The Combination Effects of Zinc, Magnesium, Sulphur Foliar Fertilizer Management on Cassava Growth and Yield Grown on Map Bon, Coarse-loamy Variant Soil

AbstractMicroelement fertilization is an important for adding efficiency of cassava (Manihot esculenta Crantz) production in Thailand. It had grater effects on quality of cassava root. The cassava cultivar KU 50, HB 60 and HB 80 were grown on Map Bon, coarse-loamy variant, sandy loam, low organic matter at Khao Hin Son Research Station, Khao Hin Son, Phanom Sarakham, Chachoengsao, Thailand, to evaluate the combination effects of zinc, magnesium and sulphur foliar fertilizer management on yield and quality of cassava. The experiment was carried out in a split plot in Randomized Complete Block Design (RCBD) with three replications during May 2010 to July 2011. There were five main plots; T1) non foliar fertilization, T2) foliar fertilization of Zn+Mg+S at the rate of 10 cc/20 liters of water, 30 cc/20 liters of water and 60g/20 liters of t ha-1water at 2 and 3 month after planting (2 times/month), T3) foliar fertilization of Zn+Mg at the rate of 10 cc/20 liters of water and 30 cc/20 liters of water at 2 and 3 month after planting (2 times/month), T4) foliar fertilization of Zn+S at the rate of 10 cc/20 liters of water and 60g/20 liters of water at 2 and 3 month after planting (2 times/month) and T5) foliar fertilization of Mg+S at the rate of 30 cc/20 liters of water and 60g/20 liters of water at 2 and 3 month after planting (2 times/month) and three cassava cultivars subplots; V1) KU 50, V2) HB 60 and V3) HB 80. The results illustrated that the treatment with various rates of zinc, magnesium and sulphur gave difference in fresh stem weight, fresh rhizome weight, fresh root weight (g/root) and root starch content, but the foliar fertilization with Zn+Mg+S gave the highest on its while KU 50 cultivar gave the greater effect on fresh stem weight and fresh rhizome weight, HB 60 cultivar tended to give higher fresh root yield (11.90 t rai-1 or 74.38 t ha-1) and fresh root weight (370.10g/root) but HB 80 cultivar tended to give higher root starch content (27.16%) and root number (13.81 root/plant). The Zn+Mg treatment sprayed on HB 60 cultivar gave the highest fresh root yield (15.77 t rai-1 or 98.56 t ha-1) and fresh root weight (442.45g/root) but the HB 80 cultivar with Zn+Mg+S foliar fertilization gave the highest root starch content of cassava by 29.33%