Almond Irrigation, Water Stress and Productivity: Where do Drought & Deficit Irrigation Research Fit In?

Transcription

1 lmond Irrigation, Water Stress and Productivity: Where do Drought & Deficit Irrigation Research Fit In? Ken Shackel, UD Plant Sciences January, 2008

2 Some drought irrigation history: a) Irrigation cutoff & drought recovery trials in Kern o. on relatively shallow sandy soil (Dave Goldhamer) b) Irrigaiton cutoff/cutback & drought recovery trials in Manteca on moderate depth sandy loam soil (Terry Prichard) c) Drought irrigation management trials N. Kern o. 3' sandy loam (Dave Goldhamer)

3 Goldhamer study, Full ET: 30" 40" in-season Yields: 1,700 #/ac (3ed year yield penalty at < 90% ET?) % ET (1991) Preharvest utoff (days)

4 Goldhamer study, Drought recovery Drought with a 60% reduction choices: a) use it at full ET until it is gone (long cutoff) b) spread it out for various levels of cutoff Results: More even spread is best

5 Prichard study, Full ET: 37" in-season Yields: 3,360 #/ac Yield (% ontrol) Deficit Treatment % ET (5) Midseason (4) Mid and Postharvest (3) Midseason (6) Plant-based (2) Postharvest (1) ontrol No yield loss at 66% ET with season-long plant-based irrigation (predawn WP < -12 bars)

6 study, Southern SJV, 18 year-old orchard ontrol (100% ETc) 3 levels of irrigation deficit 3 patterns of deficit B

7 Seasonal pattern in water application (% of control) Equal irrigation deficit all season 100 (ontrol = 100% season long, about 42 ) (Target about 34 ) 70 (Target about 28 ) (Target about 23 ) MRH PRIL MY JUNE JULY UGUST SEPT OT NOV Date (Goldhamer et al., 2006)

8 B Seasonal pattern in water application (% of control) Some deficit early, most deficit post-harvest 100 B B B B BB B B B BB MRH PRIL MY JUNE JULY UGUST SEPT OT NOV Date (Goldhamer et al., 2006)

9 Seasonal pattern in water application (% of control) More deficit early, less deficit postharvest MRH PRIL MY JUNE JULY UGUST SEPT OT NOV Date (Goldhamer et al., 2006)

10 Mean Yield Kernel Yield (lbs/ac) B B (100% ETc ONTROL) B (ONLY 2 TRETMENTS WITH SUBSTNTIL 3ED YER REDUTION) B Kernel Size (g/nut) 1.20 B 1.15 B Seasonal pplied Irrigation (inches) (Goldhamer et al., 2006)

11 rop Load (Thousand nuts/acre) B B 600 B Seasonal pplied Irrigation (inches) (Goldhamer et al., 2006)

12 Question: is the amount and timing of irrigation all you need to know to describe the stress experienced by the tree? Kernel Yield (lbs/ac) B B B Seasonal pplied Irrigation (inches) (Goldhamer et al., 2006)

13 nswer: probably not, maybe better to ask the tree?

14

15 Example of the daily pattern in stem water potential (SWP) in lmonds (Magnum ranch, Lassen Land o., ugust 4, 2005) 0-5 (Wetter condition) SWP (bars) (Drier condition) (MIDDY SWP) -30 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 24:00 Local time

16 Midday SWP values in lmond 0-5 (Minimal stress) Expected range even under fully irrigated conditions -10 SWP (Bars) (Mild stress) (Moderate stress) Will reduce overall growth of young trees, and shoot growth of older trees, but may also have some beneficial effects on older trees Interior leaf yellowing and drop usually apparent. Not unusual to find under almond production conditions, but probably reduces tree productivity, particularly if these levels occur regularly -30 (Severe stress) Leaf drop, flagging, wilting. an occur under almond production conditions, particularly around harvest. -35

17 Goldhamer study, predawn water potential 0 PR MY JUN JUL UG SEP OT Predawn leaf water potential (bars) , 23, (Goldhamer et al., 2006)

18 Midday SWP values in lmond 0-5 (Minimal stress) Expected range even under fully irrigated conditions -10 SWP (Bars) (Mild stress) (Moderate stress) Will reduce overall growth of young trees, and shoot growth of older trees, but may also have some beneficial effects on older trees Interior leaf yellowing and drop usually apparent. Not unusual to find under almond production conditions, but probably reduces tree productivity, particularly if these levels occur regularly -30 (Severe stress) Leaf drop, flagging, wilting. an occur under almond production conditions, particularly around harvest. -35

19 Example: Midday stem water potential (bars) in 2006, Lampinen et al., Spur Dynamics T1 (high water, high N), Seasonal mean = bars T2 (high water, mod. N), Seasonal mean = bars T3 (mod. water high N), Seasonal mean = bars T4 (mod. water mod. N), Seasonal mean = bars -35 pril May June July ug Sep Date, 2006 Oct

20 Lampinen study, canopy development (5 th leaf 11 th leaf orchard) 80 Seasonal average midday light interception (%) high water, high N high water, mod. N mod. water, high N 20 mod. water, mod. N Year (Lampinen study)

21 Midday light interception (%) Kernel yield (lbs/acre) Walnut lmond- Nonpareil Spur Dynamics lmond- Nonpareil RVTs lmond- Nonpareil- Duncan trial onclusions: Midday light interception (%) anopy development determines yield potential pproximately 10% loss in rate of canopy development per bar of seasonal average midday stem water potential deficit (Lampinen study)

22 Midday light interception (%) Kernel yield (lbs/acre) Walnut lmond- Nonpareil Spur Dynamics lmond- Nonpareil RVTs lmond- Nonpareil- Duncan trial Midday light interception (%) anopy development determines yield potential pproximately 10% loss in rate of canopy development per bar of seasonal average midday stem water potential deficit (Lampinen study)

23 Goldhamer study, predawn water potential 0 PR MY JUN JUL UG SEP OT Predawn leaf water potential (bars) , 23, (Goldhamer et al., 2006)

24 Question: Is it possible that stress can be determined by factors other than irrigation amount and timing? nswer: Yes we have a good example of a non-uniform field that required substantial irrigation compensation to make it uniform.

25 orning location Farm dvisors: llan Fulton, Rick Buchner Grower: Brian rane, rane-mills, orning, System: microsprinkler Bomber: ayle Little (lmonds) EXPERIMENTL PLOT

26 WEST (gravel) EST (silt)

27 % Hull Split, armel variety (East/West difference similar in all varieties) Date, ug 16 ug 22 ug 31 ug 6 Sep 14 Sep East (verage SWP = -8.4 bars) West (verage SWP = bars) 0% 0% 5% 13% 32% 40% 4% 23% 60% 83% 85% 91% Problems with uneven hull split timing: - Uncertain timing for hull split spray - Irrigation management problems - Uneven/delayed harvest

28 NonPareil variety (orning) Hull Split (RDI treatment) 2001: East (silt) Date % HS JUL 13 2 JUL JUL UG 1 70 UG West (gravel) Date % HS JUL 13 2 JUL JUL UG 1 75 UG : East (silt) Date % HS JUL UG 7 96 UG UG West (gravel) Date % HS JUL UG 7 88 UG UG

29 orning location irrigation summary (RDI) Soil Water applied utoff date Water applied utoff date Water applied utback date East (silt) Jul 14 1-Jul 18 7-Jun West (gravel) ug 41 4-Sep Sep ETc Very long cutoff/cutback OK on East (silt) soil

30

31 lmond RDI sites: ounty Location Soil type ge (yr) Irrigation Tehama orning(e) Silt-Loam 9 Microsprinkler Tehama orning (W) Gravel-Loam 9 Microsprinkler Butte hico Vina-Loam 9 Solid-set Sprinkler olusa rbuckle Gravel-Loam (II) 13 Single line drip Solano Dixon Yolo-S/Loam 8 Solid-set Sprinkler Madera Madera Dinuba FSL 10 Microsprinkler Kern Shafter Sandy Loam 15 Microsprinkler Question: an we use RDI in the same location(s) over many years without reducing yield?

32 Four year yield summary (lbs. nutmeats per acre) Treatment (2 sites) (7 sites) (7 sites) (7 sites) Grower 2,400 3,170 2,860 2,650 RDI 2,430 3,080 2,660 2,680

33 Selected sites where differences in stress only occurred during hull split (15 paired comparisons) Irrigation Treatment (Measured Value) Grower RDI SWP (bar) ± ± 2.1 Yield (lbs/ac) 2,812 ± 787 2,858 ± 751 Nut Size (g) 1.22 ± ± 0.20

34 Four year ( ) harvest effects summary Hull rot (strikes/tree) Location Grower RDI Days RDI advance in HS Other effects orning (silt) orning (gravel) hico rbuckle Dixon % mummy reduction, '02 Madera Grower required 2 shakes, '02 Kern % sticktight reduction, '03, '04

35 Magnum Ranch, Lassen Land co. RDI study. Nutmeat yields, Lbs. nutmeats/acre ONTROL 0 RDI YER

36 Benefits of RDI (mild stress) for almonds during hull split: 1) Speed up Hull Split (use water as a management tool) 2) Reduce Hull rot 3) Reduce Sticktights (Improve Harvestability) 4) Save Water 5) No negative impact on yield