The Effects of Manurial Treatments on The Yield and Quality of Carrot Seed

Abstract

Seed crops of carrots were grown in 1962, 1963 and 1964, on plots of a 24 N, P, K and farmyard manure factorial experiment. Significant seed yield responses were obtained to each of the fertilizers and to manure, as compared with the yields from the control plot with no manure or fertilizers.Except when a seed-borne disease caused by Stemphylium radicinum was present, the germination of the ungraded seed was well above the statutory declarable minimum of 60% and there were no significant differences in germination caused by the manurial treatments.The seed produced in 1963 and 1964 was of similar mean chemical composition to commercial seed and, although its composition was affected by the nitrogen and farmyard manure dressings, these variations in composition did not affect the yield of roots obtained from field sowings of the 1963 seed. The 1962 seed was exceptional in having a lower mean phosphorus concentration than commercial seed. The seed with the lowest phosphorus concentration was obtained from the plots which had received nitrogen but not phosphorus fertilizers, and the root yields from such seed were significantly lower than those from the seed containing higher concentrations of phosphorus.