Wheat Growth and Development Presentation by Chad Lee

Most of the information comes from: ID-125: A Comprehensive Guide to Wheat Management in

Objectives • Review Growth Stages • Freeze Sensitivity • Key developmental stages Chad Lee

Wheat in Kentucky: Soft Red Winter Wheat • Flour for cookies, pastries, crackers, etc. • 4 th most valuable crop in Kentucky. • Approximately 400, 000 acres raised for grain. Chad Lee © 2006 University of Kentucky 4

Wheat Growth Stages Growth Period Tillering Stem Extension Heading Flowering Ripening Feekes Description 1 -5 One shoot through pseudo-stem. 6 – 10 First node visible through flag leaf sheath fully visible. 10. 1 – 10. 5 First spikelet of head visible through All heads out of sheaths. 10. 51 - 10. 54 Beginning of flowering through flowering completed. 11. 1 – 11. 4 Chad Lee © 2006 University of Kentucky Milky ripe seeds to ripe for harvesting. 5

Important Steps in Development Tiller Number Feekes 6 Head Size Feekes 3 Chad Lee

Feekes Scale Stage Tillering Stem Extension Heading Scale 1 -5 6 -10 10. 1

Feekes Scale Stage Tillering Scale Description One shoot, first leaf through 1 2 3 Chad Lee © 2006 University of Kentucky coleoptile. Beginning tillering: one shoot, one tiller. Tillers formed, leaves often twisted spirally. Main shoot and six tillers. In some varieties, plant may be creeping. 8

Feekes Scale Stage Tillering Scale Description Start of erection of pseudo 4 5 Chad Lee © 2006 University of Kentucky stem; leaf sheaths beginning to lengthen. Pseudo-stem (formed by sheaths of leaves) strongly erected. 9

Feekes Scale Stage Scale Description 1 st node of main stem visible at Stem 6 base of shoot. Extension 2 nd node of main stem; next to 7 8 last leaf visible. Flag leaf (last leaf) visible but still rolled up; ear beginning to swell. 9 Ligule of flag leaf just visible. 10 Chad Lee © 2006 University of Kentucky Sheath of flag leaf completely grown out; ear swollen but not yet visible. 10

Feekes Scale Stage Heading Scale Description 10. 1 First spikelet of head just 10. 2 visible. ¼ of heading process completed. 10. 3 ½ of heading process completed. 10. 4 ¾ of heading process completed. 10. 5 All heads out of sheath. Chad Lee © 2006 University of Kentucky 11

Feekes Scale Stage Flowering Scale Description 10. 51 Beginning of flowering. 10. 52 Flowering complete to top of head. 10. 53 Flowering complete at base of head. 10. 54 Flowering complete; kernel watery ripe. Chad Lee © 2006 University of Kentucky 12

Feekes Scale Stage Ripening Scale Description 11. 1 Milky ripe. 11. 2 Mealy rip; contents of kernel soft but dry. 11. 3 Kernel hard (difficult to divide with thumbnail) 11. 4 Ripe for cutting. Straw dead. Chad Lee © 2006 University of Kentucky 13

Freeze Injury to Wheat Chad Lee © 2006 University of Kentucky 14

Freeze Injury to Wheat Stage Feekes Stage Approx. Injurious Temp. , 2 hrs Yield Effect (ºF) Tillering 1 -5 12 Slight to Moderate Jointing 6 -7 24 Moderate to Severe Boot 10 28 Moderate to Severe 10. 110. 5 30 Severe Heading Chad Lee © 2006 University of Kentucky 15

Freeze Injury to Wheat Stage Flowering Feekes Stage Approx. Injurious Temp. , 2 hrs Yield Effect (ºF) 10. 5110. 54 30 Severe Milk 11. 1 28 Moderate to Severe Dough 11. 2 28 Slight to Moderate Chad Lee © 2006 University of Kentucky 16