Demand of passion fruit for fresh consumption has been increasing. For fresh consumption, low acid content and long shelf life are demanded. Matured fruit abscises from plant and falls to ground, but effects of falling impact on fruit quality were not well determined. Then, fruit was fallen from 30, 60, 90, 180 cm height and fruit quality was estimated and respiration and ethylene production rates during after-harvest were measured. By 90 and 180 cm falling, acidity increased and sugar/acid ratio decreased. By sensory evaluation, the differences were also recognized. By 180 cm falling six of thirty fruits had crack on pericarp, and acidity of the cracked fruit was lower than that of non-cracked fruit. Except for the cracked fruit, no visible damage was observed on external appearance, though inner structure was damaged by 60, 90, 180 cm falling. Juice leaked from aril by 90 and 180 cm falling. Shelf life was shortened by even 30 cm falling because of mold. Respiration rate at just after falling increased as falling distance increased, though six to ten days after falling that decreased as falling distance increased. Ethylene production rate increased one day after harvest without falling, though the rate did not increase with falling. Impact force increased as falling distance increased and acidity increased as impact force increased. In conclusion, fruit quality was reduced by more than 90 cm falling and shelf life decreased by more than 30 cm falling.

In this study, we investigated the rate of brown spotted leaf (BSL) and the rate of leaf fall (LF) in tankan (Citrus tankan Hayata) ‘Tarumizu ichigo’ onto trifoliate orange (Poncirus trifoliata (L.) Raf.) during winter for seven years, and clarified the relation between BSL and LF and the climate conditions. The cumulative rate of BSL and LF in March fluctuated annually in the range of 21.7-99.7% and 5.7-88.3%, respectively. Years with cumulative rate of BSL and LF of 90% or more and 80% or more in March were defined as higher rate years, and years with cumulative rate of BSL and LF of 50% or less and 10% or less were defined as lower rate years. The cumulative rate of BSL and LF in March were related to the average temperature in December. The average temperature in December was 8.5-10.0°C in the higher rate years and 11.5-12.0°C in the lower rate years. The cumulative rate of BSL and LF in March were also related to the precipitation in November. The precipitation in November tended to be lower in the higher rate years than in the lower rate years. In the year when BSL occurred in November, there was little precipitation in November.

To investigate the potential for sugarcane production in sourthern Higashi Mikawa, Aichi Prefecture, a commercial cultivar NiF8 was cultivated over years. Although the study area belongs to temperate zone, the spring-plant and ratoon canes yielded 5.0 – 5.5 t 10a^-1 and 7.0 – 8.0 t 10a^-1 and recorded 12.2 – 14.9% and 13.2 – 15.9% of pol in cane, respectively. Pol in cane continuously increased until late December, exhibiting the maximum value during late December and early January, and decreased thereafter due to low temperatures and frost. As a result, brown sugar could be produced from all cane stalks obtained in the study area. During mid-July to early September, sugarcane showed remarkable growth, and the elongation rate was even greater than in Okinawa. Plant height was high in March- and April-plant canes; therefore, it is recommended to plant sugarcane during late March and late April. The suitable harvest time is considered December before sugar content decreases. Precipitation significantly affected the elongation under rainfed conditions. During end of July to September, the growth rate after rainfall increased once, sometimes over 30 mm d^-1. However it dropped down to 0 – 1 mm d^-1 when fine weather continued, which strongly demonstrated the importance of irrigation. Ratoon cultivation is encouraged since the second ratoon exhibited a greater yield than the plant cane. From the present study, appropriate plant and harvest times were revealed and it is concluded that sugarcane production was sufficiently possible in southern Higashi Mikawa.

Forecasting sugarcane yields from evapotranspiration is useful in Okinawa because water resources are limited and unstable. In this report, the evapotranspiration in a sugarcane field was estimated using the improved tank model that incorporates the radiation method that takes into account changes in soil moisture content. The purpose of this study is to clarify the relationships between estimated evapotranspiration(ΣETe) and dry weight production(DW) in fields where sugarcane is cultivated with different m e t h o d s and in different seasons in the southern part of Okinawa Island. The relationship between ΣETe and DW can be approximated by a logistic curve for new planting and a straight line for ratooning, and a significant positive correlation(new planting, r=0.99; ratooning, r=0.99) was observed. The reason for the early growth in ratoonings is caused by the early increase of sprout and leaf area. The DW estimation contributes to forecast yield, and also to make plans for using irrigation water effectively.

Under greenhouse cultivation of ‘Irwin’ mango, coloring disorder tentatively called red bruise and mottled skin occurs. The red bruise is a symptom of red spots on the fruit skin, and mottled skin is a symptom of red and orange patches on the fruit skin. We investigated the effects of high humidity conditions on coloring disorder and fruit quality in ‘Irwin’ mango. We also investigated the relation between days after full bloom stage (DAFBS) and coloring disorder. The duration of humidity treatment was 21 days from 15 May to 4 June, 2019. During this duration, the relative humidity in the humidification treatment (HT) maintained higher than that in the dehumidification treatment (dHT), and the average value of the vapor pressure deficit in day time was 1.72 kPa in the HT and 10.36 kPa in the dHT. The degree of red bruise, mottled skin and resin fruit was higher in the HT than in the dHT. The degree of red bruise and mottled skin was higher in 70-90 DAFBS than in 80-100 DAFBS. Compared to the dHT, the a* value in the equator and stylar end of fruit was lower in the HT. The sugar content in the HT was lower than that in the dHT by more than 2 ^oBrix. In conclusion, it was clarified that high humidity contributes to the occurring of coloring disorder, and that the sugar content also decreases in ‘Irwin’ mango.

Chrysanthemum indicum of the flower is used as herbal medicines. Since they are wild products and the cultivation method is not established, there are few studies on the suitable nitrogen fertilizer concentration and cultivation in tropical region. Nitrogen foliar application (NF) has immediate effect with a small amount compared to soil fertilization, and it can be expected to increase yield. Therefore, in this study, we first set nitrogen concentrations of 0, 4, 10 and 20 mM in four levels to clarify the optimum soil nitrogen fertilization from growth, and were set different levels of foliar nitrogen fertilizer concentrations of 0, 1, 2, 4 and 8 mM, and were investigated growth, dry weight and flower components. The result of nitrogen fertilization to soil showed that the growth and photosynthetic rate of C. indicum increased when the NF is higher than 10 mM. Furthermore, the dry weight and chlorophyll content were also saturated at 10 mM. The results of NF in addition to 10 mM soil nitrogen fertilization showed that leaf dry weight and leaf area increased significantly above NF 2 mM. The total number of flowers and dry weight of total flowers was significantly higher at NF 8 mM. The total content of flowers in plant was significantly higher at NF 8 mM for 6 components. It was suggested that soil nitrogen fertilization was saturated at 10 mM, and that NF 8 mM nitrogen concentration was optimum reproductive period.