SEED-GERMINATION, NITROGEN NUTRITION AND WATER REQUIREMENTS OF THE EDIBLE HERB CORCHORUS TRIDENS (TILIACEA)

The use of Corchorus tridens for food and medicine is popular among ru ral communities in the Eastern Transvaal lowveld of South Africa. its prolific seed production, spontaneous germination, and distribution in water stressed regions suggest that cultivation of this species could be feasible. A study was initiated to investigate this. Seed coat sca rification improved the percentage of germination by almost 30%. A hig h temperature range (15-30 degrees C) increased germination relative t o a low temperature range (Ie 20 degrees C). A factorial experiment co nsisting of three nitrogen forms (ammonium sulphate, potassium nitrate and a 1:1 mixture of these) and three levels of irrigation (at 35%, 5 0% and 75% field capacity) was conducted. Productivity improved mostly with nitrate fertiliser, followed by a nitrate-ammonium mixture and l astly with ammonium applications. The nitrogen form and water treatmen t did not significantly increase total dry weight production, mean rel ative growth rates or root:shoot ratios.