PRUNING AND CANOPY MANAGEMENT OF AVOCADO TREES

Pruning of avocado fruit trees is one of the most undervalued farm operations among small-scale African farmers. Pruning is essential as it makes a difference in the value of the fruits produced by the farmer hence more income.

Well maintained and pruned trees produce fruits with higher amounts of avocado oil; trees are less susceptible to diseases and produce healthy fruits.

When you don't prune avocado fruit trees, they grow very tall thus ruling out spraying pesticides and fungicides on them using cheap and simple equipment for example knapsack sprayers.

During pruning, we create an excellent avocado tree architecture that enhances a proper spray distribution and penetration; the maintain the avocado tree at a maximum height of 5.5 meters.

4 Reasons Why We Prune Avocado Trees

1. To get better light penetration into the tree

Pruning of avocado trees allows us to expose a large percentage of the tree's foliage to sunlight thus making the leaves more efficient in the production of food for the development of fruits.

If branches crowd together, humidity within the canopy of the tree increases--a condition that diseases.

High humidity around the flowers provides suitable conditions for fungal spores to penetrate developing fruits; thus pruning serves to reduce the moisture while increasing light inside the tree canopy. 

2. Control size and vigor

Avocado trees become tall and dangerous if structural pruning is not carried out.

Varieties such as Fuerte can reach a height of 10 meters which makes harvesting hard and hazardous. Pruning, therefore, helps to make the tree of a manageable height.

3. Maintain yield and quality

The market prefers bigger fruits, but when a tree bears an unusually high number of developing fruits, they tend to be smaller.

To discourage the production of many small avocado fruits, we remove some of the developing fruits (thinning out)--a practice will tend to produce heavier avocadoes.

4. Bring neglected Avocado trees back into condition

Pruning stimulates the growth of new shoots and rejuvenates old trees.

TYPES OF PRUNING

1. Training provides the basic framework of the tree as it grows from a seedling to a mature tree.

2. When the tree is fruiting, we carry out Renewal pruning. Its purpose is to remove weak or dead material and control or encourage vigor.

If the tree is growing too tall, the strong vertical growth is cut or headed back.

3. Thinning out is involves the removal of excess fruits when the tree has very many of them. Thining out discourages biennial bearing which is a tendency for some trees to produce bumper harvests one year and poor ones the next.

WHEN TO PRUNE AN AVOCADO TREE

1. During transplanting the first pruning takes place at this stage. We trim any broken or very long roots so that they can fit into the planting hole.

2. At the close of harvest and before flowering For mature plants, pruning is typically carried out at this stage. Excess branches are removed to open up the tree to air and light.

Grafted avocado plants sometimes produce suckers.  Removing these suckers is a part of pruning. Suckers are those shoots that emerge from the rootstalk that have the potential to grow into new plants.

When suckers are left to grow, they will compete with the tree for nutrients and eventually reduce the yields of the main tree.

3. When the tree has produces very many fruits we remove some of them to encourage the remaining ones to grow bigger.

This process of removing some fruits is known as thinning out; a process that discourages biennial bearing.

A guide is correct tree height is to prune, so that canopy height becomes 70% of row width with triangular shape for the best light interception.

Precautions During Pruning of Avocado Trees

Any damaged or broken growth must be removed using a setaceous, a sharp panga or pruning saw.

To prevent the transfer of viral diseases from tree to tree, you once you finish pruning one tree, you must sterilize the pruning tools before you move to the next tree.

Sterilization of pruning tools is easy. All you have to do is It means dip the pruning-devices in a disinfectant of 20% household bleach solution between trees to prevent spreading of any sap–borne diseases such as viral infections or fungal problems like Phytophthora from an infected plant to healthy ones.

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PRACTICES DURING HARVEST AND COOLING LEADING TO CONTAMINATION OF FARM PRODUCE

Contamination of fresh produce by Microbes can occur easily during harvesting.

Contamination is commonly caused by field workers or by the physical environment of the produce.

Environmental sources of contaminants include soil, water, air, hands, containers, etc.

Preventing contamination of produce with pathogens is critical, since their presence increases the risk of illness for consumers and lowers food safety.

Contamination of agricultural produce during harvest

Some products like grapes and strawberries; are manually harvested, never cooled nor washed at harvest and packed in the field immediately after harvest.

Packing in the field generates a condition where contamination can occur easily from soil, other solid contaminants and disease causing microbes from the hands of the packer.

Since manual harvesting (the use of hands during harvest) is involved, there is a great deal of handling and contamination of the product is likely.

Some farmers use water taken directly from rivers or holding ponds for washing produce whose safety is doubtful.

When fruits and vegetables are immersed in such water containing pathogens, they can become contaminated.

Others do not clean machines for use in harvesting and handling produce before and after use, a practice that allows residues from the previous harvest to contaminate the new harvest.

Others handle containers and packing materials carelessly, allowing them to be full of dirt and other contaminants.

How produce is contaminated during cooling

Cooling methods using water and ice as the cooling media have the greatest potential for contamination of fruits and vegetables.

It is crucial that ice used in cooling is produced from chlorinated, potable water and stored in a hygienic manner.

Water and ice used for cooling systems should be free of bacterial contamination.

Practices that minimize contamination of agricultural produce

Add an approved disinfectant  to keep  water free from micro-organisms.

These include disinfectants such as sodium hypochlorite, calcium hypochlorite or liquid chlorine.

Good hygienic practices should be followed in handling containers and packing materials to prevent product contamination.

It is important to place a water settling and filtration device in the cooling-water treatment system to remove organic material.

Cooling water should be replaced regularly (at least once a day, depending on the amount used and condition of the produce).

Sick people should not be allowed to work in the farm especially during harvest as some diseases like typhoid among others are spread though contact.