1. Level II Agricultural Business Operations

2.  Scale proposed by the Dutch phytopathologist, Jan C. Zadoks  Know as Zadoks scale, it gives the plant a figure based on the current growth stage of the plant.  Scales goes from 00-99.

3.  Knowing the stages of development of a crop is critical in many management decisions that growers make.  Eg, Nitrogen application GS21 Herbicide application GS11 Fungicide application GS32 Growth regulatorGS32

4. GS 31 GS 39 GS 61 Harvest SlowRapidSlow 40 % of total N uptake in 4 weeks 17 % of total N uptake

7.  T1, T2 & T3 are linked to timing of fungicide spraying.  T1 is generally GS 32-33  T2 is GS 39  T3 is a ear wash at GS 65  Some other T values have been developing e.g. T0.5, T1.5 etc. Becoming more popular in NI

8.  Link from HGCA website.  http://www.hgca.com/media/180128/g49- cereals-growth-stages-a-guide-for-crop- treatments.pdf http://www.hgca.com/media/180128/g49- cereals-growth-stages-a-guide-for-crop- treatments.pdf

9.  Seedling Growth11-19  Tillering20-29  Stem Elongation30-39  Booting41-49  Ear Emergence51-59  Flowering61-69  Milk Development71-79  Dough Development81-89  Ripening91-99

10. GS10 First leaf through coleoptile GS11 First leaf unfolded (ligule visible) GS13 - 3 leaves unfolded GS15 - 5 leaves unfolded GS19 - 9 or more leaves unfolded

13.  GS20 Main shoot only  GS21 Main shoot and 1 tiller  GS23 Main shoot and 3 tillers  GS25 Main shoot and 5 tillers  GS29 Main shoot and 9 or more tillers

15.  GS30 Ear at 1cm (pseudostem erect)  GS31 First node detectable  GS32 Second node detectable  GS33 Third node detectable  GS37 Flag leaf just visible  GS39 Flag leaf blade all visible

16.  Very Important Period ◦ Fungicide Timing ◦ Growth regulator

19.  For a quick, but crude assessment, fold back the leaf sheaths then count the slight 'bumps' caused by each node.  The exact stage is revealed by stripping off leaves and cutting the main stem longitudinally with a sharp knife.

21.  GS41 Flag leaf sheath extending  GS43 Flag leaf sheath just visibly swollen  GS45 Flag leaf sheath swollen  GS47 Flag leaf sheath opening  GS49 First awns visible (if an awned variety) Barley only

22.  GS51 First spikelet of ear just visible above flag leaf ligule  GS55 Half of ear emerged above flag leaf ligule  GS59 Ear completely emerged above flag leaf ligule

24.  GS61 Start of flowering  GS65 Flowering half-way  GS69 Flowering complete

26.  GS71 Grain watery ripe  GS73 Early milk  GS75 Medium milk  GS77 Late milk

27.  GS83 Early dough  GS85 Soft dough  GS87 Hard dough (thumbnail impression held)

28.  GS91 Grain hard (difficult to divide)  GS92 Grain hard (not dented by thumbnail)  GS93 Grain loosening in daytime

30.  Correct timing of sprays and fertiliser treatments is critical to success in growing cereals.  Many instructions and guides state ‘Apply at GSXX.”

31.  Take 5-10 typical plants from across the field, ideally digging them up rather than pulling up to avoid damaging stems and leaves.

33.  Knowing the growth stage is important to ensure that timing of pesticides are applied in line with manufactures recommendations.  Correct timing can have a bigger impact on crop response/performance than product type!