Peanut shell wastes as a culture medium for greenhouse tomato in soilless culture

Coir is one of the preferred substances in greenhouse tomato production in soilless culture systems. However, there has been growing interest in replacing this material with other organic materials due to its limited availability and high price. In order to evaluate the effect of composted peanut shell wastes mixed with coir and perlite on some traits of greenhouse tomato, a randomized complete block design was carried out in three replications. The treatments included 50% coir + 50% perlite (as control), 25% coir + 25% composted peanut shell wastes + 50% perlite, and 50% composted peanut shell wastes + 50% perlite. Results showed that the effect of culture medium on all measured traits was significant. The highest aerial fresh and dry weight, root fresh and dry weight, chlorophyll a, chlorophyll b, total yield, and water use efficiency was obtained in 50% coir + 50% perlite (control), but there was no significant difference with 25% coir + 25% composted peanut shell wastes + 50% perlite treatment. Complete replacement of coir with the peanut shell significantly reduced the above-mentioned measured traits. Therefore, it is recommended to replace up to 25% of coir in the culture medium of tomato with composted peanut shell wastes as it is not expected to reduce the vegetative and reproductive traits. The bulk density, porosity, pH and EC of culture medium consisting of 25% coir + 25% composted peanut shell wastes + 50% perlite were 0.22 g cm^‑3, 90%, 5.8 and 2.3 dS m^‑1, respectively.