Why is my Tamarillo fruit damaged?

[JayPea]

 Hi,

my Tamarillo Tree is 3-4yrs old and this is the first year it has had an abundance of fruit appear however I am loosing a significant amount as they are dropping with these markings. 
I recently sprayed for caterpillars which has done wonders for my chewed-to-pieces leaves but I think it may have damaged the fruit?!

Any advice would be appreciated!

[mich1972]

Good afternoon @JayPea

Welcome to the Workshop Community 😃 Now that is really interesting to see, it almost looks like it has been burned. Thank you for sharing your question. I’m wondering if it’s been burnt by insecticide exposure or sunburn ? May I ask what State you’re in please. Here in Perth we are going through a heatwave, that’s what it looks like, a burn. I am going to tag in the wonderful @Noelle as I would like to get her opinion 😃 could even be a fungal infection maybe. 

[Noelle]

Hi @JayPea 

My thinking is that it could be heat damage in association with insufficient water. It would be unusual for sun-burned fruits to drop if everything else was OK - they would continue to grow and ripen but with severe skin blemishes. The actual fruit looks pale and soft, as if it hasn't absorbed enough moisture to keep it firm and plump.

It is possible too for an insecticide to burn the skin but again that would not account for the lack of plumpness and fruits dropping.

Any tree that is stressed for whatever reason will drop its fruits in order to try to keep itself alive.

Like @mich1972 , I'd like to know a bit more about where you live, what the climate and soil are like, how often you water and so on before making a more accurate diagnosis of what is happening. Some photos of the tree overall and of the leaves and other fruits on the trees would be helpful, if you could please.

[mich1972]

Thanks for replying @Noelle  I didn’t even think of the watering.😊

[JayPea]

Hi @mich1972  and @Noelle,

Thankyou for responding.

I am also in Perth and the week of close to 40°C temps and gusting easterlies have been been terrible and my tree is exposed to both!

I have been watering every other night (15mins) with a sprinkler at ground level. Once a week she gets a drink of Seasol and I have spread  Triple C mulch from the base approx. 2m diameter. 
I’ve included an image of what happens to the leaves before they drop and one of two fruit that have been ripening for the past 5mths.
These fruit and the plethora of flowers gave me great hope for its future  - I hope it’s not too late to turn things around!

 

 

 

 

 

  

[Noelle]

Hi Again @JayPea 

Tamarillo 'trees' have very shallow root systems that, in your climate and in the current hot weather, will dry out rapidly especially as the tree is in an open spot with absolutely no shade from overhanging trees/branches. Watering every second night may not be adequate. Keep in mind that the feeder roots may be as far out from the trunk as the outer edge of the leaf canopy, so you need to ensure that entire circle is thoroughly watered every evening while the hot weather continues.

Tamarillos do best in tropical and subtropical areas and around the warmer coastal rim of Australia. While the enjoy the warmth, they will burn easily if in full, hot sun all day. Your tree is very exposed so I am now thinking that the summer heat in Perth along with probably not enough water are key to why the leaves and fruits look as they do.

It's pretty well impossible to transplant a large shade tree into the garden, but that shade umbrella in the background may do the trick if it is relocated to provide some shade to the tamarillo, even if only over the soil around the tree, to keep the roots cooler (and moister for longer).

I don't think it is a pest or disease problem, rather one of the growing conditions being not quite right.

This guide to growing tamarillos is written for New Zealand conditions but the advice can be applied in Aus as well.

[JayPea]

Thankyou for your insight and have taken your advice.

Growing up in NZ eating kilos of tamarillos as a child and realising the differences in growing conditions between here and there, she has been a surprise all round - I’ll do my best to keep her thriving!

All the best!