ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 52 Number 4
Deficiency of sulphur and nitrogen in seedling cocoa on an alluvial grassland of Guadalcanal, Solomon Islands
Three months after planting cocoa under Leucaena leucocephata shade trees established on a Themeda australis grassland alluvial plain, some cocoa seedlings had died, others were stunted, and their leaves were chlorotic with marginal necrosis. Deficiencies of nitrogen and possibly sulphur were suspected. A field trial compared effects of ammonium sulphate with equivalent amounts of S and N as gypsum and urea, separately and together. Nitrogen alone aggravated the condition and responses to sulphur alone were small. Good response were obtained on plants receiving either formulation providing both N and S.