Maximum Yield Australia/New Zealand May/June 2019 | Page 68

VARIETIES
There are a number of modern commercial varieties of hops
bred for specific uses, as well as many older, general purpose
heirloom types. Popular varieties include Cascade, Chinook,
Columbus, Magnum, and Centennial, each with different
compositional qualities. Research into hydroponic hops has
shown that Cascade and Chinook are suitable varieties for
small-scale hydroponic production and perform well under
greenhouse production. The Cascade variety is the most
widely utilised by craft brewers in the US and is used in the
production of many types of ale and some lagers. With a high
alpha acid content (4.5-6 per cent) and a pleasant citrus like
aromatic quality, Cascade is a general-purpose hop variety
well suited to hydroponic production
GROWING
Hop cones are produced on long bines (vine-like stems) which support
the plant by clinging to support structures.
Greenhouse-grown hops may be grown for year round production of `wet
hops’ for the craft beer industry.
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Hops are relatively easy to grow as they are extremely vigor-
ous and heavy feeders that benefit from the controlled nutri-
tion of hydroponic systems. Hops produce separate male and
female plants, with only the female plants producing cones,
thus hop propagation is typically carried out vegetatively
to ensure only female plants are grown. If male flowers are
present in a hop crop, the pollination of the female flowers
results in seeds that are undesirable for brewing beer. For
small-scale growers, hops are typically obtained during
the dormant winter season as short sections of rhizome
containing a number of dormant buds. Once planted into
warm conditions, rhizomes establish quickly and produce
several young shoots. Hop cuttings can also be taken from
established plants that will produce roots readily at leaf
nodes without the requirement for any rooting hormone
application. At certain times of the year, young potted hop
plants are available for purchase. Once growth has begun,
the hops produce long, climbing shoots called bines that
develop short, stiff hairs along the stem surface, allow-
ing the bine to cling and climb upwards (vines on the other
hand, use tendrils or other means to cling to surfaces). This
rapid upward growth of the bines requires support, and
hydroponic hops are well-suited to being grown on train-
ing systems similar to those used for tomato and cucum-
ber crops. Tomahook tomato support systems — overhead
wires with strings or trellis — may be used to support hops
and plants will readily climb and cling with no assistance.
Since hop plant bines grow to considerable length and
height, for indoor and greenhouse production the “lean and
lower” system of training, commonly used for commercial
tomato crops, appears to work well. As the bines increase in
height, the supporting string is detached and lowered along
the floor or lower levels of the cropping area as required.
Alternatively, the tops of the bines can be trained verti-
cally along supports at the top of crop, or allowed to grow
upwards, and then trail back down towards the floor.