grape growing

Pruning affects cold hardiness of trees and vines

January 28, 2014 by Jason Leave a Comment

Here’s a link to a great article put out by the Penn State College of Agricultural Sciences. It describes how fall pruning can adversely affect trees and vines. Whether I knew it or not, I was always a suspect of pruning in the late fall. I always wait until spring and prune my vines and trees at bud swell… just before bud break. My reasoning is that appendages sticking out into the cold air are the first to get frostbite, and die.

An analogy would be just like how the tips of your fingers or toes get cold first when you go outside in the cold weather. If you didn’t do anything about it, you would suffer frostbite, and in the extreme, tissue death. If you didn’t have any fingers, what would be the next thing to freeze? Your knuckles? Your hand? I always leave pruning for the spring, when things are firing back up. It’s also more obvious as to what wood is dead and needs to be removed before the growing season. One thing for sure is, during the course of a cold winter, there will be a lot of frozen limbs and vines that die from frostbite. So, I wait to prune my fruit trees and vineyard in the spring.

Here’s an abstract of the article

It seems that we are experiencing more unusually warm periods during mid- and late-winter, so trees may be more susceptible than in the past to moderately low winter temperatures. Lessons from years in which there was a sudden drop in temperature indicate that trees most injured were those that lacked adequate vigor, those that were too vigorous, and those that had been pruned before the cold event.

Read the full article here

2014 outlook on fruit crops

January 1, 2014 by Jason Leave a Comment

The following is an update with concerns from the recent cold snap and how it could affect the 2014 growing season from Peter Hirst and Bruce Bordelon at the Purdue Ag. Extension. I follow Bruce extensively and have spoken to him a number of times in the past. He’s a great person to know if you’re growing grapes in the Midwest. Check out some of the drastic steps I have taken around the ranch in the past with cold temps.

With the frigid temperatures blanketing the state, damage to fruit crops is likely. We were fortunate in having good snow cover prior to cold temperatures to protect roots from damage. Trying to predict the amount of bud/tree/vine damage we might expect is a little complicated because damage is influenced by many factors including minimum temps, duration of cold temps, acclimation and previous season’s crop load. The temperature in West Lafayette and across much of the midwest has been as low as –15 F or so. What damage can we expect at these temperatures? Apples and Pears are very hardy but we’re close to the temperatures where we could start to see some bud damage. It seems unlikely that bud damage will be severe enough to reduce crops.

Peaches and Nectarines – The rule of thumb I learned from Dick Hayden is that you start to see some flower bud kill at –10 F and for every degree below –10 F you lose 10% of your flower buds. At –20F expect complete flower bud mortality. Given that the temperature here right now is –13 F (and assuming this is as bad as it gets), we expect to have some early thinning occurring but crop reduction shouldn’t be too severe.

Sweet and tart cherries – tart cherries are a little more hardy than sweets, but we could see a little bud damage to both sweets and tarts, but at current temps this is unlikely to limit 2014 crops.

Blueberries – highbush blueberries are generally tolerant of temperatures down to –15, but the extended period of cold will likely lead to some flower bud kill.

Blackberries – thorny and thornless blackberries are not hardy below –10 so we would expect to see considerable damage to vascular tissue in canes and potentially buds themselves. In severe cases we would expect all above ground growth to be killed. Blackberries commonly exhibit a delayed winter injury response where the buds may have survived the winter cold and begin to grow in the spring, but the damage to the vascular tissue in the canes results in collapse of the new growth a few days or weeks after the start of growth.

Raspberries – red and black raspberries are fairly cold hardy and we would expect minimal damage to varieties that are adapted to the Midwest. Some red raspberry varieties from the Pacific Northwest are not very cold hardy and may have been damaged.

Grapes – varieties will vary widely in amount of damage. Grapes have a compound bud, with primary, secondary and tertiary growing points. The primaries are usually the first to show cold damage. We would expect hardy hybrid and American varieties to have 0-25% primary bud damage at the temperatures we experienced. That is manageable as we can adjust pruning severity to account for those losses. Less hardy hybrids may have 50% or more bud damage, which could lead to some yield reduction and potentially cane and cordon damage. Cold tender vinifera varieties likely have experienced considerable damage to buds, canes, and cordons and possible damage to trunks above the snow line.

The extended duration of cold temperatures expected may increase the amount of damage we see. We’ll know more in a week or so. Right now there’s nothing growers can do except stay inside, keep warm, and keep their fingers crossed.

Peter Hirst and Bruce Bordelon

A mild winter’s impact on grapes

February 16, 2012 by Jason Leave a Comment

The following is by Bruce Bordelon from the Purdue Wine Grape team. I’ve spoken to Bruce many times in the past about pruning, spray regimens and dealing with a number of issues in the vineyard. I respect his advice when it comes to growing grapes in Indiana. Looks like we will be in for a challenging Spring.

Bruce Bordelon @ Ertle Cellars/Purdue Wine Grape Workshop.

—-

The unusually mild winter has many people asking about what effects the mild temperatures are having on fruit crops. It’s a bit complicated. Most temperate zone plants like apples, grapes, blueberries, etc. go dormant in the fall and will remain dormant even though we may have some mild temperatures during the winter months. They are adapted to this climate by having a “chilling requirement” necessary for them to break dormancy. The must receive a certain amount of “chilling” in order to complete the dormancy process and begin normal grow in the spring. “Chilling” occurs when temperatures are in the range of 34 to 54˚F, with an optimum of about 42˚F. Temperatures colder than 34˚F do not satisfy the chilling requirement and temperatures above 54˚F can actually cause a loss of accumulated hours. There are several models to monitor chilling hour accumulation and the Utah model, developed in peaches, is widely used. The amount of chilling necessary varies by species and varieties, but for most fruit crops is in the range of 500-1,000 hours. Grapes are on the low end of that scale, and vary by variety and species background.

During normal winters, we accumulate some (200 or so) chilling hours in November, but few in December and January, as the average temperature gets too low to satisfy the chilling requirement. Chilling hours accumulate again in February and March, with most crops achieving the necessary hours to fulfill the requirement during the last month of winter. After that point, plants will be ready to respond to warm conditions and begin growth.

This year is unusual in that we received a significant number of chilling hours during December and January. In Tippecanoe County, for instance, we have accumulated 915 hours from Nov. 1 to Feb. 1. During the same period in 2011 we accumulated only 373 hours. At 915 hours we have satisfied the chilling requirement for grapes, raspberries, blackberries and peaches. Apples and blueberries need 1,000-1,200.

In addition to being no longer dormant, plants have also likely experienced cold hardiness de-acclimation in the past month. My colleagues in Ohio recently posted a nice article on this topic in the Ohio Grape-Wine Electronic Newsletter

So what does all this mean to Indiana fruit growers?

It means that your crops are no longer dormant, probably have reduced cold hardiness, and are ready to grow as soon as we get a few days of 50 degree weather. The risk of winter cold damage from temperatures near zero is diminished as we move through February, but the risk of spring freeze damage would be very high if plants begin growth before mid-March or early April. Recall that the frost free date (50% chance of 28˚F) is early May across central Indiana. We have a long way to go….

What can you do?

Growers can avoid frost damage by delaying pruning as long as possible. Unpruned plants are more cold hardy and their buds develop more slowly compared to pruned plants. Grape growers can also use a technique called “long or double pruning.” This method is especially good for varieties that tend to bud out early. The procedure utilizes the apical dominance of buds on a cane. The first buds to begin growing are those on the tip of a cane, while buds closer to the base begin growth later. To perform long pruning, select canes to be used for fruiting spurs during the normal pruning practice and remove the rest of the wood. Instead of cutting the selected canes back to 3-4 node spurs, leave them long, with 10-15 more buds than desired. The extra buds will help delay the development of the desired basal buds, which helps avoid frost injury. After the date of the last probable spring freeze has passed, the canes are shortened to the desired length to properly adjust the bud number for the vine. Growth of the basal buds can be delayed as much as two weeks if weather conditions are favorable. While this procedure requires an extra trip through the vineyard, it can mean the difference between a full crop and little or no crop.

I would be happy to answer questions and respond to comments.

~~~~~~~~~~~~~~~~~~~~~
Bruce Bordelon, Ph.D.
Professor and Extension Specialist, Viticulture and Small Fruit
Purdue University
Department of Horticulture and Landscape Architecture
625 Agriculture Mall Drive
West Lafayette, IN 47907-2010
http://www.hort.purdue.edu/fruitveg/

Grape variety is a major factor for success in Indiana

July 1, 2009 by Jason Leave a Comment

lg_vidal — Vidal Blanc. I have a row of these growing and they seem to be the last ones out each season. Smaller grapes, longer clusters.

Check out this paper just released from the Purdue Agricultural Extension by Bruce Bordelon. I consult with Bruce… and he actually responds to questions from home-boys like me. I appreciate the efforts of his team and want to echo their efforts to other growers in SE Indiana!

Selecting an appropriate grape variety is a major factor for successful production in Indiana and all parts of the Midwest. There are literally thousands of grape varieties available. Realistically, however, there are only a few dozen that are grown to any extent worldwide, and fewer than 20 make up the bulk of world production.

Consistent production of high quality grapes requires properly matching the variety to the climate of the vineyard site. This publication identifies these climactic factors, and then examines wine grape varieties and table grape varieties. Tables 1, 2, and 3 provide the varieties best adapted for Indiana, their relative cold hardiness and disease susceptibility, and their yield performance at two
test locations in the state.

Grape Varieties for Indiana

by Bruce Bordelon
Purdue Horticulture and Landscape Architecture
www.hort.purdue.edu
All photos by Bruce Bordelon and Steve Somermeyer

June 2009 Grape Update

June 20, 2009 by Jason Leave a Comment

Some varieties are doing ok… but the Catawba has been hit with black rot. I’m about to throw in the towel with these. I’ve been diligent in cleaning out the vineyard last fall… spraying early… before, at and after bud break… Did captan once…waited two weeks and been on a regimen of spraying 1-2 times a week with Stylet oil. I have done cluster thinning, canopy thinning to let air blow through… all to no avail… The black rot is HIGH-PRESSURE around here this year. I am suffering like a mo-fo.

I’ll be contacting Bruce Bordelon at the Purdue extension next. I just went in and plucked clusters… and rotten berries to get out everything I can. I have it clean now. Thinking of spraying again. Right now, it’s latched on to my Catawba the hardest (not as bad last year) The others are OK but I’m still picking leaves and things off as I see them.

See the pics. Here are the questions I’m posing to my experts.

Is it true I should be pulling out leaves, clusters… and whole stems that I see are infected? Just don’t want to overdo it for the storage of needed carbs over winter.
True that we want to pull leaves to give wind and sun a direct route through?
If the pressure is high and black-rot is eminent, what do the experts try?
Regarding pruning: Would like training suggestions on what to do with some of my double trunks… and lower cordons. I’m seeing that lower cordons are just a direct transfer of rot from the ground to higher up. I have cut them off of some

Growing grapes is a task. I respect vineyard managers. I would like to think as my vines mature that they would build up an immunity to the rot in future years. Will report again next month.