Seed & seeding

Guide to Soybean Growth Stages

October 4, 2017
Soybean Critical Growth Stages SYNGENTA SOYBEANS – A SYSTEMS APPROACH
soy-masters
SOYBEAN STAGING
DESCRIPTION
Management Highlights and Observations
SEED
CERTIFIED & TREATED
  • Unique, high performing genetics – maximum genetic potential
  • Select top quality seed and protect with treatment (insecticide & fungicide)
  • Every viable seed able to achieve maximum yield
seed
VE
VEGETATIVE EMERGENCE
  • Critical stage – monitor for insects & diseases, ruptured hypocotyl, broken neck, frost damage, etc.
  • Minimize emergence period to achieve targeted population
  • A strong, uniform start allows each plant to achieve full genetic potential (G X E X M)
ve
VC
VEGETATIVE COTYLEDONS
  • Examine seedlings for insect and/or disease damage on cotyledons (eg. Telltale signs of seed corn maggot feeding)
  • Evaluate for missing cotyledons as high retention is important
vc
VU
VEGETATIVE UNIFOLIATE
  • Examine unifoliates for disease (eg. Septoria)
  • Auxiliary branching at this node may occur under optimum conditions
  • Watch for Bean Leaf Beetle feeding
vu
V1
VEGETATIVE – 1ST TRIFOLIATE
  • First true compound leaf
  • Monitor closely for insect, disease and herbicide injury
  • Consider as initial staging for tissue analysis
v1
V2-V3
VEGETATIVE - 2ND TO 3RD TRIFOLIATE
  • Document initiation of numerous, healthy nodules
  • Cotyledons should still be attached at least until V3
  • Monitor foliage for general health to ensure maximum photosynthetic capacity
v2-v3
R1 - R3.5
COMBINED REPRODUCTIVE AND VEGETATIVE GROWTH
  • Plant is building the photosynthetic factory while maximizing the number of reproductive nodes, flowers and ultimately pods
  • Nodal growth establishes yield potential)
  • Ideal timing for fungicides to manage foliar diseases
  • Monitor plant’s nutrition with tissue analysis
R1
INITIATION OF REPRODUCTIVE PHASE
  • Appearance of first flower
  • Plant currently in vegetative and reproductive phase – indeterminant growth
  • Usually occurs at V4 – V5 on or near the summer solstice
R1
R2
FORMATION OF “PIN PODS”
  • Watch for formation of pin pods from the first flowers on lower nodes
  • Determines fungicide application – “Prior to or After”
R2
R3.5
FORMATION OF TERMINAL BUD
  • Emergence of the final flowers at top node-often appears later as strong top pod cluster
  • Some varieties can re-flower along the main stem
  • Identify stage as final trifoliates tend to be significantly smaller
  • Comparable stage to corn is tassel & silking (full flower), plant at maximum height & yield potential set
R3.5
R4 - R6
BEAN FILL PHASE
  • Plant in 100% reproductive
  • Critical “Bean Fill” and “Yield Maintenance” phase. Important to maximize “Bean-Flex” opportunity
  • Nutrient & moisture demands extremely high; monitor plant nutrition by tissue testing
  • Focus on crop health. “Stay strong–Finish strong”
  • Watch sucking or chewing insects – in field scouting
R4 - R6
R6.5
PHYSIOLOGICAL MATURITY
  • Yield is final - comparable stage to Black Layer in corn. Occurs when pods are yellow and seed is easily detached from inside pod
  • No impact from late season frost at this stage.
  • Application of burn-down will not affect dry matter (yield) accumulation
R6.5
R8
HARVEST READY
  • Beans rattle in the pod and combine ready.
R8

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