Northeast Region Certified Crop Adviser (NRCCA) Study Resources

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• PO 5 & 6 Staging systems and identifying growth stages of corn
• PO 7 & 8 Staging systems and identifying growth stages of legumes
• PO 9 Calculating growing degree days
• PO 10 Relationship of growth and development

Competency Area 2: Crop Staging, Growth and Development

PO 7. Describe the systems used to stage forage legumes and grasses.
&
PO 8. Use the staging systems to identify growth stages of forage legumes and grasses.

Alfalfa - Mean Stage by Count (see also http://css.cals.cornell.edu/cals/css/extension/upload/AlfalfaBulletin.pdf).
The mean stage of maturity by count (MSC) method consists of taking random, representative field samples, and scoring individual stems for stage of development. Stems in the vegetative stages are scored 0-2, bud stage 3-4, flowering 5-6, and seed production 7-9. The MSC is calculated as the weighted mean stage of all stems collected in the sample.
Click on images to enlarge

	Stage 0: Early vegetative. Stem length < 6 inches.
	Stage 1: Mid-vegetative. Stem length 6-12 inches.
	Stage 2: Late vegetative. Stem length > 12 inches (no visible buds).
	Stage 3: Early bud. 1-2 nodes with visible buds.
	Stage 4: Late bud. > 3 nodes with visible buds.
	Stage 5: Early flower. One node with one open flower.
	Stage 6: Late flower. > 2 nodes with open flowers.
	Stage 7: Early seed pod. 1-3 nodes with green seed pods.
	Stage 8: Late seed pod. > 4 nodes with green seed pods.
	Stage 9: Ripe seed pod. Nodes with brown mature seed pods.

Perennial grass staging system
Perennial grass proceeds through a sequence of developmental stages: 1) germination, 2) vegetative; 3) elongation; 4) reproductive, and 5) seed ripening. The vegetative growth period is characterized by the development of leaves. Elongation is the period during which stem internodes elongate and is also referred to as jointing. During elongation the developing inflorescence pushes through the uppermost leaf sheath commonly referred to as boot stage. The reproductive stage is the period during which the developing inflorescence emerges and pollination occurs.

Information on quantifying growth stages can be found at (Moore et al. (1991) Describing and Quantifying Growth Stages of Perennial Forage Grasses. Agron. J. 83:1073). The five growth stages above have been related to a continuous numerical index. Germination stages are numbered from 0 to 0.9 and seed production stages are numbered from 4.0 to 4.9 on the numerical scale. Vegetative stages 1.0 to 1.9 start with emergence of first leaf and the index increases with each additional collared leaf. Elongation stages range from 2.0 to 2.9 starting with onset of elongation and the index increases with each additional palpable/visible node. The Reproductive stages range from 3.0 to 3.9 and start with boot stage. The emergence of the inflorescence through post-anthesis is included. Each stage of the system also has a mnemonic code (e.g. R1 = inflorescence emergence).

Primary and secondary growth stages and their numerical indices and descriptions for staging growth and development of perennial grasses.

Stage	Index	Description
Germination
G0	0.0	Dry seed
G1	0.1	Imbibition
G2	0.3	Radicle emergence
G3	0.5	Coleoptile emergence
G4	0.7	Mesocotyl and/or coleoptile elongation
G5 from soil	0.9	Coleoptile emergence from soil
Vegetative-Leaf development
VE or V0	1.0	Emergence of first leaf
V1	(1/N)+0.9	First leaf collared
V2	(2/N)+0.9	Second leaf collared
Vn	(n/N)+0.9	Nth leaf collared
Elongation-Stem elongation
E0	2.0	Onset of stem elongation
E1	(1/N)+1.9	First node palpable/visible
E2	(2/N)+1.9	Second node palpable/visible
En	(n/N)+1.9	Nth node palpable/visible
Reproductive-Floral development
R0	3.0	Boot stage
R1	3.1	Inflorescence emergence/1st spikelet visible
R2	3.3	Spikelets fully emerged/peduncle not emerged
R3	3.5	Inflorescence emerged /peduncle fully elongated
R4	3.7	Anther emergence/anthesis
R5	3.9	Post anthesis/fertilization
Seed development and ripening
S0	4.0	Caryopsis visible
S1	4.1	Milk
S2	4.3	Soft dough
S3	4.5	Hard dough
S4	4.7	Endosperm hard/physiological maturity
S5	4.9	Endosperm dry/seed ripe