The dissertation is devoted to the study of the processes of growth and
development of corn hybrid plants, the formation of its photosynthetic productivity
with the search for optimal options for the maximum implementation of the
specified processes in the quantitative and qualitative indicators of the formed crop
at different sowing rates and optimization of the fertilizer system.
The dissertation studies the features and patterns of dry matter growth of
corn hybrid plants in relation to the development and formation of their leaf
surface.
We conducted experimental studies with corn hybrids of foreign selection
with high grain productivity potential, determined effective plant nutrition
parameters using elements of biologized cultivation technologies, which in turn
contributed to the formation of high productivity and increased economic and
energy efficiency of cultivation.
It was found that the use of biofertilizer on the background of mineral
fertilizer significantly affected the height of plants, photosynthetic and grain
productivity of the studied corn hybrids. Thus, on average over the years of
research, the most productive combination of technological methods was the
application of Groundfix biofertilizer at a rate of 6 l/ha on the background of
complete mineral fertilizer N1 2 0P6 0K6 0 , with these variants recording the maximum
plant height in the experiment from 210.8 cm to 222.2 cm in the P8834 hybrid
(FAO 280) and from 216.4 cm to 226.3 cm in the P9074 hybrid (FAO 330),
depending on the sowing density. It is worth noting that in variants with a higher
seeding density (70 thousand/ha), due to competition for moisture and nutrients,
plants were 4.1 cm - 11.4 cm taller than crops with a density of 65 thousand/ha.
Studies have shown that this model of corn hybrid cultivation technology
provided the formation of the highest photosynthetic productivity of crops in the
experiment, while in the flowering phase, at a plant density of 65 thousand/ha, the
leaf surface area of the hybrid P8834 (FAO 280) was 42.4 thousand m /ha, and that
of the hybrid P9074 (FAO 330) was 41.1 thousand m2/ha, increasing the seeding
density to 70 thousand/ha provided an increase in leaf area by an average of 4.6
6.6% to 43.0 and 45.2 thousand. m /ha. The photosynthetic potential was 3.316 -
9 9
3.198 million m xday/ha and 3.542 - 3.385 million m xday/ha.
It was established that the optimization of mineral nutrition of corn plants
by applying the biofertilizer Groundfix (6 l/ha) on the background of N120P60K60,
contributed to the formation of the maximum in the experiment indicators of
individual plant productivity. Thus, on these variants, at a seeding density of 65
thousand/ha, the highest number of grains in a row was formed - 32.8 pcs. in the
hybrid P8834 (FAO 280) and 33.1 pcs. in the hybrid P9074 (FAO 330), the mass
of grains per cob, respectively, 181.8 g and 171.9 g and the mass of 1000 grains
326.7 g and 307.3 g.
On average over the years of research, against the background of complete
mineral fertilizer (N120P60K60), the use of the biological fertilizer Graunfix at a rate
of 4 l/ha provided an increase in the mass of grain per ear, depending on the
density of plants, in the hybrid P8834 by 5.8-8.3%, and at a rate of 6 l/ha by 8.6
10.4%. In the variants of the experiment where the hybrid P9074 was sown under a
similar fertilizer scheme, these indicators were somewhat lower and amounted to,
respectively, 4.2-6.7% and 6.7-10.8%.
It was found that increasing plant density on the area from 65 thousand/ha
to 70 thousand/ha provided a decrease in the mass of grain per cob by 9.2-13.9 g,
or by 7.8-8.4%, depending on the level of fertilization, in the P8834 hybrid and by
10.4-15.6 g, or by 6.4-10.7% in the P9074 hybrid.
7
It was found that grain yield consistently increased when the technological
scheme of corn cultivation was saturated with soil biofertilizer Groundfix and the
seeding rate was increased. The maximum grain yield of 11.15 t/ha in terms of
experimental variants was noted in the variant with the hybrid P8834 sown at a
density of 70 thousand/ha with fertilizer N120P60K60 + Groundfix 6 l/ha.
