Potato Review

www.potatoreview.com POTATO REVIEW JANUARY/FEBRUARY 2023 27 HAULM PULLING relying on the time lag between herbicide application and it starting to be e ective. e result means much less time between haulm pulling and harvest, with skin set achieved in as little as 10 days. is reduction in time between hardening and harvest also reduces the likelihood of rhizoctonia infection taking hold, which is particularly important for seed producers. Branston also looked to see if the crop stopped bulking quicker, but because of the heat and drought during the 2022 season, bulking rates were so low, no di erence was seen between pull and ail plus spray. Martin said: “We did see a small reduction in latent bulking last year on the pulled sample as removing the tubers from the plant stops any pull back of nutrients and water normally seen as the plant dies back.” He said no di erence was seen either in terms of disease loading but felt that if harvest had taken place seven to 10 days earlier than the ail plus spray, latent disease risk would be greatly reduced. Branston will be following the Laura seed crop into store to look for signs of any deterioration on the tubers. is was also done last year and no detrimental e ects were seen . Virus control Late season virus control is also a major potential bene t of haulm pulling. Martin said: “By removing all green leaf and stem by pulling, this eliminates the risk of re- growth which can often be a source of late potato virus Y ingress in seed crops. is is something we intend to look at in more detail when we continue trials next year.” e Branston team says the technology could prove extremely useful for organic growers as it is more sustainable and environmentally friendly compared to alternatives such as gas burning and intends to roll the method out into further trials covering seed, organic and ware crops next year. e Standen machine was also on hire to some seed and ware growers both in North Yorkshire and Norfolk later on this season. Both growers had instances where the crops have been pre-topped and dessicated, yet, even after eight weeks, post desiccation the crops were still hanging on. is was causing blockages in the harvesters where the haulm rollers couldn’t separate the tubers from the haulm. e growers both said using the haulm puller has been the di erence between being able to harvest or not. “The pulled crop had 100% stolon detachment two weeks after pulling compared to the fail plus spray crop which still had 50% tubers tightly hanging on to the stolons.” Martin Stothard, Technical Lead at Branston