The Tropical Fruit Forum

Citrus => Citrus General Discussion => Topic started by: hereistay on October 01, 2018, 10:06:33 AM

Title: Is this phytophthora?
Post by: hereistay on October 01, 2018, 10:06:33 AM

Hi there!
I have few plants grafted onto macrophylla bought two years ago. They all died and had the same symptoms. They started to have the leaf tips and new shoots blackened...then they felt down and twigs started to dieback. If I cut the ill twigs the process started again. Those plants where little plants. By the way I noticed similar symptoms onto other bigger plants and I have an orange with some twigs with these symptoms but the vegetation started again. According to some hobbyist with plants with similar symptoms the problem is phytophthora.
According to my knowledge phytophthora should start from the base and the plant should make gum at the collar. My plants did not had gum or cankers, only this sort of dieback and death in 2-3 weeks.
What's the problem accordion to you?
Thank you very much.

(https://i.postimg.cc/N9XyKhW8/FB_IMG_1538395792222.jpg) (https://postimg.cc/N9XyKhW8)

(https://i.postimg.cc/K4nkF27x/FB_IMG_1538395796917.jpg) (https://postimg.cc/K4nkF27x)

(https://i.postimg.cc/7CGhR8Yv/FB_IMG_1538395800992.jpg) (https://postimg.cc/7CGhR8Yv)

(https://i.postimg.cc/pyYfC86f/IMG_20181001_141347.jpg) (https://postimg.cc/pyYfC86f)

(https://i.postimg.cc/gX40XYgZ/IMG_20181001_141610.jpg) (https://postimg.cc/gX40XYgZ)

(https://i.postimg.cc/QHFMCZ1F/IMG_20181001_141635.jpg) (https://postimg.cc/QHFMCZ1F)

Title: Re: Is this phytophthora?
Post by: lebmung on October 01, 2018, 10:28:52 AM

Take the plant up and see the roots.
Seems like a die back disease.

Title: Re: Is this phytophthora?
Post by: hereistay on October 01, 2018, 10:35:22 AM

Just controlled when I changed the pot.
Roots were ok.

Title: Re: Is this phytophthora?
Post by: lebmung on October 01, 2018, 11:11:26 AM

Then it seems to be an infection which makes its way from the cuts.
Cut the dead twigs then brush the stem with 0.5% Copper Oxychloride which will kill on contact both fungi and bacteria, then keep them in high humidity so stem doesn't dry easily.

Title: Re: Is this phytophthora?
Post by: hereistay on October 01, 2018, 11:16:55 AM

Just did it with the died plants.
At the end they died.

Title: Re: Is this phytophthora?
Post by: Millet on October 01, 2018, 03:24:04 PM

It is not Phytophthora. Twig dieback is associated with a number of factors. The greatest contributing factor is rapid water loss from young tissues.  Rapid water loss is usually caused by high temperatures, wind, and low humidity.  Root problems, including those associated with cold and water logged soils, nutritional deficiencies especially zincc, insects, and diseases can also contribute.