Pruning Timing Options to Avoid Wood Diseases in Young Almonds. Carolyn DeBuse, Farm Advisor Solano & Yolo Counties

Transcription

1 Pruning Timing Options to Avoid Wood Diseases in Young Almonds Carolyn DeBuse, Farm Advisor Solano & Yolo Counties

2 Overview The Problem Canker Diseases Past studies Fall timing Current studies Spring timing Weather

3 Botryosphaeria Phytophthora Eutypa Ceratocystis Canker Diseases

4 Cankers in the crotch of the tree

5 Cankers in the crotch of the tree

6 Canker Diseases To infect your tree Fungus spores or conidia Open wound Cold weather Slower wound healing Some do better in cool temperatures Spread by water/rain/irrigation Fungus grow better in damp conditions

7 Timing of Pruning Standard pruning timing Prune directly at plant at 36 inches height

8 Timing of Pruning Standard pruning timing Following year prune during dormant season Choose scaffolds take everything else off

9 1991 Wilbur Reil, W. Micke, J. Yeager, C. Langston. 8 year old orchard Thinning out 3 6 branches of 2 4 inch diameter 3 pruning timings October 15 th November 15 th December 15 th Past Studies

10 Past Studies No Significant differences between treatments for yield or tree size

11 First year tree 2010 Studies 64 Nonpareil trees planted March 19, heading timings & 2 pruning heights (4 reps of 4 trees each) 1) 36 high at planting, March 19th 2) 36 high at leaf bud break 3) 48 high at leaf bud break 4) 36 high during leaf expansion Measurements of diameter, height, and branch number

12 2010 Studies Second year tree 72 Nonpareil trees planted winter of 2008/09 3 pruning timings (6 replicates of 4 trees each) 1) Dormant, February 16 th 2) Leaf bud break, March 9 th 3) During leaf expansion, April 27 th Measurements of circumference, height, and canopy size

13 2010 Dormant Second Leaf February 16 th

14 2010 Leaf Bud Break, Second Leaf March 9th

15 2010 Leaf Expansion, Second Leaf April 27th

16 2010 Results Second Leaf 30 Comparison of circumference (cm) of second year trees with different timing of pruning Circumference (cm) 400 Height (cm) Comparison of height (cm) of second year trees with different timing of pruning 25 Circumference (cm) Height (cm) April November 0 April November Pruning dormant, Feb. 16, 2010 Pruning at leaf bud break, March 9, 2010 Pruning during leaf expansion, April 27, 2010 No Significant Differences between timings

17 2010 Results First Year Comparison of average diameter (mm) of one year old trees with different timings of the heading cut after planting Diameter (mm) Comparison of average height (cm) of one year old trees with different timings of the heading cut after planting Height (cm) Diameter (mm) Height (cm) June November 0 November heading cut at 36 inches at leaf bud break 19 days after planting heading cut at 36 inches during leaf expansion 42 days after planting heading cut at 48 inches at leaf bud break 19 days after planting Control heading cut made at 36 inches at planting on March 19, 2010 No Significant Differences between timings

18 Second year tree Three varieties: Nonpareil (112 trees) Winters(56 trees) Monterey(56 trees) 2011 Studies Pruning Treatments 3 pruning timings (replicates of 4 trees each) 1. Dormant, February 4 th 2. Leaf bud break, March 9 th 3. During leaf expansion, April 2 th

19 2011 Studies Third year tree Continuing the trial from Nonpareil trees planted winter of 2008/09 Pruning Treatments 3 pruning timings (replicates of 4 trees each) 1. Dormant, February 4 th 2. Leaf bud break, March 9 th 3. During leaf expansion, April 2 th

20 2011 Second Leaf Dormant Feb. 4 th Leaf Bud Break March 9 th Leaf Expansion April 2nd

21 2011 Results Second Year Trees Nonpareil Circumference (cm) April 2011 Circumference (cm) Oct 2011 Percent increase Height (M) Oct 2011 Pruning 'dormant a a 99% 3.21 a Pruning 'leaf bud break' a b 98% 3.12 ab Pruning leaf expansion' a c 92% 3.08 b Monterey Pruning 'dormant b a 124% 2.66 b Pruning 'leaf bud break' a a 108% 2.74 ab Pruning leaf expansion' a a 105% 2.85 a Winters Pruning 'dormant a a 99% 2.92 a Pruning 'leaf bud break' a a 107% 2.82 a Pruning leaf expansion' a a 99% 2.97 a

22 2011 Results Third Year Trees Nonpareil Circumference (cm) Oct 2011 Height (M) Oct 2011 Pruning 'dormant' Pruning 'leaf bud break' Pruning leaf expansion' No Significant Differences between timings

23 Weather Perciptation Average Daily temperature Inches Perciptation 2011 Temperature F Average Daily Temperature 2011 Inches julian Date Jan Julian Date Nov Jan Nov

24 Conclusion You can prune in Spring as late as bud break in the first two years to avoid wet weather You can prune in October without any difference Weather dependent every year Think about canker diseases when making that decision