when do u give ur plants their first feed of the day?

[keepleft]

ive always started the first feed at lights on.

 

but ive recently read material from both canna and grodan stating that first feed should not commence until at least 1hr to 2hrs after lights turn on

 

whats the logic in this? ive been told that if plants are fed during times of rapid temperature increase it promotes elongation.

[Bundy]

i feed mine when i actually remember to

[loylty gets u nothing]

wow i always have had em go on at lights on

u reckon to wait some time

wat a sort of let the roots wake up sort of thing??

like they need to have a cooffee 1st.......

does it stress the plants by feeding straight on lights on??

good thread KL

peace

billo

[Stoney]

hey there guys

 

i think the logic behind this one is that it takes ya plant rufly 80-90 minutes to actually wake up abit like me in the morning so by waiting for an hour or so would be so that the plant is fully awake and active to absorb the water better

 

cheerz :Dj:

[keepleft]

hi all ive done some more research on this issue. here is some info i found per water management guidelines on the grodan website. i know its specific to the grodan medium but im assuming the principles can generally be applied universally

 

The first irrigation or start time should occur after the crop has become ‘active’ in the morning, when the Water Content in the slab will be at its lowest level. Start times can vary depending on climate conditions, substrate volume (l/m2) and water content (%) in the slab.

 

Table 1 therein says that the STANDARD irrigation start time in relation to sunrise is 1-2 hours.

 

Similarly in relation to irrigation end time:

 

The last Irrigation of the day marks the end of P2 (i.e. last irrigation of the day) and the beginning of P3 (time between last irrigation of the day and first irrigation of the next day). Stop times can vary depending on climate conditions, substrate volume (l/m2)and water content (%) in the slab.

 

Table 4 therein say that the STANDARD irrigation stop time is 1-3 hours before sunset.

 

Start time and stop time, in combination with irrigation volume, can greatly influence the course of the water content in the slab and in turn, plant growth.

 

To illustrate these concepts, here are some examples of strategies

 

late start plus an early stop in combination with a large irrigation volume per session will cause the WC in the slab to gradually reduce over time. This is a generative strategy

 

An early start plus a late stop in combination with small irrigation volumes per session will result in continuously high WC in the slab and give the plants a strong vegetative influence

 

Be aware that early irrigation starts under low light conditions may cause unwanted root pressure leading to cracked fruit and soft, disease-prone plants. Botrytis and Mycosphaerella are encouraged under these conditions.

 

Irrigation volume per session

 

The applied irrigation volume (cc/m2) has less influence on the increase or decrease of the slab WC than the daily irrigation start and stop times. This does not mean that irrigation volume per session cannot be a useful tool for controlling WC in the slab. The usefulness of irrigation volume per session becomes evident for the effective control of EC and the stimulation of root growth and penetration (large volumes applied infrequently will stimulate root growth).

 

 

Over the last 12 months i have experimented with various watering strategies. ive found that by ending my final watering session 3hrs before lights out has been beneficial. ive also found that by having higher irrigation volumes less frequently, it creates more root growth under the slab (maybe the roots searching for a feed).

 

ive always started the first watering session at lights on though. i may try delaying this an hour. unless someone can tell me this is a definite no no.

 

cheers

[palmtrees]

i like to feed mine (outdoors) any time a fter the sun sets till say 10pm i reckon it gives everything to soak in and get the roots nice and moist then its got the next day under then sun to absorb all that good shit up. and another thing is my plants seem to grow most at night, some mornings i come back and damn there looking good.

[keepleft]

im wondering whether indoors versus outdoors is the key difference.

 

obviously outdoors, the sun rises slowly and temps also therefore will increase incrementally, so it makes sense to delay the first watering for an hour or 2.

 

whereas indoors the lights snap on and within 10 mins temps are generlally up to the average peak, so maybe it would be more appropriate to feed at lights on versus a 1 hour delay? any thoughts?

[Bundy]

ever had somebody come into your room while your sleeping, flick the light on and dump a bucket of water on you?

 

it's not fun

[Luke Skywalker]

I would imagine it is distinctly different for grodan rockwool media as opposed to far more open media like perlite or clay.

 

I water about 1/2 hr after lights on, and ensure final feeding is a minimum of 1/2 hr before lights off. That's in perlite.

 

An interesting discussion though. Mind you, you should keep in mind that rockwool holds on to moisture in such a way as it's still available to the plant even when it drops down to very low levels. So this may be a contributing factor in their advice.

 

Plus, they're talking about greenhouse conditions, not indoor growroom conditions which may appear superficially similar, but are really quite different. (7m+ roof height, sun as primary source of light, etc)

[keepleft]

hey bundy i like ur thinking about the bucket of water!

 

luke i was thinking the same thing about greenhouse versus indoors.

 

only thing that worries me about not watering until 1hr after lights on is whether the medium/slab which has not been watered for almost 12 -15hrs would have a very low water content and high salt content. and therefore would be a bad environment until the first feed