HERBICIDE SENSITIVITY OF PEAR UNDERSTOCKS

Authors studied the effects of 6 different, licensed herbicides in 3 doses each (recommended by the manufacturer, double dose, tenfold dose) on the pear understocks: Egervár I wild pear seedlings and the quince EM-A, during 2 years, 1995 and 1996. Both understocks proved to be very sensitive to chloramino-triazine compounds, therefore, these are not recommended at all in pear orchards.
The acetochlor (Acenit A 500 EC, recommended dose-RD: 5 l/ha), metachlor (Dual 960 EC, RD: 2.2 l/ha), and pendimetalin (Stomp 330, RD: 6 l/ha) are well tolerated by both understocks, because even the tenfold dose displayed no symptoms of phytotoxicity.
Higher doses, however, were phytotoxic, except pendimetalin. In young pear plantings, the use of Aktikon PK, Hungazin PK, diuron (Lucenit 80 WP), chlorbromuron (Maloran 50 WP) is risky and not recommended.
The effect of season was very strong on the expression of phytotoxicity (Dual 960 EC, Lucenit 80 WP, Maloran 50 WP). Those treatments, which did not induce toxic symptoms in 1995, caused chlorosis and partial necrosis in 1996. The rootstock EM-A proved to be more sensitive to the herbicides studied (chlorosis and necrosis) than Egervár I.

VII International Symposium on Pear Growing

I. Béres, J. Iváncsics, J. Nyéki

pear rootstocks, wild pear, quince, phytotoxicity

https://doi.org/10.17660/ActaHortic.1998.475.23