Two decades of search­ing for the best

Apri­cot growers are lin­ing up to plant new va­ri­eties de­vel­oped at Plant & Food’s Re­search sta­tion near Clyde where apri­cot breeder Ar­lene Nixon has spent nearly 20 years search­ing for the per­fect fruit.

The Orchardist - - News - By Dianne King

New cul­ti­vars have been planted in trial blocks in Cen­tral Otago or­chards and the out­come of th­ese will be new va­ri­eties for con­sumers to en­joy… soon. New cul­ti­vars were bred us­ing con­ven­tional breed­ing meth­ods as Ar­lene and her team take over the role of the bees and fer­tilise bloom on se­lected trees to de­velop pop­u­la­tions of seedling trees.

Breed­ing new va­ri­eties of fruit is a long process and one which Ar­lene, a Cana­dian who came from a back­ground in an­i­mal breed­ing, is pas­sion­ate about. Her 20-year an­niver­sary will be in Fe­bru­ary next year but she will al­ways be search­ing for a new apri­cot, even though she has found some that New Zealand con­sumers will en­joy. She be­lieves she’s looked at thou­sands of pos­si­ble trees over the years.

When an Asian buyer vis­ited one of her trial blocks at the Plant & Food Re­search sta­tion Ar­lene pointed out her three top choices. He did a tast­ing. It was a lit­tle like Goldilocks with him try­ing the one in the mid­dle, the one on the left and the one on the right. And his choice of the one on the right demon­strated that Asian con­sumers can have a dif­fer­ent palate to New Zealan­ders.

As po­ten­tial cul­ti­vars go into an elite stage of test­ing, con­sumer tri­als are added to dis­cern those that may be best suited to fu­ture mar­kets. Ar­lene said she al­ways re­mem­bers this when se­lect­ing cul­ti­vars to go out to growers.

Stor­age tri­als, funded by Sum­mer­fruitNZ, test some of the late ma­tur­ing ad­vanced se­lec­tions for long stor­age and eth­yl­ene pro­duc­tion. Th­ese tri­als in­ves­ti­gate the rate at which apri­cots nat­u­rally pro­duce eth­yl­ene and are an in­di­ca­tor that fruit could po­ten­tially be shipped to for­eign mar­kets.

“I have a shop­ping list for the char­ac­ter­is­tics I’m look­ing for dur­ing the se­lec­tion process and this in­volves look­ing at it from the com­mer­cial an­gle for the growers,” she said.

“I have a shop­ping list for the char­ac­ter­is­tics I’m look­ing for dur­ing the se­lec­tion process and this in­volves look­ing at it from the com­mer­cial an­gle for the growers.”

“There are a lot of char­ac­ters, such as flavour, sugar acid, ap­pear­ance, tree health and tol­er­ance to han­dling, add up to the tree be­ing com­mer­cially vi­able. The growers want to grow a good piece of fruit, and nat­u­rally they have to be able to profit from their ef­forts.

“Con­sumer at­tributes are very im­por­tant and the key to re­peat pur­chas­ing. The aim of the pro­gramme is high qual­ity full-flavoured apri­cots of good size, with eye-ap­peal, high colour, smooth skin, shine, shape sym­me­try and with in­cred­i­ble flavours.”

Pic­ture this… each day of the blos­som sea­son an apri­cot “mother” tree ready to burst into bloom is sur­rounded by work­ers be­neath its branches car­ry­ing out hand­pol­li­na­tion. In­di­vid­ual blos­soms at the “pop­corn” stage are care­fully opened, the lit­tle petals re­moved and the an­thers re­moved. The fe­male parts are now ready to be hand pol­li­nated with golden pollen from a par­ent tree.

Dur­ing the Sump­tu­ous Sum­mer­fruit pro­gramme four work­ers per tree were work­ing quickly, some with a pair of tweez­ers, to dab pollen on each blos­som be­fore a blos­som opened nat­u­rally. Each branch of each tree could have dif­fer­ent pollen ap­plied in or­der to have enough crosses to cap­ture the best at­tributes of Plant & Food’s

col­lec­tion of apri­cot trees.

Both par­ents have been care­fully cho­sen for the

at­tributes they can con­trib­ute to the pro­gramme.

A few weeks ear­lier the pollen was care­fully combed from blos­soms forced to bloom early in the lab­o­ra­tory. This is per­formed with the use of a nit comb which is used to care­fully tease the an­thers from freshly

opened blos­soms.

When all pos­si­ble blos­soms – po­ten­tially thou­sands per tree have been cov­ered – the tree is cov­ered with a plas­tic tent and a propane heater is used to keep the frost away. This pat­tern is re­peated day af­ter day un­til all re­quired “mother” trees have been


The trees are not thinned as each fruit con­tains a

seed that could be­come the next new cul­ti­var. The apri­cots grow, ripen and are har­vested. Stones are col­lected for grow­ing on in glasshouses in Hawke’s Bay Re­search Cen­tre.

More than 4000 stones may have been col­lected but af­ter grow­ing the trees and eval­u­at­ing the fruit, only two or three trees may have what it takes for a new cul­ti­var. The seedling trees are re­turned to Cen­tral Otago in spring when they mea­sure about 30cm in height. Once the trees fruit Ar­lene walks the blocks daily search­ing for seedlings with the po­ten­tial to be­come an­other com­mer­cial re­lease or con­trib­ute to the breed­ing pro­gramme.

“A grower needs a healthy tree that crops well and pro­duces high qual­ity fruit which will go over the grader with­out scuff­ing and also han­dle ship­ping,” she said.

“It needs to have stor­age ca­pa­bil­ity in or­der to reach the mar­ket-place and still have some shelf-life.”

Apri­cot trees re­quire chill­ing in or­der to set fruit. This is not a prob­lem in Cen­tral Otago, where lower tem­per­a­tures en­sure plenty of buds, but is more of a chal­lenge in the North Is­land where low chill apri­cot trees are re­quired.

While trees with less chill will fruit, th­ese are of­ten not of the same high qual­ity as high chill apri­cots.

“Breed­ing a high qual­ity, low chill apri­cot is an­other of our breed­ing goals and a very im­por­tant one, as the first fruit of the sea­son can set a con­sumer’s buy­ing habits for the sea­son,” she said.

“If a con­sumer has a bad eat­ing ex­pe­ri­ence they may not re­peat pur­chase for over a month. We need to give the con­sumer a great eat­ing ex­pe­ri­ence right through the sea­son, start­ing from that first apri­cot they pur­chase and so they con­tinue to buy apri­cots.

“Luck­ily North Is­land growers are very aware of this and very sup­port­ive of ef­forts to breed low chill va­ri­eties.”

Back in 2011 Ar­lene told growers at a Sum­mer­fruit Con­fer­ence that a new cul­ti­var MacKen­zie 12/45 had stun­ning flavour and she saw the pos­si­bil­i­ties of us­ing this as a par­ent. But she stressed that ad­vanced ma­te­rial needed sev­eral sea­son of eval­u­a­tions be­fore de­ci­sions could be made re­gard­ing its re­lease as a new cul­ti­var. Now this MacKen­zie seedling has made a big im­pact on seedling blocks at Clyde and had been named NZ Sum­mer 2.

Over the years many gen­er­a­tions of seedlings have been eval­u­ated and the most promises have been bud­ded on to Golden Queen peach root­stocks for fur­ther eval­u­a­tion as ad­vanced se­lec­tions.

“We are at the stage now of work­ing through the ma­te­rial gen­er­ated from the crosses we did sev­eral years ago,” she said.

“The seedling blocks are mostly gone and a large block of ad­vanced se­lec­tions is be­ing eval­u­ated for com­mer­cial suit­abil­ity.”

Long stor­age is one of the goals of the breed­ing pro­gramme. Dr Jill Stanley and her team have been look­ing at eth­yl­ene pro­duc­tion in apri­cots. Apri­cots are a fruit which pro­duces this gas nat­u­rally and its pres­ence sig­nals soft­en­ing and ripen­ing.

“Some of the new apri­cots pro­duce very lit­tle eth­yl­ene so do not soften as much as older va­ri­eties dur­ing the ripen­ing process which means they store longer en­abling apri­cots to be shipped to for­eign mar­kets and still of­fer a good eat­ing ex­pe­ri­ence,” Ar­lene said. An­other of the cul­ti­vars de­vel­oped from the orig­i­nal MacKen­zie block is NZSum­mer 4, an early har­vest, do­mes­tic apri­cot, har­vested in early to mid-De­cem­ber in Clyde.

The search for late har­vest va­ri­eties of per­fect fruit with crunch, apri­cot flavour, high brix lev­els, red blushed, bright colour high colour and long stor­age is on­go­ing.

The pro­gramme’s newly re­leased cul­ti­vars, bred more than 10 years ago, are now be­ing planted in grower or­chards so should be avail­able on do­mes­tic mar­kets over the next few years.

Con­sumers will be in for a treat, Ar­lene be­lieves.

“It’s all ex­cit­ing isn’t it?”

Apri­cot breeder Ar­lene Nixon has a shovel at the ready to plant a seedling cul­ti­var bred at Plant & Food Re­search, Clyde.

One of the McKen­zie new cul­ti­vars. Im­age credit: Plant & Food Re­search New Zealand

Apri­cot stones, a tube and a sprin­kling of golden pollen used in the search for new apri­cot va­ri­eties at Plant & Food Re­search Or­chard at Clyde.

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