Introduction to the Problem

Anthracnose is one of the most damaging diseases of olive fruit, caused by several Colletotrichum fungi. In Australia and worldwide, this disease leads to fruit rot, premature fruit drop, and a severe decline in yield and olive oil quality. It tends to strike as olives ripen, posing a serious threat to production – infected olives often fall before harvest and yield only turbid, highly acidic oil of poor quality. Anthracnose is especially problematic in humid olive-growing regions; in Australian groves of susceptible cultivars like Barnea, Manzanillo, or Kalamata, up to 80% of the fruit can be affected in a bad season. The fungus can persist from season to season on plant material, so without proactive management, the disease pressure builds over time. Urgent pre-harvest action is critical, as waiting until symptoms explode at harvest is often too late to save the crop.

Symptoms and Disease Progression 

Olive fruit with anthracnose showing a soft, circular shoulder lesion oozing orange-pink spore masses. As olives approach maturity, anthracnose infection becomes visible as soft, sunken brown rot spots on the fruit (often near the shoulder). Under high humidity, these fruit lesions exude telltale gelatinous, orange or salmon-pink masses of spores on the surface. Affected olives start to look water-soaked or greasy – a symptom sometimes called “soapy olive” due to the slimy appearance. In the early stages, the rot may be localised, but it rapidly expands, causing the olive to collapse into a soft mush. Infections can develop and produce new spore masses very quickly (within about 4 days on a ripe fruit in moist conditions), meaning a small outbreak can turn into a major fruit rot epidemic in under a week if the weather is conducive.

Advanced anthracnose on olives – the fruit has shrivelled, browned, and begun to mummify on the tree. As the disease progresses, many infected olives shrivel, turn brown or black, and dry up. These mummified fruit often remain clinging to twigs or fall to the ground. Clusters of olives on a branch may all become infected, creating a concentration of spore-producing mummies (as shown in the image). Such dried, mummified fruit is a hallmark of late-stage anthracnose and serves as a reservoir of the fungus. In severe cases, you may find twig dieback associated with heavy fruit infection – the fungus can invade pedicels and stems, causing leaves on that shoot to wilt and die. Anthracnose can also occasionally infect flowers in spring (blossom blight), causing brown, withered blooms that drop off, though early symptoms often go unnoticed. Generally, olives show no external sign of infection until they begin to ripen, at which point lesions erupt and spore masses spread to neighbouring fruit in the canopy. 

Olive branch with multiple anthracnose-infected fruit. Many olives exhibit dark, sunken lesions and fungal spore masses, and some have dried into mummies. Without intervention, an anthracnose outbreak can escalate rapidly as harvest time nears. Infected olives may drop to the ground in large numbers, resulting in direct yield loss. Those that remain on the tree are often unusable – when pressed, they yield oil with elevated free fatty acids and unpleasant flavours, unsuitable for extra virgin grade. The disease cycle can carry over into the next season via the persistent mummified fruit and any infected twigs left on the tree, so the severity may increase each year if not managed. Thus, recognising anthracnose symptoms early (and implementing controls) is vital to preventing extensive crop and quality losses. 

Biology and Infection Cycle of Colletotrichum in Australia 

Anthracnose in olives is caused by a complex of fungi in the genus Colletotrichum. Traditionally, C. acutatum and C. gloeosporioides were identified as the culprits, but taxonomists have since split these groups into multiple species. In Australia, at least three Colletotrichum species are known to cause olive anthracnose (C. acutatum, C. gloeosporioides, and C. simmondsii), with additional species reported overseas. All produce a similar syndrome on olives. The pathogen’s life cycle allows it to survive between seasons and infect the host at multiple points: - Overwintering: The fungus persists on infected plant debris, especially mummified olives that remain on the tree or ground, and can also survive in infected twigs or leaves. These serve as the primary inoculum sources in the new season. The fungi form masses of conidia (spores) on these residues, which are spread by winter and spring rains. (Insects and birds can also passively transfer some spores on their bodies, though rain-splash is the main dispersal mechanism.)

• Primary infection in Spring: During spring, when olive trees flower and set fruit, the anthracnose spores germinate and infect flowers, young fruit, and sometimes leaves. Prolonged wetness is required – at least 24–48 hours of moisture on the tissues – and moderate warmth (10–25 °C, with an optimum around 17–20 °C) for infections to occur. If wet, humid weather coincides with bloom or fruit set, the fungus can invade these tissues. Notably, infections at this early stage remain latent: the fungus may colonise the surface or tissue of the olive without immediate symptoms. The young fruit typically continues to develop normally over summer, harbouring quiescent infections. (Latent infection is why anthracnose is considered a “stealth” or latent disease – the damage often isn’t apparent until much later .) Leaves or shoots that become infected in spring may show some lesions or dieback, which can further harbour the pathogen. 
• Secondary infection cycles: As autumn arrives and fruits begin to ripen, the latent infections activate. If rain or heavy dew events occur in the ripening period, those initially infected olives swiftly develop the characteristic rot and spore masses. The now-symptomatic fruit becomes a new spore source, releasing millions of conidia that rain-splash onto other olives, causing secondary infections on any remaining healthy fruit. Warm, wet weather during the harvest period greatly accelerates this cycle – new infections can produce a new generation of spores in just a few days under ideal conditions. This can lead to an exponential spread in the canopy just when the fruit is nearing maturity.
• Cycle continuation: After harvest, any infected fruit left behind will mummify and retain the fungus. These mummies (along with infected twigs or leaves) carry the pathogen through winter. The following spring, they kickstart the cycle again by releasing spores with the rains. The disease may thus build up each year if infected material isn’t removed, especially in climates where frequent spring/ autumn rains provide regular infection opportunities. 
  

Impacts on Oil Quality and Yield

Anthracnose directly reduces olive yields and can essentially ruin the crop’s marketable value. Infected flowers may lead to blossom drop or poor fruit set, and later infection causes fruit rot and drop before harvest. It’s not uncommon for heavily infected trees to lose a large portion of their olives to the ground before picking. Those fruits that remain on the tree are often badly rotted or desiccated and contribute little to the yield. Australian growers have reported crop losses ranging from 10–50% in moderate outbreaks to nearly total loss in extreme cases on very susceptible cultivars.

Quality degradation is a major concern even for the portion of the crop that can be harvested. Oil produced from anthracnose-infected olives is of much lower quality than oil from healthy fruit. The rotting process raises the free fatty acid levels and peroxides in the fruit, resulting in rancid or “fusty” off-flavours and high acidity in the oil. Even a relatively small percentage of diseased olives in a press batch can downgrade the entire lot of oil. For example, field observations suggest that if around 15–20% of the olives going into the mill are anthracnose-infected, the oil will likely fail to meet Extra Virgin standards. In practice, oils from anthracnose-affected fruit are often only suitable for lampante (non-food) oil due to excess acidity and defects. Aside from acidity and flavour issues, the pigments from the fungal decay can give the oil an abnormal dark, cloudy appearance (sometimes described as a reddish or brownish turbid oil). This makes anthracnose not only a yield robber but also a threat to achieving quality premiums — growers may end up with substantially reduced income even from the portion of the crop that is salvaged.

Additionally, severe anthracnose can cause longer-term impacts on the olive trees themselves. Heavy defoliation or twig dieback from infection can weaken trees and reduce the following year’s flowering wood. Repeated epidemics in successive years, therefore, can have a cumulative debilitating effect on orchard productivity. For all these reasons, anthracnose is considered a critical disease to manage for both yield and quality – preventing the disease is far more effective than trying to salvage a heavily infected crop at the last minute.

Conditions that Favour Disease Spread 

Anthracnose thrives under specific environmental conditions that are unfortunately common in parts of Australia. The fungus requires moisture and warmth to infect and spread. Extended periods of leaf wetness (from rain, heavy fog/mist, or even over-irrigation) are the single biggest factor driving outbreaks. Spores germinate and penetrate olive tissues only when free water is present for many hours. Thus, a prolonged autumn rain or back-to-back days of drizzle and dew can trigger a wave of new infections just as fruit is ripening. The disease is favoured by high humidity and rainy weather at temperatures around 10–25 °C. The optimal temperature for anthracnose development is about ~18 °C (typical of mild humid spring or autumn days), but infection can occur over a broad cool–warm range as long as moisture is available. Hot, dry conditions, on the other hand, tend to suppress the disease, which is why anthracnose is seldom a problem in arid inland groves or during drought years.

Climatically, anthracnose is most severe in regions with summer or early autumn rainfall patterns. In Australia, groves in parts of Queensland and New South Wales (where warm-season rains and humid late summers are common) experience much higher anthracnose pressure than those in Mediterranean-type climates (e.g. South Australia or Western Australia’s olive regions with dry summers). A sudden unseasonal rain spell before harvest in an otherwise dry area, however, can still cause localised outbreaks, so no region is completely immune if the weather turns wet at the wrong time. 

Within the grove, microclimate and cultural conditions also influence disease spread: - Canopy Density and Airflow: Trees that are densely foliated or closely planted retain more moisture in the canopy after rain. Poor air circulation means fruit and leaves stay wet longer, greatly increasing infection risk. It’s been observed that high-density and super-high-density plantings can see faster anthracnose development compared to widely spaced trees. Similarly, unpruned trees with dense interiors create a humid microclimate ideal for the fungus.

• Overhead Irrigation and Drainage: Overhead sprinkler irrigation or lack of drainage can simulate the prolonged wetness that anthracnose loves. Continual wetting of foliage/fruit (or waterlogging, which increases humidity) will favour the disease. Growers in anthracnose-prone areas should avoid excessive overhead watering, especially as fruit nears maturity. 
•  Inoculum Levels: If the grove had a history of anthracnose and many mummified fruits remain, even a short wet period can lead to a quick flare-up because there are abundant spores ready to go. Conversely, a grove that’s never had anthracnose might withstand a brief rain with minimal infection (due to lack of spores present). Unfortunately, once anthracnose establishes, spore inoculum tends to accumulate year over year if not aggressively managed. This is why the disease can seem minor initially, then “explode” after a couple of conducive seasons.
  
• Cultivar Susceptibility: As noted, certain olive varieties are more prone to infection. Having a block of a very susceptible cultivar increases the likelihood of disease spread (and even nearby less-susceptible trees can receive a high spore load from those infection centres). For instance, if Barnea trees (highly susceptible) are mixed in an orchard, they can act as a nucleus for anthracnose in a wet year, spreading spores to neighbouring rows. 

Integrated Management Strategies 

Managing olive anthracnose in Australia requires an integrated approach, combining cultural practices, careful monitoring, and strategic use of fungicides. The goal is to prevent or greatly reduce infections before they take hold, because once the fruit is rotting, options are limited. Below are key strategies: 

Cultural Controls (Orchard Hygiene & Canopy Management): 

The foundation of anthracnose management is reducing the sources of the fungus and making the canopy less hospitable to it. A top priority is orchard sanitation: - Remove and destroy mummified fruit – After harvest (and even during the season), growers should remove any dried, blackened “mummy” olives that remain on the trees. These mummies are loaded with spores and will rain down infection in the next wet spell. Table olive growers often hand-pick remaining fruit; oil olive growers may need to strip or knock off leftover fruit and rake up fallen ones. Completely removing them from the grove or deep-burying them helps break the cycle. It’s laborious, but it can significantly cut back spring spore inoculum. 

• Prune for an open canopy – Regular pruning to increase air flow and sunlight penetration into trees is critical. An open canopy dries faster after rain, reducing the wetness duration that the fungus needs. Pruning also lets fungicide sprays penetrate more effectively. Remove dense interior shoots and any dead or diseased twigs (those with dieback or remaining fruit stems from infected olives) and destroy that pruned material off-site. Pruning is best done during the dry season or winter dormancy; avoid pruning in wet conditions to prevent spreading spores on tools (disinfect pruning equipment if anthracnose is present). Proper canopy management not only helps with anthracnose but also improves overall tree health and productivity.
  
• Avoid highly susceptible cultivars in high-risk areas – Where possible, choose olive varieties that are less prone to anthracnose if you are planting in a humid or summer-wet region. For example, Barnea has shown extreme susceptibility in Australia, so it may be wise to avoid planting Barnea in anthracnose-prone climates. If you already have susceptible varieties, be extra vigilant with those blocks – they might need more intensive monitoring and fungicide protection. In contrast, more tolerant varieties (like Picual or Frantoio) can be planted in higher-pressure areas with a lower risk of severe loss (though not zero). 
  
• General grove hygiene – Clean up leaf litter and dead wood, as these can harbour other pathogens that might complicate disease management. While Colletotrichum primarily overwinters in fruit mummies, a healthy, well-maintained grove will better resist all diseases. Also, sanitise picking bins and equipment that might carry spore-laden pulp or debris from an infected grove to a clean one. It’s rare but possible to transfer anthracnose via contaminated equipment or clothing, especially when handling squashed infected fruit, so if moving between groves, basic sanitation can’t hurt. 
  

• Regular monitoring is vital to time interventions and assess effectiveness: - Inspect trees at key times – From spring through harvest, growers should routinely scout the orchard. In spring, check for any blossom blight or early fruitlet rot (though uncommon, flag it if seen). More critically, as fruit begins to ripen (colour change), inspect a sample of olives closely each week for any tiny brown sunken spots or signs of orange spore ooze. Early detection of a few infected fruit can warn you that anthracnose is active, giving a chance to act (for instance, applying a fungicide before it explodes). Look especially in the denser parts of trees and lower branches, where humidity is higher.
• Weather monitoring – Pay close attention to weather forecasts, especially in the lead-up to harvest. If a significant rainfall event or period of high humidity is predicted when olives are near ripe, consider protective measures (like a preventative spray) ahead of that weather. Some growers use disease forecasting models based on temperature and leaf wetness duration – while formal models for olive anthracnose are still under development, a practical approach is to note when conditions (e.g. two days of rain with mild temperatures) could trigger infections and treat proactively. 
  
• Spore trapping or lab testing – In research settings, spore traps or monitoring kits can detect Colletotrichum spores in the orchard air. While not commonly used by growers, knowing spore presence could theoretically guide sprays. More pragmatically, growers can send suspicious fruit samples to a lab (or DPI pathologist) for confirmation if unsure whether a fruit rot is anthracnose or something else. But typically, the field signs (orange-pink spore masses on rotting fruit) are distinctive enough for on-site diagnosis.
  
• Record and learn – Document which blocks or varieties get anthracnose and under what conditions. Often, the disease will start in one part of a grove (for example, a low-lying section that stays damp or a block of a vulnerable cultivar). Identifying these hotspots allows targeted management – you might spray those sections first or more frequently, or harvest those blocks early to minimise exposure.
  

Chemical intervention is an important tool, used in conjunction with the above cultural practices and guided by monitoring. Fungicides are most effective when applied preventatively or at the very earliest stage of infection, rather than trying to “cure” heavily diseased fruit. In Australia, there are a few fungicide options available (see next section for specific products). Spray timing and coverage are critical: - Protective sprays around flowering and fruit set: Research and expert recommendations indicate that the pre-flowering through early fruit set period is a critical infection window for anthracnose. Even though symptoms won’t show until much later, applying fungicides during this period can greatly reduce the number of latent infections that establish. For example, a common strategy is two sprays – one at early bloom (white bud) and another at the small fruit stage – in spring if conditions are wet. This can protect flowers and young olives from that primary infection wave. Copper-based fungicides are often used here (they help against other diseases like peacock spot too), or other permitted fungicides can be applied according to label/permit.

• Cover sprays before autumn rains: If significant rain is forecast during the ripening period, a preharvest protective spray is highly advisable on susceptible blocks. A fungicide application in late summer or early autumn, timed just before a rain front, can protect the fruit from new infection and possibly slow any existing infections from sporulating. This is essentially an “insurance” spray to prevent an epidemic as you approach harvest. Copper fungicides or a systemic like azoxystrobin (under permit) are options here, keeping in mind any withholding periods before harvest.
• Continue if conditions persist: In a very wet season, multiple sprays may be needed. Fungicides generally provide a protective window of around 2–3 weeks, but heavy rain can wash residues off. Growers in high-pressure, wet conditions often follow a schedule of sprays at 3–4 week intervals from spring through harvest, focusing on times when rain is likely. For instance, in parts of Queensland, some growers spray copper every 4 weeks from flowering until picking as a preventative measure. The cost of multiple sprays has to be weighed against the potential crop loss (in severe anthracnose areas like parts of Spain, routine fungicide programs costing hundreds of dollars per hectare are standard ). Each grower should tailor the spray frequency to the orchard’s disease history and climatic risk. 
  
• Fungicide selection and rotation: Use fungicides that are effective against anthracnose and rotate chemical groups to avoid resistance. Copper formulations provide broad-spectrum protection, and the fungus has virtually no resistance to copper (since it’s a multi-site contact fungicide). Strobilurin fungicides (Group 11, e.g. azoxystrobin or pyraclostrobin) are highly effective systemics against anthracnose, but they should be rotated or mixed with other fungicides because fungi can develop resistance to single-site modes of action. In some crops, Colletotrichum resistance to strobilurins has been reported, so we use them judiciously. A typical rotation might be copper, then a strobilurin, then copper again, etc., if multiple sprays are needed. Also note that azoxystrobin (Amistar®) can be phytotoxic to some apple varieties, so avoid drift if you have apple orchards nearby.
  
•  Application techniques: Ensure thorough coverage of the trees when spraying. Anthracnose often starts high in the tree or in thick canopies, so complete coverage (including the tops of tall trees) is important. Use sufficient water volume and consider spray additives/spreaders to help cover fruit surfaces. Poor coverage leads to gaps in protection, which the fungus can exploit. If your trees are very large and hard to spray, aggressive pruning (to reduce tree size) might be needed as part of the integrated approach, since incomplete spray coverage on large trees is a known issue with anthracnose control. 
  

Fungicide Options – Registered and Permitted Chemicals 

Several chemical controls are available (either fully registered or via permit) for anthracnose in olives. Always check current APVMA registrations and permits for up-to-date usage instructions, rates, and withholding periods, as these can change. As of the mid-2020s, the key fungicide options include:

• Copper-Based Fungicides (Group M1) – Copper hydroxide, copper oxychloride, and tribasic copper sulphate formulations are widely used as protectant fungicides against anthracnose and other olive diseases. Copper is registered for olives in Australia (e.g. some copper products have a 1-day WHP on olives). Copper is applied preventatively; for example, copper hydroxide sprays from flowering through fruit development (repeated every few weeks in wet weather) can significantly suppress anthracnose. Copper fungicides are also organically acceptable in olive production. They work by creating a protective film that kills spores on contact. Note that copper is best used before infection – it has limited curative action once the fungus is inside the fruit. Good coverage is essential, and excessive use can cause leaf spotting or build-up in soils, so follow label rates.  
• Azoxystrobin (e.g. Amistar® – Group 11) – A systemic strobilurin fungicide that is highly effective against anthracnose. In olives, azoxystrobin use has been under a minor-use permit (e.g. Permit PER14580) for anthracnose control. It can protect developing fruit and also has some curative activity (it inhibits fungal growth within tissues). Typically, a maximum of two applications per season is allowed, with a 3-week re-treatment interval and a pre-harvest withholding period (21 days under past permits). Azoxystrobin should be rotated with non-Group 11 fungicides to manage resistance. It’s a good option to apply just before a high-risk weather period, as it can move into plant tissue and provide protection for a couple of weeks. Growers should ensure any permit conditions (such as not spraying near sensitive crops like apples, as mentioned earlier) are followed. 
  
• Pyraclostrobin + Metiram (Aero® – Groups 11 + M3) – This is a pre-mix of a strobilurin (pyraclostrobin) with a contact protectant (metiram). It has been used under permit in olives (Permit PER14908) for anthracnose. The combination of a systemic and a multi-site fungicide offers protective and some curative action. Like azoxystrobin, only two sprays per season were permitted, with similar timing restrictions. If available, this product can be effective, but note metiram (like mancozeb) has a 21-day WHP and the product should not be used too close to harvest. As with any strobilurin-containing product, avoid back-to-back Aero sprays – rotate with copper or other chemistry. 
  
• Mancozeb (Group M3) – A broad-spectrum protectant fungicide (multi-site mode of action) that has been used under permit for olive anthracnose in the past. Mancozeb acts similarly to metiram (both are EBDC fungicides), providing a protective barrier on fruit. It was typically allowed as a few applications up to mid-season (older permits had it not too close to harvest). Mancozeb can help as part of a rotation (it’s a different mode of action from copper and strobilurins), though by itself it’s less commonly used than copper for olives. Growers should check the current permit status for mancozeb on olives, as regulations may have changed since the previous permits (which expired in 2018 ).  
  
• Other fungicides – Research is ongoing into other fungicides for anthracnose. In some countries, fungicides like tebuconazole (a DMI/triazole) or fludioxonil have been tested on olives. However, in Australia, these are not currently registered or widely permitted for olives. Always refer to the latest Australian Olive industry guidelines or APVMA resources for new permits. Also, always adhere to label or permit conditions (rate, timing, PPE, etc.) for any chemical use.
  

Recommendations for Preventive Action and Grove Hygiene

To wrap up, here is a summary checklist of preventative measures and hygiene practices for managing olive anthracnose. Adopting these practices before the disease gets out of hand will pay off at harvest:

• Remove all old fruit (“mummies”) from trees and ground during and after harvest. Dispose of them far from the grove (burn, bury, or trash) to eliminate overwintering inoculum. This is one of the most effective ways to reduce disease carryover. 
• Prune and destroy diseased twigs/branches during the dormant season. Cut out shoots showing dieback or withered fruit stems, as they may harbour the fungus. Also, prune generally for an open, airy canopy – sunlight and airflow will suppress fungal growth and dry out moisture faster.
• Optimise irrigation and drainage. Avoid overhead irrigation, or if used, water in the early morning so foliage dries quickly. Do not over-water; excessive humidity and wet feet encourage anthracnose. Ensure good drainage to prevent standing water or overly humid microclimates in the grove. 
• Plant resistant or less-susceptible cultivars in high-risk climates. For new groves in humid/ rainy areas, consider varieties like Arbequina or Picual. If susceptible varieties (e.g. Barnea, Manzanillo) are grown, be prepared to manage them intensively or harvest early to escape heavy disease. 
• Apply preventive fungicides at critical times. Protect the crop with well-timed sprays (for example, at flowering, fruit set, and pre-harvest if needed) when wet weather is anticipated. Don’t wait for severe symptoms – preventative action is far more effective. Rotate fungicide modes of action and follow label/permit directions. 
• Monitor vigilantly. Scout your grove regularly for early signs of anthracnose, and track weather forecasts. If you catch the first signs of infection or forecasted risk conditions, you can implement controls (spraying, early harvest, etc.) before it’s too late. 
• Maintain overall grove health. Balanced fertilisation and minimising other stresses can help trees resist infections. While anthracnose largely depends on wetness, a robust tree may suffer less damage and recover faster. Conversely, a stressed tree (nutrient deficiencies, other pests) may be more prone to severe outbreaks. 
• Harvest promptly in risky seasons. If your region is entering a wet period and fruit is nearing maturity, consider harvesting olives as early as feasible. Anthracnose damage accelerates the longer the ripe fruit hangs in wet conditions. An early harvest can sometimes dodge the worst of an epidemic (though oil yields might be slightly lower, it’s better than losing the crop entirely). 
• Practice good sanitation between groves. If equipment, bins, or workers move from an infected grove to another grove, clean off any plant debris or fruit residues to avoid transferring spores. It’s a minor concern relative to wind and rain spread, but good biosecurity can help limit new introductions of the pathogen.

By following these preventative and hygiene steps, growers create an environment where the anthracnose fungus struggles to get established. The key is to be proactive – once orange spores are running down your olives, the damage is largely done. Australian industry experts emphasise taking action before harvest time to protect your crop. With vigilance and an integrated strategy, even growers in higher-risk regions can successfully manage anthracnose and deliver healthy olives to the press. 

Sources

• Spooner-Hart, R., Tesoriero, L., & Hall, B. (2007). Field Guide to Olive Pests, Diseases and Disorders in Australia. RIRDC Publication No. 07/153. 
• Spooner-Hart, R. (2005). Sustainable Pest and Disease Management in Australian Olive Production. RIRDC Publication No. 05/080. 
  
• Spooner-Hart, R. (2015). Strategies for Managing the Top 5 Olive Pests and Diseases. Presentation at Olive Exposium, November 2015. 
  
• Tesoriero, L. (2020). Managing Olive Anthracnose (IPDM Tutorial #7). Australian Olive Association (olivebiz).
  
• Tesoriero, L. (2013). Managing Olive Anthracnose – Lessons from Australia. (Seminar presentation, Olive Council Workshop). 
  
• Sergeeva, V. (2012). Interview in Olive Oil Times: “The Cost of Anthracnose” by J. Butler. 
  

Problem

I have a couple of olive trees with a bark problem.  This particular tree is a bit stressed from lace bug I believe, I'm not sure they've had their full care for the last couple of years due to the transition. It needs a bit of a prune too which I will take care of before I spray it. But will wait for your comments first.  See image below.

About Sunburn Damage

Sunburn can occur in olive trees as damage to bark, foliage, fruit which is caused by excessive solar radiation exposure and seriously affect growth.

Sunburn can cause the tree the olive tree to be more susceptible to borers.  Olive trees affected by sunburn are typically poor in health and if severe enough can result in premature death.

Sunburn in olive trees is usually associated with warm weather coupled with water deficit.

Although olive trees are well adapted to hot and dry conditions, too much heat can result in lower yields, leaf wilt, and reduced photosynthesis as the olive tree shuts down critical functions to respond to heat stress.

Older trees can be damaged when the bark is newly exposed to the sun because of pruning or premature leaf drop. Heavy pruning of olive trees can lead to increase reflected light or radiate heat around established trees can also lead to sunburn.

Identification

Sunburn to trunks can leave the tissue dried, cracked and sunken and the bark may peel away leaving the wood susceptible for borer attack or fungal infections to enter the bark for further damage to the exposed hardwood underneath.

Foliage may be brown and necrosis begins at leaf tips, margins and between veins. 

Heat stress usually results in fruit drop if an olive crop is present.

Solutions

Encourage good soil health and moisture-holding capacity.  Encourage branch structure with proper pruning and plant training.  Retain branches that will help to shade the trunk and be beneficial for cropping.

Give trees adequate irrigation to reduce stress and do not overwater trees.

For olive trees and fruit to reduce the risk of sunburn use Kaolin clay applied as a foliar film to help offer protection in reducing heat stress and intense solar radiation.

Whitewashing trunks may help prevent sunburn which is usually seen as an application of rubberised tree sealant.  Sometimes water-based paints are used.

If leaves have not already been killed, sunburn injury to foliage can often be remedied by adequate irrigation, adding shade or shelter, and improving soil conditions.

Sunburn Olive Tree

Bark has been affected by intense sun radiation exposure and also water deficit.

This summer cropping season is facing unprecedented challenges in fertiliser supply. Availability of MAP fertiliser (monoammonium phosphate) and DAP fertiliser (diammonium phosphate) is expected to remain extremely limited worldwide, with serious implications for growers planning their nutrient programs.

Why is Fertiliser Supply Tight

China’s Export Restrictions Continue

Since 2021, China has imposed strict quotas and inspection rules on phosphate fertiliser exports to protect domestic prices and safeguard food security. 

The impact has been dramatic:

• March 2025 exports: just 13,000 tonnes, compared with 950,000 tonnes in March 2022.
• Q1 2025 exports: 111,000 tonnes, versus a three-year average of 785,000 tonnes.

Other Suppliers Cannot Fill the Gap

Although Morocco, Russia, the USA, and Saudi Arabia also produce MAP and DAP, they cannot offset the sharp drop in Chinese exports. 

The result is:

• Rising global fertiliser prices
• Longer delivery lead times
• Stricter supplier allocations
• Reduced pricing flexibility across the summer cropping season

What This Means for Growers

For olive growers and other professional producers, the impacts are already being felt:

• Reduced fertiliser availability for summer cropping
• Higher input costs with delivery delays
• Less flexibility in nutrient timing and program planning

Our Recommendations - Secure Your Supply Now

Do not wait for traditional ordering windows. Place orders immediately and consider forward contracting for next season. Securing current pricing now helps protect your operation against higher costs and potential shortages later.

Optimise Your Nutrient Strategy

• Review alternative phosphate fertiliser options
• Adjust application rates where agronomically feasible
• Consider split applications to maximise nutrient efficiency
• Explore precision application technologies to reduce overall fertiliser requirements

AgroBest is an Australian manufacturer with a wide range of crop protection and liquid fertiliser products to help keep your olive trees healthy and productive. This guide gives you a practical overview of the AgroBest range available through The Olive Centre and how they can fit into your nutritional grove program across the season. We’ll walk through foliar feeds, soil conditioners, pest and disease support products, spray adjuvants and biostimulants, explaining when to use, and how to help with common olive problems. Whether you’re dealing with nutritional needs or tired trees that just aren’t performing, this guide is designed to help you quickly match the right AgroBest product to the needs of your grove.  A soil and leaf analysis are recommended to narrow down the correct product(s).

Foliar Nutrition Products (NPK & Trace Elements) 

Foliar nutrition is critical for addressing immediate nutrient needs and boosting olive tree productivity. AgroBest offers several NPK foliar fertilisers and trace element sprays designed for quick uptake through leaves. These products provide balanced macronutrients (nitrogen, phosphorus, potassium) often enhanced with micronutrients or biostimulants to improve efficacy.

• QuickStart - A fully soluble NPK liquid fertiliser with added trace elements, formulated to support flowering and fruiting stages. QuickStart delivers a blend of nitrogen, phosphorus, and potassium along with micronutrients to ensure olive trees have the nutrition needed for abundant bloom and fruit set. It’s typically applied as a foliar spray pre- and post-bloom. (Available in 20L, 200L, and 1000L sizes.)

• Beyond Foliar - A balanced N-P-K foliar feed enriched with seaweed extract and micronutrients, aimed at improving fruit fill, tree vigour, and overall yield and quality. This liquid concentrate supplies a moderate NPK ratio along with natural growth promotants from seaweed. Olive growers use Beyond Foliar after fruit set to enhance olive size, colour, and flavour development. (Common pack sizes: 20L, 200L)

• Plant Food - A liquid NPK concentrate tailored as a young plant starter fertiliser. With a gentle, balanced nutrient profile, Plant Food encourages healthy early growth in newly planted olive trees or nursery stock. It ensures seedlings and young groves establish strong roots and foliage without the risk of burn. (Available in 5L, 20L, etc.)
  

• Agro NK - A highly available liquid combination of nitrogen, potassium, and phosphorus designed for rapid uptake. Agro NK delivers these macronutrients in readily absorbed forms, making it ideal for mid-season foliar feeding when olive trees demand extra nitrogen (for canopy growth) and potassium (for fruit development). Growers apply Agro NK to correct general nutrient deficiencies quickly and to sustain growth during critical periods. (Available in 20L, 200L, 1000L) 
• AgroCal N - A specialty foliar nutrient focusing on calcium and nitrogen for crops with high Ca demand (like olives during pit hardening). Calcium is vital for cell wall strength and fruit firmness, while nitrogen fuels vegetative growth. AgroCal N provides a chelated calcium source together with nitrogen to address Ca deficiencies in olive foliage or developing fruit, improving tissue strength and reducing problems like tip burn or fruit drop. (Available in multiple sizes, e.g. 20L, 200L)
  

• High PK - A liquid phosphorus and potassium booster formulated to stimulate flowering and fruit set in olives. High PK supplies a surge of P and K right when olive trees transition to the reproductive phase, promoting abundant flowers and supporting early fruit development. It’s typically sprayed at pre-bloom and again during fruit sizing. Adequate phosphorus ensures strong bloom and root support, while potassium enhances flowering, fruit retention, and oil synthesis in olives. (Available in 20L, 200L) 

• Green N42 - A 42% nitrogen foliar fertiliser for fast correction of nitrogen deficiency and to drive vigorous canopy growth. Green N42 is a high-analysis N solution containing urea, ammonium, and nitrate forms of nitrogen for both immediate and sustained uptake. This multi-form formulation ensures rapid greening of yellowed olive leaves and prolonged feeding to support extended vegetative growth. Growers use Green N42 in spring or after heavy rain leaching to restore N levels, resulting in lush foliage and improved shoot growth in high-yield groves. (Offered in 20L drums, 200L drums, and 1000L IBCs)

• Green N32 + Humic - A high-analysis nitrogen (32%) fertiliser blended with humic acids. This product not only provides a quick nitrogen supply but also incorporates organic humic substances to improve soil nutrient retention and microbial activity. Foliar or fertigated use of Green N32+Humic gives the dual benefit of boosting immediate growth while also enhancing soil health and nutrient efficiency. It’s especially useful in olive orchards on sandy or low-organic-matter soils, where humics aid in holding nitrogen and other nutrients in the root zone. (Available in 20L, 200L, 1000L)

• Extra Cal - A unique calcium supplement with cytokinin (plant hormone) carrier. Extra Cal delivers calcium in an organically complexed form along with natural cytokinins that help drive calcium into fruit and leaf tissues. This foliar spray is used to correct calcium deficiencies (e.g. preventing pitless olives or soft fruit) and to improve fruit firmness. The cytokinin component stimulates cellular activity and nutrient mobilisation, so Extra Cal is ideal during olive fruit sizing - ensuring better calcium uptake into developing olives for stronger skin and reduced incidence of disorders. (Typically available in 5L, 20L quantities.) 
• Trace Element Sprays (AgroBest AgroDex Range) - In addition to NPK feeds, AgroBest provides a full suite of micronutrient foliar sprays under the AgroDex line. These are chelated trace element solutions that address specific nutrient deficiencies quickly via foliar application. For example, AgroDex Boron is a high-analysis boron (B) formula complexed with organic acids for efficient uptake, used at flowering to improve pollen viability, fruit set, and aid calcium mobility in olives. AgroDex CaB combines calcium with boron and nitrogen to support fruit quality, shoot growth, and reproductive development - helpful in preventing calcium-related fruit drop and improving olive size. There are also single-element sprays like AgroDex Fe (EDTA-chelated iron) to correct iron chlorosis and boost chlorophyll production for greener leaves, AgroDex Mg for magnesium deficiency to improve photosynthesis and leaf colour, AgroDex Mn for manganese needs (critical for enzyme activation and carbohydrate production), and AgroDex Moly (molybdenum with phosphorus) to enhance nitrogen conversion and protein synthesis in the tree. For potassium, growers can choose AgroDex K-Fill, a clear non-staining potassium solution that enhances fruit colour, size and uniform ripening, or the concentrated AgroDex K35 / K45 formulas, which supply high K with organic acids to boost fruit sweetness, oil content, and crop finishing. These trace element products are typically used as foliar sprays during periods of known deficiency or high demand (e.g. postflowering for boron, summer for magnesium, etc.). All are available in convenient liquid form (usually 20L drums up to 200L and 1000L for large operations).  This range is great for dealing with specific deficiencies.

Soil Conditioners & Soil-Applied Fertilisers 

Healthy soil is the foundation of productive olive groves. AgroBest offers products that improve soil fertility, structure, and microbiology - ensuring roots have access to nutrients and water. These soil conditioners and granular/liquid fertilisers are applied to the soil (via drench, fertigation, or banding) rather than sprayed on foliage. 

• Kickstart Bio 25 - A soil-applied NPK fertiliser with added trace elements and humic compounds. Kickstart Bio 25 is a humic-based starter fertiliser formulated to promote robust root development and early crop growth when establishing orchards or during spring flush. It provides a balanced mix of nutrients (including nitrogen, phosphorus, potassium and micros) in a carbon-rich humate matrix, which improves nutrient uptake and soil structure. Olive growers often use Kickstart at planting or at the start of the season to “kick start” root systems - the humic acids enhance nutrient availability and stimulate soil microbial activity, leading to stronger root biomass and better early vigour. (Available in granular or liquid form; common sizes 20L liquid or 25kg bags if granular.)

• GroMate 5-5-5 - An organic liquid fertiliser (N-P-K 5-5-5) designed for building soil health and general crop nutrition. GroMate’s balanced 5-5-5 analysis comes entirely from organic inputs, making it ideal for improving soil fertility naturally. It contributes organic matter, feeds soil microbes, and releases nutrients slowly to the olive trees’ roots. Regular applications of GroMate can improve soil structure and root strength over time. This product suits groves aiming for organic certification or simply looking to enhance soil carbon and biological activity. It’s often applied via fertigation or as a soil drench around the root zone. (BFA certified organic; available in 20L, 200L, 1000L IBC.) 

• Fish Emulsion - A classic organic bio-stimulant fertiliser made from fish extracts, rich in nitrogen, phosphorus, trace elements, amino acids, and oils. AgroBest’s Fish Emulsion is formulated to boost soil microbial life and provide a gentle nutrient release to crops. In olives, fish emulsion can be applied to the soil to feed beneficial microbes and improve nutrient cycling, or even foliar-sprayed at low concentrations as a mild feed. Growers appreciate that it improves soil tilth and root health while also supplying minor nutrients naturally. Fish Emulsion is especially useful for correcting general nutrient deficiencies in an organic-friendly way and for mitigating transplant shock in young trees. (Available in 5L, 20L, 200L; has an organic certification.) 

• CalMate - A humic acid solution designed to be compatible with calcium fertilisers. CalMate is essentially a soil conditioner that can be combined with calcium sources (like lime or gypsum, or liquid Ca) to enhance calcium availability and uptake by plants. When olive orchards have calcareous soils or when applying calcium, adding CalMate helps chelate the calcium, keeping it soluble. This results in better Ca absorption by olive roots or leaves and can improve the efficiency of calcium fertilisation. CalMate also contributes humic substances that improve overall nutrient efficiency and bolster plant resilience under stress. Olive growers might add CalMate to their fertigation mix, especially if tissue tests show calcium deficiency or if they want to ensure maximum benefit from a foliar Ca spray (the humic acid prevents tie-up and enhances translocation). (Liquid concentrate; typical size 20L.)

• Soil pH & Structure Amendments: While not a separate product per se in the AgroBest range, it’s worth noting that some AgroBest nutritionals assist indirectly with soil structure. For example, CarboCal (though often foliar) can also be applied via drip irrigation; its organic acid-rich formulation can help flocculate soil particles and improve calcium levels in the root zone. CarboCal supplies plant-available calcium coupled with over 50 organic acids, which not only feed microbes but can help open up clay soils. Improved calcium in soil leads to better soil aggregation and drainage - crucial for olives, which don’t like waterlogging. Additionally, Green N32 + Humic (mentioned earlier) contributes humic matter that conditions the soil and reduces nitrogen leaching. In summary, many of AgroBest’s products have dual roles, acting as both fertilisers and soil conditioners due to their organic components. 

Using these soil-oriented products, olive growers can address issues like poor soil fertility, low organic matter, or imbalanced nutrients in the root zone. For instance, if an olive grove is suffering from nutrient lock-up or weak root growth, a combination of humic-enriched Kickstart and organic GroMate can rebuild soil life. If soil calcium or pH is an issue, products like CarboCal can supply calcium in a plant-accessible form that strengthens soil and trees alike. Healthier soil translates to stronger, more resilient olive trees with better uptake of nutrients and water. 

Control Aids 

While AgroBest’s focus is on nutrition, some of its products also play a role in crop protection - either by directly deterring stresses or by strengthening the plant against pests and diseases. Olive growers face challenges such as black scale insects, fungal diseases like peacock spot and anthracnose, as well as environmental stresses (frost, heat) that can predispose trees to problems. AgroBest products can be part of an integrated strategy to tackle these issues.

• Envy Frost & Sunburn Protectant - A unique anti-transpirant spray that creates a protective barrier on plant surfaces. Envy is formulated with natural compounds (e.g. pine resin) that shield crops from frost, heat, and sunburn stress by reducing transpiration and forming a micro-film on leaves and fruit. In olives, late spring frosts or extreme summer heat can damage developing fruit and foliage; applying Envy beforehand helps mitigate this. For example, spraying Envy before a forecasted frost can significantly reduce ice nucleation on olive buds and leaves, preventing frost burn. It’s equally useful ahead of heatwaves to minimise sunscald on olive fruit or desiccation of leaves. While not a pesticide, Envy falls under crop protection because a less-stressed tree is more resistant to pests and disease. (This product is used in low concentrations - e.g. 1:15 or as directed - and comes in small volumes like 1L or 5L that can treat large areas given the high dilution.)

• Spraytech OIL (Organic Adjuvant) - Primarily an adjuvant (see next section), Spraytech Oil is a vegetable oil-based spraying oil that may also have some effect for  improving pesticide efficacy. Spraytech OIL is a certified organic non-ionic oil.  Additionally, if chemical control is needed (for example, mixing an insect growth regulator for scale), adding Spraytech OIL improves that insecticide’s coverage, duration, uptake, and rainfastness. This means better pest knockdown with lower risk of spray drift. In short, Spraytech OIL can assist  with spray efficacy to boost the performance of fungicide or insecticide sprays application targeting olive diseases/pests.

• Nutritional Strengthening for Disease Resistance - A key strategy in disease management is ensuring the olive tree has sufficient nutrients to maintain strong defensive structures. Several AgroBest products indirectly help with diseases like anthracnose or peacock spot by fortifying the plant. For instance, CarboCal (the calcium organic supplement) markedly improves cell wall strength and fruit robustness. Adequate calcium in plant tissues leads to stronger cell walls, greater resistance to disease and insect attack, and reduced post-harvest damage. By regularly using CarboCal or the combined Ca-B sprays (AgroDex CaB), growers can reduce incidences of anthracnose on fruit - the pathogen finds it harder to penetrate calcium-rich, sturdy fruit skin. Calcium also helps minimise olive fruit cracking and bruising, which in turn lowers infection entry points. Another example: Fuze Copper is AgroBest’s EDTA-chelated copper micronutrient spray for correcting copper deficiency. While its main role is to fix pale leaves or dieback due to a lack of copper, it can also contribute to disease management. Copper is a well-known fungicidal element; ensuring olives have sufficient copper in their tissues can bolster their natural defence against fungal diseases like Peacock Spot (leaf fungus) or Cercospora. Growers might use Fuze Copper foliar sprays post-harvest or in spring - not only to green up the foliage but also as part of their regime to keep fungal diseases at bay (complementing any copper-based protectant sprays they may use). In general, the MultiTrace products, such as Titan (with zinc, iron, copper, etc.) help “heal” a nutritionally stressed tree; a healthier olive tree will better resist pest infestations and disease outbreaks.

It’s important to note that AgroBest does not produce synthetic pesticides or fungicides - instead, their offerings focus on prevention and plant strength. For active infestations like a severe black scale attack or an anthracnose epidemic, growers would still use specific registered pesticides (e.g. a petroleum spray or an IGR for scale, or a copper fungicide for anthracnose/fungal issue). However, integrating AgroBest products could mean fewer such interventions are needed. By using nutritionals and protectants like Envy and Spraytech Oil proactively, olive growers can reduce stress and pest pressure on their groves. This integrated approach leads to a more sustainable pest and disease management, leveraging plant health to fight off challenges naturally.   Always test product compatibility before mixing.

Adjuvants and Spray Aids 

Adjuvants are “helper” products that improve the performance of agrochemical sprays - ensuring that nutrients or pesticides stick  as intended. AgroBest’s adjuvants are especially valuable in olive production, where the undersides of leaves and the waxy surfaces of olive foliage can make spray coverage difficult. Using the right adjuvant means more of your spray actually reaches the target and stays there, rather than bouncing off or drifting away. Two key adjuvant products in the AgroBest range are: 

• Spraytech OIL - This was mentioned earlier for pest control, but as an adjuvant, it’s a game-changer for spray applications. Spraytech OIL is an organic, non-ionic surfactant/oil blend derived from vegetable oil, approved for organic use. It has a unique mode of action: it encapsulates spray droplets and pesticide molecules, reducing their evaporation and protecting them from degradation (e.g. by UV light). For olive growers, this means when you mix Spraytech OIL into your fungicide, insecticide, or foliar feed tank, you get better adhesion of the spray to olive leaves (which are notoriously slick). It greatly minimises drift and off-target losses by reducing fine droplet formation. It also buffers poor-quality water - if your spray water is slightly alkaline or hard, Spraytech OIL helps stabilise the pH and prevents things like phosphates from precipitating. In practical terms, adding 0.5 - 2.0 litres of Spraytech OIL per 1000L tank can improve the coverage of a foliar nutrient spray (ensuring the tree actually absorbs those nutrients) and can enhance pesticide uptake through the leaf cuticle. This adjuvant also confers some rainfastness; sprays are less likely to wash off in the next rain event. And because it’s made from natural oils, it’s softer on beneficial insects than harsh synthetic surfactants. (Spraytech OIL is available in a wide range of sizes - from 0.5L and 1L bottles for backyard growers, up to 20L drums and 200L for large orchards .)

AgroBest AgroChelate - An organic acid concentrate used as a water conditioner, compatibility agent, and nutrient uptake enhancer. Agro “Chelate” is essentially a blend of organic acids and amino acids. When added to a spray tank or fertigation system, it acidifies the solution slightly (bringing pH to a plant-friendly level), chelates micronutrients (preventing them from reacting with other chemicals or getting locked up), and improves the mixing of otherwise incompatible inputs. For example, olive growers often want to tank-mix calcium with phosphorus fertilisers or combine multiple trace elements - this can cause precipitation or antagonism. AgroBest’s Chelate product helps keep such mixes stable and ensures the nutrients remain in a form the plant can absorb. It also acts as a mild biostimulant due to its amino acid content, so foliar feeds with AgroChelate might show improved uptake into leaves. In summary, Agro Chelate is used as an adjuvant to condition spray water (especially if it’s alkaline or hard), to prevent clogging and leaf burn, and to facilitate smooth absorption of nutrients through the leaf cuticle. It’s particularly useful in foliar trace element programs and fertigation systems. (Available in liquid form; e.g. 5L and 20L containers.)

Using adjuvants like these is highly recommended in olive spray programs. Olives have small, waxy leaves and a dense canopy; getting sprays to penetrate and stick can be challenging. By using Spraytech OIL, growers report more uniform coverage and better results from both pest control and foliar feeding efforts (the improved uptake means you might achieve desired results with lower application rates, saving cost). Similarly, with AgroBest’s chelating adjuvant, complex tank mixes become more stable - meaning you can, for instance, mix your zinc, boron, and magnesium foliar feeds with confidence that each will remain available to the tree. In sum, AgroBest adjuvants ensure you get the maximum benefit from every spray, an important consideration given the time and cost involved in spraying an olive grove. 

Biostimulants and Growth Enhancers 

Biostimulants are products that don’t fit the traditional “fertiliser” mould of simply providing N-P-K, but instead contain natural compounds (like seaweed extracts, humic acids, beneficial microbes, etc.) that enhance plant growth and resilience. AgroBest has embraced this technology by offering several biostimulant products that can give olive trees an extra edge - improving root growth, boosting stress tolerance, and increasing nutrient uptake efficiency. These are especially relevant to olives, which often face stresses like drought, high salinity, and poor soils.

• SeaFil - A fermented seaweed extract biostimulant (derived from kelp) that boosts root development, photosynthesis, and overall plant resilience. SeaFil is rich in natural growth hormones (auxins, cytokinins), trace minerals, alginates, and amino acids from seaweed. When applied to olives (either as a foliar spray or via fertigation), it acts as a general tonic - stimulating root growth, improving leaf chlorophyll content, and helping the tree cope with stress. For example, SeaFil is often used after harvest or during spring bud-break to reinvigorate olive trees, as well as in summer to help them tolerate heat and limited water. Fermented seaweed products like this have been shown to trigger defensive mechanisms in plants; an olive tree treated with SeaFil may be better prepared to resist fungal infections or recover from pest damage. The product is 100% natural and can be used in organic groves. (SeaFil comes in powder or liquid concentrate; available in small 1kg packs for making solutions, or liquids in 20L and even bulk 1000L IBC for large farms .) 

• Fulfil - An 85% seaweed ferment biostimulant fortified with plant growth regulators (PGRs). Fulfil is another seaweed-based product, but with a higher concentration of active compounds and possibly added hormones or vitamins to really drive plant responses. In olives, Fulfil is used to enhance root mass, improve flowering and fruit set quality, and increase the tree’s tolerance to stress (like drought or heavy crop load). The auxins in Fulfil encourage new root hair formation (great for nutrient uptake), while cytokinins from the seaweed promote new shoots and can improve fruit size and quality. This product might be applied at key stages like pre-flowering (to improve inflorescence health), at fruit development (to size up olives), or after any stress event (to help recovery). Growers have observed more uniform olive fruit and healthier canopies after using Fulfil, thanks to its stress-mitigating properties. 

• Trapeaze - A seaweed-based trace element and growth promotant formula. Trapeze stands out by combining seaweed extract with essential micronutrients and natural growth stimulants like betaines, auxins, and cytokinins. It’s essentially a biostimulant + foliar feed hybrid, which makes it very convenient. When you spray Trapeze on olive trees, you are both feeding them minor nutrients and triggering growth responses. The product improves crop vigour and yield by addressing any subtle micronutrient deficits (it contains a broad spectrum of trace elements) and simultaneously encouraging the plant’s own growth processes. Olive growers might use Trapeze during mid-season to keep trees in peak condition - the micronutrients prevent hidden deficiencies that could limit yield, and the seaweed hormones keep the trees actively growing and filling fruits. It’s also used post-harvest to help trees store reserves and set up buds for the next season. (Liquid product; usually in 5L, 20L sizes; can be tank-mixed with other foliar sprays.)

• Fish Emulsion & Humate Products - In addition to SeaFil and other seaweed products, recall that Fish Emulsion (described in Soil Conditioners) also acts as a biostimulant. Its content of amino acids and organic matter feeds soil biota and can improve plant immune responses. Many olive growers use fish emulsions as part of biostimulant programs, not just as fertiliser. Similarly, humic acid products like CalMate or the humic component in Kickstart have biostimulant effects - humics can stimulate root enzymes and improve nutrient uptake. These help olive trees, especially in stress conditions (e.g. a humic foliar spray during drought can help leaves retain water and keep stomata functioning). 

By integrating biostimulants into their regime, olive growers can tackle challenges like nutrient-poor soils, irregular bearing, or climate stress in a more natural way. For example, facing a scenario of “off-year” in an alternate-bearing olive grove, one might apply SeaFil or Fulfil to reinvigorate the trees and potentially improve the next bloom. In drought-prone areas or saline irrigation conditions, biostimulants help olive trees maintain growth and yield where they otherwise might suffer. These products do not replace standard NPK fertilisers but rather supplement the nutrition program by ensuring that the plant can make the most of nutrients and overcome growth hurdles. They are akin to vitamins and probiotics for your olive trees - not absolutely required, but when used properly, they often lead to healthier, more productive plants.

Product Sizes & Usage Note: Most AgroBest biostimulants are available in various sizes to suit different scales of operation - from 1-5 L bottles for small groves up to 200 L drums for large farms. They are generally applied at low concentrations (e.g. a few litres per hectare as a foliar spray). It’s important to follow recommended timing - many biostimulants show best results when applied at specific growth stages (like root flush, pre-flowering, or stress events). 

Leaf and Soil Analysis

In Australian agriculture, understanding the hidden nutrients in your soil and plants can make the difference between an average harvest and a thriving one. Leaf and soil analysis give farmers, agronomists, olive growers, and even hobby gardeners a scientific window into their crops’ health. By regularly testing both the soil and the leaves (foliage) of your olive trees or other plants, you gain precise data to fine-tune fertiliser use, correct deficiencies, and boost overall productivity. The result is healthier olive groves, higher yields of quality fruit, and more sustainable soil management - an investment that pays off in both the short and long term through improved crop performance and soil health.

• Maximise yields and quality with targeted nutrition: Soil testing takes the guesswork out of fertilising by revealing exactly which nutrients your soil is lacking (or has in excess). This allows you to apply the right type and amount of fertiliser for optimal growth and olive production, rather than relying on assumptions. With a clear nutrient report in hand, you can boost fruit yields and oil quality by ensuring trees get precisely what they need. For example, a balanced foliar fertiliser like Beyond Foliar can supply a tailored blend of NPK and micronutrients to match those needs. In short, leaf and soil analysis translates into more productive crops and better-quality harvests for you as a grower.
• Detecting hidden deficiencies through leaf analysis: A leaf tissue analysis is essentially a “health check-up” for your olive trees, showing which nutrients the plant has actually absorbed. It can uncover silent nutrient deficiencies or toxicities in the tree that might not be obvious from a soil test alone. For example, a lack of boron or calcium will never be obvious just by looking, yet it may lead to poor flower pollination, low fruit set, or reduced olive oil quality if unaddressed - issues that can be remedied once identified through testing. Applying targeted foliar solutions like AgroDex BORON (a high-analysis liquid boron fertiliser) or CARBOCAL (an organic calcium supplement) can correct these hidden deficiencies. Regular leaf analysis lets you catch these problems early and correct them before they impact your crop’s yield or quality.
  
• Protect soil health and tree vigour for the long run: Soil analysis provides a comprehensive snapshot of your soil’s fertility, measuring pH, salinity, organic matter, and essential macro- and micro-nutrients (like nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, and more). This holistic soil health assessment highlights imbalances that can silently undermine tree growth - for instance, excessive salts or the wrong pH can lock up nutrients and damage roots. By testing regularly, you’ll spot issues like nutrient deficiencies or adverse soil conditions in time to fix them. Armed with this information, you can apply targeted soil conditioners to rebalance the field - for instance, using a natural bio-stimulant such as Fish Emulsion to stimulate beneficial soil microbes and improve overall fertility, or a humic-acid concentrate like CalMATE to enhance nutrient uptake and plant resilience under stress. In turn, your olive trees will grow in a balanced environment, leading to stronger roots, better disease resistance, and overall improved vitality in the grove.
  
• Save money and farm more sustainably: Using leaf and soil analysis can actually reduce your input costs while benefiting the environment. The data from these tests helps you avoid wasting money on unnecessary or excessive fertiliser applications. Instead of blanket-feeding your crops (which risks over-fertilising), you can target only the nutrients that are truly needed. For example, AgroBest’s own Olive Leaf Analysis and Total Soil testing services pinpoint specific deficiencies, allowing you to remedy them with a precise input - such as a quick-release foliar blend like Quickstart (a fully soluble NPK fertiliser enhanced with trace elements for flowering and fruiting) - rather than a one-size-fits-all approach. This precision not only saves you dollars, but it also prevents nutrient runoff into waterways and minimises other environmental impacts from over-fertilising. In short, you’ll be fertilising smarter - doing more with less and keeping your land and local ecosystem healthier.
  

In Summary, AgroBest’s range of products on The Olive Centre spans everything from core fertilisers to innovative biostimulants, all geared toward improving plant nutrition and resilience. By grouping products into foliar feeds, soil conditioners, protection aids, adjuvants, and biostimulants, we see that each category addresses different aspects of olive grove management: 

• Foliar Nutrition: ensures quick correction of nutrient deficiencies and fuels key growth phases (with products like QuickStart, Beyond Foliar, High PK, and the AgroDex micronutrient line). This directly tackles issues like yellowing leaves or poor fruit set due to nutrition, and indirectly helps with disease by keeping trees vigorous. 
• Soil Conditioners: improve root environment and long-term soil health (e.g. Kickstart for root establishment, GroMate and Fish Emulsion for organic matter, humic acids for structure). Healthy soil leads to stronger trees that can better withstand pests like root rot or scale infestation. 
  
• Pest & Disease Control Aids: though not pesticides, products like Envy and Spraytech Oil protect olives from abiotic stress and make pest control more effective, while nutritionals like CarboCal and Fuze Copper build the tree’s own defences. 
  
• Adjuvants: ensure every spray counts, reducing waste and enhancing uptake. Spraytech OIL and AgroChelate improve the performance of both AgroBest’s own nutrition products and any other sprays a grower uses, thereby safeguarding investment and environmental safety by reducing drift. 
  
• Biostimulants: act on the plant’s physiology to promote growth and stress tolerance naturally. Seaweed extracts and humates help olive trees cope with challenges like salinity, drought, and alternate bearing, leading to more consistent production.