Silage maturity of maize in a foothill area with NIRS method support

Abstract

The aim of this work was to identify and quantify the relationships between the classification of maize (Zea mays L.) hybrids into FAO groups and the dry matter content in the dynamics of vegetation development in a foothill area. The work summarises the results of 9 experiments (140 hybrids, 20 FAO groups). Determining dry matter content was made by a combination of gravimetric determination and NIRS method. Dynamics of the development of dry matter content were evaluated at the level of vegetation days and calendar days. The assessment at the level of the calendar day has sufficient informative value and is more suitable for practical use. Climatic factors were expressed by the index of the relative condition of field crops (RKPP) and we monitored their influence on the dynamics of the development of dry matter content. We found statistically significant differences in the RKPP index between the harvest seasons in each area and at one of the three monitored localities. ± 1 unit of RKPP means a shift of ± 2.66 days of silage maturity. We defined the silage maturity in terms of reaching a dry matter content of 30%. In individual experiments, it was reached on average on the 273rd day, but in a wide range of 40 days. This range was 44 days at the level of individual hybrids and the level of FAO groups. The FAO230 group (the most numerous) range of silage maturity reached 28 days. We have compiled a proposal for a model for the evaluation of silage maize hybrids based on silage maturity. The results show that the use of FAO maturity groups does not provide a suitable basis for estimating silage maturity.