Plant density effect on oil seed yield and quality of industrial hemp cv. Fasamo in Canterbury

Abstract

Industrial hemp (Cannabis sativa) is an ancient crop. The majority of hemp production has been for fibre, but more recently interest in the use of hemp seed oil has developed. The German-bred monoecious dual-purpose cultivar 'Fasamo' was trialled over two years in Canterbury to determine the optimum plant population for oilseed production. Target populations were 125, 150, 175, 200, 225 and 250 plants/m2. Actual established populations ranged from 124 to 346 plants/m2. In 2006-07, yields ranged from 804 kg/ha to 931 kg/ha, with a positive linear trend of 0.823 kg/ha yield gain for every extra plant/m2 established. Economic return ranged from $3,482 to $3,838/ha, with a non-significant positive linear trend of $2.44 nett gain for every extra plant/m2 established. In 2007-08 yields were much higher, ranging from 1,640 to 1,849 kg/ha producing an economic return of $7,183 to $8,092/ha. However, there was no significant linear trend found between established plant density and either yield or economic return. Oil quality did not appear to be affected by differing plant populations. Agronomic management and climatic conditions during production appeared to have a greater impact on yield and economic return than plant population. Considering both practical and quantitative factors, a target plant population of 150-225 plants/m2 is recommended for Fasamo oilseed production in Canterbury depending on site yield potential. Keywords: Cannabis sativa, oil content, plant population, economic return, essential fatty acids, α-linolenic acid, γ-linolenic acid, linoleic acid, oleic acid