Physical and Cultural Weed Control Working Group of - European ...

9 th EWRS Workshop on Physical and Cultural Weed Control 58
Samsun, Turkey, 28 – 30 March 2011
The critical period for weed control in red pepper (Capsicum annum L.)
Nihat Tursun1 1 , Irfan Ersin Akinci 2 , Ahmet Uludag 3 , Zuleyha Pamukoglu 1 ,
Doğan Gozcu 4
1 KSU. Agricultural Faculty, Plant Production, Kahramanmaras, Turkey
2 KSU. Agricultural Faculty, Horticulture, Kahramanmaras, Turkey
3 IU. Agricultural Faculty, Plant Production, Igdir, Turkey
4 Agricultural Research Institute, Kahramanmaras, Turkey
Field studies were conducted in Kahramanmaraş, Turkey, in 2008 and 2009. Weeds are a major
constraint in red pepper production. Understanding the critical period for weed control (CPWC) can
be a tool for effective weed control and reducing the impacts of weeds. The critical period for weed
control in red pepper based on a 2.5%, 5% and 10% acceptable yield loss level was calculated by
fitting logistic and Gompertz equations to relative yield data. The critical period for weed control in
red pepper was determined to be from 0 to 1087 growing degree days (GDD) in 2008 and from 109
to 796 GDD in 2009 for 10% yield loss after emergence in red pepper; for 2.5-5% yield loss, the
critical period starts with germination and lasts longer. Preemergence (PRE) or presowing (PPI)
herbicides would be preferred to avoid higher yield losses. If a farmer can tolerate 10% yield loss, a
postemergence (POST) herbicide can be applied in between beginning of the germination and 1-2
nd week after crop germination, and the field should be kept weed free for corresponds 7 weeks to
7-8 weeks.