Bassanezi R B, Montesino L H, Sanches A L, Spósito M B, Stuchi E S, Barbosa J C
Departamento Científico, Fundecitrus, C.P. 391, 14801-970, Araraquara, SP, Brazil.
Embrapa Mandioca e Fruticultura Tropical/Estação Experimental de Citricultura de Bebedouro, CP 74, 14700-971, Bebedouro, SP, Brazil.
Plant Dis. 2007 Nov;91(11):1407-1412. doi: 10.1094/PDIS-91-11-1407.
Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize and quantify CSD damage, fruit yield and quality were assessed in each combination of sweet orange cultivar (Hamlin, Pera, Natal, and Valencia), age class (3 to 5, 6 to 10, and 11 to 15 years old), and CSD severity class (0 = no symptom, 1 = initial symptoms, and 2 = severe symptoms). For each combination, 10 trees were harvested and 20 fruit were taken for quality analysis. Damage was characterized by reduction of: (i) total weight of fruit/tree (36 and 67% for severity class 1 and 2, respectively), (ii) number of fruit/tree (27 and 55%), (iii) fruit size (13 and 25% in diameter and height [stem to styler distance]), (iv) fruit weight (32 and 56%), (v) total soluble solids (TSS)/fruit (18 and 42%), and increase of (vi) Brix (14 and 34%), (vii) acidity (16 and 41%), and (viii) TSS/90-lb. box (21 and 33%). There was no alteration on Brix/acidity ratio and percentage of juice on fruit of affected trees. Sweet orange cultivars did not differ in percentage of reduction or increase of all yield and quality variables, with the exception of Pera, which expressed increases of Brix and acidity. For more severe affected trees, the youngest plants showed a higher reduction in fruit number/tree, whereas plants 6 to 10 years old showed a higher increase in fruit acidity and TSS/box. However, no differences in percentage of reduction or increase for other variables were observed among different age classes. The damage to the above probably was associated with reduced water absorption capacity of CSD-affected trees.
柑橘猝死病（CSD）对巴西圣保罗州和米纳斯吉拉斯州嫁接在兰普莱檬上的甜橙品种造成了极大影响。为了描述和量化CSD造成的损害，对甜橙品种（哈姆林、佩拉、纳塔尔和巴伦西亚）、树龄类别（3至5年、6至10年和11至15年）以及CSD严重程度类别（0 = 无症状，1 = 初期症状，2 = 严重症状）的每种组合的果实产量和品质进行了评估。对于每种组合，收获了10棵树，并选取20个果实进行品质分析。损害的特征表现为以下方面的降低：（i）每棵树的果实总重量（严重程度类别1和2分别降低36%和67%），（ii）每棵树的果实数量（降低27%和55%），（iii）果实大小（直径和高度[果梗到花柱距离]分别降低13%和25%），（iv）果实重量（降低32%和56%），（v）每个果实的总可溶性固形物（TSS）（降低18%和42%），以及以下方面的增加：（vi）糖度（增加14%和34%），（vii）酸度（增加16%和41%），以及（viii）每90磅箱的TSS（增加21%和33%）。受影响树的果实的糖酸比和果汁百分比没有变化。除了佩拉甜橙表现出糖度和酸度增加外，所有产量和品质变量的降低或增加百分比在甜橙品种之间没有差异。对于受影响更严重的树，最年轻的植株每棵树的果实数量减少幅度更大，而6至10年树龄的植株果实酸度和每箱TSS增加幅度更大。然而，在不同树龄类别之间，其他变量的降低或增加百分比没有差异。上述损害可能与受CSD影响的树的吸水能力降低有关。
