October 2014 Crop development 15 October 2014 Pergamino

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1 October 2014 Crop development 15 October 2014 Pergamino Dr Derrick Moot Professor of Plant Science

2 The website Info on: Current projects Field day presentations Scientific publications FAQs Postgraduate study Photo Diary Direct link to BLOG

3 ENVIRONMENT Nutrient availability Temperature Daylength Solar radiation Soil moisture/ Rain Mineral nutrition MANAGEMENT Cultivar Sowing date Population Fertilizer Irrigation Phenological development Canopy development Biomass accumulation Yield Partitioning PROCESSES Quality Relationship between environment and management factors and the physiological processes that regulate crop yield and quality. (Source: Hay & Porter 2006).

4 Growth vs. Development Growth: an irreversible increase in DM - function of light interception and - photosynthesis and then - assimilate partitioning Development: irreversible change in the state of an organism - fixed pattern and reversion is rare e.g. silking, flowering, anthesis

5 Main measurements - Growth and development - Weekly measurements Crowns and taproots Shoots LAI Leaf appearance & branching

6 Measurements Light environment Soil moisture Chemical Analysis: -N (shoots and roots) -Starch in roots -Soluble sugars in roots Temperature - Air and soil Photosynthesis

7 Plant development A) Vegetative Emergence and - temperature Leaf appearance rates (phyllochron)- temperature B) Reproductive Time of flowering (anthesis), Temperature and photoperiod Duration of grain fill -temperature Driven by temperature modified by photoperiod and vernalization

8 Light Complex & dynamic signal Quantity of light photons falling /area/time Quality of light plant responses

9 Development Rate & Environment Temperature i. largest effect on development ii. quantified as a rate between two development stages iii. approx. linear to a maximum (25-30 o C) iv. temperature is perceived by the apex

11 Development Rate & Environment t (d) 1/t (d -1 ) T ( C) Tb T ( C)

12 Quantifying thermal time (using mean daily temperatures) 1) Simplest: Tt = Tmin + Tmax - T b ( o Cd) 2 - good for short periods - need similar day and night tempatures - inaccurate for low/high extremes - temperature cycles through a day

13 Sowing to emergence Thermal time - soil temperature ~ Cd

14 Time for germination Days to 75% germination Ryegrass Temperature ( C) Moot et al. 2000

15 Germination rate Germination rate (1/days) Tt = 65 Cd T opt T b T max Temperature ( C) Moot et al. 2000

16 Quantifying thermal time (using mean daily temperature) 2) Diurnal pattern: TmaxB Tmin Tmax TminA A B C D 0 Sunrise Sunset Hours Jones et al. 1986

17 Jones et al Where; Tt = 1 8 r = 8 r = 1 [ ] T H T b Cd T H = T + r T T ) min ( max min and; r 1 = + cos90 1 2r ( ) i.e. 8 x 3 hourly calculations summed to give daily Tt = T H Max or Min outside linear portion

18 Forage crops

19 Quantifying thermal time (using mean daily temperatures) Note: i) Negative temperatures or < T b count as zero (0) ii) Function reaches a maximum at 2 pm and minimum at 2 am iii) Not all temperatures contribute equally to development 30 (34, 26) T opt Thermal units ( Cd) (18,10) e.g. Maize: T b = 8 o C, T opt = 34 o C, T max = 44 o C 0 T b T max Temperature ( C) Wilson et al. 1995

20 Flowering Flowering is the crucial moment in development i.e. shift from vegetative to reproductive priority. Growth can occur without development e.g. Sugarbeet Development can occur to induce flowering in plants of vastly difference dry weight

21 Scale

22 Grain-filling: constant in thermal time air temperature

24 Stem height

25 Nodes to first flower 13 Number of nodes Nov 97 May 98 Nov 98 May 99 Date Moot et al. 2001

26 Thermal time to early-bud 600 Thermal time ( Cd) Photo-period (h) Moot et al. 2003

27 Thermal time response 30 Daily thermal time ( Cd) Original Modified ( C) Temperature ( C) Moot et al. 2001

28 Conclusions Development - driven by temperature - modified by Pp Alfalfa - flowering Pp change Alfalfa - Tb (air) modified below 15 C Measuring the correct temperature matters Understand crop growth and development as a basis for agronomy and plant breeding.

29 References & Links Dryland Pastures Website: Dryland Pastures Blog: Lincoln University student website: Hay, R. J. M. and Porter, J. R The Physiology of Crop Yield (2nd Ed). Oxford: Blackwell Publishing Ltd. 314 pp. Jones, C. A., Ritchie, J. T., Kiniry, J. R. and Godwin, D. C Subroutine structure. In: C. A. Jones and J. R. Kiniry (eds). CERES- Maize: A Simulation Model of Maize Growth and Development. Texas: A & M University Press, Moot, D. J., Brown, H. E., Teixeira, E. I. and Pollock, K. M Crop growth and development affect seasonal priorities for lucerne management. In: D. J. Moot (ed). Legumes for Dryland Pastures Proceedings of a New Zealand Grassland Association Inc Symposium held at Lincoln University, November, Christchurch: New Zealand Grassland Association, Online: Moot, D. J., Robertson, M. J. and Pollock, K. M Validation of the APSIM-Lucerne model for phenological development in a cool-temperate climate. Science and Technology: Delivering Results for Agriculture? Proceedings of the 10th Australian Agronomy Conference. January Online: Moot, D. J., Scott, W. R., Roy, A. M. and Nicholls, A. C Base temperature and thermal time requirements for germination and emergence of temperate pasture species. New Zealand Journal of Agricultural Research, 43, Online: Wilson, D. R., Muchow, R. C. and Murgatroyd, C. J Model analysis of temperature and solar radiation limitations to maize potential productivity in a cool climate. Field Crops Research, 43, Online:

October 2014 Crop growth 15 October 2014 Pergamino

October 2014 Crop growth 15 October 2014 Pergamino October Crop growth October Pergamino Dr Derrick Moot Professor of Plant Science ENVIRONMENT Nutrient availability Temperature Daylength Solar radiation Soil moisture/ Rain Mineral nutrition MANAGEMENT