| It is not surprising, then, that avocado farming ticks lots of boxes in our 2030 Vision and most recently in President Uhuru’s Big 4. Food security and agricultural development are key pillars. There is a great deal of talk and action around avocado farming at county level. It is most important to retain our reputation for good quality sustainable production in the Global Market.
Avocados are the fatty fruit of the avocado tree, Persea Americana, native to Central and South America. They have a smooth creamy texture, suitable for young children and a pleasant flavor. They are packed with fiber, and heart healthy mono-saturated fats, and are rich in vitamins and minerals. They are low in sugar, sodium and cholesterol. They contain 1.6 times more potassium than bananas and act as a nutrient booster by increasing the absorption of fat soluble vitamins such as A, D, K and E.
Avocado Farming – where to start
Avocado farming is a long-term project, with initial high costs at planting, followed by a 3-5 year wait for the trees to come into production. To reap healthy rewards, it is essential to do a full risk assessment before you start and maintain a healthy plantation that gives top yields for many years.
Climate and variety
These two are interlinked. Variety is market driven (for e.g. Fuerte is preferred for the domestic market and Hass for export). West Indian cultivars originated in the humid tropical lowlands of Central America and prefer higher temperatures and humidity and do not tolerate frost. The Mexican races are more frost tolerant and grow at lower temperatures and humidity. Guatemalan cultivars originated from tropical highlands and are sensitive to high temperatures (38C) and low humidity (<65%) which cause flower and fruit drop. Fuerte cultivar is a natural hybrid between cultivars and has a wider climatic tolerance.
In general, cool temperatures (mean daily 20-24C) are best because hot dry weather causes fruit drop. Areas with little to no frost. Humidity should exceed 50% at midday especially during flowering, pollination and fruit set. Avocados hate wind. They have brittle branches that snap off easily. Wind damages the fruit.
Water
Rain-fed avocados need >1000 mm rainfall a year, spread out through out the year, with a two-month drier season pre-flowering. Most avocados need irrigating. Plants require about 25 mm water per week. Farmers should ensure that they have access to enough water year-round as droughted avocado trees die fast. Irrigation water quality should be tested. High pH and bicarbonates create a free lime build up in the soil. High salts, sodium and chloride have a very negative affect on the plants.
Planting
Plants should be certified clean, well hardened, grafted plants. Plant the trees as soon as possible to prevent them from becoming root bound or developing nutrient deficiencies. Store plants in the shade, because containers can become hot and the roots can easily burn.
If soil preparation is done properly a small planting hole should be dug, plants placed in the hole and the soil pressed gently in around the roots. Plant trees to the same depth as they are in the planting bag with a slight mound around the base to prevent water puddling on the stem. Young trees are very susceptible to salt damage and a well-prepared orchard should not require fertilizer in the planting hole. Support the trees with sturdy props and whitewash the stems to prevent sunburn.
Proper irrigation is critical to get a good plant stand. Young trees have a very small root system and are used to frequent irrigation. Avocados are very sensitive to moisture stress. Apply frequent light irrigations, and regularly check the subsoil moisture status and apply intermittent larger irrigations to re-fill the subsoil. Note over irrigation is just as harmful as under irrigation.
A thick organic mulch is recommended in young plants to reduce evaporation off the soil and prevent very high and low root temperatures and salinity buildup. As the trees grow and mature they will make their own thick layer of mulch. Very often the feeder roots will establish in this mulch. The mulch also reduces weed competition.
Analysis and Fertilizer Application
A full irrigation water and pre-plant complete soil analysis of top soil and sub soil are required at least 6 months before you plant. Thereafter, an annual soil analysis is required to check the nutrient status of the soil. This should be accompanied by a leaf analysis and irrigation water analysis.
The amount and type of fertilizer required depends on the soil nutrient status, water quality, plant size, plant density and yield expectation. To get good consistent soil and plant status results, 20 healthy, representative, well distributed trees should be marked and the soil and leaf samples taken from these. To get a good fertilizer program going, at least five years of soil and leaf samples should be taken, and the history noted. It is not always possible to correct nutrient in-balances in one season because it is a gradual process.
Young transplanted avocado trees should not be fertilized too early. Trees must first become properly established and vigorously growing (6-12 months). Never apply fertilizer against the stems of the trees. Each fertilizer application should be followed by a light controlled irrigation. DO NOT work the fertilizers into the soil – this will damage the shallow roots. For irrigated trees, fertigation is preferable to prevent soil Electrical Conductivity (EC) spikes and to get an even distribution of fertilizer in the root zone.
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