Hi everyone, I'm new here... :) I have a question regarding a plant that my dad is trying to cultivate. The plant's name is Hylocereus Undatus, also often referred to as Dragon Fruit or Red Pitaya. My dad is trying to grow this in Indonesia. It is a tropical country with lots of humidity and full sun. (Temperature range is well above 25 C/ 77F) There are only dry and wet season in the country. Since it's a species of the Cactaceae genus, it wouldn't be able to stand too much water. We have approximately 2 acres of land in which these plants are growing. However, the plants, for some reason, constantly get this fungi infection that look like the attached pictures. Is there any cost-efficient way to get rid of this fungi infection? I've read that Abamectin, Benomyl and Maconzeb may take care of the problem but I wasn't sure if it was cost-efficient. Also, can the fungi possibly be due to too much water being absorbed by the plants? We have been trying to cultivate this plant for about 6 months now but it has never been fully successful. So far, we have only experienced dry season and the fungi is there. Now that it's turning to be a wet season, the fungi seems to be infecting more plants. How do we get rid of this problem? Thanks!
Looks like some scary stuff! I would be terrified if my Pitaya got any of that. I have read that it is a better option to cultivate white pitaya over red because of it's natural resistance to disease. As far as your infection goes, it could be Dothiorella blight but I am not certain.
^You are probably right. It is easier to cultivate the white pitaya. But the white pitaya is sour, if I am not mistaken, while the red pitaya is sweet. In Asia, I think, sweet is preferable.
White pitahaya isn't sour - that's a misconception based on trying to grow them in non-volcanic soils. White pitahaya are among the sweetest cactus fruit grown in South America. I'm going to disagree with you about water tolerances as well, since the very best pitahaya in Ecuador come from the edge of the Amazon basin (the province of Morona-Santiago) where the average yearly rainfall is in excess of 3 m. The plants thrive in this zone and throw very large fruits. What you have there looks like Dotholaria blight to me, as well. I like Benomyl when my plants are affected, but check the costs in your area; one of the other fungicides you reccomended may be more cost effective. If they all seem out of reach financially, a 5% solution of Copper (II) Sulfate in water also works quite well.
Dear friend, In my experience your plants show symptoms caused by one pest (Leptoglossus spp.) and a particular disease (Botryosphaeria dothidea) that we call "fish eye". Bacteria occureence is also not discard. This disease (fish eye) is particularly difficult to erradicate becasuse it cause canker on stem tissues. Key of management is to control de pest. Please if you have more questions do not doubt in contact me. Dr. A. Valencia-BotÃn University of Guadalajara Mexico
I had that disease on hylocereus and aporophyllum too. I solved it using a medicine named Captan.. It`s a antifungus powder... I should you to cutt of all the diseased leaves.. and then use captan..
@lorax, I suggested the Copper Solution to my dad and he said he was about to experiment with that too! :D Would you mind suggesting a good ballpark concentration to start with to treat the leafs? I'm not sure about the availability of Benomyl there. He told me that it might not be economical enough to use it for a commercial scale. He was using Redomil but it's not very effective. @Abotin 77 and the rest, Thank you so much for your insights. I guess I haven't mentioned this but we have tried various methods to no avail. Since the last update that I got from my father (It would be great if he could post here himself but unfortunately his English is not very good), it seems that they are cutting the infected part of the trees and burning it. However, since the young plants are difficult and expensive to obtain, we are recycling some of the cut leafs to be new plants. We try to get ones that are not infected (Meaning: there are no dots on the leafs). If we do this, would the young plant have the disease as well?
Between 5 and 10% usually works for me; it's my fungicide of choice for most plants, especially cacti and bananas.
Thank you all for the info. My dragon fruit cactus have been hit by Botryospaheria dothidea (Dragon spots) just like the ones shown in the pic. There are a few encouraging suggestions of different treatment options on this thread. I was wondering if someone would be so kind as provide some additional details regarding a proven treatment method to get rid of this scourge. Specifically looking for: * Anti-fungal brand name/chemical name * Concentration (%) * Application dose (how much and how many times) * Application location (soil or spray) * Any other insightful considerations Thanks! Tom