Maximum Yield Cannabis Canada 2017 November/December | Page 38

legumes The peanut plant produces its pods on the ends of pegs, long stems that develop from the aerial portion of the plant after flowering and then burrow down under the growing media to develop the young fruit.” For hydroponic systems, either tall or shorter varieties can be grown. Taller vines need some form of support, while shorter cultivars are up to two feet in height and are often self-supporting. Indeterminate, shorter varieties of peas are the preferred choice for those with limited space, as these can be planted in double rows or groups so that plants support each other without the need for trellising. Choosing pea varieties with powdery mildew resistance is recommended and many of the new and improved cultivars are worth trialling in hydroponic systems. Peas prefer lower overall growing temperatures than beans, with optimums in the 13-18°C range for most varieties. Temperatures above 29°C can lead to minimal vegetative growth and poor flower development and fruit set. Peas also benefit from good air flow around the base of the plants and avoidance of overcrowding, which can promote the development of fungal diseases. PEANUTS Drip-irrigated peanut production system. 38 grow cycle Peanuts are another legume crop that performs well in hydroponics and makes an attractive, interesting, and unique addition to an indoor garden. The peanut plant produces its pods on the ends of pegs, long stems that develop from the aerial portion of the plant after flowering and then burrow down under the growing media to develop the young fruit (peanut seeds inside brown pods). For this reason, hydroponic systems for peanut plant production need to have substrate that is soft, friable, and light, and with the surface under the plant exposed for the pegs to grow down into. Finer grades of sterilized coconut fibre or blended coconut fibre and perlite make ideal substrates for this crop. A well-grown peanut plant can have up to 30-40 pods, so a growing container or bed that holds at least 9.8 litres of media is required when growing hydro- ponically. Also, peanut plants need a warm growing environment with reasonably high light levels for maximum growth and good air flow up and under the crop, as damp condi- tions favour fungal pathogen development. Crop timing under ideal growing conditions is usually around 140 days, although this is somewhat variety dependant. Outdoors, peanuts are harvested when the foliage begins to turn yellow and die back; however, in a hydroponic system, it is possible to dig back some of the growing substrate, observe the development of the young pods, and determine when the peanuts are large enough to harvest some or all from the plant. Harvested peanuts then need to be dried inside the pods in a warm place for about four weeks before they can be stored.