The cotton season is in full swing so what nutrients should growers be looking at to maximise boll yield and quality? Well assuming major nutrient (NPK) inputs are adequate, growers should be looking to address any micro nutrient issues via foliar sprays. The most critical trace elements for cotton production that are likely to be low on many soil types are zinc and boron. If you are growing on alkaline soils, then iron, copper and manganese may also need to be addressed.

Zinc is the most limiting trace element in agricultural crops in Australia, and deficiencies are very common, particularly in the early growth period up to flowering. Zinc is essential for the production of the growth hormone auxin, and deficiencies lead to reduced vegetative growth as well as poor flowering and boll set. Boron is critical for flowering due to its role in pollen tube development & auxin regulation. It is also very important for fibre development so is required right through the growing period.

Foliar application of these nutrients is far more efficient than soil application, particularly in alkaline or high pH soils that tend to lock out trace elements & phosphorous. Also foliar sprays like LIG-ZINC + BORON can be easily applied via aeroplane if required. For maximum benefit it is important that zinc & boron are applied prior to flowering and usually first square is the optimal time to apply these nutrients. New products like Zn-COTT also offer the convenience of glyphosate compatibility without impacting weed kill.

In stress situations (eg. waterlogging) or where other trace elements are limiting SJB has a range of chelated foliar products (see below) to aid crop recovery or correct micro nutrient deficiencies. In cold soil conditions where development of young plants is restricted, foliar application of VLP can be used to stimulate crop growth.

Zinc deficiency in cotton – Interveinal chlorosis (yellowing) in the young leaves. Plants or leaves may also be stunted or small.

Products of interest for cotton production.







Slow or waterlogged crops




Check out our Cotton Foliar Program

Foliar nutrient sprays are a very effective tool that broadacre farmers can utilize to enhance grain yield and quality. Trace elements such as zinc, manganese and copper are deficient in many cropping regions, but can be easily and cost effectively corrected using foliar sprays. Numerous independent scientific trials with SJB zinc & manganese chelates have shown 10-40% increases in grain yield on deficient soils & 5-10% increases on soils with adequate trace element levels where crops are showing no visual signs of deficiency. At a cost as little as $4/ha for a zinc spray, even a 1% increase in yield would return a profit to the grower on his investment.

In cereal & legume crops, zinc, copper & manganese (see LIG-MALLEE, LIG-PENINSULA) are common issues, particularly in the high pH & calcareous soil types found in South Australia and the Victorian Mallee. The simple reason for this is that in alkaline soil conditions these trace elements are precipitated (chemically bound) so their solubility and availability to the crop are significantly reduced. All these micro-nutrients play important roles in hormone and sugar production which has a significant impact on reproduction (seed set) while copper deficiency can also lead to lodging and subsequent yield loss.

Another benefit of these nutrients is they promote anti-oxidant production that increases the crop’s natural protection against disease and pest attack. In many cases this can reduce or even eliminate the need for in-crop fungicide & insecticide sprays. Early timing of these nutrients is critical for optimum crop response, so they need to be applied well before anthesis/flowering usually at the 4-6 leaf stage. Later applications of copper & magnesium at booting/flag leaf stage can also be beneficial on deficient soils and should be easily identified with tissue analysis.

For canola & legume crops, boron is a particularly important nutrient for flowering & seed yield. Boron is required for pollen tube development and low boron levels inhibit pollen tube growth thus significantly reducing the likelihood of successful fertilization. Again boron needs to be applied early prior to flowering, however for canola, good results have also been achieved with foliar sprays during the bolting-early flowering period. Foliar boron is a very safe option as there is little chance of inducing toxicity that can be an issue with soil application. Legume crops also respond very well to zinc and manganese sprays, prior to, as well as post-flowering.

Another nutrient that can have a significant impact on yield is magnesium. Deficiencies are usually seen on sandy acid soils but can also be induced by high soil potassium levels or application of ammonium fertilizers. Like zinc/copper/manganese, magnesium also drives sugar/starch production critical for optimum seed set so early application is important, however crops also respond well to foliar magnesium sprays later in the season.

Molybdenum is an important trace element for broadacre production. Moly is essential for germination, anthesis in maize crops, nitrogen fixation in legumes & the conversion of soluble nitrates to amino acids. Cereals with molybdenum deficiency can be significantly stunted and yields reduced by up to 30%. Molybdenum deficiency is common on acid soils & often application of lime can correct the issue. Application of sulphates (eg. gypsum) can also reduce uptake of the molybdate anion due to competition in the root zone. Copper & molybdenum have an antagonistic relationship in the soil (high copper will reduce moly uptake & vice versa). Soil application at seeding is a common practice, however if soil pH is not corrected, availability will be limited. Mo is plant (phloem) mobile so foliar sprays are highly effective with only low rates required to correct a deficiency.

A lesser utilized foliar nutrient is phosphorous. Obviously being a major nutrient it is critical for crop production in both the early and later stages of development. On most soil types phosphorous has low availability (<15%) and therefore growers have traditionally over-applied P fertilizers to compensate for this low efficiency. However we have found that even on soils with good Colwell P levels (eg. >60 ppm), crops will still respond to foliar P sprays even though tissue analysis is indicating “Adequate” P status. Another benefit we have observed is that foliar P sprays encourage root uptake of trace elements which can be clearly seen in tissue analysis following application. In the field we have also noted that this can enhance drought tolerance and increase wheat protein levels.

For stressed crops, complete nutrient options such as VLP & GREENA can aid recovery by supplying essential available nutrients at a time when soil availability & root uptake is restricted.

Also check out this Tech Sheet that discusses the different forms of foliar nutrients available to growers and the advantages of SJB Chelates.

Nutrient seed dressings should be a high priority for broadacre farmers as they are the most efficient and cost effective method of supplying essential trace elements like zinc & manganese to the crop. For less than $1 an acre, growers can treat their seed and expect a minimum 5% increase in grain yields in most seasons where an average crop is harvested. A recent study found that Australian wheat had the lowest zinc levels of all the major wheat producing countries and this has significant implications for both animal and human health. It also means that the seed you are planting is already low in zinc and this has potential to limit early development and yields.

Zinc seed dressings are the most commonly used due to the universal nature of zinc deficiency across most soil types in Australia and the importance of zinc for early crop development. Zinc is required for the synthesis of the growth hormone auxin which promotes root and top development. Seed dressings are also a very efficient way to supply available zinc at this early stage as zinc is immobile in the soil and availability of zinc applied with base or planting fertilizers is often limited due to precipitation in alkaline or high pH soil conditions.

Other nutrients that can aid germination and early development are manganese, copper (at low levels as it can be toxic), molybdenum & phosphorous. In legume and canola crops boron can also enhance early growth & establishment. One advantage is that many of these formulations are compatible with seed pickles (eg. bunticides, smuticides) so a separate dressing operation is usually not required. Some are also possibly compatible with legume innoculants however those containing copper may be toxic to rhizobium so care needs to be taken.

Aside from yield benefits, seed dressings usually have quite positive effects on root development and germination. Farmers often report that treated seed will emerge 2-5 days before untreated, while the image below shows the significant increase in early root development due to nutrient seed treatment (left). Obviously increased root growth is a major advantage for a plant in terms of water and nutrient availability and this tends to reduce plant stress and enhance crop tolerance to disease & pest attack. The independent scientific trials we have commissioned in NSW, VIC, SA & WA have shown grain yield increases of up 18%.

A question we are often asked is, “Do I still need to apply a zinc foliar spray if I use a seed dressing?”. There is no single answer to this question and much will depend on your soil type and yield potential. Generally we find that there is still a yield benefit with foliar sprays on deficient soils like those in SA and the Victorian Mallee and seed quality (eg. protein levels) is also enhanced. In many areas there will be a need to apply a foliar spray of manganese (eg. SA) or copper (WA) anyway as these nutrients cannot be fully supplied as a seed dressing so most growers will also top up with zinc as well. Leaf tests at 3-5 leaf stage should give you a good idea of zinc status and if extra foliar zinc is required.

SJB has several seed dressing products to suit any crop or soil type.


Soil Nutrients – Nitrogen and potassium are the biggest nutrient requirements for almond crops and generally it is recommended that about 1/4 of the total N & K requirements are applied post-harvest, however this should be assessed based on the current season’s crop load. Almonds use these nutrients to supply energy and sugars for flower and early shoot development for the next season. It is critical to ensure soil moisture levels are optimal when N & K are applied (or any soil fertilizer for that matter) otherwise fertilizer efficiency/uptake will be low and there is also potential for root damage in dry soils due to the high salt index.

Phosphorous is essential for reproduction, energy production (eg. ATP) and cell division. While almond trees do not have a large P requirement (30 kg P/ha for maintenance in bearing trees) it is critical during the bud-burst to fruit set period so it needs to be available as soon as roots become active in late winter. If soils are low in sulphur then applying Single Super post-harvest will be beneficial, while more available forms (eg. MAP/DAP/MKP/APP) should all be applied pre-flowering & during early fruit development.

Some growers may also be applying phosphonate (eg. PHOSIC 600) post-harvest to address any phytophthora concerns. While some companies may claim that the phosphorous (eg. phosphite) in their phos acid products is available to the trees as a nutrient source, this is simply not true at least in the short to medium term. Phosphite that remains in the soil will over time (eg. 6-12 months) be converted to the plant available phosphate form, however it should not be relied upon as a P nutrient source for the coming season. Growers should also be aware that the phosphite MRL for almonds going into Europe has been lowered to 2ppm as of Dec 31 2015, so you may need to find an alternative product if your nuts are going to this market.

Post-harvest is also a good time to apply calcium if exchangeable levels are low in the soil or pH needs adjusting. While calcium may be considered a less important nutrient by many, my experience in the field indicates that there is a direct relationship between tissue calcium levels and kernel yield. Calcium is also an important nutrient for reproduction and pollen tube development, so it is essential that tree calcium levels are optimal before they go into dormancy (pre-flowering application of calcium nitrate will also be beneficial).

Zinc and boron are both essential trace elements for almond production and are required for reproduction, shoot development and fruit filling. In seasons where you have average to good yields with good shoot development, demand for boron and zinc will be high so levels in the trees may be depleted and therefore post-harvest application is even more critical in this situation. Boron is quite mobile in lighter soils & so has good availability but can also be lost through leaching if over applied. If soil boron levels are <0.5 mg/kg then look at applying 1-2 kg B/ha. If boron hull levels are also <80 mg/kg consider the higher rate. Unlike boron, zinc is basically immobile in the soil and therefore soil application is less efficient, particularly if soil pH is alkaline. Best zinc availability will be seen on sandy acid soil types where exchangeable zinc is <2 mg/kg. Young trees will usually benefit the most from regular soil zinc application. Look at applying 1-2 kg Zn/ha.

Foliar Nutrients – Post-harvest foliar sprays are essentially aimed at ‘bud building’ for the coming season and nitrogen, zinc and boron are the main nutrients of interest in this regard. Lo bi urea is used in many crops to aid bud development/health and the Almond Board recommends applying a 1% solution (eg. 1 kg urea/100L) in late April and early May. Numerous studies in almonds indicate a consistent benefit from post-harvest foliar boron sprays in terms of improved fruit set and nut retention in the following season (250-500 g B/1000L). Given the high boron requirement for almond production, I would still recommend both soil and foliar application, particularly on low boron soils. Like boron, foliar zinc has also shown to be beneficial for bud development and fruit set, mainly due to its role in auxin production (an essential plant growth hormone).

While there are various factors that determine potential fruit set, nutrition is one that (unlike the weather) can be controlled & manipulated by growers to ensure their trees have the best chance of setting an optimal crop.

Defoliation – There has been some discussion on the best option for defoliation of trees prior to dormancy. Traditionally, high or phytotoxic rates of zinc sulphate have been used and it was thought this would provide some zinc to enhance bud development for the coming season. The other alternative is to use high buiret urea (eg. 70 kg/1000L) to defoliate. In terms of foliar absorption, nitrogen is absorbed much faster (hours) than zinc (2-5 days) which only has limited plant mobility. Also the condition or health of leaves has a major effect on foliar uptake and at this time of the season the condition of leaves is usually not that suitable for foliar uptake anyhow. So the reality is that zinc sulphate will probably not supply any available zinc for the coming season, whereas urea is more likely to supply some nitrogen for bud development.

SJB Soil Applied Nutrients

Boron PLEX

Calcium + Boron PLEX


SJB Foliar Applied Nutrients for Bud-building





Systemic Fungicide for Phytophthora Control

PHOSIC 600 (can be applied to the soil or as a foliar spray)

Calcium is an essential nutrient for crop quality & requires a holistic management strategy to achieve optimum fruit calcium levels & quality.

Read more

Zinc is the most common trace element deficiency in Australian crops & addressing it early in the season is essential for optimum crop growth & quality.

Read more

Nutrition plays an essential role in flowering, however application timing is critical to ensure crop nutrient levels are optimal for reproduction. Nutrition can also have a major impact on plant health, yield & seed quality of beans, peas, lentils & lupins. Key nutrients for pulses include, calcium, sulphur, boron, zinc, manganese, copper & molybdenum.

Early in the season, sulphur, copper, iron & molybdenum are essential for nodulation/nitrogen fixation & so early development can be inhibited if these nutrients are deficient. Other important nutrients for vegetative growth are zinc and manganese. All these need to be addressed well before flowering otherwise crop yields will be significantly reduced. With wet conditions in many growing areas this season, soil availability of sulphur, zinc and iron may be reduced, so crops should respond well to early foliar sprays of these nutrients. A major advantage of SJB Chelates is that every product contains available sulphur (1-4%) which plays a major role in growth, yield & quality of pulse crops.

For flowering & pod set, plants need optimal levels of calcium, boron and zinc. Boron is phloem mobile in most pulse crops so foliar sprays can be effective from early development through to flowering as it can be mobilised within the plant and translocated to reproductive organs. Calcium and zinc are immobile and therefore timing is more critical. Foliar calcium is most effective when applied to buds and flowers as it can be readily absorbed and utilized. Zinc is required early, however on deficient soils (eg. alkaline calcareous clays) pulse crops will usually benefit from multiple applications so a second spray should be applied just prior to flowering.

Pulse crops are also very responsive to manganese & deficiencies cause major quality issues in lupin (split seed). If you are on alkaline soils, include manganese with your early & later zinc sprays (1:1 Zn/Mn ratio will achieve the best results).

An area of nutrition that is less known about & utilised is the application of calcium & trace elements for disease resistance. In wet or humid conditions crops can be quite susceptible to fungal diseases (eg. chocolate spot in beans) & optimal levels of calcium, boron & copper increase structural integrity while copper, zinc & manganese promote the synthesis of antioxidants & phytoalexins that fight disease organisms. Including a multi-trace spray such as LIG-TRACE with your post emergent protectants (eg. mancozeb) can greatly enhance disease tolerance. The excellent binding & wetting properties of SJB Chelates also enhance fungicide efficacy. In some cases, our clients have simply replaced their fungicides with trace sprays as they find the nutrients more effective!

If you are looking for a spray additive to promote flowering, reduce stress, aid crop recovery & enhance cover spray efficacy then our newly released product – GREENA – featuring Awaken & NutriSync D technology is a great all-round solution. At 2-3 L/ha it is also a very cost competitive option for growers.

Foliar nutrient options for Pulse crops



Zinc options – LIG-ZINC + BORON & LIG-ZINC + Mn @ 1-2 L/ha.

Also speak to us about our new zinc, boron, moly product – LIG-ZBM @ 2 L/ha.

Bud development to flowering

Calcium & boron options – LIG-CALCIUM + BORON @ 2 L/ha, PASTURE CAL @ 2-3 L/ha, LIGNO-BORON @ 1 L/ha.

Talk to us about new LIG-CBM (Ca 8%, B 1%, Mo 0.25%).

Enhance Disease Tolerance


Reduce Crop Stress, Increase Spray Efficacy, Improve Nutrient Utilization

GREENA @ 2-3 L/ha

With optimal growing conditions in 2016, vegetative growth & yield potential of wheat crops is high and with this comes the risk of significant yield losses due to lodging later in the season. Lodging is the result of poor structural integrity (strength) of stems usually caused by excessive vegetative growth (ie. optimal soil moisture & high nitrogen availability) in high yielding crops where stems are not able to support the weight of the dense canopy & loaded heads. Late season rain and wind also compound this issue.

Nutrition does play an important role in the severity of lodging losses and there are a number of key nutrients that need to be managed well to avoid significant yield losses. Nitrogen of course is the highest input nutrient for cereal production and has a significant effect on vegetative growth and grain protein. The key for nitrogen is not to put too much on too early but try and split applications if possible to reduce excessive vigour during stem elongation. Applying early molybdenum sprays on susceptible soils (eg. strongly acid) will help nitrogen (nitrate) conversion & reduce excessive vigour & weak stems.

Optimising levels of key essential nutrients that play important roles in structural integrity is also critical for reducing lodging losses. The three major ones are calcium, copper and boron. Calcium is an essential component of all cell walls and vital for building strong plants. While calcium demand is lower for cereals compared to canola and pulses, it is still required is reasonable amounts (>5000 mg/kg DM). Furthermore, high nitrogen combined with excessive vegetative growth increases calcium demand often leading to a dilution of cellular calcium thus making crops more prone to structural weakness & disease issues. In-crop foliar sprays can be helpful, however the bulk of the calcium supply comes from the soil and this really needs to be addressed pre-sowing as post-emergent soil application is usually too slow to be of major benefit.

Copper deficiency is common in cereals grown on a wide variety of soil types throughout Australia. Alkaline soils or those high in organic matter, lock up copper making it unavailable to the crop. Crops grown on many of the heavily leached acid sands in Western Australia also have significant copper deficiency issues due to the very low levels of residual copper. Copper is required for the lignification of stems and deficiencies greatly reduce the crop’s physical strength & ability to resist disease attack. Nutrient balance is important here as high nitrates reduce copper uptake while also increasing copper demand for vegetative development. Copper is also essential for anthesis & seed set so if you are on low copper soils you should be applying at least one early foliar spray (4 leaf) as standard practice & possibly another at booting if yield potential is high.

Boron like calcium is a key component of cell walls, hence its importance for plant structure. Some of you may be a bit wary about applying boron on wheat as usually it is associated with toxicities rather than deficiencies in cereals. However if tissue levels are low (< 4 mg/kg) there can be positive responses to foliar boron application in terms of reduced lodging and improved anthesis. Boron also facilitates calcium uptake so provides additional benefits with regard to plant health and strength.

Looking at overall nutrient balance, growers should also keep an eye on potassium and magnesium levels in relation to nitrogen. These nutrients are important for sugar and carbohydrate production and help balance the detrimental effect of excessive nitrogen on crop health and development.

Foliar nutrient options for Wheat

4-5 leaf – LIG-GRAIN PLUS (Zn, Cu, B, Mo) @ 2 L/ha, LIG-ZINC + Cu @ 1 L/ha, LIG-COPPER @ 1 L/ha, Pasture Cal @ 2-3 L/ha.

Looking for a calcium, boron & moly product? Talk to us about LIG-CBM (Ca 8%, B 1%, Mo 0.25%).

Booting/pre-anthesis – LIG-COPPER @ 1 L/ha.

Many growers will have experienced issues with poor flowering or pod set in their canola crops but may not know the reasons behind this. Seasonal factors outside the grower’s control such as soil moisture, rainfall, temperature & frosts can all influence flowering, however nutrition also plays an essential role in crop reproduction & importantly it is something growers can manipulate.

Nutrients including nitrogen, calcium, boron, zinc, copper & molybdenum are all required for optimal reproduction, seed set & pod retention. Nutrient balance is also critical here as high nitrogen (eg. nitrates) will impair fertilization as well as reducing uptake and/or increasing demand of these other critical nutrients.

Calcium is required by all crops for flowering due to its major function in cell wall structure & integrity (structural or physical integrity of reproductive organs is a key element to successful fertilization – see boron & copper). Calcium, being a major nutrient, needs to be addressed primarily pre-sowing either as lime or gypsum application. Calcium however is very immobile so soil availability may be limited & deficiencies may still arise even though exchangeable levels are “adequate”. Many ‘experts’ advise not applying calcium as a foliar spray because it is immobile. Indeed it is (it doesn’t translocate or move around the plant) however it is readily absorbed by leaves, stems, buds and flowers. It is common practice in many horticultural crops to apply bud or flowering sprays containing calcium, boron & zinc to enhance flowering and fruit set. So timing is critical here but foliar calcium will definitely help set if buds & flowers can be targeted (you don’t need high rates either). With excellent growing conditions this season calcium demand for new growth will be high, so supplementing soil calcium with strategic foliar sprays should pay dividends with increased pod retention & yields.

Being a brassica, canola has a very high boron requirement. Like calcium, boron is a structural component of cell walls and therefore deficiencies cause cell breakdown, or specifically in canola, impaired growth of pollen tubes. Boron is also a regulator of auxins, a plant hormone required for optimal flowering. Unlike calcium however, boron is a trace element and also plant mobile in canola, therefore deficiencies can be corrected solely through foliar application if required. Due to its mobility, the window for boron application is a bit wider than calcium, but generally you want to apply it prior to flowering (5-8 leaf) or during bud development or the early bolting stage. When applying boron to the leaves uptake is slow because the cuticle has a negative charge that repels anions (eg. borates, molybdates, phosphates). SJB boron products employ a unique complex formulation to give boron a neutral charge so it moves into the plant more readily than boron salts.

Zinc is essential for the synthesis of auxin, an important plant growth hormone involved in reproduction. Zinc deficient plants will also be stunted and therefore their production of carbohydrates is reduced and unable to meet the high energy requirements needed during flowering & pod set. Zinc is immobile in the soil and only has limited mobility in the plant, so multiple applications may be beneficial in very deficient situations, however canola appears to be reasonably efficient at accessing soil zinc so a single early spray (4-5 leaf) is usually sufficient.

Like calcium & boron, copper is also important for structural integrity due to its role in lignification. Poor lignification means that pollen tubes don’t develop normally, thus fertilization is compromised. Copper is also essential for photosynthesis (starch production) and deficiencies during flowering result in an energy deficit that reduces seed set. High soil nitrate levels increase vegetative growth & copper requirements, so with good moisture and optimal growing conditions this season, potential for deficiencies is high on susceptible soil types. Like zinc, copper is basically immobile so an early application (4-6 leaf) is important to optimise photosynthetic activity prior to flowering.

Molybdenum (Mo) is an important trace element for brassica crops, and the requirement for canola is five times that of wheat. Moly is required for nitrogen utilization by the crop as it produces an enzyme that converts nitrates into amino acids. We have already discussed the potential problems that high plant nitrate levels can cause regarding reproduction and Mo deficiency only compounds this. High nitrates will also affect the hormone balance within the plant so it is likely to remain in the vegetative mode for longer which compromises the reproductive phase of development. Moly deficiencies are most common on acidic soils & may be corrected simply through lime application. Foliar sprays are very effective as Mo is plant mobile and can move to areas of greatest demand. Sprays should be effective from early emergence right through to flowering.

Foliar nutrient options for Canola:

4-8 leaf – LIG-GRAIN PLUS (Zn, Cu, B, Mo) @ 2 L/ha, LIG-ZINC + BORON @ 1 L/ha.

Bud development to flowering – LIG-CALCIUM + BORON @ 2 L/ha, LIGNO-BORON + MOLY @ 1-2 L/ha.

Before your vines shut down for a well deserved winter break, some strategic nutrient applications can help set the vines up for the critical bud burst to flowering period.

While nitrogen is often associated with excessive vigour and poor fruit quality, it is nonetheless an essential major nutrient and post harvest is often the optimum time for nitrogen application in most varieties. You can usually apply 50-75% of the vines total N requirements post-harvest and the remainder around bud burst. On alkaline soils, ammonium (NH4) forms (eg. ammonium sulphate & NOT urea) are preferred because of their acidifying effect that is often beneficial for the release of locked up nutrients. Nitrates (NO3) are less acidifying but also very mobile and readily leached on lighter soil types.

Phosphorous is an essential nutrient for energy production and cell division, however it generally has low mobility and availability on most soil types, so it needs to be applied and taken up by the vine well before it is needed. Again post-harvest is an excellent time to apply phosphorous because it does give the vine feeder roots an opportunity to take up P prior to dormancy. Generally P sources like MAP/DAP/APP are more soluble than Single Super which tends to release P more slowly over a longer period. If your soil is low in sulphur and you are not applying ammonium sulphate or gypsum post-harvest then Single Super is a good option. Additional P (eg. MAP) can be applied at bud burst if required. A maintenance rate of 20 kg P/ha should suffice for most varieties, though if soil P levels are low (< 50 mg/kg Colwell) then you should double the maintenance rate.

If you are growing on sandy soils low in potassium or have had heavy yields then consider post-harvest application of potassium. An NPK mix like CR NPKomplete is ideal in this situation and can also supply maintenance levels of nitrogen and phosphorous.

Zinc is the most limiting trace element in Australia and very important for vine production. Zinc is required for the production of the growth hormone auxin that promotes shoot growth and enhanced flowering and fruit set. Zinc deficiency is commonly called “Little leaf” disease as it results in stunted growth (rosetting) and small leaves (see below). Because of the role of auxin in reproduction, low zinc can also cause uneven fruit set or ‘hen & chicken’ bunches. While soil application of zinc can be effective on some soil types, foliar zinc sprays are the most cost effective and efficient way to address deficiency issues. Zinc is required very early for shoot growth so post-harvest sprays allow zinc to be stored in the vine and utilized from bud burst onwards and vines can be topped up once shoot growth is sufficient for foliar absorption.

Like zinc, boron plays an important role in reproduction and good levels are required for optimum flowering and preventing ‘hen & chicken’. Boron is also required for root health and function so good levels in the vine will ensure optimal moisture and nutrient uptake post-harvest and when roots become active again prior to bud burst.

Post-harvest is also a good time to apply lime or gypsum if required. Remember that these products work fairly slowly (liquid or burnt limes will react quicker than normal ag lime) so if your soils are low in calcium and/or magnesium then look at applying more soluble sources (eg. calcium nitrate, magnesium sulphate) in the spring to supplement the slower release of lime/gypsum.

Zinc deficient vine leaves (below).


Fertigation Products

CR NPKomplete (10-4-8, Mg 1% + trace elements)



Foliar Sprays



LIG-ZINC + Mn (5+5)

LIG-TRACE (Zn, Mn, Fe, Cu, B, Mo, Mg)

VLP (10-2-7, Mg 0.5% + trace elements)