Liming and Rhizoctonia root rot of soybean

The objective of this study was to verify the effect of liming on the incidence of Rhizoctonia root rot and the limestone dose that provides the highest soybean yield in four fields with different soil classes. The treatments were arranged in a factorial scheme of 4 fields with different soil classes (Paleudult, Cambisol Ta, Cambisol Tb and Nitosol) x 2 sites within each field (inside and outside of the patch) x 4 doses of limestone (0, 3, 6 and 9 Mg ha-1). The experimental design within each site in the field was in a complete randomized block with four replications. The variables evaluated were: incidence (%) of the disease (INC); area under the disease progress curve (AUDPC), soybean yield (YIELD), height (cm) of plant (PLH), height (cm) of insertion of the first pod (INSH), number of branches per plant (BRA), number of nodes per plant (TNOD), number of fertile nodes per plant (FNOD), number of pods per plant (PODS), and number of grains per plant (GRAINS), 1000-grain weight in grams (WEIGHT), and number of plants per meter (PLANTS).本研究旨在验证石灰施用对丝核菌根腐病（Rhizoctonia root rot）发病率的影响，以及4个不同土壤类别的田块中可实现大豆最高产量的石灰施用量。试验处理采用析因设计：4种不同土壤类别的田块（Paleudult、Cambisol Ta、Cambisol Tb和Nitosol）×每个田块内的2个样点（斑块内外）×4个石灰施用量梯度（0、3、6和9 Mg ha⁻¹）。各田块样点内的试验设计为完全随机区组设计，设置4次重复。本研究测定的指标包括：病害发病率（INC，%）、病害进展曲线下面积（AUDPC）、大豆产量（YIELD）、植株株高（PLH，cm）、第一荚着生节位高度（INSH，cm）、单株分枝数（BRA）、单株总节数（TNOD）、单株有效节数（FNOD）、单株荚数（PODS）、单株粒数（GRAINS）、千粒重（WEIGHT，g）以及每米行长植株数（PLANTS）。