Marcelo Berlanda and I were talking about the need for proper implementation of key areas of grove management. It must be stressed that if any of these areas are lacking then production in your grove can be greatly affected, even to the extent of non-production of a commercial grove.
In reflection, this is the time of the year when you have just completed harvest and now is the time to prepare a management plan for the grove.
Let’s go into detail together and work out why you need a Grove Management Plan and what you need to do!
A Grove Management Plan must take into account the following key areas:
- Pest and Disease control
“A grove without a proper irrigation system is unlikely to produce consistent yields year in year out. The great majority of growers still underestimate the olive tree’s water requirements. Also very few growers check soil moisture levels. This is the reason why there is a large number of groves that have never produced a commercial crop”. says Marcelo.
Water stress has a serious impact on Flowering, Fruit Set, Oil Accumulation (oil production), Fruit Size (table olives), Fruit Quality and Tree Health. Still many growers do not have a proper soil moisture monitoring procedure in place or a system that would help them control irrigation.
Marcelo says, “My recommendation is that growers must inspect the soil profile on a weekly basis during spring and summer and every two weeks in autumn and winter. Â The procedure consist in digging with a shovel under the tree canopy to at least 400mm depth to observe how much moisture the profile is holding. If the soil is too hard to dig, then the profile is too dry and the tree is suffering water stress even though there are no visual signs on the canopy”.
There are also soil moisture monitoring devices that provide reliable information through a highly visible display or through a computer software that displays the information on the screen in the form of a chart.
Growers who are serious about their groves must check the soil moisture regularly and ensure the trees do not suffer water stress.
On previous occasions I have explained the importance of taking leaf samples to check the nutritional condition of the trees. Based on that information obtained from the leaf analysis this information is used to establish a Fertiliser program. A fertiliser program is the key to improving or maintaining yields. In most cases there is no need for fertiliser application during winter, only soil amelioration may be required at this time of the year. However I have seen many groves with severe nutritional deficiencies which require fertiliser application even during winter. There are many groves which do not have an proper irrigation system and therefore growers are unable to apply the fertiliser efficiently through fertigation. Instead growers must apply fertiliser on the ground prior to rain so the fertiliser is disolved and carried into the soil profile by the rainfall. This is certainly not efficient use of the resources, but some growers have no option.
In cases like these, it is recommended to apply fertiliser under the canopy and if possible cultivate the soil to incorporate the fertiliser into the soil profile. This also helps reducing volatilization of product and therefore reducing fertiliser loses.
Olives requiere the application of 4 essential nutrients:
Nitrogen, Phosphorous, Potassium and Calcium. They come in a wide range of products and growers need to look closely on the labels to see the content of each nutrient in the package. As a guideline I would suggest the following ratio: N15% – P5% or less – K10% or less and Calcium 2% or less.
Avoid pruning during the coldest part of Winter. It is also crucial to avoid pruning after rain or when the weather is foggy, or when there is dew on the leaves and branches. The reason for this is to avoid spreading of Bacterial and Fungal diseases.
The objective of pruning is to clean the canopy from dead branches, reduce the canopy size and to bring balance to the tree, promote new healthy growth and increase fruit set in Spring.
TIP: It is also a very good practice to spray the trees with a copper compound immediately after pruning, to protect the wounds caused by the saws, secateurs or chainsaw from fungal and bacterial diseases.
This aspect of olive grove management plays a key role on yields and tree health. Winter is usually a time of the year where the pressure from insect is reduced due to frost and could provide a good opportunity to get on top of the pests issues that could be affecting the grove. In order to achieve optimum results it is essential to set up a Pest and Disease monitoring program which can be followed on a weekly basis. Monitoring allows timely intervention and ensures the pests and diseases can be kept under control.
A good way to monitor the grove is to mark several trees (with a marking tape) in areas where previously there has been a pest or disease outbreak. Once those trees are marked, growers need to check each tree on a regular basis (in winter every two weeks is enough, but in spring monitoring should be done every week)
It is important to look closely under the leaves and new branches for crawlers, yellow spots, black sooty mold and any other unusual sign.
Growers need to be proactive, and follow their management plan every week if they want to be successful.
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