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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Fig leaf tea processed from fig (Ficus carica L.) leaves has type I allergy suppressive effects. The presumed inhibitory mechanism of fig leaf tea, the dissociation of IgE antibodies from inflammatory cells, could be applied in developing new anti-allergic foods. Therefore, this study aimed to explore the efficacy of fig leaf tea on a small scale as a pilot study for a large-scale human intervention study. Participants with cedar pollinosis were divided into fig leaf tea and green tea intake groups (five participants per group), and each tea was consumed for eight weeks. IgE antibody titers and subjective symptoms worsened in both groups with increasing pollen dispersal. However, nasal examinations indicated a trend toward improvement during the study period. The proportion of Th2 cells was significantly lower in the fig leaf tea group. Therefore, fig leaf tea-induced reduction of Th2 cells was linked to the trend of nasal symptom improvement. Future research into the efficacy of fig leaf tea in alleviating hay fever could use water or other non-bioactive substances as a placebo and nasal symptom assessments as the primary outcome.

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