Maximizing the performance of high-density plantings, such as this second-leaf Fuji block at Zingler Farms in Kendall, New York, was the focus of July’s Lake Ontario Fruit Summer Tour organized by Cornell Cooperative Extension. <b>(Kate Prengaman/Good Fruit Grower)</b>

Maximizing the performance of high-density plantings, such as this second-leaf Fuji block at Zingler Farms in Kendall, New York, was the focus of July’s Lake Ontario Fruit Summer Tour organized by Cornell Cooperative Extension. (Kate Prengaman/Good Fruit Grower)

As New York growers seek to expand fresh market production of high quality fruit, they are looking for ways to maximize performance of high-density apple plantings and recoup the investments of new orchards faster.

Luckily, Cornell University researchers continue to learn how to optimize horticultural practices in the region’s signature tall-spindle systems, and they shared their findings on irrigation, nutrition and chemical thinning with growers at a summer field day at five farms in the Lake Ontario fruit belt.

Although it’s been a wet season so far, growers haven’t forgotten the drought of the previous year, with losses of 47 percent for those without irrigation, according to a Cornell study.

More growers are investing in irrigation systems said Mario Miranda Sazo, extension educator for Cornell Cooperative Extension’s Lake Ontario Fruit Program.

“When I came here in 2009 and started talking about irrigation, you all said, ‘You don’t know our weather here,’” Miranda Sazo joked with the tour group. “But we should be putting irrigation on these new plantings and little by little, growers are installing it. You have to baby-sit these trees from the get-go.”

But, according to Miranda Sazo and Jaume Lordan, a Cornell postdoctoral researcher focused on horticulture, it doesn’t take a drought for water stress to take a toll on densely planted apple trees.

“We used to have 100 trees per acre, now we have 1,000,” Lordan said. “Now, we are putting in more trees, growing bigger apples on rootstocks with smaller root systems, so we really should irrigate.”

Cornell’s Jaume Lordan and Mario Miranda Sazo discuss the importance of irrigation in high density apple plantings on the Lake Ontario Fruit Summer Tour. <b>(Kate Prengaman/Good Fruit Grower)</b>

Cornell’s Jaume Lordan and Mario Miranda Sazo discuss the importance of irrigation in high density apple plantings on the Lake Ontario Fruit Summer Tour. (Kate Prengaman/Good Fruit Grower)

He said that high-density orchards in Western New York need about 400,000 gallons of water per acre during the growing season — based on transpiration rates — and average rainfall provides about 350,000 gallons per acre. “Last year, we only got 200,000 gallons of rainfall, just half of what we needed,” Lordan told growers.

Water stress can cost thousands of dollars an acre, in terms of smaller fruit size and lower quality, he said.

Maintaining soil moisture also ensures that trees can take advantage of fertilizers. “If there is no water, you can keep putting out nutrients but they will not be taken up,” Lordan said.

He urged growers to use a weather-based irrigation tool for apples on Cornell’s Network for Environment and Weather Applications website to guide water decisions.

Precision thinning

Online models are also available to help growers make more careful chemical thinning decisions — taking into consideration the role of temperature and sunlight on tree carbohydrate supply and thinner effectiveness.

It’s part of a strategy known as the precision thinning protocol, which is slowly gaining converts, said Poliana Francescatto, a Cornell postdoctoral researcher who runs the program.

About 20 growers are now using the tool in New York, along with others in Michigan, she said. “Every year, we get a few more growers who see the value of it.”

The protocol relies on repeated measurements of fruitlets following thinning sprays, so that changes in the growth rate can tell growers how many have stopped growing well before drop, ensuring they have a chance to apply another thinning spray if needed. Data is collected on 15 clusters on each of five representative trees.

“Precision is the key word,” she said. “It looks easy but it depends on a lot of work.” The model is only as accurate as data put into it, and something as simple as missing a fruitlet in a cluster or taking a measurement not at the widest point on a lopsided fruitlet can skew the numbers.

To make the work easier, this year the New York Farm Viability Institute provided funding for Bluetooth-enabled calipers for fruitlet measuring, so that one worker can send data straight to a smartphone, instead of requiring two people to collect and record data.

It was a welcome idea, but grower Jimmy Zingler said that it didn’t save as much time as he expected, because of the need to repeatedly check that the device was recording data.

Zingler said that he and his father started their chemical thinning trial in 2015 on Fujis and Galas and they are still fine-tuning the use of the model.

This year, they ended up over-thinning and have about 126 fruit per tree in their Fuji block, even though the model says they should have ended up with 175, he said. Still, he urged growers to try out the protocol.

“It’s not rocket science, it just takes some time,” he said.

Grower Rod Farrow also praised the precision thinning protocol as the most beneficial tool to come out of Cornell research. “We use this to make $5 million worth of chemical thinning decisions. This is the kind of information that you want to have in your back pocket.”

But Farrow went on to say that he prefers not to trust the weather prediction-based spray recommendations.

The model suggests adjusting sprays because cool and sunny periods lead to reduced natural drop and less response to thinners, while cloudy and hot weather causes carbohydrate deficits in the trees, leading to more natural drop and stronger response to thinners.

“We put on a rate so that we know we’ll never over-thin, no matter the weather,” Farrow said. “Then, we match up what we put on with the weather as it happens” and then factor that influence of that weather on the thinner’s effectiveness when deciding if they need additional sprays.

Precision nutrition

The fertilizer focus is to get newly planted trees growing into their space and fruiting as fast as possible.

“With these new plantings, we want to get the trees to full yield faster,” said Ken Morse, a crop consultant with Crop Production Services. “We want to recoup that investment fast — it’s pretty critical to your survival,” he told the gathered growers — more than 100 on the tour’s first stop.

The most efficient way to feed your trees is through liquid nutrients so that growers can apply fewer pounds per acre to get the same, or better, results. That starts with planting, Morse said. But an efficient fertilizer program also relies on extensive soil tests to get a good picture of the soil so that nutrients can be customized for each orchard block.

“Really, nutrient management is all about getting to know your soil and getting to know your tree needs,” said Lailiang Cheng, a professor of fruit physiology at Cornell.

Recently, his research has focused on the unique nutritional needs of Honeycrisp, which is very susceptible to bitter pit because the tree moves calcium less efficiently into the fruit. As a result, the fruit ends up with higher levels of potassium and phosphorus than other apple varieties.

To address this, Cheng recommends reducing the potassium replacement by about 30 percent and giving trees about 3.5 to 4 pounds of calcium per acre throughout the season. Other good horticultural practices can help the Honeycrisp trees make the most of the nutrients available.

“In high-density systems, we recommend setting up drip systems to ensure that calcium is taken up by the roots,” Cheng said. “And you want to ensure a medium crop load, because if you have just a few fruits, each gets too much potassium.”

It just goes to show that when it comes to growing perfect fruit, it’s all connected.  •

Irrigation? Location, location, location

Last summer’s record-setting drought illustrated the benefit of irrigation for many Western New York growers, but costs and access to water vary widely. Some growers tap county water systems, while others have invested in wells or storage ponds.

At Bittner-Singer Orchards in Appleton, New York, trickle irrigation is a part of every planting, from peaches to organic apples, said field manager Kevin Bittner.

“That initial planting year is when you get the biggest bang for your buck,” he told the tour group, referring to a recently planted peach block. The farm irrigates with county water, which costs $1.50 per thousand gallons.
“We’re fortunate in Niagara County to have water along every county road,” Bittner said. “It’s more efficient for us to use the fire hydrants than to pay for the pumps.”

That sounded like a steal to other growers in attendance, some of whom pay upward of $3 per thousand gallons to the east in Wayne County or farm in areas that lack access to county water or other sources entirely.

Even growers who believe that high-density apple systems benefit from irrigation will choose not to install it if limited access to water makes it cost prohibitive.

That’s the situation for a second-leaf, 80-acre Fuji block at Zingler Farms in Kendall, New York, which is in Orleans Country.

Owner Mike Zingler said that he expects rainfall to be more than sufficient in most years, but added that in recent years he has invested in irrigation at two other sites.

In intensively managed, expensive new plantings, he said, “water, if you have it available, is one more element of control.”

– by Kate Prengaman