Nutrition in Macadamia Tree Nut ProductionFoliar Nutrition in Macadamia Tree Nut ProductionFoliar Nutrition in Macadamia Tree Nut Production

International International International International Macadamia Symposium Macadamia Symposium Macadamia Symposium Macadamia Symposium ---- Brisbane Brisbane Brisbane Brisbane September September September September 2012201220122012

Dr. Deepak Dr. Deepak Dr. Deepak Dr. Deepak MathurMathurMathurMathur, Ph.D., Ph.D., Ph.D., Ph.D.Director: Technical Services, Director: Technical Services, Director: Technical Services, Director: Technical Services, AgrichemAgrichemAgrichemAgrichem

4 Hovey Road, 4 Hovey Road, 4 Hovey Road, 4 Hovey Road, YatalaYatalaYatalaYatala, , , , QldQldQldQld 4207, Australia 4207, Australia 4207, Australia 4207, Australia

� Production constraints

� Limiting Nutrient

� General aspects of foliar nutrition

1. Stomatal role

2. Pathways

3. Dynamics & Efficiency

4. Stage specific nutrition

� Foliar nutrition in Macadamia

Global Constraints: Agricultural Production Systems

•Limited irrigation water supplies•Nutrient use efficiency•Diminishing Micronutrient pool•Rising salinity•Problem soils•Water Quality issues•Environmental issues•Global food shortage

FAO: WE MUST DOUBLE FOOD PRODUCTION BY 2030

• Justus von Liebig

•His laws reformed agriculture

“Whichever nutrient is in the

least amount relative to the

required amount, will determine

the yield of a plant”

� Foliar feedingFoliar feedingFoliar feedingFoliar feeding is a technique of feeding plants by applying liquid fertilizer directly to their leaves. Nutrients are absorbed through the leaf cuticle.

� The cuticle is the outermost layer of the leaf that consists of epicuticular wax and is negatively charged due to the presence of polygalactouronic acid

� Improves Yield

� Restores tree health

� Improves canopy growth after pruning

� Foliar-applied calcium, boron, copper, and zinc, used alone or in combination, have been shown to enhance acclimation or repair of stress-injured tissues.

� Further understanding of the oxidative stress may offer new approaches for the use of foliar-applied nutrients on perennial fruit plants

� Foliar applied nutrients create a negative osmotic pressure within the leaf tissues that triggers roots to absorb more water from soil. As a result the roots also absorb soil applied nutrients that moves en masse with water. Hence foliar nutrition also improves the efficacy of soil applied nutrientsimproves the efficacy of soil applied nutrientsimproves the efficacy of soil applied nutrientsimproves the efficacy of soil applied nutrients.

� Maximum impact of foliar sprays can be seen under:

Adverse Soil Conditions

Low Nutrient Availability in soil through adverse interactions such as calcium and phosphorus

� Stomata, the tiny leaf openings on the upper and lower surfaces of the leaf, do not play any significant role in the absorption of foliar nutrients

� The mechanical force of pushing water vapor out through the process of transpiration restricts the entry of nutrients through stomata

� The night time foliar nutrient uptake exceeds the day time absorption through leaves as demonstrated by radio isotope studies

� Plants are also able to absorb nutrients through their bark and bark does not contain stomata.

� Foliar nutrition application goal:Foliar nutrition application goal:Foliar nutrition application goal:Foliar nutrition application goal:

◦ Increase duration of leaf wetness to increase availability of elementsIncrease duration of leaf wetness to increase availability of elementsIncrease duration of leaf wetness to increase availability of elementsIncrease duration of leaf wetness to increase availability of elements

◦ Increase Increase Increase Increase cationcationcationcation movement through leaf cuticlemovement through leaf cuticlemovement through leaf cuticlemovement through leaf cuticle

Without Surfactant With Surfactant

Mn Mn Mn Mn Mn Mn Mn Mn Mn

Increased Wetness

Increased

Increased

Increased

Increased

Catio

nCatio

nCatio

nCatio

nMovement

Movement

Movement

Movement

Coverage,

Deposition,

Wetting

Coverage,

Deposition,

Wetting

Cuticle &

Stomates

Cuticle &

Stomates

Limits at

the

Membrane

Limits at

the

Membrane

Cell to Cell

Movement

Cell to Cell

Movement

Movement

in

Conducting

Tissues

Movement

in

Conducting

Tissues

� E= Stage x Time x Combination x RatesE= Stage x Time x Combination x RatesE= Stage x Time x Combination x RatesE= Stage x Time x Combination x Rates

Where, E is the efficacy of spray productWhere, E is the efficacy of spray productWhere, E is the efficacy of spray productWhere, E is the efficacy of spray productS is the crop stageS is the crop stageS is the crop stageS is the crop stageT is the time of the dayT is the time of the dayT is the time of the dayT is the time of the dayC is compatibility of nutrientsC is compatibility of nutrientsC is compatibility of nutrientsC is compatibility of nutrientsR is the rate of applicationR is the rate of applicationR is the rate of applicationR is the rate of application

� Droplet size and distributionDroplet size and distributionDroplet size and distributionDroplet size and distribution� Surfactants useSurfactants useSurfactants useSurfactants use

Maximum impactMaximum impactMaximum impactMaximum impact� Nutrient is deficientNutrient is deficientNutrient is deficientNutrient is deficient� Low soil temperatureLow soil temperatureLow soil temperatureLow soil temperature� Decreased root activity Decreased root activity Decreased root activity Decreased root activity

Caution: Do not spray a water stressed cropCaution: Do not spray a water stressed cropCaution: Do not spray a water stressed cropCaution: Do not spray a water stressed crop

� Spring Flush Tissue test and then apply NPK+ TE product (Fe)

� 3 weeks Pre-Flowering: N, B, Ca, Mg, Zn� No Foliar Sprays at Flowering: Flower dropTissue test recommended: Post flowering

� Nut set- Ca, B, Zn, Mg+ High auxin/cyt kelp� Early Nut fill- K, B, Mg, Fe� Late nut fill- K, Mg, CaTissue test after 85-90% pick

� Post harvest- N, Ca, Mg, B, K, Fe� Foliar compliments soil applied ferts.

4Kg±0.06/tree 5.5Kg±0.07/tree

VARIETY 816 VARIETY 741 OptimumTissue test Control Foliar Treated Control Foliar Treated Reference

N % Kjel 1.2 1.7 1.1 1.5 1.4-1.7

P % 0.10 0.15 0.11 0.13 0.07-0.1

K % 0.68 0.79 0.70 0.73 0.4-0.8

S % 0.16 0.18 0.12 0.16 0.15-0.25

Ca % 0.3 0.36 0.44 0.49 0.6-0.9

Mg % 0.09 0.09 0.13 0.12 0.08-0.12

Zn ppm 8 13 10 18 6.0-50.0

Fe 11 33 20 29 30-200

Mn 40 52 70 89 47-1850

Cu 3.1 4.2 3 3.5 4.5-20

B 18 28 17 25 40-80

Thank you, Question time!