Picture: Eric Anderson of Scottish Agronomy
An application of Reglone a week before planned flail operations will significantly increase the speed of flailing, achieve a far cleaner haulm removal, reduce the risk of vascular browning tuber damage, and could save potato growers an average £7/ha in costs, according to Eric Anderson of Scottish Agronomy.
Trials by Scottish Agronomy have consistently shown flail work rates increase by an average 30% when the crop has been treated with Reglone at 0.5 l/ha five days before flailing, and over 50% faster following a 1.0 l/ha application. Fuel costs were also reduced, from £6.17/ha in the untreated, to £4.68 and £4.06 respectively with 0.5 and 1.0l/ha Reglone applications.
The result is as overall saving of £7/ha, including cost of Reglone, calculates Mr Anderson.
Treatment Operating speed Fuel cost
Untreated 1.14 ha/hr £6.17/ha
Reglone 0.5 l/ha pre-flail 1.5 ha/hr £4.68/ha
Reglone 1.0 l/ha pre-flail 1.73 ha/hr £4.06/ha
Pre-flail Reglone increases operating speed and reduces fuel costs
Source: Scottish Agronomy
"Faster flail operation can avoid a bottleneck in the system and help growers achieve more timely harvesting," advises Mr Anderson. "They will also achieve a much cleaner flail chop and reduced material going over the harvester." For larger crops, eg King Edward or Maris Piper, he advocates 1 l/ha of Reglone; for less dense crops, such as Estima, the initial application may be just 0.5 l/ha.
In a dry year Mr Anderson believes removing the leaf and bulk of the green material with a pre-flail application could reduce the crop's water transpiration rate and allow tubers to rehydrate - which could reduce susceptibility to bruising. Furthermore, the action of triggering skin set and senescence reduces the risk of vascular browning, which trials have shown could result from the shock of flailing an untreated vigorous crop.
The pre-flail Reglone application can be used to control tuber size if there are delays with the flail getting around. It is far more precise if growers are aiming to hit critical size markets, such as salad crops or seed. The initial application also starts the skin set process.
He recommends the ideal flail length is to leave 15 - 20 cm of stem, as a target for a follow-up Reglone application three to five days after flailing to complete the stem kill. The longer stem left at flailing reduces the risk of tuber bruising and damage from contact with the ridge.
In very wet conditions Mr Anderson advises growers to leave the flail in the shed completely, to avoid the risk of excessive soil damage. In these situation he would advocate growers use a split-dose Reglone, usually with an initial 1.5 l/ha, followed by 2.5 l/ha seven days later as his standard recommendation.
Growers' experience
Herefordshire potato grower Ian Prior of Holsty Farm, Vowchurch is one of the growers who has tried the pre-flail Reglone treatment for the first time this year, on his particularly vigorous Estima crops.
He reports a significantly reduced amount of haulm to be flailed six days after the initial 1.0l/ha dose helped to speed the operation, improve the quality of the chop, reduce wear and tear and, increasingly importantly, cut fuel consumption.
Mr Prior's six-meter George Moate flail-and-spray machine applied an additional 2.0l/ha of Reglone onto the stems during the flail process. "The flail operator also found that with the crop opened up, following rows was far easier and resulted in less ridge damage," he added.
Mr Prior was especially pleased that skin set was complete 16 days after the initial Reglone application, with total haulm kill ready for lifting; previously they had been looking at around three-weeks from flail/spray to full skin set.
The initial Reglone application was made in conjunction with Shirlan blight spray, avoiding any additional pass through the crop or costs.
