Effects of foliar fertilisers containing magnesium, copper and Zinc on yield and quality of mature tea

Abstract

Tea plantations of Southdown estate are deficient in nutrients such as Copper, Magnesium, and Zinc. This was shown by leaf analysis done in 2012 to mature tea in several tea gardens of Southdown estate. These nutrients have been given little attention in Zimbabwe tea fertilizer recommendations despite their continual removal from the tea fields during harvesting. A study was therefore conducted to assess the effect of Copper, Magnesium and Zinc foliar fertilizers on yield and quality of tea at Southdown estate, Chipinge in Zimbabwe. The experiment was laid in a randomized complete block design with 3 replications. The treatments were; no fertilizer application (control), Copper sulphate, Zinc oxide, Magnesium oxide and a combination of Copper sulphate, Magnesium oxide and Zinc oxide. The different foliar fertilizers affected yield (shoot weight and shoot density) significantly (P<0.05), Copper sulphate reduced the yield significantly, 27.3% lower than the control. Zinc oxide increased yield significantly, 23.82% higher than the control. Magnesium oxide did not have a significant effect on yield of tea. Tea quality parameters (brightness, briskness, colour of liquor, strength of liquor and milk take) were affected significantly (P<0.05) by the different foliar fertilizers. Copper sulphate gave the highest average score implying highest quality, whilst the control (no fertilizer application) gave the lowest total average score, thus the lowest yield. The different foliar fertilisers increased the quality of tea. Results from this study showed that application of Copper sulphate results in increase in quality but not in yield. Application Zinc oxide increases both yield and quality of tea. Application of Magnesium oxide results in increase in quality but not yield. Application of the combination of Copper sulphate, Magnesium oxide and Zinc oxide only improved quality but not yield of tea. There is need for further researches on the different concentrations of foliar fertilizers to determine the best concentration which improves both quality and yield of tea. There is also need to repeat the experiment for more than one season and also in different sites.