Posts Tagged ‘Prunus persica’

Pleistocene Peaches (Prunus kunningensis =P. persica)

July 17, 2018

The ancestor of the modern cultivated peach (P. persica) depended upon megafauna for dispersal and is now extinct in the wild.  Asian elephants and primates such as macaques and early humans ate the fruit and distributed the seeds throughout the environment, but without these species P. persica disappeared from the wild, and now only exists in cultivated fruit orchards tended by modern humans.  Peaches originated in China, and peach seeds dating to 2.5 million years BP have been found there.  Scientists designated these ancient peaches as a unique species they refer to as P. kunningensis, but they admit there is no real difference between this species and P. persica.  Peaches have been cultivated in China for at least 7500 years where evidence of early peach cultivation has been found in the Yangtze River Valley.  Farmers began grafting varieties with larger fruit to pit ratios on to root stocks of other peach trees then.

Peach cultivation spread from China to Persia (today known as Iran) and from there to Europe.  Early Spanish explorers brought the fruit to southeastern North America during the 1500’s, and John Lawson found peach trees thriving in Indian villages when he explored and settled in North Carolina between 1700-1711. (See: https://markgelbart.wordpress.com/2012/07/27/john-lawsons-voyage-to-carolina-1700-1711/ )  The quality of some of the fruit was so much better than European peaches Lawson mistakenly thought some varieties originated in North America.  The real reason American peaches were better than the European fruit was because the climate in southeastern North America was similar to their land of origin–China.  Lawson planted peaches in his orchard, and he had 1 freestone yellow nectarine tree that produced 15-20 bushels every year, unless there was a late spring frost. (A nectarine is simply a smooth-skinned variety of peach.)  He claimed peach trees planted from seed bore fruit in 2-3 years, and the fruit from the offspring was the same as from the parent.  Peaches were so abundant he fed the excess fruit and corn to the hogs, resulting in sweet pork. He also made vinegar from peaches.

Lawson’s account of raising a peach orchard from seeds fascinated me.  Most fruit varieties are mutants grafted on to rootstocks because most wild trees produce fruit of inferior quality.  I researched online and found a discrepancy.  Some agreed with Lawson and claimed fruit from peach seeds produced fruit similar to their parent, but a study written by an horticulturalist from LSU found that fruit grown from seed was usually inferior.  So I conducted my own experiment.  I noticed peach trees often germinated in my compost pile.  I took these seedlings and transplanted them in my yard.  Now, 5 years later I have 4 trees that are bearing heavily.  1 tree produces freestone peaches during the last 2 weeks of June.  All the peaches on this tree were infested with plum curculio larva.  Plum curculio is a beetle that damages all kinds of fruit.  However, I cut away the worm-infested, bird-pecked parts and tasted the fruit.  (Birds get a double treat from my peaches–fruit and protein.)  For an early ripening variety it is a good peach.  The other 3 trees have fruit that ripens throughout July.  1 of them was partially infested with plum curculio, but the fruit is excellent.  Another tree produces very large peaches that are as good as the best farmer’s market peaches.  The 4th tree produces small, bitter, heart-shaped peaches that in appearance resemble the most common variety grown in Georgia and South Carolina–the red globe peach.  I’ve concluded Lawson was mostly right, and the LSU study was wrong.  75% of my peach seeds produced good quality fruit.

Late June peaches from a tree I planted from seed in my yard.  The fruit from this tree had an 100% plum curculio infestation rate.  They were still edible, if I cut away the damaged part.  The quality was good for an early season peach.

This tree produces large luscious peaches. None were insect-damaged but some cracked open because of rain, even though the soil in my yard is sandy and well-drained.  This was the best-tasting peach I ate all season.

This tree is a bit of a natural dwarf.  The fruit is small and bitter.  I’ve read thinning out the fruit may have improved the quality.  I might try that next year.

My experience with this peach tree growing experiment has taught me a few things.  Spraying insecticide doesn’t work.  Rain washes the insecticide off, and the insects just return.  The peaches with no insect damage were growing in open sunlight with no undergrowth.  I hypothesize shade and undergrowth shelters insects from predators and harsh sunlight.  I can’t do anything about reducing the shade over my other 2 peach trees, but I will try harder to control the Virginia creeper.  This vine is tenacious, but I think a thicker layer of mulch might suppress it.  Peaches need more nitrogen than other fruits–more evidence they evolved in plots rich in megafauna manure.  My fastest growing peaches just happen to be growing over the drain field to my septic tank.

The Georgia extension office recommends 58 varieties of peaches, but they don’t even list 3 of my favorite varieties–Indian blood cling, Oregold, and Halehaven.  Peaches stay in storage for just 2 weeks, so many varieties that have different ripening schedules have been developed to extend the season.  They recommend 1 late April variety, 12 May varieties, 16 June varieties, 23 July varieties, and 6 August varieties.  The mid-season free-stone peaches are the best-tasting.  There are also white peaches.  These are sweeter and more aromatic, and in my opinion taste like a completely different fruit.  After my difficult experience however, I recommend other fruit for the casual home gardener in Augusta, Georgia.  Blueberries, figs, muscadine grapes, and even apples are much easier to grow than peaches here, even though Georgia is known as the peach state.

References:

Su Tao; et. al.

“Peaches Precede Humans: Fossil Evidence from Southwest China”

Scientific Reports 2015