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Brown Spot on Passion Fruit Trees

General    None Given

Which fungi causes leaf spot in passion fruit trees and which fungicide can i use to remedy the problem. i am in Kenya in the plains of Usin Gishu county growing non grafted purple passion.


Posted by: samwel (1 point) samwel
Posted: July 1, 2013


David Hughes commented,
Where are you located (which country). This impacts the answer.
about 11 years ago.



Answers

1
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The fungus commonly causing brown spot on passion fruit is Alternaria passiflorae.

The disease is common in Australia and New Zealand but the first record from the US (Florida) was in 1991.

Much of the control strategies for growers in New Zealand/Australia have mentioned that when the fungus is seen on leaves/fruit then control with fungicides is too late. The main control is cutting the canopy to increase air flow to draw out the leaves (and fungus)

Do please provide more information



Posted by: David Hughes (67 points) David Hughes
Posted: July 2, 2013




1
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Brown spot of passion fruit is caused by the fungi Alternaria passiflorae and Alternaria tenuis and can be very damaging, particularly to purple passion fruit which is more susceptible to the disease than yellow passion fruit varieties. The fungus causes circular brown spots on leaves which enlarge and can cause leaves to drop from the tree prematurely. When the fungus infects the fruits it can cause severe economic losses. The disease appears as tiny specks on the fruit which enlarge into sunken circular lesions with a brown center. The fruit shrivels and drops from the vine.

Brown spot is common on purple passion fruit in New Zealand and East Africa but is more common on yellow passion fruit in the US state of Hawaii. Which variety are you growing and where?

Control of brown spot relies on cultural practices such as allowing adequate space between plants, pruning back leaders to open the canopy, thus reducing humidity and promoting good air circulation around the foliage, and good sanitation practices e.g. destroying crop debris and disinfecting tools and equipment regularly.

In terms of fungicide application, protective copper sprays can be used for organic production. Certain chemicals, such as mancozeb, have been shown to be effective against the fungus but are not approved by the FDA for use in the US. That is why it is important to tell us your geographic location...



Posted by: Lindsay McMenemy (4 points) Lindsay McMenemy
Posted: July 3, 2013




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