study of the effect of substrates with different effective air-filled pore space on greenhouse tomato transplant growth

soilless media have different physical properties. change in air space of mix substrate can cause change in fertigation management and plant growth and yield. physical properties (water holding capacity, effective air-filled pore space, effective pore space) of 50 mixed substrates were measured to evaluate the effect of air-filled pore space on growth of tomato transplant and it's water use efficiency. media with different effective air-filled pore space and similar water- holding capacity and effective pore space selected as treatments. randomized complete block design with 3 replications and 12 observations in each experimental unit was used. results showed that air-filled pore space of a mixed medium can affect growth properties of tomato transplant and irrigation water use efficiency. plants grown in sand-cocopeat media with effective air filled pore space of %10.85 had considerable superiority over those grown in substrates with effective air volumes of 21.3% and 17%. there were not significant differences during initial days and the differences became more significant while the plant grew up. there was an obvious differences amount irrigation water use efficiency of experimental plant grown in different media.