A simplified maturity index to quantify the development stage of perennial ryegrass (Lolium perenne L.) and its relationship with yield and nutritive value

Heba Salama; Marc Loesche; Antje Herrmann; Friedhelm Taube; Martin Gierus

doi:10.1515/boku-2017-0009

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A simplified maturity index to quantify the development stage of perennial ryegrass (Lolium perenne L.) and its relationship with yield and nutritive value

Die Bodenkultur: Journal of Land Management, Food and Environment

Volume 68 (2017): Issue 2 (June 2017)

By: Heba Salama, Marc Loesche, Antje Herrmann, Friedhelm Taube and Martin Gierus

Open Access

|Jun 2017

Figures & Tables

Table 1

Genotypes included in the study

Tabelle 1. Liste der in der Studie verwendeten Sorten

Genotype	Heading date*	Registration year
1	54	1993
2	56	1997
3	58	1987
4	63	1995
5	53	†
6	53	†
7	62	†
8	63	†
9	61	2005
10	55	1999
11	60	2003
12	62	2004
13	63	2009
14	55	2008
15	61	†
16	64	†
17	54	2007
18	55	†
19	55	2007
20	56	2007

* the heading date is provided as number of days after April 1^st

† not registered

Table 2

Harvesting schedule for the two experimental seasons

Tabelle 2. Erntetermine für die zwei Versuchsjahre

Cut	Sampling number	Year 1	Year 2
	1	15 May	08 May
1	2	29 May	13 May
	3	09 June	23 May

	1	28 June	18 June
2	2	03 July	22 June
	3	11 July	03 July

3	1	23 Aug.	17 Aug.

4	1	10 Oct.	10 Oct.

Table 3

Classification of Lolium perenne L. developmental stages according to Park (1980)

Tabelle 3. Klassifizierung des Entwicklungsstadiums von Lolium perenne L. nach Park (1980)

Code	Abbreviation	Description
1	S0	No elongated leaf sheath
2	S1	1 elongated leaf sheath (1 fully developed leaf)
3	S2	2 elongated leaf sheaths (2 fully developed leafs)
4	S3	3 or more elongated leaf sheaths (3 fully developed leafs)
5	K1	1 tactile node
6	K2	2 tactile nodes
7	K3	3 or more tactile nodes
8	B	Swelling of the upper leaf sheath indicating presence of the inflorescence inside it (boot stage)
9	G1.1	Beginning of heading, the upper 1-2 cm of the inflorescence is visible
10	G1.5	50 % of the inflorescence emerged
11	G1.9	The inflorescence fully emerged and the inflorescence peduncle is visible
12	OH	Inflorescence peduncle fully emerged
13	G2.1	Beginning of flowering (anthesis), some anthers are visible
14	G2.5	Full flowering, maximum number of anthers are visible
15	G2.9	End of flowering, only few anthers are still visible
16	G3	Milk ripe
17	G4	Dough ripe

Table 4

Statistical data of the calibration of NIRS for NDF, ADF, ADL and DOM of the investigated genotypes

Tabelle 4. NIRS Kalibrationsstatistik für NDF, ADF, ADL und VOM der untersuchten Sorten

Parameter (g kg^-1)	n†	Mean	Range	R²	SEC	SEV
NDF	96	566.5	413.9-692.6	0.93	16.00	20.79
ADF	92	280.0	173.5-362.7	0.97	7.03	10.28
ADL	63	20.0	3.7-41.1	0.54	5.60	5.32
DOM	99	768.7	610.0-897.1	0.98	9.90	15.50

† n: number of samples; SEC: Standard error of calibration; SEV: Standard error of validation

Table 5

Spearman’s rank correlation coefficients between the tested maturity indices, i.e., Mean stage by count (MSC) and Simple maturity indices SMI_i (i = 3-12), and forage quality parameters

Tabelle 5. Spearman Korrelationskoeffizienten zwischen den getesteten Indices, d.h. “mean stage by count” (MSC) und “simply maturity indices” SMI_i (i = 3-12), und Futterqualitätsparameter

									SMI_i

Cur	Sampling date	Parameter	MSC	3	4	5	6	7	8	9	10	11	12

				S2	S3	K1	K2	K3	B	Gl.l	G1.5	G1.9	OH
1	1	NDF	0.32**	0.04	0.10	0.36**	0.31*	0.21*	0.22*	0.17
1	1	ADF	0.34**	0.06	0.14	0.37**	0.32*	0.20*	0.24*	0.22*
1	1	ADL	0.54**	0.03	0.18	0.48**	0.55**	0.48**	0.44**	0.40**
1	1	DOM	-0.84**	-0.03	-0.49**	-0.85**	-0.82**	-0.69**	-0.74**	-0.59**
1	1	Yield	0.04	0.07	0.03	0.01	0.09	0.07	0.02	0.1
1	2	NDF	0.57**	0.06	0.54**	0.48**	0.59**	0.52**	0.62**	0.58**	0.57**
1	2	ADF	0.67**	0.11	0.62**	0.56**	0.68**	0.62**	0.68**	0.59**	0.61**
1	2	ADL	0.51**	0.05	0.44**	0.42**	0.52**	0.47**	0.63**	0.55**	0.58**
1	2	DOM	-0.69**	-0.08	-0.59**	-0.53**	-0.72**	-0.65**	-0.68**	-0.64**	-0.69**
1	2	Yield	0.34	0.07	0.16	0.39	0.40*	0.39	0.23	0.22	0.08

1	3	NDF	0.78**	0.22*	0.25*	0.48**	0.70**	0.76**	0.81**	0.67**	0.64**	0.39**
1	3	ADF	0.72**	0.31*	0.32**	0.53**	0.72**	0.74**	0.74**	0.55**	0.56**	0.59**
1	3	ADL	0.83**	0.21*	0.19	0.37**	0.59**	0.70**	0.83**	0.79**	0.77**	0.55**
1	3	DOM	-0.81**	-0.23*	-0.21*	-0.39**	-0.63**	-0.75**	-0.81**	-0.73**	-0.73**	-0.54**
1	3	Yield	0.26	0.71**	0.37	0.37	0.49*	0.40*	0.21	0.04	0.04	0.0002

2	1	NDF	0.47**	0.14	0.21*	0.43**	0.39**	0.33**	0.39**	0.49**	0.55**	0.56**	0.40**
2	1	ADF	0.39**	0.17	0.21*	0.32**	0.27*	0.23*	0.32**	0.43**	0.50**	0.49**	0.32**
2	1	ADL	0.48**	0.17	0.31*	0.54**	0.49**	0.40**	0.38**	0.41**	0.46**	0.46**	0.31*
2	1	DOM	-0.51**	-0.12	-0.26*	-0.44**	-0.41**	-0.37**	-0.41**	-0.56**	-0.66**	-0.65**	-0.51**
2	1	Yield	0.12	0.02	0.02	0.06	0.04	0.03	0.04	0.19	0.33**	0.28*	0.28*

2	2	NDF	0.31*	0.04	0.037	0.20*	0.22*	0.26*	0.28*	0.36**	0.40**	0.21*	0.19
2	2	ADF	0.33**	0.18	0.08	0.17	0.18	0.25*	0.34**	0.37**	0.38**	0.20*	0.21*
2	2	ADL	0.47**	0.12	0.11	0.34**	0.36**	0.37**	0.31*	0.39**	0.49**	0.36**	0.31*
2	2	DOM	-0.35**	-0.10	-0.05	-0.28*	-0.28*	-0.30*	-0.26*	-0.33**	-0.42**	-0.24*	-0.23*
2	2	Yield	0.003	0.006	0.005	0.002	0.002	0.02	0.03	0.02	0.004	0.007	0.004

2	3	NDF	0.18	0.03	0.20*	0.09	0.13	0.17	0.18	0.26*	0.29*	0.16	0.09
2	3	ADF	0.18	0.001	0.20*	0.09	0.16	0.18	0.20*	0.27*	0.30*	0.17	0.09
2	3	ADL	0.21*	0.0006	0.24*	0.16	0.20*	0.23*	0.23*	0.28*	0.33**	0.22*	0.15
2	3	DOM	-0.40**	-0.01	-0.39**	-0.28*	-0.37**	-0.41**	-0.43**	-0.50**	-0.54**	-0.41**	-0.24*
2	3	Yield	0.14	0.0004	0.15	0.21*	0.21*	0.18	0.16	0.13	0.14	0.17	0.35**

[i] SMI_i denotes the percentage of tillers with a developmental stage of i and beyond; Maturity stages S2 to OH classified according to Park (1980); data were averaged over year and replicate.

Table 6

F-values of genotype, sampling date, cut and their interactions on yield and feed quality parameters without using covariable (SMI8)

Tabelle 6. F-Werte für Sorte, Erntetermin, Aufwuchs und Wechselwirkungen für Ertrag und Futterqualität ohne Kovariable (SMI8)

Factor	Dry matter yield (t ha^-1)	NDF	ADF	ADL	DOM
Factor	Dry matter yield (t ha^-1)		--------------g kg^-1--------------
Genotype (G)	1.70	8.95***	7.23***	6.67***	16.21***
Cut (C)	0.00	688.95***	460.61***	391.26***	759.43***
Sampling date (SD)	367.78***	179.69***	366.78***	105.18***	1144.59***
Block	0.07	14.95***	13.79***	2.70	0.84
G × C	2.07†	2.89**	2.68**	3.44***	5.17***
G × SD	1.48	0.77	0.91	1.13	1.39
C × SD	109.45***	18.14***	47.64***	1.58	46.50***
G × C × SD	0.89	0.98	1.07	1.16	1.59

*** Significant at 0.001 level of probability

† Non-significant after applying Bonferroni-Holm test.

** Significant at 0.01 level of probability

*** Significant at 0.001 level of probability

Table 7

F-values of genotype, sampling date, cut and their interactions on yield and forage quality parameters with covariable (SMI8)

Tabelle 7. F-Werte für Sorte, Erntetermin, Aufwuchs und Wechselwirkungen für Ertrag und Futterqualität mit Kovariable (SMI8)

Factor	Dry matter yield (t ha^-1)	NDF	ADF	ADL	DOM
Factor	Dry matter yield (t ha^-1)	------------------------g kg^-1------------------------
Genotype (G)	1.47	6.78***	5.35***	4.42***	8.78***
Cut (C)	0.06	775.99***	526.60***	493.86***	980.28***
Sampling date (SD)	122.78***	87.94***	167.79***	44.71***	278.84***
Block	0.15	15.94***	14.97***	2.53	1.26
Covariable (SMI8)	8.64**	8.95**	15.41***	12.27**	20.65***
G × C	1.54	2.09*	2.00*	2.19*	3.80***
G × SD	1.35	0.74	0.90	0.97	1.21
C × SD	65.34***	7.62**	23.69***	3.51*	12.58***
G × C × SD	1.03	1.04	1.11	1.15	1.60

Slope	0.90	0.30	0.30	0.05	-0.43

SMI8 represents the percentage of tillers beyond the boot stage in the herbage sample. Slope represents degree of dependency of the yield and quality parameters on the covariable.