Soybean growth

Both lantana and common purslane are weed pests in some crops. Common purslane root exudates inhibited soybean growth but showed stimulation in other bioassays reported in this paper. This may be a concentration and bioassay species dependent effect, since the effect of any toxin varies according to concentration and bloassay species (12). Lantana root exudates showed the strongest inhibitory effect on soybean growth of any of the species tested. Lantana is not found in soybean fields but is a weed pest in some areas in citrus orchards. Holm (13) included lantana, johnsongrass, and cogongrass in his list of the worst weed pests in the world. 

Table I. Soybean growth bioassay of root exudates...

As in Study 1, no adverse effects of either mulch or tillage were observed on corn or soybean growth. 

Ransome, C.S. and R.H. Dowdy. 1987. Soybean growth and boron distribution in a sandy soil amended with scrubber sludge. Jour. Environ. Qual. 16 171-175. 

Almquist, H. J., and Merritt, J. B., 1953, Accentuation of dietary amino acid deficiency by raw soybean growth inhibitor, Proc. Soc. Exp. Biol. Med., 84 333-334. 

Since feeds contain other substances than those required by the animals of interest, studies have also been conducted on antinutritional factors in feedstuffs and on the use of additives. Certain feed ingredients contain chemicals that retard growth or may actually be toxic. Examples are gossypol in cottonseed meal and trypsin inhibitor in soybean meal. Restriction on the amount of the feedstuffs used is one way to avoid problems. In some cases, as is tme of trypsin inhibitor, proper processing can destroy the antinutritional factor. In this case, heating of soybean meal is effective. 

Soybeans are the predominant oilseed crop in the world, providing one-half of the total oilseed production (Table 7). Cottonseed is second. Worldwide, rapeseed is in third place, but this is stiU a minor oilseed in the United States. Peanuts and sunflower are fourth and fifth, respectively. Since becoming estabhshed as a crop in the United States, soybeans have shown phenomenal growth and contribute significantly to the agricultural economy (Table 8). 

Sterile agar slants are prepared using the Streptomyces sporulation medium of Hickey and Tresner, J. Bact., vol. 64, pages 891-892 (1952). Four of these slants are inoculated with lyophilized spores of Streptomyces antibioticus NRRL 3238, incubated at 28°C for 7 days or until aerial spore growth is well-advanced, and then stored at 5°C. The spores from the four slants are suspended in 40 ml of 0.1% sterile sodium heptadecyl sulfate solution. A nutrient medium having the following composition is then prepared 2.0% glucose monohydrate 1.0% soybean meal, solvent extracted, 44% protein 0.5% animal peptone (Wilson s protopeptone 159) 0.2% ammonium chloride 0.5% sodium chloride 0.25% calcium carbonate and water to make 100%. 

Microbial insecticides are very complex materials in their final formulation, because they are produced by fermentation of a variety of natural products. For growth, the bacteria must be provided with a source of carbon, nitrogen, and mineral salts. Sufficient nutrient is provided to take the strain of choice through its life cycle to complete sporulation with concomitant parasporal body formation. Certain crystalliferous bacilli require sources of preformed vitamins and/or amino acids for growth. Media for growing these bacilli may vary from completely soluble, defined formulations, usable for bench scale work, to rich media containing insoluble constituents for production situations (10,27). Complex natural materials such as cottonseed, soybean, and fish meal are commonly used. In fact, one such commercial production method (25) is based on use of a semisolid medium, a bran, which becomes part of the final product. 

Vitamins and lipids are often required for animal cells to grow in serum-free medium. Phosphoethanolamine and ethanolamine are key additives that facilitate the growth of the mammary tumor cell line 64024 (Kano-Sueoka and Errick, 1981). In addition, ethanolamine promotes the growth of human lymphocytes and mouse hybridoma cells. Short-term cultures of human diploid lung and foreskin fibroblasts grow in medium that includes among its supplements soybean lecithin, cholesterol, sphingomyelin, and vitamin E. 

Meyer, R.F. Boyer, J.S. (1981). Osmoregulation, solute distribution, and growth in soybean seedlings having low water potentials. Planta, 151,482-9. 

ZHOU J R, GUGGER E T, TANAKA T, GUO Y BLACKBURN G L and CLINTON S K (1999) Soybean phytochemicals inhibit the growth of transplantable human prostate carcinoma and tumor angiogenesis in mice. J Nutr. 129 (9) 1628-35. 

V. D. Jolley and J. C. Brown, Soybean response to iron-deficiency stre.ss as related to iron supply in the growth medium. Journal of Plant Nutrition 10 631 (1987). 

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