Effects of compost tea source and application method on lettuce (Lactuca sativa) yield and nutrient content, grown in a vermicompost amended medium
Compost tea source and application method may influence direct and indirect benefits attributed to its application. A factorial experiment was conducted in an open ventilated greenhouse that compared thermophillic compost tea (TCT) to vermicompost tea (VCT) applied either as a root drench or to lettuce leaves. The study consisted of two 4-week trials, after which yield, shoot dry matter (SDM), root dry matter (RDM) and tissue macro nutrient content was measured and analysed. Yield and SDM were greater for drench applied TCT, with the difference being significant in trial 2. Yield increased approximately 2-fold for all treatment combinations in trial 2 compared to trial 1. Contrastingly, RDM showed relatively little response to tea treatments in trial 2. No-amendment control treatments resulted in a lower RDM than tea treatments. Similarly, lettuce tissue nutrient content was not affected by combinations of compost tea source and application method, except for Mg. Across both trials VCT resulted in higher tissue Mg with significantly higher values for foliar application of VCT in trial 2. Compost teas failed to supply adequate quantities of N for plant growth and development. However, tissue P and K levels were within acceptable ranges. Drench application favoured plant growth and dry matter allocation to shoot and is suggested as the preferred application method for lettuce cultivation.
Eudoxie, G.D., Khan, F. and Martin, M. 2017. Effects of compost tea source and application method on lettuce (Lactuca sativa) yield and nutrient content, grown in a vermicompost amended medium. Acta Hort. (ISHS) 1168:175-184
root dry matter, macronutrients, foliar application, root drench, phytohormones