Articles
EFFECTS OF IONIC STRENGTH OF NUTRIENT SOLUTION ON THE GROWTH AND FRUIT QUALITY OF ‘MUDEUNGSAN’ WATERMELON (CITRULLUS LANATUS THUNB.) GROWN IN ROCKWOOL
Overall plant growth was better in the order of 3/2>1>½X of "Enshi" nutrient solution in terms of plant height, number of leaves, stem diameter, leaf length, and leaf width at fruit development stage.
This indicates that the interaction between nutrient concentrations at the seedling stage and main growth stage was highly significant.
The uptake of nutrients was high in the order of 3/2>1>½X nutrient solutions but water uptake was high in the order of ½>1>3/2X. The fruit quality was best in 1x and worst in half-strength (½X) solution.
In all cases water uptake increased substantially i.e. up to 3 liters in 10 days after transplanting.
The nutrient solution uptake per plant which was 2 to 3 liters at the pollination stage, increased to 3 to 5 liters in 7 to 10 days after pollination, and then decreased to 1 to 2 liters 10 days after pollination.
Water uptake decreased slowly as the ionic strength of the nutrient solution increased, this was also influenced by climatic conditions.
In both slab and drainage the pH value of the nutrient solution rose to 7 to 8 after 10 days of pollination from the initial pH of 6 to 7, but dropped down to 5 to 6 again at the time of harvest.
In conclusion, the optimal nutrient concentration for culturing ‘Mudeungsan’ watermelon was determined as 1 to 2X of "Enshi" nutrient solution when raising seedlings, and 1 to 2/3X until pollination after transplanting, and ½X from pollination to harvest in the main culture beds.