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
Agenda Background/hypothesis Vegetative growth data Shoot growth Wine quality YAN Color Pruning weights Vine water status Fruit quality Berry weight Malic acid Conclusions
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
Experimental Design 3 treatment levels Under trellis ground cover(utgc) Herbicide vs. Cover crop creeping red fescue Rootstock 11 14, 14 42 A, riparia i Gloire Root Manipulation (RM) No root restriction (NRR) vs. root restriction (RR)
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
28 14 UTGC n/a gth (cm) 12 1 8 Shoot Len 6 4 2 11 14 42 A riparia Rootstock NRR RR average 11-14 2.6 1.4 2. a 42-A 2.5 1.3 1.9 a riparia 1.9.9 1.4 b 14 12 Effect p-value Rootstock <.1 RM <.1 Rootstock X RM.381 Shoot le ngth (cm) 1 8 6 4 2 NRR RR
29 12 12 Shoot Len nth (cm) 1 8 6 4 2 Cover Crop Herbicide Shoot le ength (cm) 1 8 6 4 2 11 14 42 A riparia shoot lengh ht (cm) 12 1 8 6 4 2 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
of canopy) Prunning weight(kg/meter 1.4 1.2 1.8.6.4 2.2 28 UTCC Herbicide NRR RR NRR RR NRR RR 11 14 42 A riparia f canopy) ing weight (kg/m o pruni 1.4 1.2 1.8.6.4.2 29 UTCC Herbicide NRR RR NRR RR NRR RR 28 29 Effect P- Value UTGC <.1 <.1 Rootstock.64.35 Roostock X UTGC ns ns RM <.1 <.1 RM X UTGC <.1 <.1 RM X Rootstock X UTGC.9 ns
29 1.8 1.6 1.4 shoot fru uitfulness 1.2 1..8.6 cover crop herbicide.4.2. NRR RR NRR RR NRR RR 11 1414 42 A riparia i
Components of yield Vine yeild (kg) Clusters per vine Cluster weight (g) Berry weight (g) Berries per cluster Treatment 28 29 28 29 28 29 28 29 28 29 Herbicide 2.8 2.9 15 21 182 139 1.4 1.5 132 95 UTCC 1.6 1.8 14 2 18 91 1.3 1.4 85 64 11 14 1.8 a 2.1 a 14 2 127 a 12 a 1.3 1.4 a 98 73 a 42 A 2.2 a 2.2 a 15 2 142 ab 19 a 1.3 1.4 a 17 77 a riparia 2.6 b 2.7 b 14 2 164 b 132 b 1.3 1.5 b 12 88 b NRR 3.3 2.9 2 24 166 118 1.4 1.5 118 77 RR 1.1 1.8 9 17 124 112 1.2 1.4 99 82 Effect p values UTGC.6 <.1 ns ns <.1 <.1.78.74 <.1 <.1.1 ns ns.1.1 Rootstock.25.86 ns ns.487.45 ns.26 ns.252 Rootstock X UTGC ns ns ns ns ns ns ns ns ns ns RM <.11.66 <.1 1 <.11.22 ns.11.33.22 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
Brix ph TA (g/l) Treatment 28 29 28 29 28 29 Herbicide 22 23 3.3 3.4 6. 6.8 UTCC 24 23 3.4 3.4 4.6 6.6 11 14 23 23 3.4 3.4 5.3 6.3 42 A 23 23 3.3 3.3 5. 6.9 riparia 23 23 3.3 3.4 5.5 6.8 NRR 23 23 3.3 3.3 5.4 7.4 RR 23 23 3.4 3.4 5.2 6. 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.1.44.35.19 ns.9 RM X UTGC ns ns.353.3 ns ns RM X Rootstock X UTGC ns ns ns ns ns ns
Wine Pre fermentation chemistry Treatment Brix ph TA (g/l) Malates (g/l) YAN (mg/l) Herbicide 23 3.8 4. 3.4 152 UTCC 23 3.7 4. 3.4 141 NRR 23 3.7 4.3 3.9 136 RR 23 3.7 3.7 3. 157 Effect p values UTGC ns.82 ns ns ns RM ns ns.6565.4848.5959 UTGC X RM.35 ns ns.18 ns
29 1.4 12 1.2 1.8.6.4.2 18 16 14 12 1 8 6 4 2 NRR RR NRR RR ns ns ns Cover crop Herbicide ns ns * Cover Crop Herbicide Yeast assimable nitrogen mg/l plant tissue analysis % nitrogen
Post fermentation color analysis Treatment A 28 A 32 A 42 A 52 Color density (A) Hue (A) Herbicide 29 11 3 4 6.65 UTCC 33 12 3 5 8.69 NRR 28 11 3 4 7.69 RR 33 12 3 5 8 65.65 Effect p values UTGC ns ns ns.463.5 ns RM ns ns ns.287.3.5 UTGC x RM ns ns ns ns ns ns
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
28.2.4 28 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.6.8 1 1.2 1.4 NRR RR MPa
.1 Jun Jun Jun Jul Jul Jul Jul Jul Aug Aug Aug Aug Sep Sep Sep 29 ψ.4.3.2 1 J 17 J 24 J 1 8 15 22 29 5 A 12 A 19 A 26 A 2 S 9 S 16 S Mpa Cover crop Herbicide ψ stem 8.7.6.5.8 2.1. Jun 7 Jun 4 Jun 1 Jul 8 Jul 5 Jul 2 Jul 9 Jul Aug Aug Aug Aug Sep Sep Sep.5.4.3.2 1 17 24 8 15 22 29 5 12 19 26 2 9 16 Mpa NRR RR.9.8.7.6 1..9
Results Cover crop Reduce vegetative growth Reduce crop level Reduce fruitfulness Increase color Rootstock (riparia) Reduce vegetative growth Increase crop level
Results Root restriction Reduce vegetative growth Reduce crop level Increase color Decrease malicacid id
Viticulture Less vegetative growth Low input canopy management Less diseasepressure Crop levell Winter hardiness Nutrient management over time Treatment function duration
Wine quality Berry weight Acidity Color