Preliminary Study of the Sap Pressure Variability between Several Clones ofScots Pine in the Centre of France

1988

S. 341-358

6 Abb., 2 Tab., 26 Lit. Ang.

Unselbständiges Werk

200014565

To discriminate several categories of resistance of Scotspine to bark- beetles attacks, a preliminary study of nycthemeral and between c lone sap pressure variation was conducted in the centre of France (Nogent-sur- Vernisson, Loiret and Orleans). Measurements were made on several Haguenau and Mossig clones as well as Pines of known maternal genetic stock. Root system are poorly developed between 0 and - 40 cm. At these depths, the water content of the soil, as indicated by a neutron probe, would lead to a certain drought in summer and an excess of water in winter. Under the climatic conditions of centralFrance, depending on the variations in sap pressure measured, discriminant val ues could be obtained around 3 p.m (T.U) after a fairly long drought period or 4 a.m when air humidity is highest.