Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

(ABA)
    Abscisic acid is a naturally occurring hormone that assists plants in adapting to environmental stresses like drought or cold temperatures. During winter, ABA converts leaves into stiff bud scales which cover the meristem, protecting it from cold damage or dehydration. In case of an early spring, ABA will also prolong dormancy, preventing premature sprouts which could be damaged by frost.
     
----
    How to get the most out of your spray
    1) Spray the bottom of the leaves. Spray with a fine mist, and do not create droplets on the leaves. Fine mist is electrically attracted by the foliage. Even young marijuana plants have waxy hairs that impair liquid penetration.
    2) Do not spray plants that are hot or when the atmosphere is too dry. Spray in low light, either before the lights go off or just as they are coming on. If spraying in hot conditions, first spray everything with plain water until the temperatures of the room and foliage drop, before applying the real spray. Spraying when the plant foliage is hot causes the spray to crystallize on the surface, and it stops the penetration. Spraying with water 10 minutes afterward often increases the penetration. Mobile nutrients move freely within a plant. Immobile nutrients move slowly, but once deposited, they stay.
    3) Apply mobile nutrients sparingly. Immobile nutrients-sulfur, boron, copper, iron, manganese, molybdenum, sulfur, and zinc-often require two or three applications. Calcium and boron are poor candidates for foliar feeding because they translocate poorly. But urea nitrogen applied as a spray in high humidity penetrates almost instantly into leaves. Be careful when spraying urea-based fertilizers, and keep them diluted. Urea also carries other nutrients into the plant and works well for a base to the mix. Foliar feeding should turn the plant around in less than a week. A second spray could be necessary at week’s end to ensure the cure sticks.
    4) Boron, calcium, and iron move slowly during flowering. A supplemental foliar dose often speeds the growth when it slows. A foliar spray of potassium can also help flowering, especially if the temperatures dip below 50°F (10°C) or above 80°F (25°C).
    5) Always spray new growth. The thin, waxy layer and a few trichomes allow for good penetration.
    6) Measure the pH of the spray, and keep it between 7 and 8.5. Potassium phosphate (K 2 HPO 4 ) becomes phytotoxic below pH 4 and above 8.5. Stomata are signaled to close within these pH ranges.
    7) Use a surfactant with all sprays, and apply these as per the instructions on the label.
    8) Add the proper amount of surfactant so droplets do not form on the leaves. Once formed, the droplets roll off the foliage, rendering it ineffective.
    9) Stop the application before the droplets form on the leaves. Make a test spray on a mirror to ensure the spray is even and does not form droplets that roll off the mirror.
    10) Spray with as fine a mist as possible to minimize the size of the drop.
----
     

    Use a spreader/sticker to keep spray droplets from bouncing off foliage.
    Used in the garden, ABA may help plants resist drought and unseasonable conditions and improve productivity, strength, and performance.
Ascorbic acid (Vitamin C)
    Vitamin C is thought to build tighter, heavier buds and act as an antioxidant. It is often combined with fructose, molasses, or sugar and added to the nutrient solution during the last two weeks before harvest. However, some botanists believe that although vitamin C is very important in fighting the free radical byproducts of photosynthesis, plants make their own vitamin C and are unlikely to recognize any benefit from its addition to the nutrient mix.
Aspirin
    Salicylic acid is a naturally occurring plant hormone associated with the Willow. It is effective in preventing pathogens by speeding up the natural “systemic acquired resistance (SAR)” thereby reducing the need for pesticides. Salicylic acid (SA) will block abscisic acid (ABA) allowing the plant to return to normal after a period of stress-something to consider if ABA is being used to strengthen plants.
    Aspirin can be used as a spray, a soak, or added to compost and rooting compounds. A 1:10,000 solution used as a spray will stimulate the SAR response, and the effects will last weeks to months. “Willow water” also makes a popular rooting bath.
Auxins
    Auxins represent a group of plant hormones that regulate growth and phototropism. They are associated with elongation of plant