Pinto Cleide M F, Maffia Luiz A, Berger Richard D, Mizubuti Eduardo S G, Casali Vicente W D
EMBRAPA/EPAMIG/CRZM, 36570-000, Viçosa, MG, Brazil.
Universidade Federal de Viçosa, Departmento de Fitopatologia, 36571-000, Viçosa, MG, Brazil.
Plant Dis. 1998 Oct;82(10):1142-1146. doi: 10.1094/PDIS.1998.82.10.1142.
In the region of Amarantina, Minas Gerais state, Brazil, four annual experiments with garlic (Allium sativum) were established in fields infested with Sclerotium cepivorum, causal agent of garlic white rot, to investigate the effect of time of planting on the day when disease was first noticed (t), incidence at harvest (y), duration of epidemics (t - t), and the response of five cultivars to white rot. Most epidemiological parameters were similar among cultivars. In 1986 to 1988, no white rot was observed on garlic planted during the warm temperatures in January. The average onset of white rot occurred at different times dependent on the day of planting as average temperatures decreased from January to May. That is, for February plantings, onset occurred after 93 to 140 days (between 1 June and 5 July); for March plantings, about 90 days (15 to 28 June); for mid-April plantings, about 77 days (1 July); and mid-May plantings, about 66 days (20 July). Because of these different times of onset, the average duration of epidemics was shorter for crops planted in February (30 days) compared to crops planted in March (48 days) or April to May (54 to 69 days). In general, most disease (highest incidence and longest duration) occurred on crops planted in March to May. Therefore, severe losses to white rot would be expected when garlic is planted at the traditional times (March and April) in areas infested with sclerotia of S. cepivorum. The early planting of garlic is recommended as an important management strategy to avoid white rot in areas with these infested soils.
在巴西米纳斯吉拉斯州的阿玛兰蒂纳地区，在遭受洋葱核盘菌（大蒜白腐病的病原菌）侵染的田地里开展了四项大蒜（葱属）年度试验，以研究种植时间对首次发现病害当天（t）、收获时发病率（y）、流行持续时间（t - t）的影响，以及五个品种对白腐病的反应。各品种间的大多数流行病学参数相似。1986年至1988年期间，1月份温暖温度时种植的大蒜未观察到白腐病。随着1月至5月平均气温下降，白腐病的平均发病时间因种植日期而异。也就是说，2月种植的，发病发生在93至140天之后（6月1日至7月5日之间）；3月种植的，约90天（6月15日至28日）；4月中旬种植的，约77天（7月1日）；5月中旬种植的，约66天（7月20日）。由于发病时间不同，2月种植的作物流行平均持续时间（30天）比3月种植的（48天）或4月至5月种植的（54至69天）短。总体而言，大多数病害（发病率最高且持续时间最长）发生在3月至5月种植的作物上。因此，在受洋葱核盘菌菌核侵染的地区，按照传统时间（3月和4月）种植大蒜时，预计会因白腐病造成严重损失。建议将大蒜早播作为在这些受侵染土壤地区避免白腐病的一项重要管理策略。
