Evaluation of potting mix composition on potato plantlet tuber production under greenhouse conditions 1 1

Abstract

Tissue culture is currently used by many seed potato (Solanum tuberosum L.) programs enabling the production of high quality, disease free seed potatoes. Potato plantlets produced by micropropagation are planted in greenhouses to produce tubers for further multiplication in the field. The objective of this study was to develop a potting medium that would maximize potato tuber production under greenhouse conditions. Two studies were conducted evaluating different combinations of vermiculite, sand and perlite. In each study where nutrient solutions were applied weekly, vegetative weight, number of stems and potato tuber weight were evaluated. Potting media had significant effects on vegetative plant weight, number of tubers and tuber weight. Significant positive relationships between percent vermiculite in the potting mixture and number of stems (R² = 0.33? and 0.44 ) and tuber weight (R² = 0.63?? and 0.52??) were observed. In the final analysis, a potting mix containing 80% vermiculite and 20% sand provided optimum tuber production in the greenhouse. The vermiculite provided an adequate cation exchange capacity for holding nutrients and high water holding capacity while the sand provided adequate aeration.