The agenda covered a range of topics, from business management and marketing, to increasing vegetable consumption and speaking up for UK farming. A series of technical sessions highlighted a number of the challenges which are faced by the UK food system, and carrot and onion growers in particular, but in terms of crop protection, four key messages stood out from the day.
Whether due to changes in the regulation of crop protection products, the development of resistance in weeds and pests, or climate change affecting pest and disease pressures, everyone present agreed that growers face unprecedented changes to the way crops will be grown.
Jack Hill, Technical Manager at Bayer, commented: “The agronomic challenges facing carrot and onion growers haven’t changed, against a backdrop of product revocations and regulatory hurdles. The loss of linuron had a big impact on both carrot and onion crops, and has left some key challenges with nettle, mayweed and volunteer potato control.”
Climate change will also create issues, with thrips becoming a bigger issue on onion crops for example, and as conventional crop protection products are lost and new approvals become more difficult, it is often minor horticultural crops which are hardest hit.
Worldwide, the market for horticultural Plant Protection Products is worth some €15 billion, putting it on a par with the global soybean market. As a result the sector attracts a significant proportion of Bayer’s €2.4 billion R&D budget. Industry collaboration and working together through projects such as AHDB’s SCEPTREplus are also essential in helping to bring solutions to the market for growers.
In the UK, subject to approval, Bayer hopes to increase the crop protection options available for carrots and onions, with products including herbicide Emerger (aclonifen) and new bio-insecticide FLiPPER (unsaturated carboxylic acids C14-C20) for both crops, and liquid nematicide Velum Prime (fluopyram) for carrots.
“We have an existing EAMU for carrots with Serenade, but we hope to gain on- label approval targeting Pythium and cavity spot,” explained Mr Hill. “FLiPPER also has an EAMU for use in carrots, leaves zero residues and has no MRL. It is classed as a Low Risk plant protection product and is approved for organic use. Hopefully it will fill some of the void created by the loss of some of the synthetic insecticides in carrots and onions.”
Another area where growers are looking for new tools is post-emergence weed control and following successful SCEPTREplus trials, and EAMU application has been submitted for post-emergence use of Emerger at up to 0.65 L/ha, within a total crop dose of 1.75 L/ha. “In terms of efficacy post emergence, it has useful activity on chenpodium species and in trials gave control of sow thistle when used at 0.33 L/ha,” said Mr Hill. “We have also seen control of volunteer sugar beet, emerged bindweed and fat hen.”
“The grower associations are telling us that they are seeing more and more challenges as they are losing chemistry,” said Joe Martin, of the AHDB Crop Protection team.
“So far, the SCEPTREplus project to identify sustainable plant protection products for use in horticultural crops has evaluated 200 conventional products, as well as 40 which are biopesticides, botanicals, biologicals or basic substances.
“We have looked at over 240 products, and although there are quite a few conventional products, we are seeing far more biopesticides and botanicals coming through the regulatory process,” he noted. “We certainly see greater activity in this area in the future. We are particularly seeing new bio- insecticides as conventional insecticides are having a tough time coming through the regulatory process.”
As a result he expects more and more biological products to come onto the market and growers will need to adopt best practice for each product in order to maximise efficacy.
Effective application is crucial to get the best performance from both biological and conventional products.
For example, the efficacy of Emerger as a pre-emergence herbicide was very much dependent on the quality of the seed bed, explained Mr Hill: “Having a fine, firm seedbed and a homogenous layer will definitely improve efficacy.”
This is because there is very little root uptake of aclonifen, which relies on shoot uptake via the hypocotyl (broad leaved weeds) or coleoptile (monocotyledons). When used as a pre-emergence herbicide, aclonifen doesn’t prevent germination; instead it kills the weeds as they emerge.
However, various trials have also shown that aclonifen is effective post emergence, potentially tank mixed with another product and applied over 2 or 3 doses.
The bio-insecticide FLiPPER (fatty acids C7-C20) marketed by Bayer has been granted four new extensions of authorisation for minor use (EAMU) for control of a broad range of insect pests in an assortment of outdoor and protected fruits, herbs and field vegetables ahead of the 2020 season.