rootstock effects on vegetative growth, crop yield components, and fruit Virginia Tech

Transcription

1 Ground cover, root zone restriction and rootstock effects on vegetative growth, crop yield components, and fruit composition of Cabernet Sauvignon Tremain Hatch Tremain Hatch Virginia Tech

2 Agenda Background/hypothesis Vegetative growth data Shoot growth Wine quality YAN Color Pruning weights Vine water status Fruit quality Berry weight Malic acid Conclusions

3 Excessive Vegetative Growth Surplus soil moisture available to vines though the growing season Deep rooting depth, fine textured high fertility soil Warm growing season Un balanced vine growth Poor fruit exposure High vineyard management cost High ihdisease pressure

4 Experimental Design 3 treatment levels Under trellis ground cover(utgc) Herbicide vs. Cover crop creeping red fescue Rootstock 11 14, A, riparia i Gloire Root Manipulation (RM) No root restriction (NRR) vs. root restriction (RR)

5 Hypothesis Treatments that predictably reduce the rate and duration of vegetative growth will produce fruitwith increased wine quality potential. Objectives Evaluate effects of treatments on vegetative growth of vines Evaluate how differences in vegetative growth influence fruitquality for wine production

6 28 14 UTGC n/a gth (cm) Shoot Len A riparia Rootstock NRR RR average a 42-A a riparia b Effect p-value Rootstock <.1 RM <.1 Rootstock X RM.381 Shoot le ngth (cm) NRR RR

7 Shoot Len nth (cm) Cover Crop Herbicide Shoot le ength (cm) A riparia shoot lengh ht (cm) NRR RR 22 May 28 May 3 Jun 9 Jun 15 Jun Effect P-value UTGC <.1 Rootstock ns UTGC X Rootstock ns RM <.1 UTGC X RM <.1 UTGC X Rootstock X RM ns

8 of canopy) Prunning weight(kg/meter UTCC Herbicide NRR RR NRR RR NRR RR A riparia f canopy) ing weight (kg/m o pruni UTCC Herbicide NRR RR NRR RR NRR RR Effect P- Value UTGC <.1 <.1 Rootstock Roostock X UTGC ns ns RM <.1 <.1 RM X UTGC <.1 <.1 RM X Rootstock X UTGC.9 ns

9 shoot fru uitfulness cover crop herbicide.4.2. NRR RR NRR RR NRR RR A riparia i

10 Components of yield Vine yeild (kg) Clusters per vine Cluster weight (g) Berry weight (g) Berries per cluster Treatment Herbicide UTCC a 2.1 a a 12 a a a 42 A 2.2 a 2.2 a ab 19 a a a riparia 2.6 b 2.7 b b 132 b b b NRR RR Effect p values UTGC.6 <.1 ns ns <.1 < <.1 <.1.1 ns ns.1.1 Rootstock ns ns ns.26 ns.252 Rootstock X UTGC ns ns ns ns ns ns ns ns ns ns RM < <.1 1 < ns ns RM X UTGC <.1 <.1 ns.19 ns ns ns ns ns ns RM X Rootstock X UTGC <.1 <.1 ns ns <.1 ns ns ns.4 ns

11 Brix ph TA (g/l) Treatment Herbicide UTCC A riparia NRR RR Effect p value UTGC.23 ns.15 ns.162 ns Rootstock ns ns ns ns ns ns Rootstock X UTGC ns ns ns ns ns ns RM ns.9 RM X UTGC ns ns ns ns RM X Rootstock X UTGC ns ns ns ns ns ns

12 Wine Pre fermentation chemistry Treatment Brix ph TA (g/l) Malates (g/l) YAN (mg/l) Herbicide UTCC NRR RR Effect p values UTGC ns.82 ns ns ns RM ns ns UTGC X RM.35 ns ns.18 ns

13 NRR RR NRR RR ns ns ns Cover crop Herbicide ns ns * Cover Crop Herbicide Yeast assimable nitrogen mg/l plant tissue analysis % nitrogen

14 Post fermentation color analysis Treatment A 28 A 32 A 42 A 52 Color density (A) Hue (A) Herbicide UTCC NRR RR Effect p values UTGC ns ns ns ns RM ns ns ns UTGC x RM ns ns ns ns ns ns

15 Water potential (ψ) Tension is caused by leaf transpiration and conducted throughout the plant to the root surface where water is drawn out of the soil, like tension pulled on a rope Morenegative value morewater stress

16 Ψ leaf 23 Jun 3 Jun 7 Jul 14 Jul 21 Jul 28 Jul 4 Aug 11 Aug 18 Aug 25 Aug 1 Sep 8 Sep 15 Sep 22 Sep 29 Sep 6 Oct NRR RR MPa

17 .1 Jun Jun Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep Sep 29 ψ J 17 J 24 J A 12 A 19 A 26 A 2 S 9 S 16 S Mpa Cover crop Herbicide ψ stem Jun 7 Jun 4 Jun 1 Jul 8 Jul 5 Jul 2 Jul 9 Jul Aug Aug Aug Aug Sep Sep Sep Mpa NRR RR

18 Results Cover crop Reduce vegetative growth Reduce crop level Reduce fruitfulness Increase color Rootstock (riparia) Reduce vegetative growth Increase crop level

19 Results Root restriction Reduce vegetative growth Reduce crop level Increase color Decrease malicacid id

20 Viticulture Less vegetative growth Low input canopy management Less diseasepressure Crop levell Winter hardiness Nutrient management over time Treatment function duration

21 Wine quality Berry weight Acidity Color