Nature of dependent origination, and is Buddhism non-duality? Is dependent arising meant for us to understand the arising of suffering -- or is it also meant to describe how phenomena in the outside World arise dependent on other conditions (for instance how water and sun causes a flower to grow)?

I think Nagarjuna says that dependent origination is not only showing how suffering arises, but also how phenomena in the World arises. He uses a sutra in the Pali Canon where the Buddha said that this World is dominated by a duality of existence and non existence, then he continued, "when one sees the origination and cessation of the World existence and non existence do not occur to one anymore".

This seems to confirm what Nagarjuna said: that dependent origination is not only describing how suffering originates, but how phenomena in the World also originate -- isn't that so?



I have another question also: how would you describe Theravada, Mahayana, Vajryana and Tibetan Buddhism -- are they non dual or not? Please describe to me the logic why you answered the way you did also.
Is dependent arising meant for us to understand the arising of suffering


According to the Pali scriptures, yes. Refer to SN 12.2 or AN 3.61. 


  or is it also meant to describe how phenomena in the outside World
  arises dependent on other conditions for instance how water and sun
  causes a flower to grow.


No. The Buddha taught about suffering &amp; its cessation (MN 22; SN 56.31; AN 3.61; etc). 


  I Think Nagarjuna says that dependent origination is not only
  showing how suffering arises but also how phenomena in the World
  arises.


Nagarjuna has his own philosophy. You are free to follow Nagarjuna rather than the Buddha.


  He uses a sutra in the Pali Canon where the Buddha said that this
  World is dominated by a duality of existence and non existence then he
  continued when one sees the origination and cessation of the World
  existence and non existence do not occur to one anymore.


The above is a misunderstanding of SN 12.15. Its funny how you think one single sutta that uses words (namely, "atthitañceva" &amp; "natthitañca") that are difficult to translate defines what the Buddha taught. Possibly, the discussion of the word 'atthi' at this link can help you. 


  This seems to confirm what Nagarjuna said that dependent
  origination is not only describing how suffering originate but how
  phenomena in the World also originate?.


No. When the Pali suttas use the word "world" ("loka"), this does not necessarily refer to the physical world. Refer to SN 12.44 and AN 4.45, which use the word "the world" synonymously with the word "suffering". 


  I have Another question also how would you describe
  Thervada,Mahayana,Vajryana and Tibetan Buddhism are they non dual or
  not and please describe to me the logic why you answered the way you
  did also.


The Buddha did not teach "non-duality". Refer to my answer here.