Pg. 19-22 Evaluating Maxim® for the increase in fruit size and retention in litchi: Second season

Maxim^®, a synthetic auxin, was evaluated on litchis for the increase of fruit size. After the first year in 2005/06 the trials were extended to include different application times.

Maxim^® was applied at the 2, 3 and 4 g fruitlet stage at three different concentrations and the effect on yield, fruit drop and fruit size was determined. All treatments increased yield and fruit size. Economical studies revealed again that the application of Maxim^® can benefit producers to a great extent.

Summary:

• Maxim is a synthetic auxin evaluated for increasing fruit size and retention in litchi, specifically the HLH Mauritius cultivar.

• The study included treatments with different Maxim concentrations (20, 40, 80 ppm) applied at various fruitlet stages (2, 3, and 4 g fruit weight).

• All Maxim treatments reduced fruit drop, particularly the 40 ppm concentration which reduced fruit drop by up to 15%.

• Maxim treatments increased overall fruit yield compared to untreated controls, with the highest yields from 20 ppm at 2 and 3 g stages and 80 ppm at 4 g stage.

• Fruit size and mass increased notably with 40 ppm treatments, especially when applied at the 3 and 4 g stages; earlier application at 2 g stage resulted in smaller fruit size.

• Fruit size distribution shifted toward larger export classes under Maxim treatment, with the 40-4 treatment having the highest percentage of extra-large fruit.

• Economic analysis showed that despite the cost of Maxim application, the increased yield and fruit size significantly improved net income for producers.

• The study recommends Maxim application at 40 ppm after the second fruit drop (3 to 4 g fruit stage) for optimal fruit size and retention in litchi.

• The research supports the registration of Maxim as a growth regulator for litchi fruit size improvement in South Africa.

• The study acknowledges the support of litchi orchard owners and laborers in conducting the trials.