Abstract: S-abscisic acid is used for promoting fruit set and/or for producing parthenocarpic fruits in useful plants. S-abscisic acid is also used as a growth inhibitor in useful plants. Methods are provided for treating useful plants with S-abscisic acid for these purposes.

Abstract: The invention relates to the use of a composition comprising S-abscisic acid or a salt thereof and another growth inhibiting active substance during a period of vegetative growth for the increase of the yield of agricultural and horticultural crops, annual as well as perennial, monocot as well as dicot crops, whereby the S-abscisic acid or the salt thereof is dosed in an amount corresponding to at most 40 g/hectare.

Abstract: This invention relates to the use of a composition in low doses containing single L-amino acids, including their precursors and biologically still active metabolites, to influence the life processes of plants, such as their growth, whereby the total amount of single L-amino acids when applying the composition is at least 0.5 g/ha and at most 250 g/ha, and wherein the L-amino acids are selected from the group of glutamine, asparagine, aspartic acid, histidine, lysine, and combinations thereof with each other and/or with arginine and/or with glutamic acid.

Abstract: Controlling insects of the superfamily of the Psylloidea in horticultural and/or agricultural crops, by using bicarbonate and carbonate salts.