Problems with Star Fruit Tree

[M Farooq]

We have a 7-8 year old star fruit tree (http://en.wikipedia.org/wiki/Carambola) but for the last few months it has been "ill". I wish I could attach pictures
but here is a description. Any suggestions what to do?

1) First of all, it is producing too many fruits which eventually never get a chance to become ripe and fall off the tree. This is surprising as an unhealthy tree shouldn't be producing many fruits.

2) Small younger branches are drying to the extent that the break like dry sticks

3) Some of the fruits appear to have "dust" covered on them- this is what what my father described. Is this some type of mite attack as this "dust" is probably eggs of some parasites/ pests?

Suggestions are welcome.

Regards,

Farooq

[ahussain]

Well,
1) Fruits fall to the ground when fully ripe. Hand pick the fruits when mature (pale green with a touch of yellow). Light Requirements: Full sun.
Star Fruit Care Guide:
Diseases.
Star fruit are disease and insect resistant and grow in a less care fashion, especially if the tree maintains good health. Leaf spot diseases are caused by Cercospora Averrhoa Petch., Corynespora cassiicola Berk. And Curt., Phomopsis sp., Gloesporium sp> and Phyllosticta sp. Observations indicate these diseases are more common on stressed or nutritionally deficient trees and occur on older leaves that normally abscise (drop) during the winter and early spring. Twigs and limbs may be attacked by red alga (Cephaleuros virescens Kunze). Symptoms include rough circular greenish-gray or rusty-red areas and shoot dieback. Ripe fruit that is injured may be attacked by the fruit rotting fungus. (Colletotrichum gloeosporioides Penz) which caused anthracnose. A superficial blackish discoloration on fruit (sooty mold) caused by Leptothyrium sp. May be found on fruit surfaces. Recently, the fungus Phthium splendens Braun has been identified as the cause of of general tree decline syndrome. Decline symptoms include loss of tree vigor, leaf drop, twig, shoot, and root die-back, and reduced fruit size and production. For more information and control measures, consult your county agricultural extension agent.

Pest

Carambola trees are attacked by a number of scale insects including Plumose [Philephedra tuberculosa(Nakahara and Gill)] scales which attack leaves and twigs causing defoliation and stem dieback. The weevil Diaprepes abbreviatus (L.) causes damage to the roots, which may lead to root and shoot dieback. Fruit damage caused by stink bugs (Nezara sp.) and squash bugs (Acanthocephala sp.) results in pinhole sized markings on the fruit surface and dry areas of the flesh under the puncture wounds. This may lead to infection by fungi which cause soft rot of the fruit. Fruit blotch miner (lepidoptera: Gracillaridae) causes a superficial damage to the waxy cuticle and can be identified by meandering brownish colored trails on the fruit surface. Brown scales [Coccus hesperidia (L.)] and red-banded thrips [Selenothrips rubrocinctus(Giard)] have also been observed feeding on carambola fruit. Birds, opossums, and raccoons may attack fruit especially early in the season. Their damage can be identified by the V-shaped marks left on the ribs of the fruit.

Outdoor
Fertilizer practices

Current fertilizer recommendations are based on observation,. In soils of low fertility, young trees 1 to 2 years old should receive light applications of a mixed fertilizer containing nitrogen, phosphorus, and potassium (¼ to ½ lb @ tree per application) every 30 to 60 days until trees are well established. As trees mature, the fertilizer rate should increase (1 to 3 lbs @ tree per application) with an application frequency of 4 to 8 times per year. Fertilizer mixtures containing 6-8% nitrogen, 2-4% available phosphoric acid, 6-8% potash and 3-4% magnesium are satisfactory.

In acid to neutral pH soils, micronutrients such as manganese, zinc, and iron may be applied in dry applications to the soil or in a liquid form and sprayed onto the leaves. Three to 6 applications should be made per year. Trees growing in calcareous soils should receive 4 to 8 foliar applications @ year of zinc and manganese. Iron deficiency may be corrected by 3 to 6 yearly soil drench applications of cheated iron specifically formulated for calcareous soils.

Spacing and training
Trees should be planted on 15 to 20 foot centers in a sunny location. No special training is recommended.

Watering
The star fruit needs moist conditions and must receive regular watering in the summer and even during dry periods in the winter.

Pruning
The main purpose of pruning is to control size and secondarily shape.

[M Farooq]

Thanks Hussain Sahab for searching about star fruit diseases but I was looking for a more specific suggestion related to the disease described in my original post. Can anyone suggest a general purpose pesticide and a fungicide? And if the pest/ fungus is in the tree roots, what should one do?

Regards,

Farooq

[UMARKHANMARDAN]

Aoa Farooq sb.i don,t know about star fruit but if you mean root rot(phytophthora foot) then its a common disease in fruits as well as in veggies just like chillies & tomatoes.its caused by fungus.its good if you use Bayer,s Aliette.we use use it for citrus & its results are very good.Die back starts from top of the tree where as foot rot(Phytophthora) starts from roots & trunk.for Dies back(Allah Tallah die back se fruit ko bache) Antracol is used.but i think in your star fruit,s case its root rot so use Aliette.may be i am wrong because i don,t know about Star fruit.but in citrus its my personal experince.this disease is also common in mango at Sindh & Punjab.

[Farhan Ahmed]

These are extracts from a book house plant survival manual which match your specified symptoms.....

Cyclamen mites
These tiny sap sucking insects lay their eggs in such a quantity that they look like a layer of dust.leaves and flowers become twisted and brittle and eventually covered in small scabs."

http://www.ipm.ucdavis.edu/PMG/r734400211.html
http://www.entomology.umn.edu/cues/Web/ ... enMite.pdf

[M Farooq]

These are extracts from a book house plant survival manual which match your specified symptoms.....

Cyclamen mites
These tiny sap sucking insects lay their eggs in such a quantity that they look like a layer of dust.leaves and flowers become twisted and brittle and eventually covered in small scabs."

http://www.ipm.ucdavis.edu/PMG/r734400211.html
http://www.entomology.umn.edu/cues/Web/ ... enMite.pdf

Thanks Farhan & Umar shab, I guess the star fruit tree has multiple issues, probably these cyclamen mites and along with something, most likely fungus, which is damaging the roots...because young shoots are drying to death. The only surprising thing is that the tree is loaded with fruits, none of them are able to mature and fall off.

[Farhan Ahmed]

DAMAGE

Cyclamen mites are primarily pests in fall-planted and second-year plantings, but they can be transplanted into first-year fields and the damage symptoms become apparent on leaves as the season progresses. Leaves heavily infested with cyclamen mites become severely stunted and crinkled, resulting in a compact leaf mass in the center of the plant. Feeding on flowers can cause them to wither and die. Fruit on infested plants is dwarfed, and the seeds stand out on the flesh of the berry. When uncontrolled, this mite can prevent plants from producing fruit.

http://www.ipm.ucdavis.edu/PMG/r734400211.html

[M Farooq]

DAMAGE

Cyclamen mites are primarily pests in fall-planted and second-year plantings, but they can be transplanted into first-year fields and the damage symptoms become apparent on leaves as the season progresses. Leaves heavily infested with cyclamen mites become severely stunted and crinkled, resulting in a compact leaf mass in the center of the plant. Feeding on flowers can cause them to wither and die. Fruit on infested plants is dwarfed, and the seeds stand out on the flesh of the berry. When uncontrolled, this mite can prevent plants from producing fruit.

http://www.ipm.ucdavis.edu/PMG/r734400211.html

It means this is not cyclamen mites as the fruit production is excessive rather. I will try to get hold of pictures.