NO - Besoin d'assistance

Composition of tomatoes and tomato products in antioxidants (WG1) page 49
__________________________________________________________________________________________
6.2.4.5. Growth and development regulators
DCPTA (2-(3,4-dichlorophenoxy)triethylamine) is a bioregulator of lipid and protein
synthesis which has been shown to increase the harvestable yield of numerous crop plants by
maintaining a balanced partitioning of photosynthetate between plant growth and crop yield.
Gibberellins are plant growth promoters through stimulation of stem elongation,
promotion of seed germination, inducement of flowering and fruit formation, changes of plant
metabolism.
CCC or Cycocel (2-chloroethyltrimethylammonium chloride), Phosphon (2,4-
dichlorobenzyl tributyl phosphonium chloride) and Alar (succinic acid 2,2-dimethyl
hydrazide) are growth retardants generally inducing dwarfing effects.
Duraset (N-metatolyl phtalamic acid) and the cytokinin Adenin (6-aminopurine) are
growth substances exhibiting auxin.
Sprays of plant growth-regulating substances (naphtalene acetamide, naphtoxyacetic
acid, indolbutyric acid, P-Chlorophenoxyacetic acid) used to improve fruit set and fruit size
under subnormal conditions of light and temperature, did not seem to have an appreciable
direct influence on fruit vitamin C concentration which varied between 190 to 250 mg/kg,
according to the season for the cultivars Marglobe and Stokesdale (Murneek et al, 1954).
Irulapp an and Muthukrishnan (1974) increased fruit ascorbic acid content of 25%
together with total soluble solids content of field grown tomatoes by Alar treatment at 1500
and 3000 mg/kg. In field grown tomatoes cultivated by Graham and Ballestero (1980),
gibberellic acid, cycocel and phosphon increased fruit ascorbic acid content.
Gabr et al.(1985) sprayed field tomato plants twice (25 and 40 days after
transplanting) with chlormequat (CCC) or alar separately at 250, 500 or 1000 mg/kg. Yields
were increased by 250 mg/kg CCC and by all doses of alar, with decreasing influence. Most
levels of CCC and alar seemed to increase slightly fruit vitamin C content (+5%; values
ranging from 200 to 230 mg/kg according to successive harvests).
Majeed et al.(1991) found that the stage and number of sprayings of DCPTA did not
influence fruit yield and vitamin C content. Increased concentration of DCPTA from 0 to 80
mg/kg doubled the fruit yield per plant and increased fruit vitamin C content from 386 to 549
mg/kg fresh matter and total soluble solids content from 4.53 to 5.48 %.