The most populated American federal state is one the biggest producing areas of berry cultures and flowers. Methyl bromide was mostly used to sanitize soil before its international ban. After proscription of this chemical harmful to climate and health, new alternatives to free soil from diseases and weeds are desperately searched for.
Since 2007 the University of California in Salinas does intensive research on different options to apply steaming technology, which has been almost forgotten in the US, although it was leading advancements at the end of the 19th century. Today steaming technology returns back to the focus of interest in America.
Results of the studies are promising. Steaming methods were explicitly compared with the usage of methyl bromide and solarization. Furthermore a combined method of hot steam and solarization has been tested. First soil was covered with insulating sheets and heated merely through sun radiation before hot steam was induced to treat deeper soil layers.
The treatment of soil with mere steam showed the best results. In particular regarding the shotting of weeds, which was even better than the excellent results of methyl bromide. The same results were gained regarding the average weight of fruits. In comparison to the control area, fruit weight increased by more than 25%.
Due to the positive results, the University of California induced further steps to do research on steaming applications for big growers. Therefore end of 2009 a “Sterilter” full automatic steaming machine which was coproduced by Ferrari Constructione and MSD GmbH, Germany-Durbach, was introduced. New experiments will be made with this machine, in order to test and advance steaming applications.