Satsuma mandarins grafted onto Swingle citrumelo for early season harvest in subtropical conditions in Brazil

ABSTRACT Although Brazil is the sixth producer of mandarins in the world, fresh fruit exports are neglectable, and few cultivars are available for the domestic market. Main harvest season comprises May to November, with Ponkan mandarin and Murcott tangor representing more than 70% of the production. Therefore, there is a need for alternative early season, seedless varieties that should also be preferably resistant to Alternaria brown spot. We investigated the horticultural performance of ten selections of Satsuma mandarin in subtropical conditions in Bebedouro, northern state of São Paulo, Brazil. Clausellina, Okitsu, Unshu SRA-529, Saigon SRA-227, Panaché SRA-579, Salzara SRA-341, Miyagawa SRA-444, Kowano SRA-167, FCAV-59 and A2 60.0 selections were grafted on Swingle citrumelo and evaluated up to 7 years old. Unshu, Miyagawa and A2 60.0 presented the highest tree size. These three selections, in addition to Okitsu and Kowano mandarins, resulted in higher fruit yield for the five first harvests (mean of 31.3 kg∙tree–1∙year–1). Panaché had the smallest yield efficiency. Miyagawa and A2 60.0 selections presented lower alternate fruit bearing in the evaluated period due to their early bearing habit. These same selections had the largest fruits with the earliest maturation; similar to the Okitsu mandarin, but with lower soluble solids and higher juice content. The overall performance of the Satsuma mandarin selections grafted on Swingle citrumelo and drip irrigated was promising under subtropical climate. The Okitsu, Miyagawa and A2 60.0 mandarins were selected because of their highest productive potential and their valuable quality traits for the Brazilian domestic market.

摘要：尽管巴西是全球第六大蜜柑生产国，但鲜果出口量微乎其微，且国内市场可供应的品种寥寥无几。主采收期为5月至11月，其中椪柑（Ponkan mandarin）和默科特橘橙（Murcott tangor）的产量占比超过70%。因此，亟需培育兼具早熟、无核特性，且优选抗链格孢褐斑病（Alternaria brown spot）的替代品种。本研究在巴西圣保罗州北部的贝贝杜鲁（Bebedouro）亚热带种植环境下，对10个温州蜜柑（Satsuma mandarin）品系的园艺性状表现开展了调查。供试的10个品系分别为克劳塞利纳（Clausellina）、日川（Okitsu）、温州SRA-529（Unshu SRA-529）、西贡SRA-227（Saigon SRA-227）、帕纳谢SRA-579（Panaché SRA-579）、萨尔扎拉SRA-341（Salzara SRA-341）、宫川SRA-444（Miyagawa SRA-444）、加纳沃SRA-167（Kowano SRA-167）、FCAV-59以及A2 60.0，所有供试材料均以斯温格尔枳柚（Swingle citrumelo）为砧木，直至树龄7年时完成观测评估。温州、宫川与A2 60.0的树体冠幅最大。这3个品系，连同日川与加纳沃蜜柑，在前5次采收期的单株产量更高，年均单株产量均值达31.3 kg·株⁻¹·年⁻¹。帕纳谢的产量效率最低。宫川与A2 60.0品系在试验周期内的隔年结果现象更弱，这得益于其早实特性。该两类品系的果实个头最大且成熟最早，其品质特性与日川蜜柑相近，但可溶性固形物含量更低，果汁出汁率更高。在亚热带气候条件下，以斯温格尔枳柚为砧木并采用滴灌栽培的温州蜜柑品系，整体表现优异。日川、宫川与A2 60.0蜜柑凭借其极高的生产潜力与适配巴西国内市场的优良品质性状，被选为适宜推广的候选品种。