FERTILITY RATE AND TIMING EFFECTS ON ORGANIC BLACK CURRANT GROWTH AND YIELD DURING ESTABLISHMENT

Abstract

A study on Prince Edward Island was initiated to assess the impact of organic fertility amendment rate and timing treatments on the growth, yield, berry size and soluble solids of black currants (Ribes nigrum ‘Titania’). Bushes were planted in the spring of 2009 at two sites with black plastic mulch as a weed control without irrigation, and fertilized with seven fertility treatments in either the spring, the summer or split between spring and summer. Rates were 50, 100 and/or 150 kg estimated available N from a blend of crab meal and poultry manure (Nutriwave®). Yield and berry soluble solids were measured in 2010 and 2011. Plants at the site with leaf P and K deficiencies showed lower growth and yield (492-2,540 kg ha-1), but had significant differences in growth response to amendments compared with the site that had adequate levels of P and K, which had no significant difference among treatments in yield in 2011 (3,935-5,016 kg ha-1) or growth among treatments in any of the three years. Where significant differences in growth were found, the medium spring fertility treatment gave the greatest growth and yield, followed by the high spring fertility treatment. The high spring treatment had the highest growth in 2010, but the lowest growth and yield in 2011.