The effects of the inorganic elemental composition of liquid fertilizers on rockwool (mineral wool) - cultivated common fig plant growth as well as fruit yield and quality were investigated. ‘Masui Dauphine’ (synonym of ‘San Piero’) plants were grown in plastic pots containing approximately 13 L rockwool and pruned to a single bearing shoot. The cultivation was performed three times in a closed-type plant cultivation room with artificial light. Two types of liquid fertilizer were applied at two concentrations based on the amount of nitrogen. The liquid fertilizers weakly affected shoot growth (length, number of nodes, and leaf color), whereas the fruiting node rate (number of fruits/number of nodes) was clearly affected by the liquid fertilizer type and concentration. Specifically, the fruiting node rate was high for the liquid fertilizer containing high phosphorus and boron contents and low potassium, magnesium and manganese contents. A comparison of the inorganic elemental composition in the leaves after harvest revealed the fruiting node rate was positively correlated with the phosphorus content, but negatively correlated with the iron content. Therefore, these inorganic elements may be important for increasing the fruit yield of common fig cultivated in rockwool.

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Fig trees (Ficus carica L.) are cultivated worldwide, but little attention has been given to their varieties concerning proper classification and fruit-growth dynamics. In this study, we compared the fruit growth characteristics of fig varieties and explored how morphological traits might help with its identification. The selected fig trees were introduced under 37 names and cultivated in an open field at the Toyo Institute of Food Technology. After analysing the similarities between tree and fruit characteristics, they were consolidated into 25 varieties, and 24 were identified as representative variety names based on the literature. Shoot basal width, fruit set date, set rate, enlargement pattern, maturation date and rate, and size and weight at maturation were recorded. Our results showed that (1) the differences in fruit size and maturation time between varieties were primarily determined by the size of the young fruit at the end of enlargement-stage I and the length of enlargement-stage II, respectively; (2) fruit maturation was characterised by order of fruit set, i.e. sequential maturation from the base of the shoots to the tips, although this was disrupted in some varieties by the excessive growth of shoots; and (3) fruit size decreased from the base to the tip of shoots in all varieties, and this pattern was most marked in larger-fruit varieties.

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A study was conducted to determine whether the efficient harvesting of fig (Ficus carica L.) tea leaves is compatible with fruit production. Pinching, lateral shoot disbudding, and leaf thinning were found to produce more leaf volume at one time than shoot disbudding among the leaf removal techniques that are frequently used on ‘Masui Dauphine’ (synonym of ‘San Piero’) fig trees grown in open fields. Leaf thinning, in particular, was considered advantageous in terms of stable harvesting because fixed number of leaves were removed uniformly, resulting in less fluctuation in leaf volume. However, the effect of leaf thinning on the tree and fruit production in ‘Masui Dauphine’ nursery stocks was investigated because its significance was unclear. It was discovered that the leaf thinning promotes fruit coloration as intended, but might slightly reduce the sugar content of the fruit. The advantages and disadvantages of leaf thinning need further research in a large scale cultivation.

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