Traditional family households in Japan, like the ones with full-time housewife, have been largely replaced by dual-income households as well as single-person households. This trend has changed the way how vegetables are consumed within and outside households. According to the Ministry of Agriculture, Forestry and Fisheries, nearly 60% of vegetables are now shipped to processing for ready-made meals as well as to food service industry. Unlike households as end users, the commercial users tend to make a strict schedule as to date and quantity of vegetables they aim to purchase, while vegetable growers are requested to prepare the commodities along the schedule. Intermediate wholesalers, who play the coordinating role between commercial users and growers, wish to know in advance the detailed schedule of harvesting for a given region or area. To facilitate the role of the coordinators, it is necessary to develop a practical method to determine the optimum harvest timing, which is currently lacking. The objective of the present study was therefore to investigate potential methods, using field experiment datasets, on Japanese radish (Raphanus sativus L.) and cabbage (Brassica oleracea L. var. capitata), the major vegetables consumed in large quantities in Japan. As for Japanese radish, the crop whose harvestable part is hidden in the soil, two methods were employed based on the relationships between accumulated air temperature and fresh root weight (M1) as well as between cumulative light interception and dry matter weight of the crop (M2). As for cabbage whose harvestable part is visible in the field, alternative two methods were employed based on the relationships between accumulated air temperature and height-to-diameter ratio of head (M3) as well as density of head (M4). M3 gives information as to the formation process of the shape of a cabbage head, which changes gradually from a sphere to an oval sphere-like shape, while M4 shows the degree of its filling. Results are summarized as follows. By using M1, the optimum harvest timing of Japanese radish in two years out of the three-year dataset, was estimated to be 83 and 81 days after sowing (DAS), which were good estimates, considering the state of the roots harvested around those DAS. As for the remaining year, however, it was estimated to be 107 DAS, even though sufficient fresh weight of root was observed at 95 DAS already in the field experiment. This discrepancy between the estimated and the observed DAS was largely attributable to relatively low temperature during growth period in that particular year. Contrary to M1, M2 gave similar estimates for three years including the specific year previously mentioned, i.e., 86, 84 and 83 DAS. M2 is thus considered to excel M1. To further improve the accuracy of M2-based decision making, it is desirable to estimate a leaf area index (LAI) curve, the essential part to derive M2, for every year, which is without doubt labor intensive and costly. Taking several patterns of LAI curves, for example, for usual, cool and warm years could be a practical compromise to handle the issue. As for cabbage, M3 gave a good estimate as to the optimum harvest timing, i.e., 86 and 75 days after planting (DAP) in two years of the field experiment, while M4 gave greater values, 104 and 87 DAP in the same two years. The estimated harvest timings resulting from M3 and M4 were both plausible, judging from the state of the cabbage heads harvested around those DAP. An interesting point was that M3 was suited for determining the beginning of harvest window, and M4 for giving information as to the end of harvest window, as cabbage heads were observed to start bursting after the density of head reached the threshold value of 0.68 g cm⁻³. Combining M3 and M4 is therefore suggested to practically determine the optimum harvest window of cabbage.

‘Fukuakane’ was developed at Kyushu Okinawa Agricultural Research Center, NARO, from 2005 and was registered in 2022. This cultivar was selected from the progeny derived from the cross ‘Takeda Zairai 87E’, which was collected in Oita prefecture, and ‘Kyuko 980-11’, to develop brown red seed cultivar suitable for cultivation in Kyushu region. The seeds of ‘Fukuakane’ is brown red, and larger than that of ‘Fukuyutaka’, which is the leading cultivar in Western Japan. ‘Fukuakane’ is inferior to ‘Fukuyutaka’ in several agricultural traits, such as seed yield, lodging tolerance and green stem disorder tolerance. However, ‘Fukuakane’ is expected to be used for the production of well-characterized soybean food, because ‘Fukuakane’ is the first registered soybean cultivar with brown red seed coat color. The production field of ‘Fukuakane’ was 32 ha in 2022, and expected to expand.

The new rice cultivars ‘Yamadawara’, ‘Emidawara’, and ‘Toyomeki’, officially registered by the Ministry of Agriculture, Forestry and Fisheries in 2014, 2022, and 2017, respectively, have been introduced to exploit the high-yielding ability of ‘Mizuhochikara’, a Japonica-Indica intermediate cultivar. ‘Yamadawara’ and ‘Emidawara’ are suitable for cultivation in the Kanto and Hokuriku regions as well as southern and western areas, whereas ‘Toyomeki’ can be cultivated in these areas as well as flat areas in southern Tohoku. The ripening period of ‘Emidawara’ is shorter than that of ‘Yamadawara’. All three cultivars have high lodging tolerance, and high yields can be obtained by high-fertilizer cultivation. Brown rice yields exceed 70 kg/a when transplanted early and are around 60 kg/a even when transplanted late. These yields are clearly higher than those of common staple food cultivars. The grain quality of ‘Yamadawara’ is inferior to that of ‘Asanohikari’, while that of ‘Emidawara’ is roughly equivalent to that of ‘Asanohikari’. The grain quality of ‘Toyomeki’ is inferior to that of ‘Koshihikari’. In terms of the physical properties of the cooked rice, all three cultivars are harder and less sticky than ‘Koshihikari’. Therefore, these cultivars can meet the demands of food service providers, being less sticky and suitable for cooking on factory lines, or for preparing pilaf or fried rice.

As the vase life of cut dahlia (Dahlia variabilis) flowers is very short, we initiated a research breeding program in 2014 to improve it. We chose 22 commercial cultivars as initial breeding materials, and repeatedly crossed and selected promising offspring with long vase life for four generations, from 2014 to 2021. Fourth-generation selected line 909-4, which has white flower color, and third-generation selected line 916-34, whose flower color gradually changes from bright red to apricot color after harvest were judged to be the most suitable as new cultivars with long vase life. We registered these cultivars with Japan’s Ministry of Agriculture, Forestry and Fisheries and released them as ‘Eternity Moon’ and ‘Eternity Sunset’. These two new dahlia cultivars had genetically determined long vase lives of 8.4 to 12.1 days (1.5 to 2.2 times the vase life of a standard cultivar, ‘Kamakura’) in distilled water, 8.8 to 11.9 days (1.5 to 1.9 times the vase life of ‘Kamakura’) in GLA (10 g·L⁻¹ glucose, 0.5 ml·L⁻¹ kathon CG, and 50 mg·L⁻¹ aluminum sulfate) under 23°C, 12-h photoperiod, and 70% RH conditions in 2021 and 2022. Cut flowers cultivated at five locations nationwide with different cultivation seasons in 2021 and 2022 also showed similar long vase life, clearly indicating that the long vase life of our two cultivars were not due to the environment but the characteristics of cultivars.