Herbicide Screening Trial 2007

Two promising new herbicide combinations have been identified for use in blackcurrants which offer viable alternatives to the standard programme (which uses diuron + Stomp - pendimethalin).

The predominant weed species were annual meadow grass, blackcurrant seedlings, groundsel and mayweed.  Cleavers, doves foot cranesbill, hairy bittercress, plantain and sowthistle were also present.  Weed cover was slow to build up initially due to the dry April. However by harvest, following wetter weather in May and June, the weed cover on some untreated plots had reached 95%.

• The most effective treatments were the unnamed product (flazasulfuron), Stomp + Artist and the standard Stomp + Diuron.

• Flazasulfuron maintained almost complete weed control through to harvest.  The few weeds that were present in these plots were mainly annual meadow grass and groundsel. 

• The alternative Stomp mixture, with Artist, performed as well as the standard Stomp + Diuron. However by harvest, there were signs that the Stomp + Artist mixture was losing efficacy with a few groundsel plants appearing.

The crops were carefully monitored after treatment but no phytotoxicity symptoms were observed.

Efficient and cost effective weed control is important in blackcurrants, to prevent yield loss from competition for water and nutrients and to enable efficient harvesting without impedance by weed growth.
• Providing information on the effectiveness and safety of a range of herbicides and tank mixtures.
• Providing the initial screening of chemicals to enable subsequent GLP residue studies to be focused on the most promising materials for SOLA applications.