Decline in vitality of propagules of Phytophthora pluvialis and Phytophthora kernoviae and their inability to contaminate or colonise bark and sapwood in Pinus radiata export log simulation studies

New Zealand Journal of Forestry Science

Table 1 Details of studies to determine the survival of propagules of Phytophthora species applied to the bark surface of segments cut from Pinus radiata stems harvested in the Bay of Plenty and Taupo regions

Study	Treatment¹	Application method	No. replicates	Segments
			(segments)	Dimensions (cm)	Age of parent tree (yr)
1	A. P. kernoviae oospores	Direct	3 (75)	30 × 9 × 9	36
	B. P. kernoviae mixed sporangia and zoospores
	C. P. pluvialis oospores (heated)²
	D. P. kernoviae oospores (heated)²
	E. Deionised water (control)
2	A. P. kernoviae oospores	On nylon mesh filter	2 (20)	30 × 9 × 9	32
	F. P. pluvialis oospores
3	B. P. kernoviae mixed sporangia and zoospores	Direct	3 (60)³	10 × 9 × 9	15
	G. P. pluvialis mixed sporangia and zoospores

¹Phytophthora isolates: refer Table 2 for details:
Study 1: P. kernoviae: 3610, 3614; P. pluvialis: 3026, 3608, 3613, 3619, 3626, 11135–1.
Study 2: P. kernoviae: 3610, 3614, 3636; P. pluvialis: 3619, 3626.
Study 3: P. kernoviae: 3604, 3614; P. pluvialis: 3613, 3619.
Isolates of each species were combined within each study.
²Heated to kill mycelial fragments prior to application.
³Cut the same day from two trees in one stand, felled immediately or 3 months earlier in late autumn, treated experimentally as separate blocks each with 30 segments (one tree felled immediately for each of Studies 1 and 2).