The second of the tomato trials was set up as a three-way trial to compare, firstly, organic vs non-organic fertiliser and secondly, green vs white shadecloth. This trial started on the 13th of December, 2020.

The fertilisers being compared are both made by Nuetrog, a local SA business. The organic fertiliser was Rooster Booster, a pelletised chicken manure product and the non-organic one was Gyganic, a similar product to the Rooster Booster but with added levels of nitrogen, phosphorus, potassium, iron and magnesium in a chemical form.

The shadecloth was 50% UV with one being white, the other green. The white cloth is reported to be superior as it reflects more heat resulting in a greater cooling effect underneath, It also lets through the full spectrum of light resulting in faster growth, whereas darker colours absorb more of the light, allowing less through but also trapping more heat than white cloth.

When discussing the colour of shadecloth, few mention the aesthetics which is small urban environments can be off greater concern than any negative aspects of reduced cooling or growth.

The tomatoes chosen for this trial were Pink Berkely Tie Die, Tigerella, San Marzano and Tommy Toe. Basil, marigold and cosmos were also planted. Each bed had 1 of each variety. Initially it was planned that each tomato plant was to be pruned to 3 main stems but this was changed early on and the plants were not pruned other than to remove the first few sets of leaves up to the first set of flowers to allow for good air flow around the plants. Bed 1 was organic, beds 2 & 3 were non-organic. Beds 1 & 2 had white shadecloth, bed 3 had green shadecloth.

There were clear differences between the organic and non-organic beds with much greater growth and fruit set observed in the non-organic bed. The exception to this was the Tommy Toe plant which in the organic bed did just as well as the non-organic beds, that is to say, it was prolific which is why this is the red cherry tomato plant I grow every year for the past several. I was genuinely surprised to see such a big difference between these fertilisers and equally surprised to see Tommy Toe show no difference at all.

The colour of the shadecloth didn’t appear to show any difference, the plants in beds 2 & 3 showed good growth and fruit set.