Evaluating Performance of Ecologically Sound Organic Substrates under Different Temperature Regimes

Evaluating Performance of Ecologically Sound Organic Substrates under Different Temperature Regimes
SHAHIDUL ISLAM, U Arkansas, INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY, 2008

ABSTRACT
Greenhouse trials were carried out over two years to investigate the high temperature (25ºC, 30ºC & 35ºC) effects on ecologically sound untreated organic substrates viz., coconut coir and rice husk charcoal, in comparison to that of rock wool using tomato (Lycopersicon esculentum Miller) as a test crop. There were no significant differences in the root dry matter, stem dry matter, fruit dry matter, shoot and root ratio, ascorbic acid, total soluble solid, fruit acidity, leaf chlorophyll contents and pH of the fruit homogenate. Among the substrates, water holding capacity was larger in rock wool followed by coconut coir and rice husk charcoal. Bulk density and total pore space were lower in rice husk charcoal than coconut coir and rock wool. Regarding the chemical properties, rice husk charcoal and coconut coir had higher EC values compared to rock wool. Rice husk charcoal had relatively higher pH followed by rock wool and coconut coir. In the case of CEC rook wool showed significantly higher values than coconut coir and rice husk charcoal. It also appeared that rice husk charcoal and coconut coir gave similar and/or better crop performance and yield of tomatoes than rock wool under high temperature stress conditions namely 30oC and 35ºC as compared with 25ºC. Thus, rice husk charcoal and coconut coir can be used successfully as growing media amendments for producing greenhouse tomato as well as other nursery crops.

Key Words: Organic substrates; Temperature; Stress; Tomato; Quality

Islam, S., 2008. Evaluating performance of ecologically sound organic substrates under different temperature regimes. Int. J. Agri. Biol.,10: 297-300