Yield, fruit quality, and survival of 'Pêra' sweet orange on eight rootstocks in tropical cohesive soils

Abstract: The objective of this work was to determine the influence of eight rootstocks on the yield, fruit quality, and survival of 'Pêra CNPMF D6' sweet orange (Citrus sinensis) trees grown under rainfed conditions in a cohesive soil of the Brazilian Northeast. In 2014-2018, the yield, fruits, and survival of trees planted in 1997 were evaluated in a randomized complete block design. Yield was assessed using annual fruit production, yield efficiency, and the alternate bearing index. Tree survival was considered the percentage of plants that remained alive until 2018. Fruit quality was evaluated by physicochemical attributes. 'Cravo' confirmed its good yield performance. Despite the lower number of trees, the 'Mazoe' rough lemon rootstock induced the highest fruit yield. The 'Cravo' x 'Cleópatra' hybrid and 'Volkameriano' lemon favored the highest trees survival, whereas 'Indio' citrandarin and 'Cravo' lime resulted in intermediate levels. The 'San Diego' and 'Riverside' citrandarins induced shorter tree with a high yield efficiency and a higher alternate bearing index, respectively. Fruits with less juice and mass were induced, respectively, by 'Riverside' citrandarin and 'Volkameriano' lemon. It can be concluded that the 'Mazoe' rootstock induces a higher fruit yield and 'Cravo' x 'Cleópatra' and 'Volkameriano', a greater survival. In addition, all rootstocks, except 'Riverside' and 'Volkameriano', induce fruit that meet the minimum quality requirements.

摘要：本研究旨在探究8种砧木对巴西东北部黏重土壤中雨养条件下种植的‘Pêra CNPMF D6’甜橙（*Citrus sinensis*）的产量、果实品质及树体存活率的影响。2014-2018年，研究人员对1997年定植的果树采用随机完全区组设计开展试验，评估其产量、果实量及存活率。产量通过年度果实总产量、产量效率及隔年结果指数进行评价；树体存活率以2018年时仍存活的植株占比计算；果实品质则通过理化属性进行测定。
‘克拉沃’砧木表现出优异的产量性能。尽管存活植株总数较少，但‘马佐埃’粗柠檬砧木的果实产量最高。‘克拉沃’ב克利奥帕特拉’杂交砧木与‘沃尔卡梅里亚诺’柠檬砧木的树体存活率最高，而‘印第奥’枳橙与‘克拉沃’酸橙砧木的存活率处于中等水平。‘圣迭戈’与‘里弗赛德’枳橙砧木分别使树体更矮化，且前者具有较高的产量效率，后者的隔年结果指数更高。‘里弗赛德’枳橙与‘沃尔卡梅里亚诺’柠檬砧木分别导致果实汁液含量与单果重降低。
综上，‘马佐埃’砧木可获得更高的果实产量，‘克拉沃’ב克利奥帕特拉’与‘沃尔卡梅里亚诺’柠檬砧木的树体存活率更优。此外，除‘里弗赛德’与‘沃尔卡梅里亚诺’柠檬砧木外，其余供试砧木所结果实均符合最低品质要求。