The suppressive effects of composts used as growth media against Botrytis cinerea in cucumber plants

Abstract

The incidence/severity of soil-borne plant diseases is often reduced when composts are used as growth media. However, much less information is available about the effects of composts on the development of foliar diseases. Here we studied the suppressive capacity of five composts (from olive marc-cotton gin trash, grape marc, cork, spent mushroom and municipal organic and yard wastes) as growth media against Botrytis cinerea disease in cucumber plants. We also examined the putative correlations of several biotic and abiotic factors involved in disease suppression. The suppressive capacity of the growth media was studied by comparing disease incidence/severity in plants grown in composts with that occurring in plants grown in commercial peats, which are conducive to most soilborne diseases. Correlations were made between the occurrence of disease and leaf nutrient status, as well as electrical conductivity (EC) and microbial activity (measured as b-glucosidase activity) in the growth media. Cucumber plants grown in the peats showed greater severity of B. cinerea during the bioassay than those grown in composts. Mo, Ca and Si content in leaves showed negative correlations with this disease. A negative correlation with disease severity was observed for EC and microbial activity in the growth media. The noticeable reduction in B. cinerea in plants grown in composts was related to the supply of specific chemical elements, a certain degree of salt stress, and the high microbial activity of composts.

Composting of wine industry wastes and their use as a substrate for growing soilless ornamental plants

“…According to Handreck (1992), NDI values between 0.8 and 1 would indicate a significant absence of N immobilisation, while those above 1 would imply the existence of a net nitrification. β-glucosidase activity, correlated with microbial activity, showed values similar to observed by Segarra et al (2007) in these materials. Borrero et al (2006) found that microbial activity in DM+GS composts is relatively high compared to the usually found in peat and coconut fibre substrates.…”

“…against soil phytopathogens (Borrero et al, 2004, 2009, Segarra et al, 2007. However, lesser references are available concerning their characterisation and utilisation as peat substitutes in soilless growing media (Reis et al, 1998).…”

Enhanced Botrytis cinerea Resistance of Arabidopsis Plants Grown in Compost May Be Explained by Increased Expression of Defense-Related Genes, as Revealed by Microarray Analysis

“…Composts have different chemical, physical and microbiological properties, depending on the source of organic matter, composting process and degree of maturation, which may explain the different results obtained when using different composts. The OMC used in the present study is similar to that described in Segarra et al [17], which induced resistance to B. cinerea in cucumber plants.…”

“…Interestingly, it has been reported that a certain degree of salinity stress correlates with the ability of several composts to produce cucumber plants that are more resistant to Botrytis cinerea [17]. The transcription factor DREB1A was found to be up-regulated by compost.…”

“…It is interesting to note that the salinity level of certain composts used as substrate correlated with the level of Botrytis cinerea resistance in cucumber plants [17]. Low temperature and dehydration are adverse environmental conditions that affect plant growth and productivity.…”