In his job, Mike Malone eats a lot of fruit. It's one of the perks of being a fruit breeder - the Plant & Food Research scientist has bred 19 peach, plum and apricot and three apple cultivars over the past 22 years.
But it can also be a hazard. "In summer, I go through a tremendous amount - several peaches a day, and apricots. Cherries are my favourite, I'd go through bucketloads of those if I could."
He tastes as much fruit as his digestive system will allow, a precise amount he has arrived at through experience. But sometimes his taste buds get the better of him. "I try to restrict myself to just one bite, but if the fruit is really good I can't help myself and keep on eating. Then I pay."
One that's caught his fancy recently is a yet-unnamed cross of a nectarine with an old Kiwi favourite, the blackboy peach. "My idea was to remove the musty flavour of the blackboy and end up with something sweeter."
It has taken several years to get to where growers are propagating budwood for trials and if all goes well it will be on the market in about three years.
"It is quite slow. It takes two generations, because you're dealing with the red-fleshed gene which is recessive to the white- fleshed gene, and the nectarine is recessive as well. In the first generation of the cross all you get back is soft white peaches so you have to save as much material as you can and then out of the progeny a quarter will have some genes that will be of interest."
Whether the blackboy name will be retained is another question. "You could say it is a pigmentally challenged fruit," he says with a laugh. "The blackboy is part of our heritage and the name seems to be acceptable to growers and people generally."
It can take 15 years or more to get a new peach or nectarine cultivar to market. Two varieties are crossed, their fruit harvested and the seeds kept to be planted the next spring.
It takes two or three years, sometimes longer, before fruit is seen. Then the best is selected to provide the seeds for a new generation of trees to be trialled by growers.
A lot of criteria have to be met. A tree must be able to withstand the climate of the region it will be grown in, have a high bud density, good flower set, high fruit numbers and be resistant to bacterial blast and fungal diseases such as brown rot and silver leaf.
The fruit must be round or slightly oblate (flat at top and bottom), of good size, weighing about 200 grams and 80 millimetres in diameter, of the right flesh colour (yellow is preferred over white because it doesn't show bruises so easily) and be sweet-tasting, with brix (a sugar measurement) of 12 per cent or higher.
Malone says worries over high-sugar fruit are unwarranted. "The body absorbs natural nutrients easily and you're far better eating fruit and vegetables than taking lots of pills."
Storage is also important, up to three weeks for local consumption and longer for export. He has been on the lookout for fruit that suppresses the release of ethylene, which induces cell wall softening, and stays edible. He has bred a plum that releases no ethylene and still tastes good, which makes it a rarity.
The ultimate test is the shopper. "Sometimes there's resistance to change but at the same time a new cultivar is a novelty. If you come up with something that is good to eat, excellent storage and has all the good growing characteristics, you don't know where it might lead to."
Gold kiwifruit, which created a huge new market, is a good example, he says.
His special interest at Plant & Food's Hawke's Bay base has been to work with the genes for texture and flavour. He's had some notable successes; the one he's most proud of is coconut ice, a crisp white-fleshed peach whose natural tendency to revert to juicy or "melting" flesh he spent several years overcoming.
Others have been a yellow-fleshed peach with a non-melting gene, the non- ethylene plum, named malone by growers in his honour, and a new flavourful high-sugar nectarine going to trials next year. "I'm thinking of calling that one candyman or sugar daddy."
But he's also had a few failures. "I had some beautiful-looking apricots - large, early maturing, well adapted to Hawke's Bay, great looking, good colour. But they don't have enough sugar in them. They're at 10 brix and I can't get them any higher."
Plums have much more volatile compounds than other summer fruit, ranging from very acidic and astringent to very sweet. "You're looking for that 1 or 2 per cent at the end of the curve that have what you want - 99 per cent of your work goes down the tubes. It looks great and then you taste it."
Taste is paramount. He tastes in the field and in the laboratory and asks growers for their views. Personal discipline is called for. "It's a bit like wine tasting. They have to curb their natural instincts; if they get a good one they might want to drink it all, but they have to spit it out and move on or they wouldn't last the day."
But sometimes taste isn't enough. He once bred a peach succulent with hints of tropical fruit flavours - he called it mangerine - but numbers on the tree were too low to be commercial.
Now, those decisions will be the concern of someone else. After 44 years in vegetable and fruit research, and shortly to turn 68 with a looming knee replacement operation, he has decided to retire.
He has a vegetable plot and one apple tree, a heritage apple called glamis castle, in his Havelock North garden and will keep his hand in attempting to breed a psyllid-resistant dwarf patio tomato. "It will be a bit of fun."
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