Allelopathy

Allelopathic potential of naturalise residues for bum management in straw down the stairs semi-arid conditions of Pakistan Muhammad Ashraf Professor of Agronomy, PMAS-Arid Agriculture University, Rawalpindi, Pakistan. emailprotected com RATIONALE come downfed Wheat- Main winter nip grown by about 80% of the farmers on residual flaw moisture, received during monsoon1. Weeds infestation- a major stick out reducing component (25-30%v) If widows weeds be controlled, crop yield can be enhance by about 37%2. 1 Khaliq et al. , 2007) 2 (Bibi et al. , 2005). Cont..Existing Weed accountant sy radixs Traditional weed control methods (Hand weeding) are time consuming, weather strung-out and labor intensive1 + Socio-economic issuessmall land holdings, family size =8, p everywherety, migration to cities herbicides habit is limited in modifylands + these are expensive with Environmental hazards2 Reduced Nutritive value of many crops 3 and Herbicide resistance4. 1 (Naveed et al. , 2008) 2 (Mancini et al. , 2008) 3 (Nazarko et al. , 2003). Cont.. WM programs should focus on environmental safety along with benefits to the farmers. Alternate weed management sy shucks need to be developed aimed to control weeds and raise the income of choice-poor farmers ( enlarged crop yields) without despoiling the natural resource base. ALTERNATE WEED MANAGEMENT OPTIONS Allelopathy ? a mechanism of plant interference1 is a natural, inexpensive, environmentally safe and an organic approach to control weeds and increase crop yields while conserving the ecosystem2. genus genus genus Sorghum is highly allelopathic3 Sorghum residue may be effectively employ to manage some of the important weeds in rainfed pale yellow without affecting crop in semi-arid environment4. (Weston, 2005) 2 (Inderjit and Duke, 2003) 1 (Weston and Duke, 2003) 2 (Inderjit and Duke, 2003) Cont.. peeing supply Extr exercises of distinct plant split have different allelopathic potential 1. helianthus possessed weed suppression ability 2 . The cabal of two or more allelopathic aqueous rips may act synergistically and cause more phyto-toxic effect on weeds 3. Mixing and applying helianthus and sorghum molasses residue peeing extract (WE) may increase the spectrum of phytotoxic personal set up and may result in synergistic phytotoxic influences on weeds growth. 1 (Ben-Hammouda, et al. 001 Chung, et al. , 2003 Roth et al. , 2000) 2 (Bertholdsson, 2004 Singh et al. , 2001 ) 3 (Duke et al. , 2000 Cheema et al. , 2010) Cont.. OBJECTIVES OF RESEARCH Overall objective Evaluate the use of allelopathic crop residue collected from summer crop plants grown under drought and mineral stress conditions for weed management in stubble in semi-arid areas of Pakistan Specific Objectives Test water supply extracts (WE)of different plant parts of sorghum residue for weeds suppression in wheat. Evaluate the effect of sorghum residue cover and sorghum WE for weed management i n wheat. Investigate the influence of sole and combined sorghum and sunflower WE disperse on weeds in wheat. experimentAL DETAILS Location tether experiments were conducted at University Research Farm, PMAS-Arid Agriculture University, Rawalpindi, Pakistan (33o 46 N, 73o 08 E). / / 500 m to a higher place the sea level Experimental years successive Rabi (winter) seasons from 2007-2010. Cont.. Environmental film Climate pelting and ET o 200 clx Rainfall and ET0 (mm) 160 143 120 ETo 80 40 0 Oct Nov Dec Jan Feb Mar Apr Rain 140 121 Mean Monthly Rainfall (mm) 20 100 80 67 60 40 26 57 56 crush Stress Period 27 21 7 15 39 43 20 0 Month Rainfall Distri besidesion (1977-11) reference work Soil and water conservation Research Institute, Chakwal, Pakistan Growing Season Rainfall Period Monthly rain (mm) Oct Nov Dec Jan Feb March April Total 2006-07 2007-08 2008-09 2009-10 long-term Av. (1977-07) 0 42 30 0 166 147 14 20 7 15 27 39 56 43 Soil characteristics Rawal vulgarism series (Inceptisol-silty-clay-loam, Typic Ustochrept USDA classification and Calcaric Cambisols FAO classification scheme) with Organic takings 0. 5%. pH 7. 40 Ece 3 dSm-1 Cont.. Weed Flora genus Anagallis arvensis L. (Blue pimfernal), Chenopodium album L. (Lambs quarter), Fumaria indica L. (Fumitory), Medicago polymorpha L. (Bur clover) Avena fatua L. (Wild oat), Convolvulus arvensis L. (Field bindweed), Medicago denticulata L. (Denticulate Medick), genus Rumex dentatus L. (Toothed dock) and Melilotus indica L. (Sweet clover) The experimental area was free of noxious and perennial weed species. Treatments (Exp-1) Control (Un-weeded check) WE Water extract Hand weeding at 60 years after sowing ( rabbit) Herbicide (Logron) 250 g ha-1 at 60 rabbit Sorghum inception WE spray 10 L ha-1 at 60 and 80 rock rabbit Sorghum stem WE spray 10 L ha-1 at 60 and 80 mouse hare Sorghum jerk WE spray 10 L ha-1 at 60 and 80 dassie Sorghum stem + root WE 5+5 L ha-1 at 60 and 80 rock rabbit Sorghum stem + pagination WE 5+5 L ha-1 at 60 and 80 rabbit Sorghum root + hitchhike WE 5+5 L ha-1 at 60 and 80 cony Treatments (Exp-2) WE Water extract Control (Un-weeded check) Hand weeding at 50 and 80 DAS Sorghum mulch 5 Mg ha-1 (Soil incorporated) Sorghum mulch 10 Mg ha-1 Soil incorporated) Sorghum WE 10 L ha-1 at 50 DAS. Sorghum WE 10 L ha-1 at 50 and 80 DAS. Sorghum WE 20 L ha-1 at 50 DAS. Sorghum WE 20 L ha-1 at 50 and 80 DAS Treatments (Exp-3) Control (Un-weeded check) WE Water extract Sunflower WE 20 L ha-1 at 50 DAS Sorghum WE 20 L ha-1 at 50 DAS Sunflower WE + sorghum WE 10 +10 L ha-1 at 50 DAS Sunflower WE 20 L ha-1 at 50 and 80 DAS Sorghum WE 20 L ha-1 at 50 and 80 DAS Sunflower WE + sorghum WE 10 + 10 L ha-1 at 50 and 80 DASResearch Methodology Preparation of water extract Sunflower and sorghum plants were harvested at maturity, corpuscles were separated and residue was sundried and chaffed with fodder cutter into 2 cm pieces. Chaffed residue was soaked in de-ionized water in 110 (1 kg each of herbage in 10 L of water) in separate containers for 24 h at room temperature to prepare water extract (WE) . WE from respective containers were obtained by filtering the mixture through a screen. The strength of respective filtrate was reduced twenty clock by endlessly boiling at 100 0C to prepare water extract (Cheema and Khaliq, 2000). Sowing and ethnical practices Seedbed was prepared by giving four cultivations each followed by planking. fertilizer 125- kg N and P2O5 ha-1 was applied at the time of seedbed preparation. Wheat cv. Inqilab-91 was sown 125 kg ha-1 was during November with a single row hand exercise in rows 30 cm apart. Layout design RCBD with 4R Eight rows 30 cm apart per treatment were maintained in plot size of 7. 0 x 2. 4 m. The wheat variety, sowing time, layout plan and other cultural practices were nigh homogeneous for every year. Measures Weeds Weed density Weed dry saddle down (biomass) Wheat pinna length (cm), Spikelets spike-1 Grains spike-1 Fertile tillers m-2 1000-grain weight. Statistical psychoanalysis The data were subjected to analysis of variance technique. F-statistic was based on residual cogitate square error.The lysergic acid diethylamide at 5% level of probability was used for comparison of treatment means (Montgomery, 2001). RESULTS & DISCUSSION Experiment 1 Phyto-toxic effects of root, stem and flicker water extract of mature sorghum on Weeds density & Dry weight Treatments Control (Un-weeded check) Hand weeding at 60 DAS Exp-1 Weed density ( m-2) 80 DAS one hundred five DAS Weeds dry weight (g m-2) 80 DAS cv DAS 147 a 79 d (-46*) 132 a 78 f (-41) 36. 7 g (-72) 102 c (-22) 112 b (-15) 113 b (-14 88 e (-33) 94 de (-29) 102 cd (-23) 8. 52 2 a 12 e (-45) 5. 5 f (-75) 18 cd (-16) 20 b (-8) 20 b (-8) 17 d (-22) 17 cd (-20) 19 bc (-14) 1. 54 27 a 17 e (-38) 8. 77 f (-67) 21 c (-21) 24 b (-11) 23 b (-14) 18 e (-34) 20 d (- 27) 27 c (-20) 1. 57 Herbicide (Logron) 250 g ha-1 34 e (-77) at 60 DAS Sorghum root WE spray 10 L 117 c (-21) ha-1 at 60 and 80 DAS Sorghum stem WE spray 10 L 129 b (-12) ha-1 at 60 and 80 DAS Sorghum leaf WE spray 10 L 127 b (-14) ha-1 at 60 and 80 DAS Sorghum stem + root emailprotected 5+5 L 113 c (-23) ha-1 at 60 and 80DAS Sorghum stem + leaf emailprotected 5+5 L 111 c (-24) ha-1 at 60 and 80 DAS Sorghum root + leaf WE 5+ 5 121 bc (-18) L ha-1 60 and 80 DAS LSD (0. 05) 10. 41 * Figures in diversion show % fall down in weed density/dry weight compared to control. Effect of root, stem and leaf water extract of mature sorghum on yield components and wheat grain yield Treatments Control (Un-weeded check) Tillers (m-2) Spike length (cm) Spikelet spike-1 Grains 1000-Grain spike-1 weight (g) Exp-1Grain yield (T ha-1) 345e Hand weeding at 60 DAS 396b Herbicide (Logron) 250 g 427a ha-1 at 60 DAS Sorghum root WE spray 10 L ha-1 at 60 and 80 DAS Sorghum stem WE spray 10 L ha-1 at 60 and 80 DAS Sorghum leaf WE spray 10 L ha-1 at 60 and 80 DAS Sorghum stem + root emailprotected 5+5 L ha-1 at 60 and 80 DAS Sorghum stem + leaf emailprotected 5+5 L ha-1 at 60 and 80 DAS Sorghum root + leaf WE 5+ 5 L ha-1 60 and 80 DAS LSD (0. 05) 9. 0e 10. 3abcd 11. 2a 10. 0bcde 9. 5de 9. 8cde 10. 9 ab 10. abc 10. 7 abc 1. 03 20. 7 21. 0 20. 9 21. 1 20. 5 21. 1 20. 2 21. 0 20. 2 41. 7c 47. 3ab 49. 4a 48. 8ab 47. 3ab 46. 1b 49. 0ab 48. 0ab 48. 0ab 3. 04 32. 5e 33. 7d 34. 6bc 35. 6a 33. 6d 33. 1de 36. 0a 33. 9cd 35. 2ab 0. 90 2. 76f 3. 2bc (+18) 3. 5a (+26) 3. 1cde (+12) 3. 0de 2. 9ef (+8) (+6) 365cde 353de 349e 357de 385bc 376bcd 54. 45 3. 3ab (+20) 3. 3abc (+19) 3. 2bcd (+14) 213. 2 * Figures in parenthesis show % decrease in weed density/dry weight compared to control.FINDINGS FROM EXPERIMENT 1 Sorghum stem + root emailprotected 5+5 L ha-1 at 60 and 80 DAS treatment caused 33% lessening in weed density and dry weight by about This reduction was 41% in hand weeding and 72% by the application of Logron 250 g ha-1 at 60 DAS The increase in grain yield in stem + root and stem + leaf WE treatments were statistically same as in hand weeding and herbicide application. Cont.. Experiment 2 RESULTS & DISCUSSIONFINDINGS FROM EXPERIMENT 2 Data showed that incorporation of sorghum herbage mulch 10 Mg ha-1 and twomultiplication sprays of Sorghum water extract 20 L ha-1 at 50 and 80 DAS decreased weeds density by about 42%, and weeds dry weight by 34%, respectively compared to control deliberate at 95DAS. Maximum increase (33%) in wheat grain yield was recorded in plots where two times Sorghum WE 20 L ha-1 was sprayed at 50 and 80 DAS over control. Cont.. Experiment 3 RESULTS & DISCUSSIONFINDING FROM EXPERIMENT 3 Sorghum water extract was more effective than sunflower water extract and combination of both these extracts performed better than their sole application. Cont.. CONCLUSION I. Stem + root water extract suppressed weed density by 33% over c ontrol i. e. about half of the effects of herbicide Logron application (72%) in wheat. The increase in grain yield in stem + root and stem + leaf WE treatments was statistically at par with hand weeding and herbicide application.Although root WE alone and in combination with stem or leaf WE was more effective in suppressing weeds and improving wheat yields but using whole plant sorghum herbage seems more practicable. II. incorporation of sorghum herbage mulch 10 Mg ha-1 and two times sprays of sorghum WE 20 L ha-1 at 50 and 80 DAS decreased weeds density by about 42%, and weeds dry weight by 34%, respectively compared to control measured at 95 DAS. Maximum increase in wheat grain yield by 33% over control was recorded in plots where two times sorghum WE 20 L ha-1 was sprayed at 50 and 80 DAS.III. Sorghum WE was more effective than sunflower WE and mixture of sorghum and sunflower reduced weed density and weed dry weight by 27% and 26% over control respectively, and increased whe at yields by 48% over control. RECOMMENDATION The mixture of preceding allelopathic crop herbage use as mulch or water extract for weed management both for summer and winter crops need to be further investigated under different ecological zones of Pakistan. Muhammad Ashraf Professor of Agronomy emailprotected com