Influence of the winter rape plant habitus on the performance

Abstract

Purpose. To investigate the performance peculiarities of winter rape accessions differing by habitus, depending on the contributions of the central and lateral branches.

Materials and methods. The study was conducted at the Plant Production Institute named after V.Ya. Yuriev of NAAS in 2014–2017, winter rape varieties of different eco-geographical origin and habitus were studied in the Eastern Forest-Steppe of Ukraine. The growth and development of winter rape plants were observed.

Results and discussion. The contributions of the number of primary branches, as well as the number of pods and seed weight from the central branch to the performance of winter rape plants with cylindrical habitus were largest. In plants with spherical habitus, the performance was attributed due to better branching, primary, secondary and tertiary branches as well as to the number of pods per plant.

Varieties of spherical habitus were most productive, with the sample average weight of seeds per plant 46.72 g, which is by 26.5% higher than that in varieties with cylindrical habitus of plants.

There was the closest and most significant correlation between the number of pods per plant and the number of pods from the central branch for rape plants with cylindrical habitus (r = 0.8). In plants with spherical habitus, this correlation was positive, but medium (r = 0.49).

In rape plants with cylindrical habitus sown thinly, the number of pods and the weight of seeds from the central branch did not significantly affect the weight of seeds per plant. This fact is explained by the development specificity of plants with cylindrical habitus with erectoid branch position, which does not favor additional branching. Plants with spherical habitus sown thinly branch intensely, and the central branch develops better. Therefore, there was the closest correlation between the central branch development (number of pods, seed weight) and the weight of seeds per plant.

Conclusions. Upon thinned sowing, different components contribute to the performance of plants with cylindrical and spherical habitus. In plants with cylindrical habitus, there was the closest and most significant correlation between the number of pods on the central branch and the number of pods per plant (r = 0.80), however, the correlation between the number of pods on the central branch and performance was insignificant (r = 0.03).

In plants with spherical habitus sown thinly, the correlations between all the traits under investigation (weight of seeds per plant, weight of seeds from the central branch, number of pods per plant, number of pods on the central branch) were positive and medium.

When selecting for performance, one should take into account the plant habitus and focus not only on the number of pods on the central branch, but also on the number of pods on lateral branches.

These results can be used to determine the seeding rates for rape varieties with different habitus.