Sunday, November 3, 2013

A Long Figgy Tale

My fig cuttings are doing well so far. B got six cuttings 12 to 14 inches long which were two year wood cuttings (stem that were from previous two growth seasons) from a friend in Adelaide, taken off a tree that produces Brown Turkey-like fruits. The cuttings were then soaked in water, which resulted in them quickly putting out root primodia and also the breba crop that was promptly removed to prevent exhausting the cuttings.
Four of my fig cuttings. The plastic container allows me to observe the root growth.
Fig cutting putting out breba crop (blue arrows) before the leaves emerge when they were first soaked in water.

Four were potted up whilst two more were ‘neglected’ and left in the water. The first four went on to produce leaves and more breba fruit that needs to be removed. The two neglected cuttings were finally planted two weeks ago and has been doing very well. In fact it produces more growth points than the first four cuttings.
The leaves are bigger than my palm.
Roots from the fig cuttings.

After pulling most of the breba off, I finally decided to leave one on just to see if it will develop and to determine the breba fruit shape since the cuttings have a lot of roots and I have been feeding it frequently.
A breba fig that I didn't cull. Notice that it comes from the older, woody section of the stem.
Blue arrow: a breba fig that I decided to let it be. Green arrow: bumps that can develop into current season figs (I am hoping it does not do so).

Since fig has become a hot item over here, below is a short explanation of fig types and pollination requirements.
Four of my fig cuttings. Now to give them a proper home.

A fig is not a proper fruit, but the ‘fruit’ that we eat is a synconium, which is an enlarged, fleshy, hollow peduncle that bears closely massed, tiny flowers on its inner wall.

Ficus carica (the common, edible fig) are gynodioecious, meaning that there are male trees with functional female flowers and female trees that only produce female flowers. The male trees are the caprifigs, and they have short-style female flowers that are fully functioning. The fruit (or rather the synconia) are usually not fleshy and rather dry, thus are only eaten by goats, hence the name caprifigs. The female trees, on the other hand, produces synconia that can develop into a sweet, juicy fruit that is highly sought. Hence caprifigs (MF plants) are considered inedible and female (F) plants are called edible figs.

Male or caprifigs produces three crops of synconia in a year in Mediterranean/temperate climate whilst the female (or edible) fig produces two crops of synconia. The first one is called breba, and is produced on the previous year’s growth (old wood) in Spring. The main crop comes later and arises from the new wood of the current year’s growth.

Now, putting sex and crop cycles aside, fig trees are also classified into another set of characteristics, based on the need (or the lack of) for actual pollination to occur to allow the synconia to mature. Thus we have the caducous (or Smyrna), persistent or San Pedro type figs.

The caducous type requires pollination to allow the synconia to develop and mature. There are caducous caprifigs and caducous edible figs. The Smyrna (and Calimyrna) figs are female caducous figs that require pollination/caprification to allow the synconia to develop into mature ‘fruit’ that we eat. Caprified edible figs have better taste partly due to the presence of mature fruit and seed inside the synconia.

Persistent type figs on the other hand, do not require pollination for the maturation of the synconia. The synconia will parthenocarpically mature despite having no pollinated flowers inside. There are also persistent caprifigs (male+female) but they are much rarer in nature.

A third type has characteristics of both the above. They are usually called San Pedro type. The first crop (breba) is persistent whilst the main crop is caducous. Thus the main crop synconia requires caprification for it to mature.

In a country where the specific symbiotic wasp (Blastophaga psenes) are not native, the planting of caducous/Smyrna type figs are avoided as it will result in the dropping of the synconia due to the lack of pollination that is required for the maturation of the synconia. Instead, persistent type and San Pedro type should be grown as it will offer large fruit crop production. A lot of Turkish sounding fig cultivars are the caducous type such as Sari Lop/Lob Injir, Bardajic and Gök Lop.

Another trend that is going around in this region is the large numbers of nurserymen selling seed-sown figs. Well, there are a few things that one needs to know about figs, especially when growing/buying seedlings (and not cuttings):

1) SEX (as in gender, not the act of…)
2) Persistent characteristic (parthenocarpic development of synconia)

Figs (as said earlier) have either 
a) female flowers with long style (eg. the edible fig is female only, whether caducous or persistant) or 
b) flowers of both sexes (caprifigs, having short-style pistillate and also staminate flowers)

Persistent characteristics
Whether it is a caprifig (male + female) or edible (female only), they either require 
i) pollination to allow for the synconia to mature (caducous/non-persistent) or 
ii) they can mature without pollination (persistent)

Persistent synconia is governed by the allele P/p. The dominant allele P (for persistence) is lethal for the ovum, and hence can only be carried by the pollen/sperm. 

So when you plant a fig seed, the following scenario comes to play

In terms of gender:
a x b [edible female fig x caprifig] = 1a : 1b [1F:1MF]
b x b [caprifig x caprifig] = 1a : 3b [1F:3MF]

So you have a 50:50 chance that the seedlings of edible figs are caprifig-type that is not considered palatable.

2) Persistent (making figs without caprification) and caducous types (figs that require caprification or pollination from a caprifig)

a) caducous fig (female) x caducous caprifig (male+female) = all caducous (not persistent). Caducous caprifigs are the common caprifig and are home to the fig wasp. These are the caprifig types used to pollinate caducous female figs, aka Smyrna types such as the Sari Lop aka Turkish dried figs.

b) caducous fig (female) x persistent caprifig (male+female) = half caducous and half persistent   (persistent caprifigs are rare in nature but have been found and are used for breeding programs).

c) Persistent fig (female) x caducous caprifig (male+female) = all caducous

d) Persistent fig x persistent caprifig = half caducous and half persistent

So only if the pollen comes from a persistent caprifig, will you have a 50:50 chance of the offspring being persistent and not require pollination. Taken with the fact that persistent caprifigs are rare and mostly found in breeding stations, hence seedlings from commercially caprified (pollinated) figs will most likely be made with caducous caprifig, thus the seedling will all be caducous, which is bad news for fruit production in a place where the wasp are not native.

Having said that, Ficus carica can also form viable seeds when pollinated by pollen from other members of the family such as Ficus pumila (the creeping fig), Ficus pseudo-carica and Ficus palmata. Hence ‘accidental pollination’ by ‘stray’ wasps that are not native to them with compatible Ficus sp. pollen that allows development of seeds will result in fruitful caprification of the synconia. Also, research has shown that pollen from other members of Moraceae, e.g. pollen from mulberry will also trigger the development of the synconia when artificially introduced, albeit no development of viable seeds. 

Consequently, the adventurous gardener here may still get a small percentage of fruit set from caducous figs despite the absence of the Blastophaga psenes wasps. One other advantage of seed grown figs is that they will be free from mosaic virus infection.

So one should not be paying high prices for seed-sown fig plants, and also do not place high hopes that the tree would be fruitful or even produce good tasting fruits since the odds are ½ female x ½ non-caducous (at best scenario where persistent caprifigs were used) x a small, small number that gives good fruit characteristics = very very very very small odds of getting a good plant. By all means do so if you have the space and time to keep them (or you are very lucky), but don’t pay high prices for the seedlings. You might as well sow your own seeds from dried figs (they are caducous female x caprifig) and hope that the farm uses persistent caprifig instead of caducous caprifig.

A long listing of older fig varieties (Condit’s paper)‎

Discussion on the sex and persistency of figs were extracted and summarised from this forum thread: