Presentation on theme: "Level II Agricultural Business Operations. Scale proposed by the Dutch phytopathologist, Jan C. Zadoks Know as Zadoks scale, it gives the plant a."— Presentation transcript:
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.
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
GS 31 GS 39 GS 61 Harvest SlowRapidSlow 40 % of total N uptake in 4 weeks 17 % of total N uptake
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
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
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.
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
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
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!