A DEFOLIANT

The invention relates to chemical means for removing leaves and for stimulating the ripening of a crop and increasing its quality. The defoliation process should cause a complete drop of the leaves and should also occur at high speed and with a mild physiological action. Harsh action of defoliants causes the appearance of brownish spots or even necroses on the leaves. In this case many leaves do not fall, which impedes harvesting of the crop. Aminotrithiophosphates which display a high defoliation capability have been developed and studied. Of the number of preparations tested, S,S-dibutylamino trithiophosphate proved especially effective. The S,S- dialkylaminotrithiophosphates are readily available compounds which are obtained from ammonia and dialkyltrithiochlorophosphates. The latter are also obtained from thiotrichlorophosphates and mercaptans with good S,S,S,- tributyltrithiophosphate butifos, since the consumption of the expensive mercaptan for its synthesis is reduced almost one third.