Durban Poison (Green Smoke Room Fast)

Not shown: germination in kitchen paper for 48 hours until they cracked and displayed a clear shoot. Temperatures can reach 40C in middle of South African summer, so the day temperature is uncomfortably high. I'm hoping the landrace genetics come through and the girls will tolerate the heat; they are growing in their home territory after all. Then again, who knows what kind of cold Northern Hemisphere growing they've gone through in the last 50 years since the 70s. For a "100% sativa" the leaves are oddly broad. I've purchased this seed from a a local seedbank with a well-established history, stretching back before the semi-Legalisation in South Africa. They've been breeding the Dutch Passion stock locally, so I'm a little more optimistic about the heat tolerance. Durban still grows monstrous outdoor plants, so it's likely a lot of their testing has been done in the full Durban heat. No problems at this stage. We have a runt among the four plants, but I don't have a backup seedling, so fingers crossed it'll catch up a little over the course of veg. Worst case scenario is it gets overshadowed by its neighbour, but I'm planning fairly aggressive topping and LST so hopefully we can clear the canopy for it.

Lowered the main grow light to 50cm and upped the nutrients. The runt is still struggling and its third set of leaves have only begun to emerge, while the others are starting to produce their fourth. I am concerned about the front right plant, which may be showing signs of leaf septoria, a fungal disease which is endemic to the region. I will buy some copper fungicide tomorrow and apply it immediately; the infection is very resilient and sporulates readily. It will stick with the plants for the entirety of the grow if it can't be brought under control early. I am considering inoculating the leaves with a bacterial fungicide to prevent resurgence. Last thing I need is a pandemic within the tent, as well as without.

The rust infection is very aggressive. On Monday the rust infection had spread to the front-left plant and had spread up the front-right plant, which is the closest to the entrance. I immediately purchased and applied a Mancozeb-based fungicide to the foliage. Mancozeb is a non-systemic fungicide that is non-toxic to wildlife and safe for humans. The drawbacks are that it is only effective in combatting infection on the leaf surface, and cannot eradicate the infection completely from within the plant. It has proving useful in controlling the spread and largely preventing infection of the back two plants. However, the infection is likely to remain in the tank until I am able to sterilise it. As the plants grow, I will remove as much affected foliage as I can to decrease the concentration of spores. I have already removed the leaves from the first node on the front two plants (not shown on the photographs). The front plants are noticeably stunted from the infection and defoliation. They have compensated by stretching. I will control the height with LST after they have been topped.

This week saw topping of the plants as the first step in creating a manifold. Plants had grown until the 6th node was emerging, and cut down to three. The growth tips from the first and second nodes were removed, as well as the leaves from the first node. The growth tips on the third node were perhaps a little small, but after only three days had grown dramatically. To support this growth, the plant used massive amounts of nutrients. Over the two days following the topping, the plants developed nutrient deficiencies. The pH had dropped to 4.5 in the reservoir, and thus I suspect a calcium / magnesium deficiency. There is some damage to the leaves from the rapid drop in pH. I added 2 ml/L of Hortimix B, which is a calmag nutrient. This seems to have arrested the deficiency, but the back-right plant still shows early signs of calcium deficiency on the leaves coming off the third node. I have decided to increase the nutrients to 6 ml/L and 7 ml/L of A and B respectively to compensate for their increased rate of growth.