Organic fertilizer source effects on protected Solanum lycopersicon L. (tomato) production in south coastal British Columbia

Low-cost hoop houses are common climate enhancing structures used by small to medium-scale farmers for intensive production of high-value crops. On-farm fertilizer production and utilization of locally available soil amendments can reduce input costs, while increasing regional sustainability. Production system specific organic fertilization programs, with respect to relative nutrient concentrations, mineralization rates, and pest and disease suppressing capabilities, are crucial for sustained high yields. The objectives of this study were to assess organic fertilizer source effects on protected, organic Solanum lycopersicon L. (tomato) production in South Coastal British Columbia, and to assess whether genotype x fertilizer source interactions are present for various growth and yield traits. Two cultivars of tomato, cv. Black Cherry and cv. Pollock were grown in a randomized complete block, split plot design, consisting of four fertilizer treatments replicated three times. Fertilizer treatments included: 1) Vicia villosa Roth. (hairy vetch) green manure (HV), 2) composted poultry manure (CPM), 3) Ecofert® ‘EcoGrow’ 3-3-4 (OMRI certified) liquid fertilizer, and 4) a no treatment control. All fertilizers were applied at a rate of 100 kg total nitrogen per hectare. Treatments had no effect on vegetative growth, except increased biomass in cv. Pollock treated with EcoGrow. Yield responses in cv. Black Cherry commenced from harvest week six onwards for CPM and HV treatments and from week eight for EcoGrow. By seasons end, all fertilizer treatments produced yield increases of 23% over the control in cv. Black Cherry plants while no yield response occurred in cv. Pollock. Both EcoGrow and HV had positive effects on foliar potassium, which was the most limiting nutrient. Total soil nitrogen and available phosphorus were considered sufficient, except foliar phosphorus was near the critical level at mid-harvest in all treatments. Foliar calcium and magnesium were high. Several fungal diseases, including late blight, powdery mildew, grey mould and verticillium wilt, infected the crop from mid-July and may have affected plant nutrition and yield. This study shows that a range of organic fertility sources can be effectively used in protected tomato production. However, cultivar lifecycle and growth habit should be considered when devising fertilization programs.Land and Food Systems, Faculty ofGraduat