Maximum Yield USA August 2017 | Page 84

trends & technology Freshly harvested raspberries are fragile and best eaten immediately after picking. “ OR THOSE WITH LIMITED SPACE, DWARF BLUEBERRIES ARE THE MOST SUITABLE CROP, WHILE RASPBERRY CANES REQUIRE MORE VERTICAL SPACE TO DEVELOP AND LEAF OUT.” One of the main considerations when growing strawberries and other berry crops hydroponically is pollination; outdoors, this is carried out by bees, other insects, and the wind. Indoor growers can manually pollinate straw- berry flowers with a small hair dryer on a cold setting directed at each indi- vidual flower, or by gently brushing the inside of each open flower with a small brush. Hand pollination needs to be carried out every day immediately after the first flowers open to ensure good fruit set as the pollen only remains viable for two to three days after the flowers open. Cranberries, Blueberries, & Raspberries Dwarf blueberry plants are a good way to produce this delicious crop in containers. 82 grow cycle Blueberries, cranberries, and raspberries are less commonly grown in a hydroponic set-up than strawberries; however, they are suited to soilless production and benefit from the protected environment of an indoor garden. Cranberries are naturally a bog plant with long, trailing stems bearing fruit. For this reason, they are ideally grown in an elevated system, three to four feet above the floor, were the stems can trail directly downwards. Dwarf blueberry cultivars, which have been bred to grow in containers, are now widely available and can produce high yields of good quality fruit. Dwarf varieties grow to around two to three feet in height and can be pruned to control size. For those with limited space, dwarf blueberries are the most suitable crop as raspberry canes require more vertical space to develop and leaf out. Raspberry canes grow upright. They are tied into place with fruit-bearing stems trained into position and pruned to keep the canopy open for air movement and disease prevention. Raspberries are categorized into two main types: primocane (fall bearing or everbearing types) and floricane (summer bearing). For hydroponics, primocane types are recommended, as these produce fruits at the top of first- year canes over a long harvest season. They also require less growing space and support than floricane types. As with strawberry plants, these berry crops are more suited to contain- erized, drip-fed, substrate-based hydroponic systems. This is both to ensure over-saturation of the root system does not occur, and to facilitate the ability to move the plants when they require chilling or become too large for the space available. Berry crops don’t require high levels of heat and will grow in similar condi- tions as many other fruiting plants. Temperatures of 72-74°F during the day and 68-70°F at night are ideal. For maximum fruit quality and sugar levels, the light requirements are similar to those of tomatoes and capsicum, and plants benefit from a long day length to push up the daily light integral. Nutrition for all berry crops is similar. A well-balanced vegetative formula- tion is required in the early stages after initial bud break, followed by a bloom or fruiting formulation that is high in potassium once fruit set has occurred.