Effective weed management strategies are limited for capsicum and chilli producers.
Current weed management practices include the use of plastic, selective grass herbicides or tillage.
There are currently no herbicides registered for broadleaf weed control in capsicums or chillies.
The development of effective broadleaf weed herbicides, to be used as part of an integrated weed management program in capsicum and chilli production in Australia, is essential.
This project identified, screened and collected efficacy, crop safety and residue data for a range of new herbicides for capsicum and chilli production.
Capsicums and chillies are a high value, intensively produced crop with significant and growing export markets.
The value of capsicum production at the farm gate was $47.1 m in 1998/99, an increase of $8.7 m from the previous year.
Production tonnage has increased from 20,207 tonne in 1992 to 30,398 tonne in 1998, produced over an area of approximately 2300 hectares.
Grown commercially from transplants, capsicums and chillies are grown throughout Australia, although over 70% of Australia’s capsicum and chilli production is in Queensland.
The major production regions are in Bowen–Burdekin and Bundaberg. Effective weed management strategies are limited for capsicum and chilli producers.
Current weed management practices include the use of plastic, selective grass herbicides or tillage. Plastic mulch is commonly used, not only for weed suppression but also for maintaining soil temperature and moisture retention.
Tillage is also sometimes used for weed control, however an over reliance on tillage can lead to soil structural issues, loss of soil moisture and damage to the crop.
The only herbicides registered for use in capsicums are for post-emergent grass control. Dacthal (chlorthal dimethyl) was previously registered, however it was taken off the market and never re-registered for use in capsicums.
The most effective herbicides identified from this work were Stomp (pendimethalin), Command (clomazone) and Raft (oxadiargyl), which all gave excellent results when applied pre-crop transplanting to weed-free soil. All three products provided effective pre-emergent control of a range of common broadleaf and grass weeds across a number of sites.
Raft and Command are recommended for registration in capsicum and chillies.
These products can potentially be used under plastic mulch, in the inter-row, or applied to bare soil if the crop is grown without plastic mulch.
Further work is recommended with Stomp under plastic before recommendations are made on this product.
Authority (sulfentrazone), Pledge (flumioxazine), Affinity (carfentrazone), Goal WP (oxyfluorfen), Lexone (metribuzin), Balance (isoxaflutole), Basagran (bentazone) and Raptor (imazamox) were also screened, but they were not further evaluated due to crop damage issues.
See Also : “Evaluation of new herbicides for capsicums and chillies”
The assistance of Lyndon Butler and Vaughan Trebilco (Forthside Vegetable Research Station), Bill Piasini, Pam Stackleroth, V. Mete, Peter Chauntler, Alan and Jenny Napier and Terry & Helen Holl who provided trial sites is gratefully acknowledged.
Serve-Ag staff who contributed to this project included Matt Sherriff, Brendan Finch, Rodney Burn, Pam Cox, Mary Trebilco, Ian Macleod, Tim Hingston and Sarah Lamprey.
The assistance of Mark Sumner (Serve-Ag WA), and Keith Lewis and David Kilpatrick (Serve-Ag BFS) who conducted trials in Queensland and Western Australia, is gratefully acknowledged.
The input and advice from Chris Monsour (Bowen Crop Monitoring Services) who also conducted the trial
This project was funded by Horticulture Australia through the National Vegetable R&D Levy.
The Australian Government provides matched funding for all HAL’s R&D activities.