Effects of sowing depth and inoculation with Pseudomonas fluorescens on the initial growth of Urochloa brizantha (syn Brachiaria brizantha ) cv. Marandú

ABSTRACT The aim of the present study was to evaluate the effects of sowing depth and inoculation with Pseudomonas fluorescens on germination, emergence, shoot and root growth of Urochloa brizantha . A completely randomized design was used, in a 6 × 2 factorial arrangement, with 12 repetitions. The following sowing depths (SD) were evaluated: 0, 1, 2, 3, 6 and 12 cm; and the seed inoculation with P . fluorescens (I): with and without. Evaluations were carried out 25 days after plant emergence. No effects of the PS × I or I interaction were observed for all variables evaluated (P> 0.05). The germination and emergence percentages decreased linearly (P 0.05). However, an effect was observed on the shoot:root ratio, where plants sown more superficially had a greater relationship. The inoculation with Pseudomonas fluorescens in the seed, has no effect on the initial growth of Marandu grass. On the other hand, greater sowing depths affects negatively the initial growth.

摘要 本研究旨在探究播种深度以及接种荧光假单胞菌（Pseudomonas fluorescens）对布氏臂形草（Urochloa brizantha）的萌发、出苗以及地上部与根系生长的影响。试验采用6×2因子排列的完全随机设计，设置12次重复。供试的播种深度（SD）梯度为0、1、2、3、6和12 cm；种子接种处理（I）分为接种与不接种荧光假单胞菌两组。于植株出苗后25天开展各项指标测定。所有供试指标均未观测到PS×I交互作用以及接种处理的主效应（P>0.05）。发芽率与出苗率呈线性下降趋势（P<0.05）。然而，根冠比存在显著差异：播种越浅的植株，其根冠比越高。种子接种荧光假单胞菌对马兰杜草的初始生长无显著影响。与之相反，更大的播种深度会对初始生长产生负面影响。