The Tropical Fruit Forum

I found these little white critters on one of my young custard apple trees.  What are they?  Ants seem to be working them like aphids.  They don't look like the white aphids shown on google search pics.

I agree with Oscar on discing the soil.   Plow, harrow, and let the weed seeds sprout.  Repeat a second time (maybe a 3rd) and you should have clean soil.  You may want to do it in bands to limit soil erosion.

For tree stumps, I think glyphosate (Round-up generic) is the way to kill them. Some species are tougher to kill that others, but  they all die off after a few treatments.

Hi John, i'm thinking maybe adding a fan inside your shadehouse would help to increase air circulation? In very muggy tropics plants inside a shadehouse w/o air circulation can develop those kinds of disease problems.

Hi Oscar,
My shadehouse gets plenty of air circulation, but I wonder about my watering technique.  I've been using a hand-held hose, filling the top of each bag for a specific number of seconds, without getting the leaves wet.  I wonder if, instead, getting the leaves wet would help wash off the mildew spores(?).

I had been watering directly into the bags - not on the leaves - because it provides more control on how much water goes in each bag.  However, between the powdery mildew and the aphids (on citrus rootstock seedlings), I wonder if a good simulated hard rain is what they need.  It's our dry season now.  What do you think?

John

Some of my mango rootstock seedlings have developed a light grey colour. See photos below.  The leaves eventually wilt and die.  It doesn't look like the powdery mildew photos I've seen on the web.  What is this?  How to treat?





It's the cool, dry season now.  None of my mature mango trees show this problem.

Thanks,
John

If your sure your graft has taken, I would cut off the un-grafted side, as Chris said, lots of energy is going into growing all those new leaves on the ungrafted side, which is what you want to go towards your grafted side.

another option, is you can also put a graft on that other side, with the same variety or another, then you will have two branches already.

Have you had any growth on the grafted side yet?

I am guessing this root stock is Gomera, I have seen so many pictures of Gomera and those big purple / copper leaves, correct?

All the leaves on the right branch came out of the graft in one growth flush.  The graft is nearly two months old now.

I don't know the name of the rootstock variety, but just now read a description of Gomera and it sounds close.  This rootstock  came from a huge old tree on the farm that must have survived many cyclones and droughts over the years.  Very fiberous little fruit.

After field grafts are successful, when is it best to cut off the unwanted parts of the tree?  I grafted a couple of mango seedlings that were planted in the ground late last year.  The grafts took, and I want to get rid of the shoots from the rootstock that I had kept both as a sap draw and a second chance if the grafts failed.

Looking at the photo below, is it best to cut off the ungrafted shoot (on the left) now, or wait until the graft (on the right) has grown more?  I don't want the plant to waste too much energy on the unwanted limb, but don't want to stress the plant too much either.  What is your thinking?



Thanks.   John

John, have you thought about direct sowing the seeds you intend to grow on either as trees or as rootstocks?
I've seen studies here where raising them directly in the spot you are planning to grow them in creates a much stronger tree, as it doesnt need to be potted on or get transplant shock and the tap root can do what it wants. It makes sense as the seedlings I pull up from the garden can have a 2 foot taproot and only be a few inchesd above ground. The study also noted less suceptibility to phytopthera and other root problems.

You make a compelling case for planting directly in the ground:  An undisturbed straight taproot, and I know there will be less disease poblems than in a densly planted shadehouse.  I wish now I had done more direct in-ground planting.  During the dry season here it makes watering bigger chore, but probably worth it. 

I had already planned to plant out most of my mango rootstock seedlings (~200) this November, at the start of the rainy season, even though most will not have been grafted yet.  My avocado (hopefully ~50 takes) should all be grafted by then and ready for the ground.

Keeping plants in the shadehouse during the rainy season is hard, too, because the bags don't drain as nicely as in-ground.  Simply too much rain.  The only significant thing I plan/hope to have in the shadehouse this rainy season is some citrus rootstocks that aren't ready for grafting.

John

The following document describes one of the techniques described above.
http://www.fshs.org/Proceedings/Password%20Protected/1962%20Vol.%2075/410-412%20%28SINGH%29.pdf

The trick is to remove all the leaves on the youngster, and girdle the mature trees stem below the graft.

Fascinating.  Thanks for sharing this study.

It's amazing that mango cultivars with such names as Coconut Cream, Pineapple Pleasure, and Pina Colada could be developed by traditional means.  Even with thousands of seedlings, if the names are really descriptive of flavor, it's amazing.

If you choose to cover the wound, consider allowing the wound to dry out first, to make it an unfavorable environment for rot.  Alternatively, cover it so that it gets sufficient ventilation while being rain-protected.

A poll on Top Favorite Fruits can be voted on and read at the link below.  I urrge those who have not yet voted in the poll to add your thinking.

http://tropicalfruitforum.com/index.php?topic=16.msg55#msg55

Steven, thank you for the thoughtful video, photos and information on how you graft avocados. 

Coincidentally, I cleft-grafted 18 seedlings last month using a method similar to yours and only had 7 'takes'.  When I compare my method to yours, in search of my problem, I can only see that I tended to use longer scions, while yours seem to only be, maybe, 7 cm (3") long.  Also, I wrapped the scions with plastic kitchen wrap instead of a bag.  My seedlings were in a 50% shadehouse.

I'd appreciate your comments on some aspects of grafting:
1) Do you keep the young grafts in total shade for the first few weeks, or partial shade?
2) Do you have success with scions that have swollen side buds but clip off the growing/leafing terminal bud?
3) What is your thinking on the ideal scion?  Which scions should we avoid?  Do you choose very green wood or older wood?

Thanks,
John

Hey Oscar and all,

Thanks for the advice.  My Mamey Sapote seed spouted this week.  It was interesting to see the seed gradually swell, and now this:



John