Agriculture Reference
In-Depth Information
Using tolerant hybrids has provided some control of
woodiness disease. However, contamination by the
severe strains, spells of cool weather or otherwise
unfavourable conditions can also cause an increased
incidence of woody fruit.
Symptoms
Infected plants lack vigour and have galls or swellings
on the roots.
•
Source of infection and spread
Root-knot nematodes are widespread, occurring in virgin
soil and have many alternative hosts. They are disseminated
in infested soil, water and equipment, as well as infected
nursery plants.
Plant vines in warm, sheltered locations.
•
The viruses are not transmitted through seed, so
seedlings will be free from the virus provided they are
not grafted to infected scions or rootstocks. Virus-free
material should be isolated from infected passionfruit
crops or
Passifl ora
weeds, as natural re-infection via
aphids from these sources can occur very quickly.
•
Importance
Nematodes cause economic loss of fruit and reduce life
of the vines. Some species of
Passifl lora
(e.g.
P. incarnata
)
are highly susceptible to root-knot nematode.
NEMATODES
■
Management
•
Cause
The nematodes
Meloidogyne incognita
and
M. javanica
.
Use nematode-resistant rootstocks. The golden
passionfruit (f.
fl avicarpa
) has good resistance
to
M. incognita
and
M. javanica.
FURTHER INFORMATION
■
M a n i c o m B , R u g g i e r o C , P l o e t z R C & d e G o e s A ( 2 0 0 3 ) D i s e a s e s
of passionfruit. In
Diseases of tropical fruit crops
. ( E d . R C P l of e t z )
pp. 413 - 441 CABI Publishing: Wallingford .
V a n d e r p l a n k J ( 1 9 9 1 )
Passion f flowers and passion fruit
. The MIT
Press: Cambridge Massachusetts .
Fig 15.23 Root galls caused by root-knot nematodes.
