Peaches are Ripe Again

It is that time of the year when we are flooded with peaches.  What this means is that peaches will be served every meal for a couple of weeks and I will be busy preserving the ones we cannot consume or share with our neighbors.  Sometimes it is hard to decipher whether this is a blessing or burden.  One thing is sure - it starts as the former and ends as the later. :)

The tree has a sad history.  The tree has suffered severe cases of  leaf curl (Taphrina deformans) in the past years drastically reducing the canopy cover not only for purposes of photosynthesis but for shading.  The location of the tree can get very hot in the summer - the sun exposed portion of the trunk can crack and separates from the cambium layer.  At present the bark on half of the trunk's girth is peeling off. We pruned the tree last year with the intention of eventually removing it.  In fact, already I bought a pluot tree to take it's place (close to the plum tree). But this year's peach crop tells me to delay the process.

Plant a fruit tree this year for the enjoyment of many 

generations to come. 

First Fig Fruit...

Fig (Ficus carica 'Brown Turkey')

At last my own fig tree bears fruits!  And it has a name - unlike the volunteer fig that has been planted by birds around my yard.  This one is 'Brown Turkey' which I chose because the tree is supposed to be a more compact than the other traditional varieties such as 'Mission' fig.

The fig fruit is very fascinating.  It is a synconium or an inverted fruit. The fig synconium is made up of multiple fruits that are fused together.  Each seed is an individual aggregate fruit.  It is similar to the strawberry, except the arrangement is reversed. The seeds in strawberry are on the surface of the fruit while the seeds in the figs are inside.  That description almost makes the fig a normal fruit.  But the fact that the fig flowers were never outside of the fruit makes it completely an odd fruit.  

Synconium:  the flowers open inside the fruit.  

Fig is probably among the earliest domesticated plants on earth.  It is mentioned multiple times in the Old Testament Bible as part of the life of mankind in the old days.  For example: the presence of a fig tree, is referred as one of the features of a good land (Deuteronomy 8:7-9); and the shade of a fig tree is symbolizes a place of safety (1 Kings 4:25).  Having a fig tree in my yard seems like owning a time machine that brings me back to that time in history.    

To eat figs off the tree in the morning, when they have been barely touched by the sun, is one of the exquisite pleasures of owning a fig tree.

Looking Back: Heavy Lessons on Thinning Young Fruits

Peaches in my garden - summer 2013 

Too much of anything is not a good thing.  There is balance to be observed between that which is beneficial and that which is permissible for a healthy life - plants included.   This year we were delighted to see a beautiful crop of peaches which is attributed to the absence of leaf curl infection.  The drier weather from late winter to early spring was not conducive for the proliferation of the pathogen Taphrina deformans.  In previous years, the tree would lose all its early leaves leaving the developing fruits to starve until the new set of healthy leaves come out.  Sometimes the fruits also get infected which results not only in low yield but poor quality crop.  

As the fruits grew larger under the summer sun, the problem slowly surfaced.  The slender stems laden with fruits began to hang straight downwards.  One of the larger branches was so heavy. I was afraid that it might break.  We had to prop it up with three pieces of 2x4x8 lumber.  I admit that my tree is not in its best form.  Pruning on this tree has been mainly for the purpose of making sure it does not arch into our neighbors' yard.  (I doubt they appreciate peaches falling into their swimming pool.)  This effort has led to the formation of a lop-sided tree.  It is a nice tree but it not strong enough to bear a heavy crop.  

   

A heavy fruit load can be detrimental to the tree.

Based on the situation described here, the problem that needed to be addressed is excessive fruits.
Under favorable growing conditions, such as what we had this year, fruit trees set more fruits than they can support adequately.  And this problem is magnified when trees have not been properly pruned in the previous season.  A heavy fruit load can result in branch breakage.  When there are too many fruits competing for carbohydrates, the fruits cannot reach their optimum size.  The tree also gets nutritionally deprived and weakened - making it more susceptible to pests and even sunburn damage.  Another possible effect of excessive fruits on trees is alternate bearing (the cycle in which the tree bears a heavy crop in one year and a skimpy or no yield in the next).  This phenomenon happens when the tree is nutritionally deprived while supporting its fruits - a situation that will continue to plague my tree until I will muster enough discipline to remove the excess fruits when they are young.  

Rule for fruit thinning:  Mature fruits should not be touching each other.

Peaches are among the fruit trees that require fruit thinning for best results - superior quality fruits are produced while maintaining a healthy tree.  As a general rule, allow room in between fruits so that at maturity fruits should not be touching each other.

Plums for the Season

Santa Rosa plums (Prunus domestica 'Sana Rosa').

Baskets of dark ripe plums have always been one of the defining marks of summer in our home.  In some years we need smaller baskets than others, but there never was a year when we did not have plums ever since we planted the tree.  Traditionally, I would preserve enough plum sauce for us and our extended family.  This year, I did not get to do any canning (except for a couple jars of plum syrup) which I hurriedly make on the day we left for Taiwan.  It was a good thing that our friends from church came to pick them while we were gone - at least the fruits were consumed and not wasted.

One week before harvest.

Towards the southern side of the plum is a mulberry tree which is growing at a very fast rate. It will have to be trimmed if not pollarded so as not to jeopardize the productivity of the plum. 

 

My daughter is perched on the mulberry tree.

 

The garden presents a never-ending list of opportunities and challenges that varies from season to season.  The gardener may never master the garden but with persistence, every experience is an added arrow into his quiver.

Parthenocarpy

Parthenocarpic Orange

Par.theno.carpy
Origin: Greek word parthénos = maiden; karpos = fruit)
Literal meaning: virgin fruit
Botanical meaning: enlargement of the ovary into a fruit without fertilization. 
(Parallel meaning: pregnancy without a developing-baby in the womb.)

Parthenocarpy is the phenomenon behind most seedless fruits.  Parthenocarpy is fruiting without the union of a male and a female egg cell.  The lack of fertilization means that there are no seeds in the fruit.  If there are seeds, they are not viable and are not capable of germinating.

Many times we take seedless fruits for granted and even despise the ones with seeds.  Although it is a natural occurrence in some varieties of some plant species (such as banana, persimmon, pineapple, and orange) parthenocarpy is an "abnormal" condition.   I say this because technically fruits are supposed to have seeds.  Seed is the reason for the fruit.  

Seedless grapes with traces of undeveloped seeds.

Fruit development begins with pollination. The moment the right pollen grain touches the stigma (the sticky surface of the pistil), fireworks of events happen as if a switch button has just been set to ON.  First a pollen tube develops as a passage way for the sperm nuclei in the pollen to the reach the ovules (part of the flower that develops into a seed). As soon as the pollen reaches its destination fertilization occurs and a zygote (fertilized egg = seed) is developed. Then several hormonal changes happen to signal a succession of events that support a continued development of the zygote. Gibberellin level suddenly rises resulting in the enlargement of the tissue surrounding the ovary. This tissue eventually differentiates to form the fruit.  Fruits tissues come in different charactreristics:  fleshy (as in grapes, peaches and apples), hard (as in nuts) or dry (as in dandelions and grains).  In short, fruit development occurs when a seed starts to develop. 

How does parthenocarpy happen? 

1.  Uncompleted Seed (Aborted Embryo).  Pollination triggers fruit development but in some cases the embryo is aborted before successfully developing into a seed.   The landing of pollen on the stigma is enough to trigger fruit formation that continues regardless of failed seed development.  Seedlessness through parthenocarpy does not involve fertilization.  However, seedlessness can still happen even after fertilization has already occurred through stenospermocarpy.  In this mechanism, the embryo is aborted just the same but at a much later time (1). The 'Thompson' and 'Flame' seedless grapes are examples of stenospermocarpy; traces of undeveloped seeds are visible when the berries are opened (see picture above).

2.  Genetic Disorder (Chromosome Imbalance).  Plant species which are triploids cannot successfully produce seeds - they are genetically sterile. The banana we buy from the grocery store is parthenocarpic because it is a sterile triploid (two sets of chromosomes from one parent and one set from the other) instead of the normal diploid where you get one set of chromosomes from each parent.  Pollination happens but fertilization does not.  The tiny black dots inside the banana are traces of the unfertilized ovules.  In the case of seedless watermelon, triploidy is induced through genetic manipulation. 

3.  Absence of a Perfect Mate (Self-Incompatibility).  Some plants species are self-incompatible - they are self sterile when pollinated by the same variety of plant.  In order to fruit, these species require pollens from a plant of different genetic makeup.  Navel oranges, pineapples, and clementines are examples of self -incompatible plants.  For example, when an orchard of the same variety of oranges is grown, fruits would come out seedless (parthenocarpic).    

4.  Manipulation by Steroids (Application of Growth-Regulators).  There are several growth hormones that play a role in parthenocarpy but for the current topic, our focus will be gibberellin.  Gibberellin is a phytohormone (plant produced-hormone) that is also produced by certain fungus called Gibberella fujikuroi.  Through this fungus, gibberellin-like compounds known as gibberellic acid (GA) can be produced apart from the plant.  GA is known to promote cell division and enlargement; when applied to plant at a strategic time and rate, the plant will respond accordingly.  This knowledge regarding the response of plants to applied GA and the knowledge that endogenous (produced within) gibberellin levels in plants increase upon fertilization and thus triggering fruit development have changed the horticulture industry.  Flowers can now be fooled into thinking that fertilization has taken place and thereby developing fruit-tissues.  In other words, fruits can be induced with the application of gibberellic acid.

Parthenocarpy is a delightful abnormality because the seedless fruit maintains the appearance and taste of its normal counterpart.  This is the reason why growers have capitalized on it to improve the commercial value of some crops.  Research work continues to exploit the application of parthenocarpy on more plant species where the seed is not for consumption.  

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1) Table Grape Berry Growth and Development: A Review

Fig: An Extraordinary Fruit

Fig (Ficus carica): Syconium

Have you ever seen fig flowers?  If you are thinking of colorful petals then it is certain that you would not have recognized the flower even if you saw one.  However, if you have already opened a fig fruit it is likely that you also have seen fig flowers.  Fig flowers are hidden.  Hundreds of tiny flowers line the inner wall of a hallow receptacle.  In the natural process of fruiting, cells around the ovary enlarge and divide soon after the ovules have been fertilized.  This growth of cells results from a natural production of the necessary plant hormones (such as gibberellin and auxin) which is triggered by the fertilization of the ovules (except in the case of parthenocapic fruits).  The fruit generally functions as attractant to organisms that would be agent to seed dispersal.  In the case of figs, the receptacle enlarges around the seeds - forming a sweet and fleshy bulbous-shape fruit.

Inverted fruit.   An ordinary plant flower is colorful and very conspicuous attracting a wide variety of pollinators.  The flower is like the flag being waved to indicate that this flower welcomes visitors.  The fig inflorescence is the opposite of the normal flower because they are hidden inside a syconium (from the Greek word sykon meaning fig).  Syconium is an inverted fruit and the fig is a syconium.  A carpet of numerous small flowers is concealed inside with only a tiny aperture called osteole on the outer end of the fruit.

Pollination Extraordinaire.  With the enclosed flowers of this tree, pollination is hardly imaginable.  However, through the mystery of a mutualistic symbiosis between the fig tree and the fig wasp, pollination takes place in a most unusual way. The flowers inside the syconium exude a subtle hint of perfume that serves as a signal for the wasps to get in at the right time.  Of all the insect species, only the fig wasp is known to pollinate the fig tree.  Likewise, of all the fruits known to these wasps, only the fig qualifies to hold their eggs. The fig tree and the fig wasp cannot live without the other.  Truly, this interesting phenomenon in plant-insect relationship cannot be explained easily without attributing it to God's design.

Cross section of a syconium showing numerous achenes. 

Figs - delicious and nutritious fruits.

Wild Blackberries: Aggregate Fruit

Wild Blackberries (Rubus fruticosus)

While wandering in one of the Redwood forests along Hwy 101 we came across a healthy patch of blackberries.  Although the samples we picked were sour, one can hardly ignore the aesthetics of the reproductive stages of the plants.  So I decided to talk a little bit about the nature of the blackberry fruit.

 

Wild blackberry flowers.

 

Blackberry Flower - Photo by Luc Viatour

Single Flower Multiple Ovaries.  The blackberry flower is composed of multiple ovaries.   Each of the yellow-green structures in the middle of the flower (above photo) is a stigma leading to an ovary that contains the ovule.  The brown structures surrounding the ovary are the stamens which bear the pollen grains.  Upon fertilization, the ovule turns into a seed that is enclosed in the fleshy tissue of an enlarged ovary- thus, a fruit is formed.  

Drupelets for an aggregate fruit.

One Aggregate Fruit Many Drupelets.   Multiple drupelets (fruitlets) form one aggregate fruit.  The blackberry is an example of aggregate fruit in botanical terms.  Each aggregate fruit comes from one flower; it is composed of many drupelets held together by a common receptacle.  Individual drupelets, like any normal fruit, develop only when the ovule is fertilized.  The size of the aggregate fruit is highly determined by the number of drupelets that develop.  As seen in the picture below, some flowers fail to develop fruits because of unsuccessful pollination.  Staggered ripening is reflective of staggered pollination and fertilization of the ovules.

Staggered ripening reflects differences in time of pollination.

“On the motionless branches of some trees, autumn berries hung like clusters of coral beads, as in those fabled orchards where the fruits were jewels . . .”

~~ Charles Dickens

Grapes

Vitis vinifera 'Cabernet Souvignon'

"Men are like a fine wine. They all start out like grapes, and it's our job to stomp on them and keep them in the dark until they mature into something you'd want to have dinner with." ~  (Unknown female)

Happy September everyone!

Sweet and Juicy

Peaches (Prunus persica)

Time is of the essence.  Two weeks ago we've started harvesting peaches only as we can eat them.   Peaches on yogurt, peaches with ice cream, peach crisp, peach pie, peach cobbler and...peaches again?  Now they all need to be harvested to defy the effects of gravity.   If I do not act now, these plump, sweet and juicy fruits will turn dimpled, sour and old.  Indeed, it is not time to rest for the gardener.

Scars from Peach Leaf Curl (Taphrina deformans) remain on the leaves

Marks of the past.  Early in the spring the tree was severely infected with  Taphrina deformans or leaf curl.  Wet and cold weather prolonged the infection that some of the fruits were affected.   Some of the leaves show some reminders of the previous infection.  I marvel at they way this tree persevered through all that stress.  By early spring, the tree was totally defoliated by the fungal leaf curl.  However, as soon as the temperatures got warmer new leaves developed and they photosynthesized like there's not tomorrow - filling up all the fruits that developed.

Every fruit will have to come down one way or the other.

Maintenance.   The fruits no matter how high they are will come down to the ground to join the earthworms.  When you have fruits like these you've got to include one more item in your daily to-do list:  collect and dispose of all fallen fruits.  Otherwise, our four-legged friends are encouraged to visit frequently or even reside in the yard.  I've learned this the hard way when I left grapes unharvested last year.  The raccoons decided that my garden was going to be their nighttime rendezvous.  Rodents (mice) also enjoy sweet fruits and like to build nests for their young near a good source of food.  As a gardener I usually encourage wildlife to find refuge in my garden but I seem to discriminate against racoons and mice.

Home-Grown and Home-Made Peach-Orange Marmalade:  A Family Favorite

Utilization.  The production of the tree is not limited to consumption ability of their owners.  In fact they produce enough to encourage us to be generous and industrious.  A lot of these peaches went to my neighbors and friends who enjoyed eating them even with the skin on.   There's a good feeling that comes from being able to give something from one's hard work.  So we give, then there will still be some fruits left that need to be preserved.   It may be warm to be working in the kitchen during the summer but Peach-Orange Marmalade will be a nice touch on pancakes in the winter time

         Frankly, I prefer pruning, weeding, and fertilizing over canning.

Bok Choy: Completed Life Makes Way for New Life

Completing a Life Cycle.  From the spring crop of bok choy (Brassica rapa), I left two plants to complete their life cycle - seed to seed.  The plants produced bright yellow flowers, they were pollinated.  About 24 hours after pollination fertilization of the egg has occurred.  Flowers turned into capsulated fruits which contained seeds. 

Siliques

Dry and Alive.  When the pods turn brown then they are ready to be detached from the plant.  They were allowed to dry on the plant before they were harvested.   The seeds needed to be completely dry to maintain their viability.  At this point the seeds are capable of germinating once required environmental conditions are met.   

Carpels in a silique are separated by translucent tissue called replum.

House of Seeds.  The seed pods of the bok choy are called siliques.  Siliques are made of two carpels which are separated by a thin film called replum as seen on the photo below I counted 12 to 20 seeds contained in each silique and there are a lot of siliques per plant.

 Home-grown seeds ready for planting.

Home-Grown.  After getting the seeds that I need for this planting, I am keeping some for next spring.  The fall crop may not be able to flower since we are approaching shorter daylength.  (If I remember right, the spring crop bolted at 15 hours daylength.)  This practice of collecting seeds from your own crop helps save money.  The only time when this may not be recommended is when you are dealing with hybrids.  Seeds collected from hybrid plants are not guaranteed to perform the same as their parents. 

Egg cartons were used to germinate the seeds.

Recycled.  Egg cartons are easy to come by; they are biodegradable and their little compartments are large enough to support the fast growing seedlings until they are ready to transplant. At planting time the sections that contain the seedlings will be separated by tearing the carton without disturbing the roots.  

Tiny seeds meet the soil.

Fast Crop.  The good thing about bok choy is that there is hardly any dormancy period.  Immediately after the seeds are mature and dry, the seeds are ready to start life.  That is the reason I am planting again because I am almost certain that the plants will reach harvestable age before the weather gets cold. 

Two days after sowing the seeds - a new plant.

A new life has begun...a month from now the food will meet the kitchen...again.

Unexpectedly Heavy

Peaches

A week from now these fruits will probably be ready for harvest.  However, as they continue to ripen not only do they get sweeter - they also get heavier and bigger putting more weight on the branches.

Something is wrong with this picture: Too many fruits/branch

This peach tree was heavily infected with peach leaf curl in the spring.  The infection was prolonged due to frequent rains and low temperatures that I did not expect the fruits to remain.  Hence, I did not see the need for any fruit thinning at the time. 

No wonder fruit thinning is such an important operation in the production of quality fruits.  It also prevents damages to the tree.

Big loss

One of the major branches of my tree broke off; it could not hold the increasing weight of the fruits anymore.   It is the fault of the gardener who did not pay attention to the happenings in one corner of the yard.  Knowing how sweet these fruits, my heart sank when I saw this fallen branch.   On the other hand, this is good for the remaining fruits.  They get a better chance to bulk more. 

 Sometimes less is better. 

Rushing to Ripen

Plums (Prunus domestica 'Santa Rosa')

The plum tree is laden with fruits this year.  When plums ripen it happens in one week or two.  It's very fast.  Last week they were green with a tint of red on some of them.   Now there's no turning back!  They're ready.   Plums can be harvested before they are totally ripe.  They continue to ripen and get sweeter as they sit on the shelf - up to a certain point. 

Harvesting plums is one of the many fun summer activities in the backyard.  I enlist my kids to harvest them.  The tree is not very tall (it's only about nine feet) so they use a stool and an apple picker for the ones that are out there.  These plums are very sweet and excellent for eating. 

These plums will be a juicy welcome to my two older kids and my husband when they come back from a mission trip.  

Ripe fruits are bluish in color.

In case we fail to bring the fruits in, the Blue-Jay birds are more than happy to help themselves.  I spotted two of them already circling the tree trying to stake their claim.

Only a day or two to go before they're ready.

 With the way they look I might need to get my canning paraphernalia ready now. 

Plums

Prunus domestica 'Santa Rosa'

The plums are gradually changing color.  

 

A promise of more "plum sauce"

The California sunshine continues to hasten the fruits to ripen.   Thanks to sufficient rainfall - there's going to be a good crop this year.   This 'Santa Rosa' plum produces sweet fruits that are excellent for eating.   I can't wait!

HortiCOOLture - Flowers Turning Into Fruit

Developing pear fruit.

I was in my garden the other day and saw these tiny fruits.  They look dainty now but soon they can be up to one-pound-size fruits.

The fruit of the pear (Pyrus communis) is considered an accessory fruit.   Accessory fruits are sometimes referred to as false fruits because technically, the fleshy part of the fruit that we eat is not the fruit.  Instead it is the enlarged receptacle.  The fruit is described as the ripened ovary.  In the case of the pear or apple the actual fruit is the core.  If you look at the picture above, remnants of the flower other parts are still visible and yet the receptacle is obviously in the process of enlarging.   The receptacle will continue to enlarge and envelop the developing fruit (core) which contains the seed.  Thanks to the receptacle or else the pear fruit would be of little food value.  To understand this concept better, look at the illustrated parts of a flower.

Stroll in your garden...it's good for you and your plants.

Removing the Fruits For Increased Fruiting

Lemon (Citrus limon)

After giving away so many lemons, this tree still stands laden with large bright yellow fruits.  I like harvesting fresh lemons whenever I need one so I could just leave the fruits on.  However, today I saw purple flower buds pushing their way out ...which means that those fruits (at least most of them) will have to come off the tree.  

Citrus Limon 'Ponderosa'

Here are some important cultural and post-harvest practices to consider:

1.  Harvest fruits before the flowers come out will ensure a good crop for the next season.   

2.  Prune to remove unproductive branches, allow sunlight to penetrate the canopy, and train the branches to grow towards desired direction. 

3.  Apply fertilizer under the following conditions: the leaves are yellowish; or when the tree is planted in a pot.   My lemon tree is planted on good soil; no fertilization is required.  On the other hand, I have two orange trees planted in large pots which need regular application of nutrients.

4.  Juice and freeze for future consumption.   Lemonades in the summer will be appreciated.   

5.  Make lemon curd; they are good for pancakes and scones. 

6.  Share.  Give some of your lemons to friends. 

Color Change in Citrus

Fruits on pot-grown oranges (Citrus sinensis)

Tropical Zone.  Citrus fruits like oranges and lemons start out green and remain in that color till maturity.  I remember, having grown up in the tropics, that all the citrus fruits I've seen were green.  When they are mature and harvested their color are still green different only from their immature counterparts by the shine and gloss on the rind.  By the time they turn orange or yellow, they are already over-ripe and cottony and tasteless.  Commercially grown citrus can be treated with ethylene after harvest to induce uniform and timely yellowing for a more appealing look. 

Temperate Zone.  Citrus plants grown in temperate places with mediterrenian-like climate, low temperatures induce a change in color to deep orange or yellow even before the fruits mature.   The color can be deceptive.  It is important to harvest the fruits when they are fully mature, it is when the sugar and the acidity balance is at its best. 

Lemon (Citrus limonia)

Hidden from our eyes are processes that are constantly happening in the plants.  Shifts in these processes are caused by a number of environmental factors.  The green color in unripe citrus plants is a result of the dominant presence of chlorophyll on the rinds.  The yellow or orange color in ripe citrus fruits is a manifestation of the high concentration of carotenoids.  When temperatures go down to a certain critical level, such as in the winter, the rate of chlorophyll production in the plant slows down or completely stops.     Furthermore, the existing chlorophyll undergoes a process of degradation while the biosynthesis of carotenoids increases, particularly in the fruits.

Stroll in your garden... its good for you and your plants.