You don't need to be the bus driver to know what makes the wheels go around. I'm sure a good number of growers know a lot about how milkweed will respond to pruning even if all they use in their predictions is their experience working with other plants. While there are a few plants that don't respond to pruning in ways we might expect (Norfolk Island Pine, for one) most plants (and I mean at least 99%) respond just as you would expect them to respond when you alter the balance of growth regulators that determine whether the plant concentrates it's growing efforts in additive or multiplicative growth. Your plant, is naturally apically dominant, so it wants to grow additively, and it is. To change it's habit temporarily to multiplicative (more branches instead of longer branches) you need to remove the source of the growth regulator (auxin) that is inhibiting multiplicative (lateral) growth. The most significant source of auxin is found in apical meristems (growing branch tips). Dr Carl Whitcomb often notes there is a "4-inch rule" that applies to pruning containerized plants. He suggests that removing an apical meristem affects the growth of other nodes for a distance of about 4" proximal to the cut. So - removing a branch tip affects the growth on that branch for approximately 4" behind that cut. I have a lit of experience doing hard pruning of plants, in which I remove up to 100% of the green growth on a given branch (or even the entire tree). I can attest that harder pruning of one branch can affect the back-budding response of the entire plant. IOW - the harder you prune, the more latent buds you can expect to be activated. Also, as noted above, WHEN you prune and how much stored energy the plant has at the time you prune impacts back-budding response. Healthy trees with lots of stored energy will be much more cooperative when it comes to back-budding than plants that are just getting by. In the picture you posted, I would have either pruned just above the first pair of leaves, then pruned again after the 2 branches that grew from buds in the leaf axils had 3 pairs of leaves - I'd have pruned the secondary branches back to 1 pair of leaves, too. If I had originally pruned back to 2 sets of leaves, I would wait for a week to ensure bud activation in all 4 leaf axils and would remove the top 2 leaves if it didn't occur in the bottom set. You really have a lot of time to pinch most plants. I pinch hardy hibiscus at least 3 times. It gives me shorter, sturdier plants and lots more blooms. In fact, I pinch a LOT of plants very regularly to force them to grow in ways I want them to grow, instead of allowing them to do their own thing. Some plants I've pinched with the specific intent of altering their growth habit: Al

Apparently Salicylic acid is a hormone or it is not a hormone. Also, salicylic acid is bananas or it is not bananas. All plant hormones are plant growth regulators, but not all plant growth regulators are hormones. If a plant growth regulator can be naturally produced inside a plant, it is a hormone even when externally applied. . . . wikipedia is also very often wrong, too. Yes, but not nearly as often as the general population. Furthermore, Wikipedia has an official policy against usage of weasel words, whereas society, in general, and these forums, in particular, have an unofficial policy of promoting the usage of weasel words.

Hello Jon. Yes it was my understanding that Chris used a systemic spray. It does sound like it is possible to parthenocarpic induce fruit set in sterile fruit with out natural pollen. We likely tried something that was available at his nursery like tomato set spray or a sales person from one of his vendors recommended a spray. Here is some information. When I have time I will give this a try? Best http://www.ubcbotanicalgarden.org/forums/showthread.php?p=21254 Tomato Fruit Set Spray User Name Remember Me? Password Register FAQ Links DB Calendar Today's Posts Search HortBoard If you are unsure about where to post your question, post it here in the Hortboard forum. New to gardening questions welcome! Search Forums Show Threads Show Posts Advanced Search Go to Page... Thread Tools #1 July 1st, 2005 Megami Generous Contributor (100+ posts) Join Date: Apr 2005 Location: Vancouver, BC Posts: 166 Tomato Fruit Set Spray -------------------------------------------------------------------------------- What is tomato fruit set spray and how/why does it work? Thanks! Megami View Public Profile Visit Megami's homepage! Find all posts by Megami #2 July 13th, 2005 Unregistered Posts: n/a Re: Tomato Fruit Set Spray -------------------------------------------------------------------------------- The active ingredient is the man-made auxin (hormone) 4-Chlorophenoxyacetic acid (4-CPA) that is well known to promote fruit set commercially. Bio101--Why it works: "...Fertilization within the ovules stimulates the ovary enclosing them to begin growing into a fruit. Within a few days the ovary begins to swell. This is called the fruit set. Fruit development is under the influence of the plant hormones auxin and gibberellin. Pollen is one of the richest natural sources of auxin, so it is thought that the initial stimulus to fruit growth comes simply from the auxin to which the pistil is exposed as a result of pollination. Applying the hormone auxin or gibberellin to the ovaries of flowers can induce a fruit to develop without pollination or fertilization. This is called a parthenocarpic fruit and is, of course, seedless." http://www.crfg.org/tidbits/gibberellic.html Gibberellic Acid for Fruit Set and Seed Germination John M. Riley The following information is taken from a article by John M. Riley that appeared in the 1987 CRFG Journal (vol. 19, pp. 10-12). See the back issue information for price and ordering information. The Germination Process The first stage of germination consists of ingesting water and an awakening or activation of the germ plasma. Protein components of the cells that were formed as the seed developed, became inactive as it matured. After an uptake of water, the system is reactivated and protein synthesis resumes. Enzymes and hormones appear and begin to digest reserve substances in the storage tissues and to translocate the digested substances in the storage tissues to the growing points of the embryo. The sequence of the metabolic pattern than occurs during germination involves the activation of specific enzymes at the proper time and regulation of their activity. Control is exercised by four classes of plant hormones: inhibitors such as abscissic acid which block germination; auxins which control root formation and growth; the gibberellins which regulate protein synthesis and stem elongation; and cytokinins that control organ differentiation. Ethylene is also believed to have a control function in some plants. Sometimes the last three controls are used together to crash through dormancy in germinating difficult seed. Gibberellic Acid Gibberellic acid (actually a group of related substances called gibberellins) was discovered as a metabolic byproduct of the fungus Gibberella fujikuroi, which causes the stems of growing rice to elongate so rapidly the plant collapsed. Synthetic forms of gibberellic acid are available commercially. Gibberellic acid (GA) is a very potent hormone whose natural occurrence in plants controls their development. Since GA regulates growth, applications of very low concentrations can have a profound effect. Timing is critical: too much GA may have an opposite effect from that desired; too little may require the plant to be repeatedly treated to sustain desired levels of GA. Effects of Gibberellic Acid Overcoming dormancy. Treatment with high concentrations of GA is effective in overcoming dormancy and causing rapid germination of seed. Concentrations of about 2 ppm can cause tubers to sprout earlier. Premature flowering. If a plant is sufficiently developed, premature flowering may be induced by direct application of GA to young plants. This action is not sustained and treatment may have to be repeated. Formation of male flowers is generally promoted by concentrations of 10 to 200 ppm., female flowers by concentrations of 200 to 300 ppm. Concentrations of more than 600 ppm markedly suppresses initiation of both male and female flowers. Increased fruit set. When there is difficulty with fruit set because of incomplete pollination, GA may be effectively used to increase fruit set. The resulting fruit maybe partially or entirely seedless. GA has increased the total yield in greenhouse tomato crops both as a result of increased fruit set and more rapid growth of the fruit. Hybridizing. Pollination within self-incompatible clones and between closely related species may some times be forced by the application of GA and cytokinin to the blooms at the time of hand pollination. Increased growth. GA applied near the terminal bud of trees may increase the rate of growth by stimulating more or less constant growth during the season. In a Department of Agriculture experiment, the GA was applied as a 1% paste in a band around the terminal bud of trees. Treatment was repeated three times during the summer. Walnut tee growth was 8.5 ft. for treated trees, 1.5 ft. for untreated trees. Frost protection. Spraying fruit trees at full-blossom or when the blossoms begin to wither can offset the detrimental effects of frost. Root formation. GA inhibits the formation of roots in cuttings. Recipes Although GA is not listed as a "poison", the following precautions should be observed: Flush with water any GA that may get into the eye. Avoid skin contact if possible. If skin contact is suspected, wash with soap and water. Do not re-enter an area after spraying until the GA spray is fully dry. Avoid ingestion of GA. The powder may be dissolved as specified below to give the desired concentration. Concentration parts/million GA mg Water ml (cup) Purpose 50 125 2400 (10 1/2) Early flowering 200 125 600 (2 1/2) Early flowering 800 125 160 (2/3) Blossom set 2000 125 60 (1/4) Seed germination 1% paste 125 5 ml (1 tsp.) lanolin Growth promoter -------------------------------------------------------------------------------- Copyright 1987,1997, California Rare Fruit Growers, Inc. Questions or comments? Contact us. http://www.super-grow.biz/GibberellicAcid.jsp#combine

>> IBA is strictly a synthetic chemical substance. It is NOT found in plant tissues. It actually has been discovered in several plant species. For example, see the work done by Jutta Ludwig-Müller titled "Indole-3-butyric acid in plant growth and development" back in November 2000 (Plant Growth Regulation Journal, Volume 32, Issue 2-3, pages 219-230). Basically, it was found that some plant species do produce IBA using IAA as the precursor. Not that it really matters though >grin>> IBA is generally easily available and very effective in inducing root formation at certain times of the year. Most commercially marketed rooting preparations are quite expensive and not very effective. IBA is good stuff and works well. You can find it very inexpensively at Wallyworld, K-mart, Home Depot and other places.. a 2oz bottle of Schultz Take-Root (0.1% IBA) powder can be had for around $6 and is good for several thousand cuttings. I've used it for years and it sure is easier than trying to make my own rooting mix.