EFFECTS OF THE NUTRIENT SOLUTION CONCENTR ATIONS ON GROWTH OF FIG PLANT AND FRUIT-QUALITY

Hardwood cuttings of fig cv. Masui Dauphine were grown in nutrient sol utions having electrical conductivities of 1.8, 2.4 or one in which th e EC was reduced from 2.4 to 0.6 dS/m in mid-sea son. The non-circulat ing closed culture system was supplied with a capillary action of rock wool and irrigation; the experiment was designed for double cropping p er year. For the first planting, cuttings were made on Jan. 10 and the rested cuttings were transplanted on Feb. 24. The EC of the 1.8 and 2 .4 dS/m solutions increased gradually to 9.5 and 10.1 dS/m, respective ly, until Jun. 30 when the first crop was harvested. 1. In the EC 2.4 dS/m plot, the amount of solution absorbed by the plant was less than that absorbed by plant in the 1.8 dS/m plot. When the EC was decreased from 2.4 to 0.6 dS/m, the amount of solution absorbed increased from May to harvest. 2. The leaf area of plants which absorbed the least am ount of solution in the three plots was smallest. At harvest the early fruit from the EC 1.8 and 0.6 dS/m plots was larger but Brix of the j uice was lower, compared to fruits from the 2.4 dS/m plot. When the be aring shoots were cut back on Jun. 30, shoot growth was renewed after 12 days. The number of fruits set for the second crop was smaller, bel ow the 10th node, compared to the first crop. Harvest of the second cr op started on Nov. 16 and continued until Dec. 28. 3. The leaf area at the highest node, fruit size and Brix of the juice were smaller than that in the first crop. Many fruits cracked in the plot where EC was d ecreased from 2.4 dS/m to 0.3 dS/m from September to December.