sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 57-64
SITE AND STAND CHARACTERISTICS OF A Pinus brutia STAND
INFECTED WITH Diplodia pinea IN TURKEY
Nevzat GÜRLEVIK 1* , H.T. Doğmuş LEHTIJÄRVI 1 , Asko LEHTIJÄRVI 1 ,
ABSTRACT
A. Gülden ADAY 1
SDU Faculty of Forestry, 32260 Isparta, TURKEY
*gurlevik@orman.sdu.edu.tr
Shoot blight can be a very costly disease for coniferous forests as it results in defoliation
and reduced growth. In this study, some of the site and stand characteristics of a Pinus
brutia Ten. stand infected with Diplodia pinea (Desm.) Kickx has been investigated.
Blight occurrence was investigated for two different years, and also some soil and foliar
nutrients were determined. Our results showed that at the first sapling time in 2006, 18 out
of 90 shoot samples had infection, while in 2008 this number fell down to 5 out of 90
samples. Results for soil analysis generally indicated somewhat poor site conditions. On
average, soil had sandy clay loam texture, reaction was 7.72 and organic matter content was
moderate with 3.84 percent. However, soil had a coarse fraction up to 62 % indicating
relatively poor nutrition. Similarly, foliar nutrient levels also showed poor site quality.
Overall, needle N concentration was lower than 1 %, indicating N deficiency on these sites.
These poor site conditions and extreme droughts may have played a role in development of
the shoot blight in these stands.
Keywords: Diplodia pinea, Pinus brutia, drought, nutrients
1. INTRODUCTION
Pinus brutia Ten. is the most commonly distributed coniferous forest tree
species in Turkey, covering approximately 5.4 million hectares. It can be found at
elevations between sea level and 1500 m. Pinus brutia grows best at elevations of
600-800m, below which very high temperature and demand for evapotranspiration,
and above which cold weather restrict its distribution and growth (Boydak, 2000)
Diplodia pinea (Desm.) Kickx is one of the most common disease agents in
coniferous forests. It causes necrosis on needles, and therefore defoliation and
death of shoots. In turn, it results in reduced growth and substantial economical
losses (Stanosz et al., 2004).
Several studies indicate higher risk of disease if plants are stressed. Especially,
water stress seems to increase the occurrence of this disease. Paoletti et al. (2001)
showed that water stressed Pinus halepensis Mill. seedlings had longer cankers of
Sphaeropsis sapinea sensu lato 5 months after inoculation. Blodgett et al. (1997a)
have also shown that 3-year-old red pine (Pinus resinosa Sol. ex Aiton) seedlings
57