Effect of chemical thinning on fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘Khalal’ stage

The aim of this research work was to study the effect of chemical thinning using NAA (Naphthalene acetic acid) and the manual thinning used by the farmer on the fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘khalal’ stage (color stage and fruit physiologically mature). Trials were carried out on an adult plantation in the Tinejdad region, Tafilalet area. Observations focused on monitoring the fruit growth of different flowering phases and fruit quality at the end of the ‘khalal’ stage. Obtained results showed that the evolution of the fruit size parameters is similar for all flowering phases and all thinning treatments and at the end of the ‘khalal’ stage there is no significant difference (p ˃ 0.05) between flowering phases and between thinning treatments for these parameters. At the end of the ‘khalal’ stage, fruit length is between 4.8 and 4.9 cm and fruit mass is between 25.0 and 25.5 g. The content of sugar in the fruit is higher at the manual thinning treatment than at the NAA treatments, whereas the flowering phases have no effect on this parameter. The pH of the fruit juice is relatively similar for all thinning treatments and all flowering phases.