Article taken from Potato Review, March 2018.
Most seed growers.will be working on long rotations of between seven to ten years in order to minimise disease pressures: Mr Steven explains. 'If you can start with a good field that has a low pest and disease burden, then it makes ongoing management during the lifecycle of the seed crop easier. However, virgin land is increasingly difficult to find, and growers are having to go further and further afield, which can make the cost of production more expensive'.
He notes that seed growers will typically start inspecting prospective fields in the autumn to establish the history of the land and he adds that the wet weather often seen in many key seed-growing areas can increase pressure on the growing crop.
'Scotland had a year's worth of rainfall between June and December 2017, making ground conditions wet and increasing the risk from diseases such as blackleg and blight. As a result of last year's weather, only a small amount of ploughing has been done to date [mid-February] so there's still a lot of ground preparation required before planting starts in April; he says.
Mr Steven warns that it's important that seed producers should not feel under pressure to get land turned over before it is ready. 'Patience and care are vital to ensure that soil preparation is done at the right time without creating compaction, either on the surface or deeper within the soil profile, which can then have an impact on yield'.
Thereafter, it's all about achieving tuber quality of a high standard with clean skin finish and no visual signs of disease, he observes. Good cold storage facilities help to ensure that the crop is dry and that dormancy is controlled before delivery. Ultimately, he adds, the relationship between seed producer and customer is one of the most important elements in producing healthy seed. 'It's vital that the buyer and grower to talk to each other about expectations of the season and how the crop is developing'.
Mike Inglis, technical manager at Albert Bartlett, describes the selection process for sourcing quality seed for the company's growers across the UK and Jersey. 'Our main priority when procuring seed is the assessment for disease in the growing crop and after harvest: he explains. 'We have a low threshold for skin diseases, particularly powdery scab, black scurf, black dot and silver scurf, as these can cause secondary infection in daughter crops.
'Once the crop has been cleared for quality purposes, we then carefully select the grower that seed is best suited to, to ensure the quality is matched with the right end market. This joined-up approach is vital and we can't afford to get it wrong'
Mr Inglis says this level of care doesn't stop once the seed reaches the farm gate. 'Once on-farm it's vital that it is stored correctly until planting to maximise the potential yield. The correct temperature is key, as is good airflow; he points out.
'Use of a proven seed treatment is also important to prevent disease wherever possible. A number of our growers will use products such as Rhino (flutolanil) once the seed is on-farm, applying it just before or after Christmas. This can be a beneficial and cost-effective option against soil borne Rhizoctonia.
'Producing quality seed is at the centre of the potato industry, therefore it's paramount that we continue to maintain the high standards of seed quality right up until planting; he concludes.
GB seed potatoes are said to have performed strongly on three Kenyan trial sites. AHDB and SASA have been running a joint project since a bilateral agreement was signed by the Scottish and Kenyan grew well, Cara appears to have been the standout performer with average yields across all three farms of over 50 tonnes/ha. Hermes and Russet Burbank also performed well with an average yield of 41 tonnes/ha while Atlantic brought up the rear with 35 tonnes/ha.
Yields achieved in the trials closely mirrored the GB average (around 46 tonnes/ha) even though most farmers in Kenya are used to yields of around 10 tonnes/ha with 95% relying on poor quality home saved stocks. This seed is blamed for the spread of endemic diseases so the Kenyan Government is keen to approve new high health imported varieties. The four candidates have now been planted for a second season and if they perform well they could be approved for export to Kenya.
Rob Burns, AHDB Head of Crop Trade Market Development, says: 'All these free varieties grow well in hotter, drier climates.' It's particularly positive to see that three of the four are performing at a similar standard or better than what is called the ""check variety"" [Dutch-bred Robyjin]. Even Atlantic, which is not quite yielding as well, is not far behind.
'We are also now looking into other African markets, such as Rwanda, which we will be visiting later this month on a trade mission with the Department for International Development (DFID):
SASA's Jackie Gibson believes that another strong trials season could open up significant opportunities for exporters. 'I think we are likely to see the strong results seen in the first season replicated in the second and if we get good yields, combined with other positive characteristics, such a better dry matter and disease resistance, we will definitely see GB varieties added to the national list'.