Critical Thresholds of Productivity Analysis due to Influences of Genetics

Abstract

A maize micro-trial network (8 locations) was organized in 2017 by the Romanian Maize Producers Association (APPR) to asses yield capacity and stability of most recent and popular 110 maize hybrids with different FAO maturity groups, from 250-290 till over 500, commercialised by seed industry companies operating in Romania. The aim was to establish critical thresholds of maize productivity analysis and to select and recommend the highest yielding and most adapted maize hybrids, commercialised by the maize seed companies, in different soil and climatic conditions from South and South east of the country, both in irrigated and non-irrigated conditions (drought and heat) for the protection and profit maximization of Romanian farmers from these geographic areas. Year 2017 was very favourable for maize crop so that 6 locations were classified without water stress (average grain yield/location was from over 9000 kg/ha till over 12500 kg/ha). Only two locations were classified with water stress: Caracal (average grain yield/location limited to 4800 kg/ha) and Berezeni, with moderate water stress (average grain yield/location around 7800 kg/ha). Variation coefficient values for both grain yield and grain moisture at harvest were under 10% in most situations, showing a reasonable quality of the data taken into analysis. F values and significance for genotype from ANOVA applied to maize hybrids trials in APPR network, 2017 were in all cases significant for P<0.001, suggesting that there were notable significant differences among tested maize hybrids. Grain yield stability, was described by regression lines between average grain yield in locations with water stress vs. average grain yield in locations without water stress for main FAO maturity groups on the market. Recommendations issued were broadcasted at the level of farmers under the form of a recommended list with the scope to better orient farmers in the multitude of the products offered by the market and to assist them for choosing the most efficient hybrids for their activity area.