GROWTH AND PHOTOSYNTHETIC PIGMENT CONTENTS OF TEA (Camellia sinensis [L.] KUNTZE) AS INFLUENCED BY LIGHT INTENSITY AND ORGANIC AMENDMENTS IN IBADAN AND OWENA

Abstract

Tea plant is a good source of antioxidants, but its production is largely limited to montane agro-ecology in Nigeria. To meet the increasing demand, there is need to expand its cultivation to the lowland. However, tea production is significantly influenced by Light Intensity (LI) and soil fertility in the lowland. Information on response of tea to Organic Fertilisers (OF) under different LI in the lowland agro-ecology is scanty. Therefore, effects of LI regulation and OF on growth and photosynthetic pigment contents of tea in Ibadan and Owena were investigated. The response of two tea cultivars, C143 and C318, to eight OF rates [Cocoa Pod Husk (CPH) and Poultry Manure (PM)], each applied at 0-F1, 75-F2, 150-F3 and 300-F4 kg Nha-1 ; NPK at 150 kg Nha-1 -F5 (inorganic check)] was evaluated in pots under four LI which were achieved with sheds of different Palm Frond Layers (PFL): L1=[(4PFL 25% LI (2.40x104 lux)]; L2=[(2PFL-45% LI (4.57x104 lux)]; L3=[(1PFL-65% LI (6.75x104 lux)] and L4=100% LI (1.04x105 lux) (control). The test samples were randomly allotted in completely randomised design in four replicates. Tea performance was further evaluated on the field with best performing treatments from the pot trial: fertiliser rates (F1, F3, F4, F5); LI (L2=45% LI, L3=65% LI, L4=100% LI, using three plantain population/ha (P1-2,222/ha; P2-1,111/ha and P3-0/ha) arranged in a randomised complete block design in four replicates. Data on Number of Leaves (NL), Leaf Area (LA, cm2 ), Dry Matter (DM, g), chlorophyll and carotenoids (mg/g) were obtained from pots and field following standard procedures. Seedling Establishment (SE), Leaf nitrogen and magnesium uptake (mg/g) were assessed on the field. Data were analysed with descriptive statistics, ANOVA and correlation at α0.05. Cultivar C143 performed significantly better than C318 in pots with 25.23±9.74NL, 665.93±297.54LA in Ibadan; and 25.38±9.82NL, 898.23±670.34LA in Owena. The L3 was superior to other LI by increasing the DM by 616.5% and 951.1% at Ibadan and Owena, respectively. Application of F4-CPH and F1 enhanced the highest DM-15.97±0.71 and the lowest-8.19±0.71, respectively, at Owena. The C143 supplied with F3-CPH under L2 in Owena had highest DM (30.85±8.66) and lowest (0.80±8.60) in F1 under L4 in Ibadan. Chlorophyll and carotenoids contents ranged from 0.21±0.87 and 0.13±0.25, respectively in C143 treated with F4-PM under L4 to 3.72±0.87 and 1.25±0.25 in C318 treated with F2-CPH and F3-CPH, respectively under L1 in Owena. Higher NL (194.50±56.30) and LA (9615.75±4056.99) were obtained in C143 which received F3-CPH under P1 on the field in Owena. The C318 that received F1 under P3 in Owena had the lowest NL (21.50±56.30), while C143 treated with F4-PM under P3 in Ibadan had the least LA (49.40±2322.08). The P1 increased DM and SE by 117.9% and 92.5%, respectively, at Ibadan, and by 94.5% and 83.3% at Owena compared to P3. Leaf nitrogen positively correlated with magnesium (r=0.96) in Ibadan, and phosphorus with iron (r=0.65) in Owena. Light intensity at 4.57x104 lux achieved with 2,222 plantain/ha enhanced tea growth, seedling establishment, chlorophyll and carotenoids content of C143 tea amended with 150 kg N/ha cocoa pod husk in Ibadan and Owena.