Effect of height and gravity on the size of fruit in a tree?

[shivakumar]

TL;DR

how is the distribution of size of fruits effected by height in relation to length of root tip to fruit and gravity?

I have seen largest guava fruits are in height of plant that is average of top most and bottom most fruit in the plant?
can there be a scientific reason for these observation?

 

[anuttarasammyak]

If it is the fact, I believe there are scientific reasons there.

 

[sophiecentaur]

The leaves in many trees vary in size over its height. I heard that it's to make best use of the incident sunlight all over the tree. There may be a gradient of nutrients as you go up - and humidity and wind speed and insect pest population even.

One thing I can be pretty sure of is that the difference in g between to and bottom would be negligible. An exercise for the student: Calculate the difference in g for a 10m tree at an distance from the Centre of Earth of 6000km, using the inverse square law. The same would apply to trees grown at different heights.

 

[Baluncore]

There certainly will be science in fruit production.

Fundamentally, the position of fruit in a tree, will depend on where the flowers develop, and if, or how, they were pollinated.

Since flowers in some species, can be stimulated by pruning during winter, it is the exposure to storms, or management by an orchardist, that decides the shape of the tree.

Each branch of a fruit tree will have an individual capacity to support fruit development. If all fruit develops, the fruit will be small. The largest individual fruit will be found where excess fruit was removed by pressure from adjacent fruit in the wind, by animals, or by management.

Scientifically, the theory of gravity is the fruit of an apple tree, and Newton's mind.

 

[davenn]

There certainly will be science in fruit production.

Fundamentally, the position of fruit in a tree, will depend on where the flowers develop, and if, or how, they were pollinated.

Since flowers in some species, can be stimulated by pruning during winter, it is the exposure to storms, or management by an orchardist, that decides the shape of the tree.

Each branch of a fruit tree will have an individual capacity to support fruit development. If all fruit develops, the fruit will be small. The largest individual fruit will be found where excess fruit was removed by pressure from adjacent fruit in the wind, by animals, or by management.

Scientifically, the theory of gravity is the fruit of an apple tree, and Newton's mind.

I suspect you totally missed the point of the Q

how is the distribution of size of fruits effected by height in relation to length of root tip to fruit and gravity?

The OP wasnt talking about cultivated trees etc
just pick any fruit tree and forget about any cultivating. pollination etc etc

Then answer that Q

 

[Baluncore]

I suspect you totally missed the point of the Q

I suspect there is no significant relationship between the size of the fruit and the distance of the fruit from the root tip. There are far too many confounding parameters that I mentioned, for it to be that simple.

Gravity and capillary action will limit the fruit to be below about 125 metres above the ground. How are you going to measure the distance from the fruit to the tip of the root? Which piece of fruit, to which root tip?

The OP wasnt talking about cultivated trees etc

That surprises me, since the OP gave only one example, the guava, a tree cultivated throughout the tropics and subtropics. I would expect the OP's observations were made in guava orchards, where the trees are trained, to produce the maximum weight of fruit each year, over a range of height, such that it could be harvested safely.

Then answer that Q

If you don't like my answer, then you should read up on the subject and answer it yourself. I would be really interested in your answer.

 

[Klystron]

Consider the progression of the growing season instead of apparent differences in fruit size due to position or height on the fruit tree. Allowing for minor variation in size, fruit is harvested when ripe.

Ripe fruit from a tree is generally of similar size, color and shape with minor variations*. Tree fruits such as cherries, olives, oranges, lemons, limes, coconuts, dates and apricots develop over the growing season but are harvested when the (individual) fruit is ripe.

Whether wild, plucked and eaten by birds and animals, or cultivated and harvested by humans, unripe fruit is left to develop and ripe fruit selected to eat. Thus the origin of the expression cherry picking.

*Grafts are one exception to generally uniform fruit on a tree. Our family orchard in Northern California grew apricot trees originally from Mediterranean environs with grafts from plum trees.

Pollination also caused hybridization where a single tree might produce apricots, plums, and pluots on different branches at various times in the season.

 

[256bits]

That surprises me, since the OP gave only one example, the guava, a tree cultivated throughout the tropics and subtropics. I would expect the OP's observations were made in guava orchards, where the trees are trained, to produce the maximum weight of fruit each year, over a range of height, such that it could be harvested safely.

I have no idea what a guava tree is, size or height, nor what the fruit looks like, nor how it is harvested.
I will just throw out there that this could be a prime example of genetics at work.
If the middle fruit were the ones picked first in eons back in the day, since one did not need to crouch down, nor extend up ( for animals as well as humans ), but instead go for the easy pickings while looking out for predators, the tree genetically modified the fruit size disparity so that the smallest, and least favourable to be able to continue the lineage are in this middle easier pickable position, so that it expends less energy and resources in middle location versus top and bottom.

TL;DR Summary: how is the distribution of size of fruits effected by height in relation to length of root tip to fruit and gravity?

I have seen largest guava fruits are in height of plant that is average of top most and bottom most fruit in the plant?

I have some difficulty parsing the expression.
I think that says fat fruit on top and bottom, and smaller fruit in the middle.
And have presented my hypothesis of genetics being responsible for middle fruit being less desirable based on the parsing.

 

[Baluncore]

Our family orchard in Northern California grew apricot trees originally from Mediterranean environs with grafts from plum trees.

Growing seed, hybridised by cross-pollination, leads to lower value fruit, on a weaker rootstock, with all trees producing slightly different fruit. It is rare that the best fruit come with the best roots, or the best structured tree.

The highest value fruit is grown on the strongest root stock. So, cuttings, (tissue culture), pruned from the branches of the best fruit tree, are grafted onto the most vigorous rootstock, usually a plum, to get a well-structured tree, with the best yield of consistent high value fruit, from the grafted tree branches.

Where several novelty garden species are grafted onto one rootstock, that rootstock, after a few years, will favour some grafts over others. That leads to the situation where the tree becomes asymmetric, and yield falls.

Commercial orchards do not mix species, or varieties, on the same rootstock. The supermarkets want consistency from a monoculture, so customers will not pick and choose between the packs of fruit.

 

[Klystron]

Where several novelty garden species are grafted onto one rootstock, that rootstock, after a few years, will favour some grafts over others. That leads to the situation where the tree becomes asymmetric, and yield falls.

Commercial orchards do not mix species, or varieties, on the same rootstock.

This all reads as true in my experience with apricots and plums. Grafts were performed on individual trees as a hobby. I inherited some truly oddball trees over the years.

My favorite tree, also the subject of several drawings and paintings due its strangely shaped limbs, produced delicious sweet almonds for several seasons, then changed to plums for one year, then no production. Reasonably sure of plum rootstock.

I brought up grafts as the exception to the general rule that these (commercial) trees produce monotonous uniform fruit. Guavas might vary in size more than plums or 'cots, as avocado sizes vary, without contradicting this premise.

Living in warm climates, I have no experience with apple orchards but I understand from reading that "Johnny Appleseed" was mostly myth. Wild and feral apples trees produce poor fruit, mainly suitable for cider. Delicious eating apples grow from grafts on selected rootstock?

How the large varieties of commercial apples are produced would make an interesting subject of another thread.

 

[sophiecentaur]

But the gravity effect??? There are very very few frontier breaking Earthbound experiments that cannot assume a uniform gravitational field so the fruit growing can pretty safely be said not to be affected by any gravitational oddities in horticulture.
That's one less worry for the food industry.