The impact of aeration on potato (Solanum tuberosum L.) minituber production under soilless conditions
Aeroponic systems are more effective than hydroponics for minituber production, as provided by the optimal system for root oxygenation. The study was conducted to improve conventional hydroponic systems by applying aeration so as to enhance potato minituber production yield via providing adequate oxygen in the root zone. The responses of Agria and Sante cultivars to different levels of aeration [0 as control, 12.5, 25 and 75% (VAir/Vmedia/min)] were compared, particularly on tuberization and growth characteristics. In both cultivars examined, increasing the level of aeration led to higher number of stolons and tubers. Agria was more responsive and consisted of more large tubers rather than Sante, which influenced the number, yield and dry matter of tubers. Aerated plants had (a) more dry matter in their haulms because of more leaves and shoots, (b) larger leaf areas, and (c) delay in physiological maturity. Higher levels of tuber growth, longer roots and more stolons led to improvements in root: shoot ratio. Leaf area index duration increased remarkably by increased aeration. These features resulted in a remarkable rise in the total minituber number up to 3600/m2 which were 70% higher compared to the non-aerated group. Moreover, the minituber yield was achieved by applying the moderate level of aeration to 23.9 kg/m2 in Agria and high level of aeration to 17 kg/m2 in Sante rather than 8.73 and 6.51 kg/m2 in the control group, respectively.
Key words: Aeroponics, hydroponics, dissolved oxygen, minituber, potato, tuberization.