Growth and development of industrial hemp (Cannabis sativa L.) in response to irrigation treatments

Opportunity exists for Australian growers to develop a commercial cannabis/hemp industry to meet globaldemand for seed, fibre and pharmaceutical products. Development of a commercial scale hemp industryrequires improved knowledge of hemp crop water relations to maximise yield, understand irrigationrequirements in new production regions, and for scheduling of harvest. Currently little is known of the hempplant-water relations. This study sought to evaluate the growth, development and physiology of industrialhemp under varying irrigation treatments. A preliminary greenhouse experiment was conducted to monitorresponse of industrial hemp cultivar Ferimon 12 to different irrigation treatments (2, 4, 6, 8 and 10 dayintervals). We found significantly taller plants for 2 day compared with the 8 and 10 day irrigation intervals.Significantly higher above ground dry biomass was observed for plants irrigated with 6, 8 and 10 dayintervals compared to the 2 and 4 days interval at 42 DAS. Significantly higher PSII photochemical capacity(Fv/Fm) and leaf chlorophyll content (SPAD value) was observed for plants irrigated with 6 and 10 dayintervals compared with the 2 day intervals. There for 6 day irrigation interval is probably the best frequencyof irrigation. Results from the preliminary experiment will be used to inform the design of future researchwhich will be used to develop irrigation recommendations and refine the hemp crop simulation model tofurther support farmer decision making regarding water management.