Effects of Paclobutrazol, Mepiquat Chloride and Thiourea Combined with Potassium Chlorate on Flowering and Fruiting of Longan cv. E – Daw in Rainy Season
This experiment aimed to study the effect of paclobutrazol, mepiquat chloride and
thiourea combined with potassium chlorate on flowering and fruiting of longan cv. E - Daw in
rainy season. The experiment was carried out during July to October 2017 at Pong Nam Ron
District, Chanthaburi Province. The experiment was designed based on completely randomized design (CRD) with 4 treatments and 4 replications as follows: 1) control (soil drenched with potassium chlorate at 20 g/m2 of canopy diameter); 2) soil drenched with potassium chlorate at 20 g/m2 combined with foliar spray with paclobutrazol 2,000 mg/L; 3) soil drenched with potassium chlorate at 20 g/m2 combined with foliar spray with mepiquat chloride 3,000 mg/L; and 4) soil drenched with potassium chlorate at 20 g/m2combined with foliar spray with thiourea 5,000 mg/L. The results revealed that the treatment of soil drenched with potassium chlorate at 20 g/m2 combined with foliar spray with thiourea 5,000 mg/L showed the highest percentage of flowering shoots (95.83 %) and lowest percentage of young leaves shoots (4.17 %) as compared to treatments 1 and 2. The flower panicle percentage of longan plants treated with treatments 3 and 4 was higher than that of treatments 1 and 2. The width and length of longan panicle tended to be reduced by treatment 2. In terms of nutrient content, the results revealed that treatments 3 and 4
showed the highest phosphorus content in the longan shoots compared to other experiments. The leafy panicle percentage, number of flowers per panicle, flower type percentage, chlorophyll content, nitrogen, potassium, calcium and magnesium content in the longan shoots, fruit number per panicle, fruit diameter, fruit circumference, peel thickness, plup thickness, total soluble solid, fresh weight and dry weight of peel, plup and seeds of longan did not significantly differ among treatments.
