PCA member Damien Manno has taken the opportunity to investigate a relatively new method for the cultivation of strawberries by using rockwool substrates.
Climate and irrigation in the new greenhouse is controlled by Galcon’s Galileo and Fertimix systems which offers a comprehensive and easy to use solution for berry and greenhouse growing.
Delays in council approvals meant completion of the greenhouse set back planting from December until February when average temperatures were higher.
Damien is predominantly growing the day neutral variety Albion with a single trial row of Safari from propagators Trandos Hydroponic Growers (THG).
The Albion stock was supplied by Toolangi’s as bare root chilled plants or ‘frigos’.
These plants were gradually brought to room temperature and then planted into rockwool ‘Delta 4’ blocks using granulate rockwool to back fill.
Both media were soaked in a complete nutrient solution prior to planting into wrapped slabs.
Alternatively, the Safari runner plants were propagated by THG entirely in rockwool plugs and blocks making the planting process inside the greenhouse incredibly quick and easy for Damien to complete.
Each plant has 2L/ hour dripper and at initial planting received 3 x 60ml irrigations per day with a drip EC 1.5 and pH 5.3.
Damien has installed an AIS Greenworks High Pressure Fogging system so that during extreme hot weather he can alleviate plant stress and get rapid establishment.
The system worked. Within three days there were new white roots visibly penetrating the slabs and the leaf canopy began to develop.
The initial flowers appeared around day 10 and were removed by hand to reallocate plant energies towards more vegetative development.
By day 40 Damien’s Albion strawberry plants were setting trusses with the first ripe fruit ready to harvest on day 44.
The benefits of using Grodan’s inert, pH neutral, consistent and uniform rockwool substrate are well known.
This growing medium is not physically interacting with the nutrition applied, meaning all ions and water are available to the plant for uptake.
Damien now has an easy ability to steer the crop in respect to root zone air / water content as well as the nutrient strength during variable light conditions.
This makes using rockwool substrates a particularly interesting and efficient alternative to traditional media for strawberry cultivation.
Initial research into cultivating strawberries in rockwool has found fruit yield can be increased by maintaining generative balance for consistent cropping with lower incidents of misshapen fruit and three to four days of extended shelf life in comparison to coconut fibre.
These benefits are attributable to the control afforded to the grower as the substrates react more rapidly to meet changing growing conditions on a day to day basis.
Gains in irrigation efficiency are also consistent with 30-50% less consumption overall, making precious use of water and fertiliser inputs to further enhance profitability and food security.