Results from silicon (Si) trials support prior research that silicon may be important in reducing the severity of fusarium wilt in cotton seedlings. Si amendments were identified that reduced disease severity under glasshouse conditions when applied to field soil, but were not effective under field conditions. It is possible that inoculum load was too high at the field site for an effect of Si fertilization to be realized. Increasing nutrient availability in an alkaline soil also can be difficult and may have contributed to poor uptake. Another consideration is that placement of fertiliser, which dictates availability of Si for uptake, may not have been optimal.