Description and evaluation of a device for measuring vertical pulling resistance in maize (Zea mays L.)

Abstract

A plant pulling device was developed to measure vertical pulling resistance in maize as evaluation method for root lodging resistance. This device allows pulling in a standardized way because it is operated by an alternating current motor with ample capacity so as not to slow down during pulling. Due to its small proportions it remains easily manoeuvrable within the experimental field. Four replicated experiments (three with single cross hybrids and one with populations) on two locations (with sandy and clay soil) were carried out to estimate various statistical and quantitative genetic parameters of pulling resistance. The number of plants pulled per plot ranged from four to seven. The mean coefficient of environmental variation was 0.14 and the heritabilities for pulling resistance in the used material, based on experimental units, ranged from 0.61 to 0.77. Selection for pulling resistance seems therefore very well possible. The correlation between the pulling values from a location with clay soil and a location with sandy soil was 0.87, so genotype × environment-interaction was small. It is argued that one obtains reliable results with the least effort by using three replications and pulling four plants per plot.