Keep'in it small

[psionblue]

I have read about LST and SCROG to keep things short, but I wondered if blowing a fan on the plants with a bit of power would also keep the plants small? There are articles that prove high winds keep plants short and wide, but nothing for weed. Has anybody tried this?

I am thinking of flowering when the plants hit 6 inches or so and keep them in 6" square pots. I want to keep the whole grow on the misdemeanor side of things.

Think it will work?

[Homergrower]

Originally Posted by psionblue

I have read about LST and SCROG to keep things short, but I wondered if blowing a fan on the plants with a bit of power would also keep the plants small? There are articles that prove high winds keep plants short and wide, but nothing for weed. Has anybody tried this?

I am thinking of flowering when the plants hit 6 inches or so and keep them in 6" square pots. I want to keep the whole grow on the misdemeanor side of things.

Think it will work?

The general idea is to keep a fan of some sort in the are to keep air flow on the grow , this strengthens the stems and keeps the plant healthy, much in the same way as an air stone keep a fish tank healthy.
I'm sure stronger wind would achieve keeping the plant a bit smaller and thicker, but it raises the problem of humidity, with such a high wind it will bring the humidity down. for vegging it should be about 60-70%. During flowering it should be about 40-50%.

[HiTCheR]

throughout my vegetation period my closet was like 40%-50% humid, but now with the hotter lights the humidity has gone up to at least 70%-80%, you can whipe water off the walls sometimes.

[psionblue]

Well I think I'll give this a try to keep the plants small(keep in mind that it is all speculative):

1-2 weeks or first leaf - light fan more for circulation
3-5 Increase fan strength so tip of stalk is bending slightly -run fan every 15 minutes for 15 minutes (or maybe all the time?) rotate plants daily to prevent permanent bending.
5-? Switch plant to 12/12 flower and continue to run the fan until the first flowers appear. Lower the fan speed, the fan is only for ventilation now. The idea would be that stretching during flowering would be slowed, but during bud production we let the plant go crazy since it has a super thick stalk and few leaves.

-fan wind speed should be around 10-15 MPH for maximum effect. The main goal is flexing the plant, use whatever speed wind that causes this

the possible benefits could be:

-Plants grow shorter and wider
-Leaves are smaller
-Fewer nodes
-thicker stalk
-more roots
-faster absorption of ferts since the plant loses water faster because of the air hitting the leaves it will absorb more through it's roots
-increased potency




i have no idea if this will work, or how much and how strong everything should be. Here are some samplings from articles and papers I found online.

In our earlier report, the results demonstrated that the addition of mechanical stimulation by artificial wind and vibration was related to an increase in the amount of moisture transported in the plant. The increased amount of moisture transported in the plant will activate photosynthesis and increase the absorption of nutrients from the roots. Based on those earlier results, the present study entailed providing artificial wind via mechanical stimuli to the Komatsuna plant (botanical name : Brassica campestris) and examining the relationship between the amount of growth (leaves area and total weight) and the photosynthetic rate in this plant. We used 1, 10, 30, 60 and 120 minutes as wind periods, with an artificial wind of 0.5m/s. For example, a 30-minute wind period consisted of 15 minutes of wind time and 15 minutes of windless time. As a result, we confirmed that both the photosynthetic rate and the amount of growth with artificial wind during the 30-minute wind period increased compared to the windless case. This result was qualitatively proved by the simulation of photosynthetic rate using the electrical circuit model.>>
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Wind is a factor that can shorten a crop. Stems thicken and internodes elongate less when they are subject to mechanical stresses like wind. Check your plants. The combination of thick stems and smaller internodes makes wind a likely cause of the shorter crop. It is unlikely that you will have any yield loss as a result of the wind. A thinner than normal stem will indicate a stress other than wind.>>
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Effect of wind velocity on ethylene release rate of intact lettuce plant was investigated. Lettuce plants were grown at wind velocities of 0.1, 0.4, 0.8, and 1.4 m s-1 for 25 to 33 days and then used for ethylene measurement. When ethylene release rate of the plants grown at a wind velocity of 0.1m s-1 was measured at wind velocities of 0.2, 0.6 and 1.0m s-1 the rate was not affected by wind velocity. This result indicates that ethylene diffusion from lettuce leaf to atmosphere is not affected by boundary layer conditions. When ethylene release rate of the plants grown at wind velocities of 0.1, 0.4, 0.8 and 1.4 m s-1 was measured at the same wind velocity as growing conditions, the rate was scarcely increased by high velocity of wind. A strong wind (4.0 m s-1), which induced wounding damage in small areas of the leaves, had no measurable effect on a ethylene release of the whole plant.>>
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In a glasshouse experiment, Lolium perenne was grown under continuous wind or drought. Subsequently the anatomy, mechanical properties, and gas exchange characteristics of leaves were compared with those of controls. Wind-exposed plants were shorter and yielded less dry weight though the rate of photosynthesis of turgid leaves was not affected by either treatment. Neither the physiology nor the anatomy was affected to any great extent. In contrast to previous findings for Festuca arundinacea, wind did not alter leaf conductance significantly while Young's modulus was decreased rather than increased by wind. The droughted plants showed effects intermediate between the wind-exposed and control plants.>>
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Summary Potted plants of various trees and shrubs (clones), exposed in the dividing strip and along the border of a motorway, showed an inhibition of leaf growth and a faster development of necrotic leaf areas, when suffering from water deficiency. In greenhouse experiments with potted aspen exposed to periodic artificial wind gusts, wind velocities of 6 m/s were sufficient to inhibit leaf growth by 50%. Therefore it is suggested that repeated strong shaking of plants grown near a motorway, caused by traffic wind, might be responsible for this inhibition. Measurements of water relations did not show obvious changes when aspen trees with1 1/2 month old leaves were treated with wind gusts, but when plants were continously treated with wind (6 m/s) significant increases in stomatal diffusive resistances and transpiration rates were found as well as a significant decrease in water potential. Aspens with young leaves, exposed to the same treatment, showed a rising of stomatal diffusive resistance in the beginning, but after about 1 1/2 h diffusive resistances suddenly decreased. Subsequently after a 2 to 3-h wind>>
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To determine the effect of wind on alpine plants, we set up five wind-shields (called WS) on a wind-blown alpine dwarf shrub community on Mount Kiso-komagatake (2956m), in the Central Japanese Alps, in June 1996. Air temperature at vegetation height, soil temperature, and relative humidity on the windward side of the WS plots and control plots were recorded. Phenological observations and growth measurements of five species, Diapensia lapponica var. obovata, Empetrum mgrum var. japonicum, Loiseleuria procumbens, Arctous alpinus var. japonicus and Vaccmium uligmosum, were conducted from June to October. By setting up the WSs, the daily mean temperature did not change significantly in comparison with the control plots. Growth periods of four species, except for D lapponica var. obovata, were extended at the WS plots, and E. nigrum var. japonicum, L procumbens and V. uliginosum bloomed earlier at the WS plots. Annual shoot length of E. nigrum var. japonicum, L procumbens and V. uligmosum was longer at the WS plots. These results suggest that one of the important effects of wind on the alpine plants was the restriction of shoot growth, probably due to decreasing leaf temperature. The effect of the wind shield was not significant for D lapponica var. obovata, which has a mat-shaped growth form.>>
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Objectives/Goals>>
The purpose of this project is to observe how much negative tropism, due to wind (Thigmotropism) is too>>
great for the positive tropism, phototropism.>>
Methods/Materials>>
Four Cardboard boxesFour table top fans, Four Plant light bulbs in the light sockets, 7 plants (Nemesia>>
fruticans), Ruler, String, 80 mL beaker, Anemometer, Protractor>>
Results>>
The only type of wind that actually allowed for plants to grow and show phototropism was the low level>>
plants. The medium level plants grew only a tiny bit and showed a tiny bit of phototropism. The high>>
level plants did not survive and did not show a bit sign of phototropism.>>
Conclusions/Discussion>>
Based on my results, 4.94 meters per second of wind (22.7 degrees Celsius) , which was the medium>>
level, leaves only enough room for minimal phototropism and minimal plant growth. 5.15 meters per>>
second of wind (22.8 degrees Celsius), which was the high level, leaves virtually no room for plant>>
growth and no room for phototropism. However, 4.20 meters per second of wind (22.5 Celsius), which>>
was the low level, was not enough to stop plant growth and the plants grew a decent amount and did>>
display phototropism. This conclusion does prove my hypothesis to be correct.>>
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Furthermore, it was shown that recurrent wind loading ceased to have any significant effect on shoot orientation after the end of the first growing period. Some characteristics of the first months of growth appear, therefore, to govern the tonic effect of wind on seedling heliotropism. Acclimation or desensitization may occur, especially with such a periodic type of signalling (Trewavas, 1999Go; Plieth and Trewavas, 2002Go), but intrinsic development is more likely to explain such a physiological switch. In particular, the huge primary growth which occurs in Maritime pine seedlings after the first dormancy period ends the competition for light with most herbaceous species and hence any detrimental consequences.>>
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Plants treated with wind showed a delay in the initiation of the inflorescence growth relative to control plants (Fig. 1A). Inflorescence emergence of wild-type plants was delayed by almost 6 d (25.6 ± 0.6 versus 31.3 ± 0.5 d for control and wind treatments, respectively), whereas emergence of etr1–3 and ein2–1 inflorescences was delayed by 3 (26.7 ± 0.3 versus 30.3 ± 0.3 d) and 8 d (28.7 ± 0.5 versus 37.0 ± 1.0 d), respectively. Wind treatment also retarded the rate of inflorescence elongation. In wild-type plants the initial rate of inflorescence elongation from inflorescence initiation to 15 cm in height was reduced from 22.0 ± 0.5 to 19.8 ± 0.6 mm/d (P < 0.01; data not shown). A more significant reduction of growth rate was evident when the increment of growth between 15 and 25 cm in height was assessed. Wild-type plants showed a reduction in growth rate from 22.8 ± 0.6 to 16.3 ± 0.4 mm/d (P < 0.001; Fig. 1B). The growth rate reduction, as a consequence of wind treatment, was also observed for both ethylene-insensitive mutants analyzed. From inflorescence emergence to elongation to 15 cm, etr1–3 growth rate was reduced from 24.3 ± 0.4 to 23.7 ± 1.1 mm/d (not significant) and ein2–1 elongation rate was changed from 23.9 ± 0.6 to 20.2 ± 0.6 mm/d (P < 0.001; data not shown). In addition, reductions in elongation rates between 15 and 25 cm were observed for the mutants. The growth rate of etr1–3 was reduced from 23.9 ± 0.8 to 15.6 ± 0.6 mm/d (P < 0.001) and that for ein2–1 was decreased from 25.3 ± 1.0 to 13.9 ± 0.8 mm/d (P < 0.001; Fig. 1B).>>
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Observations on the growth-rate of stands of young plants of Brassica napus in a wind tunnel show that relative growth-rate rises with wind speed at low wind speeds but falls again when wind speed is further increased. A wind speed of 0.3m./sec. caused optimal growth in these experiments. Changes in relative growth-rate were small.>>
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Morphological measurements>>
The treatments had a significant effect only on plant height (Table 1). The two-way ANOVA showed that both air flow (F1.56=4.86, P=0.032) and flexing (F1.56=60.40, P <0.001) had significant effects; air flow increased height by about 7%, while flexing decreased it by about 22%. No significant two-way interaction between wind and flexing was observed. Neither stem diameter nor leaf area was significantly affected by the treatments.>>
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Stem hydraulic conductivity>>
Both treatments had a significant effect on the conductivity of internode 1 (Table 1). Air flow increased conductivity by about 8% (F1.56=8.05, P=0.006) whereas flexing decreased it by about 16% (F1.56=33.5, P <0.001). No significant two-way interaction between wind and flexing was observed.>>
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Stem mechanical properties>>
The results for the mechanical tests are shown in Table 2. The mechanical properties of the internodes were all affected in the opposite way to conductance by the treatments. Rigidity was reduced by about 23% by air flow (F1.56=12.05, P=0.001) and increased by 12% by flexing (F1.56=5.01, P=0.029). Strength was similarly reduced by about 23% by air flow (F1.56=12.53, P=0.001) and increased by 26% by flexing (F1.56=16.62, P <0.001). No significant two-way interaction between wind and flexing was observed.>>
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The material properties of the internodes was also affected in the same manner. Stiffness was reduced by about 31% by air flow (F1.56=17.89, P <0.001) though not significantly affected by flexing. Maximum stress was reduced by about 29% by air flow (F1.56=27.22, P=0.001) and increased by 27% by flexing (F1.56=12.13, P=0.001). No significant two-way interaction between wind and flexing was observed.>>
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Probably the three most significant points brought out by these experiments are the
demonstration: i. That the morphological and anatomical changes of the leaves can be
considered advantageous with respect to their water economy. 2. That use of the
assimilatory products as shown in the altered root/shoot balance is likely to affect water
balance advantageously. 3. That the whole plant becomes smaller with increasing wind
speed and that this is achieved by the development of a smaller leaf area and not hy a
reduction of photosynthetic rate per unit area. Further, this reduction on leaf area is
accompanied by a corresponding reduction of internode length.
In general it may be said that the phenotype becomes more xeromorphic as the wind
speed is increased and that it has been demonstrated that these changes can be expected
to be advantageous in respect of water relations. It is not intended to discuss at this point,
the causation involved in these changes, except to point out that since photosynthetic rate
is unaffected, it is probable that a disturbance of the operation of growth substances controlling
leaf expansion and internode elongation appears most likely.
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Hairs on plants are extremely variable in their presence across species, location on plant organs, density (even within a species), and therefore functionality. However, several basic functions or advantages of having surface hairs can be listed. It is likely that in many cases, hairs interfere with the feeding of at least some small herbivores and, depending upon stiffness and irritability to the "palate", large herbivores as well. Hairs on plants growing in areas subject to frost keep the frost away from the living surface cells. In windy locations, hairs break-up the flow of air across the plant surface, reducing evaporation. Dense coatings of hairs reflect solar radiation, protecting the more delicate tissues underneath in hot, dry, open habitats. And in locations where much of the available moisture comes from cloud drip, hairs appear to enhance this process.>>
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A study in wild Indian plants showed more glandular trichomes and more cannabinoids in plants from warm, dry, and windy locations at lower elevations [Planta Mdecia 37, 219)>>
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Air circulation brings a mild wind to your grow and this is very important for stem and branch growth. By stressing it slightly, the wind will cause the plant to react with thicker stem and branch growth. This is important for bud production, and the plant will be thicker, stronger and healthier overall. I've witnessed growers use fans in their grow rooms that can triple the width of a stem. On more than one occasion I've seen indoor stems that are two inches thick on a plant that is only four feet tall.These plants tended to produce the most bud in the same strain population too. The reason for this was because they were located very near to the main fan and placed directly under the light. In other words, the growing conditions were optimal for that plant.>>