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Drought tolerant rootstocks for sultana

This information may be useful in helping to determine the best rootstocks to use to minimise the effects of drought conditions on vines for dried fruit production.

 

Low water availability sultana production

During times of low water availability such as drought, vines may have to be irrigated with less than the optimum amount of water. Research has shown that the rootstock has a significant impact on the vine’s survival and ability to recover following low water conditions. The results show a number of rootstocks are quite drought tolerant and can survive in low water conditions. These same rootstocks also recover well in the following year with full irrigation.

 

The drought simulation trial

A trial was conducted in Sunraysia from 2007-2009 to simulate the effects of drought and then recovery on a range of common rootstocks that were grafted with Sultana.

During the 2007/08 growing season the trial vines were not irrigated. The only water they received was rainfall and this was well below average. A late irrigation was applied in February 2008 to stimulate the start of the recovery process.

In the 2008/09 season the vines were irrigated as per grower practice so that they received all the water they needed for optimum crop production.

A range of measurements were taken to determine the effects of the drought conditions and the rootstocks ability to recover once water returned to normal. These included measuring the amount of leaf area and fruit the vine produced in both seasons. Fruit quality and quantity was also assessed as many bunches on some rootstocks were unmarketable in 2007/08.

 

What were the results?

Clear results were seen after the 2007/08 season with vines on a number of rootstocks struggling to produce any canopy, while others did remarkably well. Schwarzmann, 101-14 and self grafted vines showed poor recovery and some vines died. The list below shows the rootstocks ranked from worst to best according to how much fruit they produced in the 2007/08 season.

Schwarzmann and 101-14 have the same parent material and so it seems likely that they are genetically predisposed to being weak performers in low water situations.

101-14(Vitis riparia x Vitis rupestris)

Schwarzmann(Vitis riparia x Vitis rupestris)

Self-grafted(Vitis vinifera)

Kober(Vitis berlandieri x Vitis riparia )

Ramsey( Vitis champinii )

Ruggeri(Vitis berlandieri x Vitis rupestris )

Paulsen(Vitis berlandieri x Vitis rupestris )

116-60 (Vitis candicans x 1613C)

187-24 (Vitis solonis x Vitis candicans)

Leaf coverage roughly corresponded to yield. Ruggeri, 116-60, Paulsen, Ramsey and 187-24 all had enough leaf canopy to keep the plant functioning. 187- 24 consistently had the highest leaf area. Ramsey performed well in leaf area but had low yield. It was the most variable of all rootstocks trialed.

 

The recovery of the rootstocks

In the following season, 2008/09, the ability of the vines to recover from the effects of drought was determined by measuring shoot development. All vines were heavily pruned as a result of many unviable canes and were watered as per crop water requirements.

Schwarzmann, 101-14 and self-grafted, showed poor recovery and indicated that it was a better option to remove them and replant on a different rootstock.

In general the leaf area in the previous season was mirrored in the plants ability to recover and develop a viable productive canopy.

 

Recommendation

When developing a vineyard a number of characteristics need to be taken into consideration when choosing which rootstock to plant. Every situation is different, however disease resistance, vigour and yield should all be considered.

If choosing solely on the basis of tolerance to water stress the rootstocks 116-60 and 187-24 consistently performed better than the other rootstocks.

 

Further information

Please contact the Agriculture Victoria Customer Service Centre on 136 186.

 

 

The advice provided here is intended as a source of information only. Always read the label before using any of the products mentioned. The VVBC does not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication