The average global production of potatoes is 17.4 tons per hectare with USA considered as the most productive country, with an average of 44.2 tons per hectare.

Experts say there is a large gap between high and low yields between countries even for the same potato varieties.

The yield gap between farms in developing and developed economies represents a loss of opportunity of more than 400 million tons of potato production, depending on the crop varieties, seed viability and quality, crop management practices and the environment where the crop is grown.

This is what has been revealed by agricultural experts in a Chinese Journal, Chilean agricultural research journal about potato growing using aeroponic technology.

The experts say application of new technologies will increase potato yields thereby contribute to food supply and farmer incomes in developing countries.

As such scientist have developed different methods examining the physiology of soilless potato tuber growth as alternatives to using field-grown plants.

These methods include the zone-separation in which the tuber formation is separated from soil and root cuttings in vitro culture solution resulting in culture hydroponics and aeroponics.

The experts anticipate that a farmer or scientists developing potato tubers for seed production will end up acquiring clean seeds because challenges such as heat stress, floods, disease and pest attacks will be avoided.

In Uganda scientists at Makerere University Agricultural Research Institute (MUARIK) Kabanyolo are using hydroponics technology for growing tomatoes while those in Kachwekano Zonal Agricultural Research and Development Institute (KaZARDI in Kabala are suing aeroponics for producing Irish potato seeds.

Seeds of Gold caught up with the experts at KaZARDI to explain modalities of application of aeroponic technology in potato seed production and below are the details

Dr Prossy Namuga in charge of the Aeroponics unit at KaZARDI defines the technology as a modern technique for growing agricultural plants by providing a nutrient solution in the air without soil. Plant roots receive a nutrient spray mist from an atomizing nozzle.

She notes that the aeroponic system is the best system for producing potatoes seed because using this approach, plant roots can be quickly nourished under controlled conditions.

The different Potato seed breeding methods

She explained that there are many potato breeding techniques in the world including conventional, micro- propagation, hydroponics, and aeroponics.

However for potato seed propagation, most farmers use the conventional methods of producing seed tubers in developing countries.

Although all the methods have their limitations and challenges, traditional techniques have the greatest limitations in relation to producing high quality seed under the conditions faced by under-resourced farmers.

In the conventional system, seed potato tubers are commonly used for propagation and production.

During the growing season, if the mother plant is infected with a disease, each new tuber may also be infected.

Moreover, seed potato growers discard poor quality seeds and must select higher quality, healthy tubers as seeds. Diseased and healthy plants are identified and isolated, and the healthy tubers are used for the next production season. 

Tissue culture

The science of cultivating plant tissues on artificial media from the parent plant is known as tissue culture and it is one of the new technologies leading to rapid daily propagation. Tissue culture is very flexible and provides high expansion within a short period of time.

Tissue culture requires very expensive specialized equipment, most of which has a very high operating cost for that reason most developing countries do not promote this system. In addition, the different growth regulators used for making growth media such as vitamins, energy, and nutrients, are very expensive.

Hydroponics

The hydroponic production of crops is characterized by propagation in solutions of water and nutrients which can be set up with or without the addition of a growth medium to provide mechanical support to the plant’s root system.

This requires artificial plant media such as charcoal, rock wool, clay granules, peat moss, gravel, sawdust and coconut shells are used for plant growth in green house.

Hydroponic systems are currently used for education, research, personal gardening of vegetables such as tomatoes, potatoes, spinach, and lettuce including fruits such as strawberries and cucumbers.

However, most hydroponic systems are operated automatically using controlled nutrients, lighting times and water volumes according to the needs of the plants. This system can be practiced in an open land meaning farmers in developing countries can resort to this as an alternative.

Aeroponics system

Aeroponics is a technique that is more or less similar to hydroponics. The only difference is that under aeroponics, plants are grown with the help of support and fine droplets of nutrient solution and they do not need a single particle of soil or substrate to support the plants.

The technique allow for higher growth rates and healthy, uniform and vigorous potato tubers. This can produce up to 10 times the yield of conventional production systems.

Aeroponics techniques are credited for making potato production more efficient and can reduce the number of steps in the potato seed multiplication costs as well as plant health and quality of the first field.

Potato earoponics

Greenhouse

Dr Namuga notes that for potato production, a normal greenhouse structure should provide a safe environment with minimal investments.

This approach will allow reduction of production costs and plants should be protected from adverse factors and pests by a controlled climate.

The location of the greenhouse is also an important factor with respect to heat during the daytime. The floor of the greenhouse should be leveled properly for smooth plant growth.

What is required?

There has to be constant source of water, power, good planting materials and treatment of the plants where in vitro plants may be placed in a light environment immediately after growing in a test tube. They can also be moved directly to the aeroponic boxes where the plants grow.

In aeroponics systems, the roots of the plants receive a nutrient spray mist which enables their growth.

A fine spray that uses air to atomize the liquid is known as pressure atomization. In most cases, high-pressure air is supplied through the air compression vessel to operate the air-atomizing nozzle when small droplets are required.

For potato plants, light energy is an important environmental factor required for controlled cultivation. The light intensity and quality not only provide energy but they also provide for a large number of morphogenesis and physiology-related responses during plant growth

Nutrient solution

The different nutrient solutions required by each potato grower depend on the water quality, the chemical used in the preparation of the nutrient solution and the varieties

Harvest and handling of minitubers

Early maturing potato varieties begin to produce minitubers after 2 weeks of transplanting. When the minitubers are 8grams it is best to harvest them when it is cool in the morning.

This will enable consequent tuber growth and after every 10 to 14 days subsequent harvests may be performed. The harvest lasts until the plant reaches approximately 6 months old.

The advantage of this system is that, farmers practicing agriculture in drought stricken areas can use this technology successfully.

Those in limited land area and outcome will be able to get good yields per unit area per year and production has nothing to do with any seasonal adverse effects, such as hot, dry, cold or windy weather. The crop can be planted all year round.

Dr Namuga and team have been able to produce quality Irish potato seed which they sell to seed multiplier with each kg sold at Shs150, 000.