E & E Forum-2013 Increasing Tea Yields Through Consolidation of Fields by Infilling M.A.Wijeratne Officer-in-Charge & Senior Research Officer, TRI Low country station B.A.D.Samansiri Head, Advisory & Extension Division 1
Then Now Declining VP tea yield (Corporate sector) Yield (kg/ha/yr) 2002 2003-2008 Up country Mid Country Uva Low Country 2228 1846 1804 1499 2070 (-7.0%) 1799 (-2.5%) 1690 (-6.3%) 1693 (12.9%) Extent (ha) 2002 2008 Up country Mid Country Uva Low Country 18311 3192 5829 9162 19312 (5.5%) 3241 (1.5%) 6093(4.5%) 8580 (-6.3%) TRI Diagnostic Survey-2008 2
Cycle Average Y ield (kg /ha/yr) Cycle Average Y ield (kg /ha/yr) 26/07/2013 Yield decline of aging tea fields Age and Productivity in Low Country Region 2400 2200 2000 1800 Diagnostic survey-2008 1600 1400 1200 1000 Low country Age and Productivity of Tea in Up Country Region 2400 2200 800 0 10 20 30 40 50 2000 Age from Planting (yr) 1800 1600 1400 1200 Up country 1000 800 0 10 20 30 40 50 Age from Planting (yr) Samansiri et al-2010 Factors affecting tea yield Tea yields vary with: Weather Cultivar Soil conditions Field management practices 3
Impact of some field practices on yield Lesson learnt from the Diagnostic survey Field condition (% satisfactory fields) High (>3000kg/ha/yr) Low (<1500 kg/ha/yr) Leader & Contour Drains 68 28 Bush formation 96 40 Canopy of the bush 85 33 Leaf litter 72 34 Pruning-Cleaning 34 26 Tipping 40 24 Mossing & Ferning 34 22 Weed management 30 61 Manuring (N requirement) 10 83 Lesson learnt from the Diagnostic survey. Percentage of satisfactory fields High (>3000kg/ha/yr) Low (<1500 kg/ha/yr) Plucking-Standard 72 24 Plucking-Active shoots 72 22 Plucking Table 74 32 Shade level-high 46 26 Shade level-medium 40 34 Shade-management 40 24 4
Yield (MT-kg/ha/yr) Tea Yield (kg/ha/yr) 26/07/2013 Lesson learnt from the Diagnostic survey Percentage of infested /affected fields High (>3000kg/ha/yr) Low (<1500 kg/ha/yr) Pest-SHB -infested 52 80 Pest-Termite -infested 10 43 Disease-Canker-present 12 35 Disease-Wood rot-present 41 74 Bush stand (%) High (>3000kg/ha/yr) Low (<1500 kg/ha/yr) Bush stand % 90 65 Bush stand (density) and tea yield Casualties vs tea yield 3500 3000 2500 2000 2500 1500 1000 2000 500 0 1500 0 20 40 60 80 1000 Percentage of casualties y = -16.99x + 1926. R² = 0.869 500 0 0 20 40 60 80 100 Percentage of Casulaties 5
Summary of the analysis Low yield is largely due to high rate of casualties with: Poor soil management In appropriate bush management practices (Pruning & Plucking) Poor Shade management Pest & disease infestation Consequences of casualties in tea lands Weed infestation & competition with tea Soil erosion & degradation Low labour productivity Low yield High COP 6
Interventions for improving tea yield by Consolidation (infilling) of field Potential for improving yield by infilling Target yield by consolidation/infilling: Average yield at the most productive age of VP tea Suitable fields for consolidation: Fields with over 50% of the target yield Diagnostic survey -2008 data VP Tea UP Uva Mid Low Average yield (kg/ha/yr) (Most productive age) Yield category considered for infilling (kg/ha/yr) 2138 1807 1860 2012 >1000 >900 >900 >1000 Extent available (ha) 9675 3271 1419 4212 % of the total VP extent 50.1 53.7 43.8 55.7 7
Outcome of infilling (estimated) Potential Contribution to national tea production (Million kg/yr) VP Present Estimated Increase Up 14.2 20.6 6.4 (45%) Uva 4.6 5.9 1.3 (28%) Mid 1.9 2.6 0.7 (36%) Low 6.6 8.5 1.9 (28%) Steps to be taken Identify suitable fields for infilling/consolidation Select fields with good soil conditions about two years prior to pruning Avoid ravines, water logged areas and patches with a shallow soil (slab rocks etc) Fields earmarked for replanting (within next 2-3 cycles) should be best avoided 8
Select suitable fields Select suitable fields/blocks 9
Select suitable blocks.. Steps to be taken Prepare field for soil improvement Remove all debilitated/weak bushes (passengers) in the periphery of the vacant patches Identify pest/disease infested areas & treat them as appropriate before planting of grasses Burn in-situ pest/disease infested bushes 10
Remove passengers if any. Passengers Steps to be taken. Improve soil by Rehabilitation Remove stones/roots etc by forking to a depth of about 45 cm Construct/renovate terraces and drains Apply dolomite and plant Mana and shade trees as appropriate Lop grasses and add fertilizer periodically until next pruning 11
Planting mana. Planting mana (block infilling). 12
Establish shade. Re-cut or de-silt drains... 13
Steps to be taken Select suitable cultivars for infilling Have well grown nursery plants (jumbo bags) of suitable cultivars/improved seedlings ready by the time of planting High elevation Mid elevation Low elevations TRI 2025, TRI 3072, TRI 3073, N2, DT1, DN, CY9, K145, PK2 TRI 2025, TRI 3019, TRI 4071, TRI 4053, TRI 4042, TRI 4046, DG7, DG 39, N2 TRI 2025, TRI 2027, TRI 4049, TRI 4059, KP 204, S106, DG7 DG 39 Select suitable cultivars. TRI 4049 14
Steps to be taken. Infilling & after-care Cut deep planting holes (30cmx60cm) Add compost to the planting hole Plant tea with the onset of monsoonal rains Protect plants from trampling by workers Follow mulching & other after-care operations of young tea fields Steps to be taken Special attention be paid while: Spraying of weedicides Lopping of shade trees Fertilizer application to old bushes Pruning of old bushes Rest before pruning Adopt all sanitation practices 15
Special attention Special attention 16
Special attention Sanitary pruning Burying of prunings Economic benefits Economic benefits of infilling Productivity (Rs/ha/Yr) COP (Rs/kg) Variable cost (Rs/kg) Total cost (Rs/ha) Revenue (Rs/ha) GM (Rs/ha/yr) GM (Rs/kg) 1000 491.72 371.19 491716 400000 28810 28.81 2000 381.54 290.39 763080 800000 219225 109.61 2500 358.51 273.59 896279 1000000 316027 126.41 NSA = Rs400/kg Shyamali HW(2013) 17
Infilling not only helps increasing tea yields But also preserves the environment Acknowledgements Author wishes to thank Staff/Advisory Division, & Dr. HW Shyamali, Head, Agric. Economics Division, TRI for providing data for this presentation. Thank you 18