1. RICE GROWTH AND DEVELOPMENT or Are you breaking the world rice yield record? Jim Hill UC Davis

2. So what is the world record? Or should we ask--is the world record really the world record?

3. So what is the world record? 1.80 cwt 2.120 cwt 3.180 cwt 4.220 cwt

4. CountryAve YieldRecord Yield (cwt) (cwt) India na 204 China 55 176 California 86 121 (M-202) 133 (exp) Reported Record Yields

5. Outline  Yield Components  panicles/area  spikelets/panicle  % filled grains  grain weight  Growth Stages and Yield  vegetative growth seedling tillering  reproductive growth panicle initiation flowering  grain ripening  Harvest Index

6. Definitions Spikelet = future grain or seed Panicle = the head or all the grains on a tiller

7. The Yield Components panicles/ area  Established Seedlings  Tillers per seedling

8. The Yield Components x panicles/ area spikelets/ Panicle

9. The Yield Components xx panicles/ area spikelets/ panicle % filled spikelets

10. The Yield Components xxx panicles/ area spikelets/ panicle % filled spikelets grain weight

11. The Yield Components xxx panicles/ area spikelets/ panicle % filled spikelets grain weight = yield

12. Example: Your crop has 60 panicles per square foot and each has 70 kernels. The kernel weight is 30 grams/1000 grains, there is 10% blanking, what is the yield? Yield Component Analysis Conversion Factors: 1 lb = 454 grams 1 a = 43,560 ft 2 Abbreviations: grams = g Pound = lb Square foot = ft 2 Step 1: 60 panicle/ft 2 x 70 kernel/panicle x 90% filled spikelets = 3780 kernels/ft 2 Step 2: 30 g/1000 kernels x 3780 kernel/ft 2  454 g/lb = 0.25 lb/ft 2 Step 3: 0.25 lb/ft 2 x 43,560 ft 2 /acre = 10,880 lb/acre

13. Example: Your crop has 60 panicles per square foot and each has 70 kernels. The kernel weight is 30 grams/1000 grains, there is 30% blanking, what is the yield? Step 1: 60 panicle/ft 2 x 70 kernel/panicle x 70% filled spikelets = 2940 kernels/ft 2 Step 2: 30 g/1000 kernels x 2940 kernel/ft 2  454 g/lb = 0.19 lb/ft 2 Step 3: 0.19 lb/ft 2 x 43,560 ft 2 /acre = 8,280 lb/acre Yield Component Analysis

14. Seeding Rates and Seed Density Seed Rate Density 1 Range 2 (lb/a) (seed/ft 2 ) (seed/ft 2 ) (S-102 to Kosh>44%) 125 45-50 38-55 150 50-55 46-66 175 55-60 54-77 200 68-72 61-88 1 typical of field run calrose varieties 2 range across California varieties based on seed weight tillers

15. Yield Components Plant Panicle Seeding RateStand Density (lb/acre) (sq ft) (sq ft) 30 11 53 60 21 65 90 27 61 120 34 66 150 34 68 210 43 75 Tillers per plant 30 lb/a = 5 60 lb/a = 3 150 lb/a = 2 210 lb/a = 1.7 tillers

16. Yield Components Plant Panicle Spikelets Seeding RateStand Density per Panicle (lb/acre) (sq ft) (sq ft) (no.) 30 11 53 90.8 60 21 65 74.8 90 27 61 71.6 120 34 66 64.3 150 34 68 63.1 210 43 75 58.9 spikelets

17. Yield Components Plant Panicle Spikelets Filled Seeding RateStand Density Per Panicle Spikelet (lb/acre) (sq ft) (sq ft) (no.) (%) 30 11 53 90.8 86.6 60 21 65 74.8 85.8 90 27 61 71.6 86.2 120 34 66 64.3 85.6 150 34 68 63.1 86.2 210 43 75 58.9 86.8 Normally about 12% Blanking % filled spikelets

18. Yield Components Plant Panicle Spikelets Filled Grain Seeding RateStand Density Per Panicle Spikelet Weight (lb/acre) (sq ft) (sq ft) (no.) (%) (mg) 30 11 53 90.8 86.6 25.2 60 21 65 74.8 85.8 25.6 90 27 61 71.6 86.2 25.8 120 34 66 64.3 85.6 25.5 150 34 68 63.1 86.2 25.9 210 43 75 58.9 86.8 25.9 grain weight

19. Yield Components Plant Panicle Spikelets Filled Grain Seeding RateStand Density Per Panicle Spikelet Weight Yield (lb/acre) (sq ft) (sq ft) (no.) (%) (mg) (lbs/acre) 30 11 53 90.8 86.6 25.2 8692 60 21 65 74.8 85.8 25.6 9267 90 27 61 71.6 86.2 25.8 9438 120 34 66 64.3 85.6 25.5 9393 150 34 68 63.1 86.2 25.9 9423 210 43 75 58.9 86.8 25.9 9456 yield

20. Yield Components Plant Panicle Spikelets Filled Grain Seeding RateStand Density Per Panicle Spikelet Weight Yield (lb/acre) (sq ft) (sq ft) (no.) (%) (mg) (lbs/acre) 30 11 53 90.8 86.6 25.2 8692 60 21 65 74.8 85.8 25.6 9267 90 27 61 71.6 86.2 25.8 9438 120 34 66 64.3 85.6 25.5 9393 150 34 68 63.1 86.2 25.9 9423 210 43 75 58.9 86.8 25.9 9456 yield Step 1: 7 plants/ft 2 x 5 tillers/plant = 35 panicles/ft 2 Step 2: 35 (60) panicle/ft 2 x 90 (70) kernel/panicle x 90% filled spikelets = 2835 (3780) kernels/ft 2 Step 2: 30 g/1000 kernels x 2835 (3780) kernel/ft 2  454 g/lb = 0.187 (0.25) lb/ft 2 Step 3: 0.187 (0.25) lb/ft 2 x 43,560 ft 2 /acre = 8,160 (10,880) lb/acre

21. Outline  Yield Components  panicles/area  spikelets/panicle  % filled grains  grain weight  Growth Stages and Yield  vegetative growth seedling tillering  reproductive growth panicle initiation flowering  grain ripening  Harvest Index

22. Growth Stages of Rice VegetativeReproductiveRipening

23. Growth Stages of Rice [-------------Vegetative------------][---Reproductive----]

24. Seedling Stage HeterotrophicAutotrophic [----------------------Vegetative----------------------]

25. Growth Stages of Rice [-------------Vegetative------------][---Reproductive----] [----Tillering----]

26. Tiller Initiation Approximately 25-30 DAS All maturities

27. Tiller Initiation

28. Growth Stages of Rice Tillering ends at or before PI [-------------Vegetative------------][---Reproductive----]

29. MaturityAve Days toAve Days CultivarGroup(County)50% headingto PIPI Range M-104VEButte734741-56 Sac815550-62 SJ926659-70 M-202EarlyButte845851-66 Sac906456-71 SJ987267-78 Glenn896355-69 M-205Early-MidButte896357-71 Colusa956962-76 Yuba916553-73 Glenn946860-75 M-206EarlyButte785244-64 Sutter855953-64 SJ946866-74 Colusa866049-68 Yuba835747-67 Average Date to 50% Heading, Estimated Time to PI and Variation in PI Range over 9 years from 2000-2008

30. Growth Stages of Rice--Reproductive Panicle is visible When stem cut about 7 days after PI but…. Spikelets per panicle are already formed

33. Cold Temperature Induced Floret Sterility

34. Collar alignment of the flag leaf and the previous leaf is an indicator of the cold sensitive period for pollen formation Left—before sensitive Middle—sensitive Right—after sensitive How many spikelets get filled is deter- mined at this stage

35. Of all the yield components, seed weight is under the tightest genetic control and LEAST influenced by environment. You can lower seed weight easily, but you can’t increase it! Plant Panicle Spikelets Filled Grain Seeding RateStand Density Per Panicle Spikelet Weight (lb/acre) (sq ft) (sq ft) (no.) (%) (mg) 30 11 53 90.8 86.6 25.2 60 21 65 74.8 85.8 25.6 90 27 61 71.6 86.2 25.8 120 34 66 64.3 85.6 25.5 150 34 68 63.1 86.2 25.9 210 43 75 58.9 86.8 25.9 This is why decisions on drain times and north winds at grain filling can mess with you!

36. Outline  Yield Components  panicles/area  spikelets/panicle  % filled grains  grain weight  Growth Stages and Yield  vegetative growth seedling tillering  reproductive growth panicle initiation flowering  grain ripening  Harvest Index

37. Harvest Index (HI) HI = (GW)/(GW + SW) where: HI = Harvest Index GW = Grain Weight SW = Straw Weight Example 1: A tall variety produces 6000 lbs of grain 7000 lbs of straw HI = 6000/(6000+7000) = 0.46 Example 2: A semidwarf variety produces 8000 lbs of grain 7500 lbs of straw HI = 8000/(8000 + 7500) = 0.52

41. Harvest Index (HI) HI = (GW)/(GW + SW) where: HI = Harvest Index GW = Grain Weight SW = Straw Weight Example 1: A tall variety produces 6000 lbs of grain 7000 lbs of straw HI = 6000/(6000+7000) = 0.46 Example 2: Let’s assume the HI =.52 for a short variety and calculate the amount of straw. 0.52 = 6000/(6000+ SW) SW = 5540 lbs

42. What yield component can be influenced most by good management? 1.Spikelets/panicle 2.Panicles/ft 2 3.Seed weight 4.% filled grains

43. What yield component is influenced least by management practices? 1.Spikelets/panicle 2.Panicles/ft 2 3.Seed weight 4.% filled grains

44. xxx panicles/ area spikelets/ panicle % filled spikelets grain weight = yield Thank you