Producing high-quality container-grown Scots pine seedlings: the role of substrate composition and plant growth regulators

Date of germinated seed recording	Modifications of substrate composition / number of germinated seeds, pcs.					p-value
Date of germinated seed recording	Bark:peat 2:1 (1)	Bark:peat 1:1 (2)	Bark:peat 1:2 (3)	Bark:peat:forest soil 1:1:1 (4)	Bark:peat:sawdust compost 1:1:1 (5)	p-value
May 13	0.0^{±0.0 a}	0.0^{±0.0 a}	0.0^{±0.0 a}	0.0^{±0.0 a}	0.0^{±0.0 a}	–
May 27	31.0^{±1.0 ab}	22.0^{±1.0 bc}	26.0^{±1.5 ab}	15.0^{±1.0 c}	20.0^{±1.5 bc}	< 0.05
June 3	42.0^{±2.0 b}	43.0^{±2.0 b}	55.5^{±1.5 a}	40.0^{±2.0 b}	39.0^{±2.0 b}	< 0.01
June 22	55.0^{±2.0 ab}	56.5^{±2.0 ab}	63.0^{±2.0 a}	48.0^{±2.5 bc}	42.0^{±2.0 c}	< 0.05
July 6	58.5^{±1.5 ab}	57.0^{±2.0 ab}	63.5^{±1.5 a}	50.5^{±1.0 bc}	42.5^{±1.5 c}	< 0.05

General appearance of Scots pine seedlings in excellent (A), satisfactory (B) and unsatisfactory (C) condition in the experimental container culture

Dynamics of Scots pine seedling condition depending on the tested substrate composition modifications as of 2024

Table 2.

Dynamics of the Average Height of Scots Pine Seedlings Depending on the Tested Substrate Composition Modifications in the Experiment

Control date	Biometric indicators	Modifications of the tested substrate compositions
Control date	Biometric indicators	Bark:peat 2:1 (1)	Bark:peat 1:1 (2)	Bark:peat 1:2 (3)	Bark:peat:forest soil 1:1:1 (4)	Bark:peat:sawdust compost 1:1:1 (5)
March 24	H	4.3^±0.9/5.1^±1.0	4.4^±1.0/5.4^±1.1	4.6^±1.0/5.5^±1.1	3.8^±0.8/4.7^±0.9	4.2^±0.9/5.4^±1.1
March 24	σ	0.7^±0.08/0.8^±0.08	0.8^±0.10/1.0^±0.12	0.8^±0.10/0.9^±0.10	0.8^±0.10/0.9^±0.10	1.3^±0.20/1.6^±0.22
September 2	H	4.1^±0.7/4.9^±0.9	3.7^±0.7/4.5^±0.8	4.4^±0.7/5.2^±0.8	3.6^±0.8/4.5^±0.9	3.6^±1.3/5.2^±1.6
September 2	σ	0.7^±0.05/0.8^±0.05	0.7^0.05/0.8^0.05	0.7^0.05/0.8^0.05	0.8^0.05/0.9^±0.05	1.3^±0.15/1.6^±0.15
October 1	H	4.3^±0.8/5.1^±0.8	4.4^±1.0/5.4^±0.9	4.6^±0.9/5.5^±0.9	3.8^±0.9/4.7^±0.7	4.2^±1.2/5.4^±0.9
October 1	σ	0.7^±0.05/0.8^±0.15	0.8^±0.05/1.0^±0.12	0.8^±0.05/0.9^±0.12	0.8^±0.05/0.9^±0.12	1.3^±0.15/1.6^±0.25

1 Note: the numerator – data for 2023; the denominator – data for 2024

1 H – average height (seedling height growth dependence); σ – standard deviation (height differentiation of seedlings for each substrate).

Table 3.

Determination of the Variation Index of Seedling Height

Modification	CV by years, %
Modification	2023	Accuracy	2024	Accuracy
Modification 1 (bark:peat 2:1)	17.07	Good	18.37	Good
Modification 2 (bark:peat 1:1)	18.92	Good	17.78	Good
Modification 3 (bark:peat 1:2)	15.91	Good	15.38	Good
Modification 4 (bark:peat:forest soil 1:1:1)	22.22	Medium	20.00	Transition zone between good and moderate
Modification 5 (bark:peat:sawdust compost 1:1:1)	36.11	Low	30.77	Low

1 Note: the numerator – data for 2023; the denominator – data for 2024

Condition of the root system of container-grown Scots pine (*Pinus sylvestris* L.) seedlings in BCC containers

Table 4.

Effect of pre-sowing treatment with plant growth regulators on the seed quality of Scots pine (Pinus sylvestris L.)

Treatment	Germination energy		Germination capacity
Treatment	%	% relative to control	%	% relative to control
Stimpo	80/78	138/132	86/84	113/109
Epin Extra	64/62	110/106	80/78	105/101
Humat Ultra	44/40	76/75	60/58	79/73
Megafol	54/52	93/91	70/68	92/93
Control	58/56	–	76/74	–

1 Note: the numerator represents data for 2023; the denominator represents data for 2024

Table 5.

Results of the study on height and root length of Scots pine (Pinus sylvestris L.) Seedlings Treated with Plant Growth Regulators

Treatment	Height, cm			Root length, cm
Treatment	M	m	t	M	m	t
Stimpo	10.5/10.7	0.23/0.33	5.0/5.2	28.0/27.5	0.24/0.31	7.0/6.7
Epin Extra	11.5/11.0	0.32/0.34	7.0/6.5*	21.5/21.8	0.33/0.44	-1.5/-1.8
Humat Ultra	14.0/13.2	0.51/0.42	12.5/12.0**	29.0/28.3	0.41/0.53	8.2/8.0*
Megafol	16.0/14.5	0.45/0.43	15.0/14.2**	32.0/31.0	0.51/0.55	11.5/11.0**
Control	9.0/8.8	0.34/0.25	–	23.0/23.5	0.37/0.36	–

1 Note. M – arithmetic mean; m – standard error of the mean; t – Student’s t-test. The statistics are defined as follows:

1* significant at the 5% level; significant at the 1% level for 2023 and 2024, respectively.

Table 6.

Biometric Parameters of Pinus sylvestris Seedlings Under the Application of Plant Growth Regulators

Treatment	Diameter of the root collar, mm			Number of lateral shoots, pcs.
Treatment	M	m	t	M	m	t
Stimpo	2.0/2.1	0.05/0.06	14.0/13.8**	1.7/1.8	0.14/10.13	0/0.2
Epin Extra	1.6/1.7	0.07/0.05	9.0/8.5*	1.5/1.6	0.12/0.14	-0.80/-0.70
Humat Ultra	1.9/1.9	0.06/0.04	13.5/14.0**	1.3/1.4	0.17/0.15	-1.50/-1.40
Megafol	2.2/2.3	0.08/0.06	16.0/15.3**	1.9/1.9	0.19/0.18	0.75/0.70
Control	1.1/1.2	0.03/0.02	–	1.4/1.5	0.25/0.22	–

1 Note. M – arithmetic mean; m – standard error of the mean; t – Student’s t-test. Statistics are defined as follows:

1* significant at the 5% level of significance;

1** significant at the 1% level of significance for the years 2023 and 2024, respectively.

Table 7.

Biomass of P. sylvestris Seedlings under the Use of Plant Growth Regulators

Treatment	Aboveground biomass, g						Root biomass, g
	M	m	t	Including needles			Root biomass, g
	M	m	t	M	m	t	M	m	t
Stimpo	1.7/1.5	0.13/0.12	4.20/3.92	1.2/1.0	0.07/0.08	4.20/3.00	0.7/0.6	0.05/0.04	4.00/3.75
Epin Extra	1.8/1.6	0.10/0.11	5.00/4.56*	1.1/1.0	0.08/0.08	5.00/3.44	0.8/0.6	0.04/0.04	4.00/3.75
Humat Ultra	1.5/1.6	0.18/0.19	3.00/2.80	0.8/0.9	0.06/0.07	3.00/2.75	0.6/0.5	0.06/0.04	3.50/3.00
Megafol	2.5/2.4	0.17/0.18	7.50/7.42*	1.5/1.4	0.07/0.11	7.50/5.75*	0.9/0.7	0.07/0.06	5.00/5.33*
Control	1.2/1.0	0.07/0.06	–	0.6/0.7	0.03/0.04	–	0.5/0.4	0.03/0.02	–

1 Note. M – arithmetic mean; m – standard error of the mean; t – Student’s t-test. Statistics are determined as follows:

1* significant at the 5% level

1** significant at the 1% level for the years 2023 and 2024, respectively.

Table 8.

Air-dry mass of P. sylvestris seedlings under the use of plant growth regulators

Treatment	Aboveground biomass, g				Root biomass		Root-to-shoot ratio
	g	Relative to control, %	Including needles		g	Relative to control, %
	g	Relative to control, %	g	Relative to control, %	g	Relative to control, %
Stimpo	48.6/48.1	160/159	33.7/30.8	157/142	19.6/18.8	172/165	0.4/0.7
Epin Extra	50.0/48.6	165/160	34.0/33.7	159/155	18.6/19.6	163/172	0.4/0.6
Humat Ultra	48.1/50.0	159/165	30.8/34.0	144/157	18.8/18.6	165/163	0.4/0.5
Megafol	76.4/76.4	252/254	47.3/47.5	220/219	26.0/27.0	228/229	0.3/0.8
Control	30.3/30.3	–/–	21.5/21.7	–/–	11.4/11.5	–/–	0.4/0.5

1 Note. The numerator shows data from 2023; the denominator shows data from 2024.

References

Authors

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Articles in this issue

DOI: https://doi.org/10.2478/ffp-2026-0008 | Journal eISSN: 2199-5907 | Journal ISSN: 0071-6677

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Language: English

Page range: 89 - 108

Submitted on: Feb 18, 2026

Accepted on: Feb 26, 2026

Published on: Jun 25, 2026

Published by: Forest Research Institute

In partnership with: Paradigm Publishing Services

Keywords:

root plant growth stimulants,

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© 2026 Vasyl Khryk, Ivan Kimeichuk, Viacheslav Chuba, Yuliya Vashchuk, Svitlana Lewandowska, Oleksandr Sytnyk, Olena Hrynyk, Heorhii Hrynyk, published by Forest Research Institute
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 68 (2026): Issue 2 (June 2026)

Producing high-quality container-grown Scots pine seedlings: the role of substrate composition and plant growth regulators

Figures & Tables

Table 1.

Figure 1.

Figure 2.