I am seriously wanting to play with extended days out of the greenhouse and in the field.
I am hoping to use 400w HPS to cover a larger area than incandescent to save on electricity as we use way too much having everything processed on site.
i just read this:
http://stfc.org.au/dragon-fruit-by-graham-reindeersLamps simulate “Long-days” The name of the game here is to shock the (Pr) {inactive} Phytochrome, which regresses during increasing dark periods, back into active (Pfr ) and to drive them back into the cell nucleus, to keep making flowering hormone. We can either light the crop continuously after dark or light the “dark” period for 25% of each hour, usually starting at about 10pm and continuing until approx 2.00am. This fools the plant into thinking it is all one long day. Plants yield better when they sleep a bit at night so they can rearrange their sugar storage efficiently. However, a continuous light from 10pm to 2.00am can be used with no real ill-effects. 100 Watt incandescent bulbs are usually used, spaced about 5 feet apart from each plant, delivering about 10 lumens {foot candles}. The actual lumen output is not very critical because all it has to do is shock the Phytochrome with a few photons. To save power, the lights can be cycled on and off to give about 25% timed light. There is a technique being used lately where 400 Watt Metal Halide or Sodium (High Intensity Discharge) lamps are mounted high enough above the crop to reach plants 40-50 feet away which are either swivelled on a boom or reflected by a reflector, like a “light house”, causing light to fall on each plant 3 of 4 times an hour between 10pm-2.00am. The HID’s are not very high in 660nm red but they make up for it in Lumen output. Again, provided that each plant feels the equivalent of about 10 lumens of light at each passing, the Phytochrome will be switched back to creating flowering hormone. Taiwan is reported to be creating an additional flowering season, extending from the Fall equinox through to the next spring equinox. This de-facto means that the plant is in continuous production. Cooler off-season crops actually have the capacity to make larger sweeter fruits because the plant can deposit more sugars in the fruit when their metabolism is not racing at full speed in the heat. Pitaya fruit can be grown from between 35 – 50 days with no excessive sweetness increase but up to 25% increase in weight. This may be a good way to get a high yield out of the second crop even if the plants get tired. Provided the plant nutrition can be adequately maintained, and the temperature kept within the plant’s comfort zone, continuous production is possible and feasible.
they mention the use being OK. 10 lumens seems like an easy deal, would also like to look into LED, but later as i already have the HPS.
so my idea was to use rails. this article mentions they need light 15 mins every hour between 10pm-2am (im sure the time frame varies). using rails would move the light in a line back and forth slowly, and could be setup to hit 15/60 mins pretty easy.
Can anyone see a flaw in this? i see it working, but want to make real sure as it takes some effort to setup outdoor things like this that can withstand typhoons.