Hi everyone

Yes so soon, we have another hot topic.

There I was, out enjoying lunch on a rear stunning Auckland day with the blue harbour in-front of me and my phone starts flashing – it’s Rex. He is walking the vineyards in Marlborough and suddenly he has “got it” and do I have a minute to hear him out (this had better be good, I thought).

So, he goes on to explain …

There may be a connection between pruning and powdery mildew that hasn’t been made before. If you think about Sauvignon Blanc, it’s not particularly susceptible to powdery mildew so why are we seeing the high levels of this disease not seen in earlier times?

The obvious (and correct) reasons include: · Poor spray coverage

  • Stretched spray intervals
  • The sexual and asexual forms of the disease cycling independently and at different times
  • The development of resistance to agrichemicals
  • An inappropriate chemical choice such as the use of protectant sprays when the disease is present
  • Greater disease pressure due to monoculture

His excitement was around a new reason – Thick Heads (I didn’t see this one coming).

As our vineyards age, it’s essential to undertake remedial pruning in the heads to maintain correct head position and cane quality. If this remedial pruning is delayed we tend to get heads with a pincushion of bud sites that invariably leads to a thicket of shoots in spring. This is especially true with vigorous varieties like Sauvignon Blanc. Walk in many Marlborough vineyards at 10-15 years of age right now and you will find heads with 10-15 canes clustered tightly. In these thick heads we create the perfect environment to catch chasmothecia as they fall or wash down from the upper canopy. If these canes aren’t cut out cleanly, preferably with a single saw cut, we generate another thicket of shoots in spring. Once these shoots reach 150-250mm they are so dense with leaf that it is impossible to get good spray coverage and those unprotected shoots are right where the chasmothecia are lurking. …so the disease cycle starts again.

If we keep shoot numbers in the head to a reasonable number we will improve early season disease control, quality of cane in the head and shoot emergence on the cane.

Go out into your vineyard and look at your older vines with fresh eyes. If you have thick heads, get out there with the saw and wound dressing before the pruning gang arrives. You will get the benefit next season. By now you are probably sharing Rex’s excitement so I ask that you contain yourself until our next Newsletter, the topic – Wound Protection. And, a reminder that we are taking orders for delivery 2017. If you wish to secure your preferred rootstock, now is the time to do it.

In the meantime, scan the list of available vines below for this year delivery:

Variety Clone Rootstock Quantity
Cabernet Sauvignon LC10
338
338
FPS29
KWV15
Riparia
3309
Riparia
Riparia
Riparia
513
148
404
200
300
Chardonnay UCD15
UCD15
UCD15
B95
B95
B95
B95
3309
101-14
Riparia
3309
101-14
Riparia
420A
626
2142
245
791
2026
398
87
Malbec BDX595
BDX595
3309
Riparia
130
2000
Merlot 181
181
3309
Riparia
1870
3012
Petit Verdot C400 3309 25
Pinot Noir 113
Abel
101-14
101-14
40
2131
Pinotage 1/48 Riparia 298
Riesling GM110 SO4 8
Sangiovese 12T Riparia 322
Semilliom C400 3309 25
Syrah 174
174
383
470
470
MS/Hermitage
MS/Hermitage
3309
Riparia
Riparia
3309
Riparia
3309
Riparia
102
326
13
513
378
15
1323
Tennat Haden
Haden
3309
Riparia
32
119
Uzbek Muscat MS Riparia 167