AHDB Horticulture Cost: £6,320
Summary: There is a perceived risk that liming immediately before potatoes increases the risk of common scab. Guidance not to lime before potatoes was included RB209 7th (2000) and 8th Editions (2010).
However, the 2016 RB209 review (Allison & Sagoo, 2016), identified two sets of unpublished data which suggested that the incidence of common scab was reduced by the application of lime and calcium containing materials at planting:
i. Three NIAB CUF experiments in 1998 and 1999 funded by CUPGRA.
ii. British Sugar LimeX experiments: fifteen field trails across five farms between 2012 and 2015.
Collectively these data suggest that the application of calcium containing products (e.g. lime and gypsum) may reduce the severity of common scab thereby increasing marketable yield. These data challenged the long-standing/widespread view on the effects of calcium/liming materials on potato yield and quality. The scientific basis for earlier advice not to lime before potatoes was unclear and the RB209 review focused on new data from 2010. Based on this new evidence, the review recommended the removal of the warning relating to liming before potato crops and also recommended a literature review to understand how current advice was derived before making any further changes to the recommendations.
i. Review available scientific information on the absorption and motility of different calcium products on courgettes and pumpkins, including their effects on BER management and pumpkin storability.
ii. The effect of boron applied at fertilisation in both courgette and pumpkin.
iii. If necessary, identify knowledge gasp and prioritize requirements for future research.
iv. Produce an AHDB Research Review report.
v. Provide recommendations for revision of guidance on application of calcium for the next revision of AHDB Nutrient Management Guide Section 6: Vegetables and Bulbs.