‘Rinka’ is an early maturing russet skin type new cultivar of Japanese pear (Pyrus pyrifolia Nakai) released in 2013 by the National Institute of Fruit Tree Science (NIFTS), National Agriculture and Food Research Organization. The cultivar originated from a cross between 269-21 (‘Hosui’ × ‘Osa – nijisseiki’) and ‘Akiakari’ in 1996, was selected as a promising tree in 2006, and subjected to the 8th national trial as Nashi Tsukuba 55 from 2007, which was conducted at 38 experimental stations in 37 prefectures throughout Japan. The cultivar was ultimately selected and released as ‘Rinka’ and was registered as No. 23912 under the Plant Variety Protection and Seed Act of Japan on March 3, 2015. ‘Rinka’ trees were intermediate and produced many fruit spurs and moderate amounts of axillary fl ower buds in the national trial. The date of full bloom of ‘Rinka’ averaged April 20, 2 days earlier than that of ‘Kosui’, and the harvest time averaged August 25, 2 days later than that of ‘Kosui’ in the national trial. It was resistant to black spot and there was no serious problem of diseases and insect pests under standard spraying program. ‘Rinka’ is cross-compatible with other leading cultivars as its S-genotype is S ₁ S ₃ , which is different from them. Since the number of fruitlets per cluster at 30 days after full bloom was averaged 3.1, which was fewer than that of ‘Kosui’ in the national trial, ‘Rinka’ possesses self-thinning trait. The fruit shape of ‘Rinka’ is oblate and uniformity of fruit is medium. The fruit weight averaged 448 g in the national trial, heavier than that of ‘Kosui’. The fl esh fi rmness of ‘Rinka’ was 4.5 lbs, softer than that of ‘Kosui’. The soluble solids content and pH in juice of ‘Rinka’ averaged 12.3% and 4.8, respectively, both of which were lower than those of ‘Kosui’. The eating quality of ‘Rinka’ was judged to be comparable with that of ‘Kosui’. The dead fl ower bud rate of ‘Rinka’ in Kagoshima prefecture (southwestern Japan) from 2011 to 2012 averaged approximately 5%, notably lower than that of ‘Kosui’, which averaged more than 40%. Therefore, ‘Rinka’is expected to be a suitable cultivar for adapting to warmer climate.

Crop cultivate farm in Hokkaido (except for paddies) have continued to their enlarge crop areas since 1960, particularly those for wheat. However, areas used to grow sugar beet have decreased. A lack of labor is currently a serious issue. Therefore, crop rotation may be reduced, resulting in crop damage due to diseases and insects, decreasing farm income. NARO have developed a “6 rows robot seedling planter” and “large 6 rows harvester” for sugar beet as a new technology that can enable crop rotation and increase farm income. Here, we compared operation costs between this new technology and current methods and determined the necessary crop area to operate the new technology. We found that for fi elds larger than 120 ha, the operational cost of the large 6 row harvester was lower than that of current methods. If the 6 row robot seedling planter can plant 1 ha in 2 h, it is 35-60, 70-120, and larger than 140 ha, the operational cost of the new planter will be lower than that of current planters. If this new planter can plant 1 ha per 2.5 h, planting only 35-45 ha will decrease operational costs compared to that of the current planter. Further, about a part of fi eld which farm cannot plant seedling because of lack of capacity of this new planter, farm plant directly it with seed instead of seedling.

We investigated the effect of cartap hydrochloride spraying in mid-May, the optimal time for suppressing first-generation persimmon bark borer (Euzophera batangensis Caradja) larvae, on the suppression of fruit damage caused by the persimmon fruit moth Stathmopoda masinissa Meyrick in a persimmon orchard. Results showed that cartap hydrochloride spraying in mid-May was effective at reducing fruit damage caused by the fi rst-generation larvae of S. masinissa.