Determination of nutrient solutions for potato (Solanum tuberosum L.) seed production under aeroponics production system

Abstract

In soilless culture like aeroponics, nutrient optimization is the most critical factor to produce high quality and high yield of clean potato seed. Each crop has an optimum nutritional requirement. Even each potato cultivar may require a specific nutrient solution in an aeroponics unit. A nutrient optimization experiment was conducted at Holetta agricultural research center to study the effect of different nutrient solution levels on the physical quality and yield of potato mini-tubers. The treatments were four different nutrient solutions of greenhouse grade macro nutrients measured in (g) for the preparation of 500 liter volume of nutrient solution that is to be restocked when the nutrient tank becomes empty. The nutrient EC and pH were adjusted as per the requirements. A=(118 g CaNO3, 252 g KNO3, 68 g KH2PO4 and 100 g MgSO4),B=(59 g CaNO3, 126 g KNO3, 68 g KH2PO4 and 100 g MgSO4), C=(118 g CaNO3, 252 g KNO3, 68 g KH2PO4 and 100 g MgSO4 until flowering and reduced by half after flowering), and D=(118 g CaNO3, 252 g KNO3, 136 g KH2PO4 and 100 g MgSO4). All treatments included 2.2g of Fe EDTA and 6 g of Fetrilon combi. The potato variety, Belete, was used for the experiment. Acclimatized plantlets were planted randomly in each box of four treatments in CRD design with three replicates. The results showed that each treatment varied in nutrient consumption rate. Treatment A took the highest amount of nutrient (3.29 kg, 28%), treatments B and D consumed the same amount (3.1 kg, 27%), while treatment C consumed the smallest amount (2.02 kg). Root length was significantly affected by nutrient solutions. Nutrient solution C resulted the maximum root length (300.8 cm), while nutrient solution A produced minimum root length (135.5 cm). Plant height was not significantly affected by nutrient solutions. Small size tubers (<8 g) were not significantly affected by either tuber number or weight. Medium (8-12 g) and large size tubers (>12 g) were significantly affected by nutrient solutions both in number and weight. The maximum tuber numbers was obtained from treatment B. Therefore, the experiment indicated that treatment B represents the optimum nutrient concentration rate to use in an aeroponics mini-tuber production system under Holetta conditions.