EFFECTS OF LEAFS AND Leucaenea leucocephala DIFFERENT TREE DEPTH SOIL ON THE ALLELOPATHY OF AGRICULTURAL CROPS

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1 ISSN (Online) J. Innov. Dev. Strategy ():-9(April ) EFFECTS OF LEAFS AND Leucaenea leucocephala DIFFERENT TREE DEPTH SOIL ON THE ALLELOPATHY OF AGRICULTURAL CROPS R. PARVIN, T.L. SHAPLA AND M.H.A. AMIN Department of Agroforestry, Hajee Mohammad Danesh Science and Technology University, Bangladesh; Assistant Professor, Department of Agroforestry & Environmental Science, Sher-e-Bangla Agricultural University, Bangladesh. Corresponding author & address: M.H.A. Amin, hafizallamin@yahoo.com Accepted for pulication on 3 March ABSTRACT Parvin R, Shapla TL, Amin MHA () Effects of leafs and Leucaenea leucocephala different tree depth soil on the allelopathy of agricultural crops. J. Innov. Dev. Strategy (), -9. A pot experiment was conducted at the Agroforestry Farm, Hajee Mohammad Danesh Science and Technology University during May 9 to July 9 to oserve the allelopathic effects of Leucaena leucocephala, two agricultural crops viz. mungean and soyean. There were five treatments viz.: T (top soil); T (root zone soil); T 3 (soil mulched with dry leaf); T (soil watered with aqueous leaf extract); T (control/fresh garden soil). The experiments were laid out in the Randomized Complete Block Design (RCBD) with four replications. The results of the present studies revealed that inhiition of germination and growth parameters of mungean and soyean were varied according to different parts of plants and soil from different place. Leucaena leucocephala: T (soil watered with aqueous leaf extract) > T (top soil) > T 3 (soil mulched with dry leaf) > T (control / fresh garden soil) >T (root zone soil). Key words: different soil depth, allelopathic effects, agricultural crops INTRODUCTION Allelopathy has traditionally een considered only the negative chemical warfare of one organism upon another (Bansal 99). Modern research suggests that allelopathic effects can e oth positive and negative, depending upon the dose and organism affected (Bhene et al. 977). Allelopathic is the active or passive effects of chemicals released into the environment, which influences the releaser, itself or other organs (Chou 98; Hale and Orcutt, 987; Miller 983). Allelopathy signifies that interactions etween plants might lead to either stimulation or inhiition of growth. Agroforestry is an integrated approach of using the interactive enefits from comining trees and shrus with crops and/or livestock. It comines agricultural and forestry technologies to create more diverse, productive, profitale, healthy and sustainale land-use systems USDA National Agroforestry Center (NAC). According to the World Agroforestry Centre, Agroforestry is a collective name for land use systems and practices in which woody perennials are delierately integrated with crops and/or animals on the same land management unit. The integration can e either in a spatial mixture or in a temporal sequence. There are normally oth ecological and economic interactions etween woody and non-woody components in agroforestry. In agroforestry systems, trees or shrus are intentionally used within agricultural systems, or nontimer forest products are cultured in forest settings. Knowledge, careful selection of species and good management of trees and crops are needed to optimize the production and positive effects within the system and to minimize negative competitive effects. Leucaena leucocephala, is the common tree species which are planted with agricultural crops e.g. Mungean, soyean, wheat, maize, rice, vegetales etc. There must e significant interaction (positive or negative) etween these components of Agroforestry i.e. woody perennials and agricultural crops. Therefore, it seems essential that the allelopathic compatiility of crops with trees should e checked efore introducing in agroforestry system (Khan and Alam, 99; Hossain et al. ). So, the study was performed to fulfill the following ojectives: to assess aout the allelopathic effects of Leucaena leucocephala used tree species on agricultural crops. MATERIALS AND METHODS The experiment was conducted in the Agroforestry research field, Department of Agroforestry, Hajee Mohmmad Danesh Science and Technology University, Dinajpur, located etween 3' latitude and 88º3' longitude and aout 37.m aove sea level. The climate of the study area is characterized y scanty rainfall during Rai season (Novemer to Feruary) and minimum rainfall during this period of the year. The mean of maximum temperature in winter (Novemer to Feruary) was 7.9 C and the mean of minimum temperature 7. C. The mean humidity during this period was 8.9. The mean rainfall was found 8.8 mm during this period from Novemer to Feruary. Duration of the experimental period was from May to July. The experiment was conducted with single factor. RCBD (Randomized Complete Block Design) were applied with four replications. These are: (Five) treatments i) T =Top soil (depth of top soil is cm.), ii) T =Root zone soil (depth of root zone soil is feet), iii) T 3 =Soil mulched with dry leaves (sun dry), iv) T =Soil watered with aqueous Leaf extract (% fresh aqueous leaf extract) and v) T =Ordinary/Fresh garden soil. The selected test crops were Mungean (Vigna radiata) and Soyean (Glycine max). The experimental pot size was 8. cm.. cm and each pot containing kg of soil as germination media. The treatment T -Top soil was collected from the native woodlots of the tree crops (depth of top soil iscm), T - root zone soil collected from the root Copyright Green Gloal Foundation J. Innov. Dev. Strategy (): April

2 Parvin et al. systems of tree crops from native woodlots (depth of root zone soil is feet), T 3 - Garden soil collected from experimental garden and oven dried crushed leaves ( gms) mulched in the upper layers of each pot, T - Garden soil watered with aqueous extract of fresh leaves of tree crops, and T - Garden soil watered with ordinary water served as control. The pots were carried in the experimental field in th April. After cleaning the weeds in the experimental field y spade, the pots were placed. 3 pots were filled with top soil and pots were filled with root zone soil in 7 th May. pots were filled with garden soil in 8 th May.% aqueous wash of the fresh leaves of tree was made in th May and ml of this extract was added to each of pots which containing garden soil. Leaves of the trees were sun dried for days. g crushed leaves were added in each pots as mulched in th May. Other pots were used as control and the pots were filled with ordinary garden soil. Source of the crops seed were BADC, Dinajpur and varieties were BINA Mung and BARI Soyean. Seeds of crops were sown in each pot in th May. The pots were watered regularly. Weeding was done periodically whenever necessary. Seed germination (%) was recorded after days of sowing. Then all plants were uprooted except plants in each pot. seedling attriutes, such as length of shoot(cm), no. of leaves, leaf length(cm), leaflet reath(cm), shoot diameter(cm) were recorded at,3, and days after sowing and root length(cm), root fresh weight(gm), shoot fresh weight(gm) were recorded at days after sowing. Fresh roots and shoots were oven dried for three days and dry weights were recorded at days after sowing. By using the sum of root dry weight and shoot dry weight, total iomass of the plants were found. The collected data on various parameters under different experiments were statistically analyzed using statistical program MSTAT to find out the statistical significance of the treatment effects. The means for all the treatments were calculated, and analysis of variance for all the characters were performed y the F-test. The significance of difference etween the pair of means was evaluated y the Least Significant Difference (LSD) test (Gomez and Gomez, 98). RESULTS AND DISCUSSION The results otained from the present studies along with statistical analysis of data have een presented here. Allelopathic effects of Leucaena leucophala on Mungean (Vigna radiata) Germination Percentage The germination percentage significantly varied in all the treatments over control (Fig. ). Among the five treatments, the maximum inhiition (-.7) was found in the treatment T (soil with aqueous leaf extracts) followed y the treatment T (top soil) and T 3 (soil mulched with dry leaf). A little stimulatory effect (+7.) was gained in the treatment T (root zone soil). Germination % % Inhiition and stimulation over control Germination % 8 aa - Numer of Leaf Fig.. Allelopathic effects of Leucaena leucocephala on germination of Mungean Note: Mean followed y a common letter is not significantly different at the % level y DMRT No. of leaf of mungean was significantly influenced in all the treatments in respects to control (Fig. ). Significantly the maximum suppression (-7.8 at DAS; -7. at 3 DAS; -. at DAS and -. at DAS) was recorded in the treatment T (soil watered with aqueous leaf extracts) and the minimum was oserved (-.9 at DAS; -.3 at 3 DAS; -.9 at DAS and -.7 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+3. at 3 DAS; +8.7 at 3 DAS; +.8 at DAS and +.88 at DAS) was found in the T treatment (root zone soil). J. Innov. Dev. Strategy (): April

3 Effects of leafs and Leucaenea leucocephala different tree depth soil on the allelopathy of agricultural crops Shoot Length (cm) Fig. Allelopathic effects of Leucaena leucocephala on no. of leaf of Mungean In respects to control shoot length of mungean was significantly varied in all the treatments (Fig. 3). Significantly the maximum suppression (-7.3 at DAS; -9. at 3 DAS; -.8 at DAS and -.33 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was noted (-.8 at DAS; -. at 3 DAS; -. at DAS and -.8 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+9.9 at 3 DAS; at 3 DAS; +. at DAS and +8.7 at DAS) was found in the T treatment (root zone soil). Shoot length (cm) 3 3 Leaf Length (cm) Fig.3. Allelopathic effects of Leucaena leucocephala on Shoot Length of Mungean Leaf length of mungean was significantly influenced in all the treatments in comparism to control (Fig.). Significantly the maximum suppression (-.83 at DAS;.93 at 3 DAS; -8. at DAS and -.9 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was reported (-.8 at DAS; -.79 at 3 DAS; -.3 at DAS and -.3 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+. at 3 DAS; at 3 DAS; +. at DAS and +.7 at DAS) was found in the T treatment (root zone soil). Leaf length (cm) 8 8 Fig.. Allelopathic effects of Leucaena leucocephala on Leaf Length of Mungean 3 J. Innov. Dev. Strategy (): April

4 Parvin et al. Leaflet Breath (cm) All the treatments significantly influenced the leaflet reath of mungean in respects to control (Fig. ). Significantly the highest suppression (-8.9 at DAS; -. at 3 DAS; -.97 at DAS and -.3 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the lowest was found (-.8 at DAS; -. at 3 DAS; -. at DAS and -. at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+9.9 at 3 DAS; +. at 3 DAS; +.3 at DAS and +.93 at DAS) was reported in the T treatment (root zone soil). 7 Leaflet reath (cm) 3 Leaflet reath(cm) Leaflet reath(cm) Leaflet reath(cm) Leaflet reath (cm) Fig.. Allelopathic effects of Leucaena leucocephala on Leaflet reath of Mungean Shoot Diameter (cm) Shoot diameter of mungean was significantly influenced in all the treatments over control (Fig.). Significantly the maximum suppression (-.7 at DAS; -.87 at 3 DAS; -. at DAS and -7.9 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was oserved (-. at DAS; -.93 at 3 DAS; -.7 at DAS and -.78 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+.7 at 3 DAS; +.93 at 3 DAS; +.7 at DAS and +.9 at DAS) was found in the T treatment (root zone soil). Shoot Diameter (cm) Fig.. Allelopathic effects of Leucaena leucocephala on Shoot diameter of Mungea Tale. Allelpoathic effects of Leucaena leucophala on Germination and Growth of Mungean Root length (cm) Shoot Fresh Shoot Dry Root Fresh Root Dry Total Dry Matter(g) T. (-.9).3c (-3.9) 3. (-.). (-.8) 3.7c (-3.) 7.3c (-3.9) T 9.a (+.7) 9.7a (+.7).39a (+9.7) 9.7a (+.9).3a (+8.8).9a (+3.7) T 3. (-.93) 7.78 (-.) 3.98 (-.).7 (-3.9).8 (-8.99) 8. (-.3) T 3.c (-.).8c (-3.) 3.c (-.).78c (-.) 3.3c (-.33).c (-3.8) T. 8.8a a 9.3 Level of sig. * * * * * * CV% Note: Mean followed y a common letter is not significantly different at the % level y DMRT * = Significant at % level of proaility; NS = Not Significant J. Innov. Dev. Strategy (): April

5 Effects of leafs and Leucaenea leucocephala different tree depth soil on the allelopathy of agricultural crops Root Length (cm) It was showed that all the treatments significantly suppress the root length of that crop (Tale ). Among five treatments, only T (root zone soil) shows little stimulatory effect (+.7) on root length of mungean. The longest inhiitory effect (-.) was otained in soil treated with T treatment (aqueous leaf extract) over control whereas, the shortest inhiitory effect (-.93) was found in the treatment T 3 (soil with dry leaf). Shoot Fresh Weight (g) Shoot fresh weight of mungean significantly suppressed under all the treatments in comparison to control (Tale ). Significantly the highest inhiition (-3.) was recorded in the treatments T (soil with aqueous leaf extract) which was statistically similar to that of T (top soil). The treatment T (root zone soil) promotes (+.7) the shoot fresh weight over control of that crop. Shoot Dry Weight (g) The highest suppression (-.) of shoot dry weight was otained in the treatment of T (soil with aqueous leaf extract). But the lowest inhiition (-.) was reported in the treatment T 3 (soil with dry leaf) which statistically followed y top soil over control. All the treatments significantly inhiit the shoot dry weight of mungean except root zone soil (Tale ). Root Fresh Weight (g) Significantly the highest inhiition (-.) of root fresh weight was oserved in the treatment T (soil with aqueous leaf extract). But the lowest inhiition (-3.9) was found in the treatment T 3 (soil with dry leaf) followed y top soil. Stimulatory effect (+.9) was gained in the treatment T (root zone soil). It was oserved that all the treatments show significant different (Tale ). Root Dry Weight (g) Root dry weight significantly inhiited in all treatments except root zone soil (Tale). The highest suppression (-.33) of root dry weight was oserved in the treatment T (soil with aqueous leaf extract) which was statistically similar to treatment T (top soil) in respects to control. But the lowest suppression (-.3) was recorded in the treatment T 3 (soil treated with dry leaf). The treatment T (root zone soil) significantly promoted (+8.8) the root dry weight of mungean. Total Dry Matter (g) All the treatments significantly inhiit the shoot dry weight of mungean except T (soil collected from root zone) which promoted the total dry matter. Mungean total dry matter inhiition (-3.8) was high in the treatment T (soil watered with aqueous leaf extract) followed y T (top soil). But the lowest inhiition (-.3) was reported in the treatment T 3 (soil treated with dry leaf) in comparison to control (Tale ). Allelopathic effects of Leucaena leucophala on Soyean (Glycine max) Germination Percentage The germination percentage significantly varied in all the treatments over control (Fig. 7). Among the five treatment, the maximum inhiition (-.3) was found in the treatment T (soil with aqueous leaf extracts) followed y the treatment T (top soil) and T 3 (soil mulched with dry leaf).there was a little stimulatory effect (+7.3) was gained in the treatment T (root zone soil). Germination % % Inhiition and stimulation over control 8 a Germination % a - Fig. 7. Allelopathic effects of Leucaena leucocephala on germination of Soyean J. Innov. Dev. Strategy (): April

6 Parvin et al. Numer of Leaf No. of leaf of soyean was significantly influenced in all the treatments in respects to control (Fig.8). Significantly the maximum suppression (-.7 at DAS; -8. at 3 DAS; -9.3 at DAS and -. at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was oserved (-7. at DAS; -.8 at 3 DAS; -.73 at DAS and -.83 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+8.7 at 3 DAS; +. at 3 DAS; +7. at DAS and +9.7 at DAS) was found in the T treatment (root zone soil) Fig.8. Allelopathic effects of Leucaena leucocephala on no. of leaf of Soyean Shoot Length (cm) All the treatments significantly influenced the shoot length of soyean in comparism to control (Fig. 9). Significantly the highest suppression (-7.3 at DAS; -9.9 at 3 DAS; -. at DAS and -.7 at DAS) was reported in the treatment T (soil watered with aqueous leaf extracts) and the lowest was oserved (-.83 at DAS; -.7 at 3 DAS; -. at DAS and -.98 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+. at 3 DAS; +. at 3 DAS; +3. at DAS and +8. at DAS) was found in the T treatment (root zone soil). 3 3 Fig.9. Allelopathic effects of Leucaena leucocephala on Shoot Length of Soyean Leaf Length (cm) Leaf length of soyean was significantly influenced in all the treatments in respects to control (Fig. ). Significantly the maximum suppression (-.33 at DAS; -.7 at 3 DAS; -8. at DAS and -.9 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was noted (-.8 at DAS; -.3 at 3 DAS; -.3 at DAS and -.3 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+.9 at 3 DAS; at 3 DAS; +. at DAS and +.7 at DAS) was found in the T treatment (root zone soil). 8 8 Fig.. Allelopathic effects of Leucaena leucocephala on Leaf Length of Soyean J. Innov. Dev. Strategy (): April

7 Effects of leafs and Leucaenea leucocephala different tree depth soil on the allelopathy of agricultural crops Leaflet Breath (cm) Leaflet reath of soyean was significantly influenced in all the treatments over control (Fig. ). Significantly the maximum suppression (-. at DAS; -. at 3 DAS; -.7 at DAS and -. at DAS) was recorded in the treatment T (soil watered with aqueous leaf extracts) and the minimum was oserved (-. at DAS; -3.3 at 3 DAS; -7.7 at DAS and -.9 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+.8 at 3 DAS; +. at 3 DAS; +. at DAS and +. at DAS) was found in the T treatment (root zone soil). Leaflet reath (cm) 3 Leaflet reath(cm) Leaflet reath(cm) Leaflet reath(cm) Leaflet reath (cm) Shoot Diameter (cm) Fig.. Allelopathic effects of Leucaena leucocephala on Leaflet Breath of Soyean There was significant variation was ovserved of shoot diameter of soyean in all the treatments (Fig. ). Significantly the maximum inhiition (-.7 at DAS; -.89 at 3 DAS; -.9 at DAS and -7.7 at DAS) was oserved in the treatment T (soil watered with aqueous leaf extracts) and the minimum was reported (-.9 at DAS; -.9 at 3 DAS; -.9 at DAS and -.79 at DAS) in T 3 (soil mulched with dry leaf). Significantly stimulatory effect (+. at 3 DAS; +.9 at 3 DAS; +.7 at DAS and +.9 at DAS) was found in the T treatment (root zone soil). Shoot Diameter (cm) Fig.. Allelopathic effects of Leucaena leucocephala on Shoot diameter of soyean Tale. Allelpoathic effects of Leucaena leucocephala on Germination and Growth of Soyean Root length(cm) Shoot Fresh Shoot Dry Root Fresh Root Dry Total Dry Matter(g) T 3. (-.9).3c (-.37). (-.7). (-.93).7c (-39.9).3c (-9.8) T 8.a (+.87) 8.7a (+7.7).39a (+79.7) 8.7a (+9.78).3a (+.8).9a (+.) T 3. (-3.).78 (-.87).98 (-.7).7 (-.) 3.8 (-3.8). (-.) T 3.c (-.93).8c (-39.9).c (-3.).78c (-9.9).3c (-9.3).c (-.7) T. 7.8a a 7.3 Level of sig. * * * * * * CV% J. Innov. Dev. Strategy (): April

8 Parvin et al. Root length (cm) Among the five treatments, T (soil collected from root zone soil) revealed the stimulatory effect (+.87) on root length of soyean (Tale ). The treatment T (soil with aqueous leaf extract) has largest inhiitory effect (-.93) on root length of soyean over control whereas, the shortest inhiitory effect (-3.) was found in the treatment T 3 (soil mulched with dry leaf). It was showed that all the treatments significantly suppressed the root length of that crop. Shoot Fresh Weight (g) Shoot fresh weight of soyean significantly suppressed under the three treatments in respects to control (Tale ). Significantly the highest inhiition (-37.9) was oserved in the treatment T (soil with aqueous leaf extract) which was statistically similar to that of T top soil. Treatment T (root zone soil) promoted (+7.7) the shoot fresh weight over control of that crop. Shoot dry weight (g) All the treatments significantly inhiit the shoot dry weight of soyean except root zone soil (Tale ). Soyean shoot dry weight inhiition (-3.) was high in the treatment T (soil with aqueous leaf extract). Significantly the lowest inhiition (-.7) was reported in the treatment T 3 (soil mulched with dry leaf) followed y T (top soil) over control. Root Fresh Weight (g) All the treatments have significant allelopathic on root fresh weight (Tale ). The highest inhiition (-9.9) of root fresh weight was oserved in the treatment T (soil with aqueous leaf extract). But the lowest inhiition (-.) was found in the treatment T 3 (soil mulched with dry leaf) which was significantly followed y top soil. Stimulatory effect (+9.78) was showed in the treatment T (root zone soil). Root dry weight (g) Root dry weight significantly inhiited in all treatments except root zone soil. The highest suppression (-9.3) was recorded in the treatment T (soil watered with aqueous leaf extract) followed y top soil in comparison to control and lowest (-3.8) was found in the treatment T 3 (soil mulched with dry leaf). The treatment T (root zone soil) promote (+.8) the root dry weight of soyean (Tale ). Total Dry Matter (g) All the treatments significantly inhiit total dry matter of soyean except T ( root zone soil) which shows promotory effects (+.) (Tale ). Soyean total dry matter inhiition (-.7) was high in the treatment T (soil with aqueous leaf extract) which was statically similar to that of T (top soil). But the lowest inhiition (-.) was reported in the treatment T 3 (soil treated with dry leaf) in respects to control. DISCUSSION The present study suggests that phytotoxic effects were oserved in Leucaena on germination and growth of test plants. From the experiment, among the five treatments, leaf extracts of Leucaena cotain more allelochemicals e.g. phenolic compounds and mimosine as well as unknown flavanoids (Pires et al. ). It is aggred in accordance Sahoo et al. (7). They reported that the leaf extract were more toxic than ark and seed and Leucaena was more inhiitory to germination. The toxic effects of Leucaena followed the order: crushed seeds > leaf litter > soil root zone. Root zone soil had little stimulatory effect over control ecause it contain small amount of mimosine and small amount of mimosine stimulate the germination and growth of test crops (Neelam and Bisaria, ) wherease dry leaf and top soil had inhiitory effects on germination and growth of mungean and soyean. They also oserved that seed germination, root length and dry matter production were depressed oth in Leucaena top soil and in aqueous extracts of the plant. CONCLUSION Significantly the highest suppression of mungen germination percentage (-.7), no. of leaf (-7.8), shoot length (-.8), leaf length (-8.), leaflet reath (-8.9), shoot diameter (-7.9), root length (-.), root fresh weight (-.), root dry weight (-.33), shoot fresh weight (-3.), shoot dry weight (-.), total dry matter (-3.8) were otained in the treatment T (soil watered with aqueous leaf extracts). Little stimulatory effects were gained in the treatment T (root zone soil). For soyean, the lowest suppression of germination percentage (-.3), no. of leaf (-.7), shoot length (-.), leaf length (-8.), leaflet reath (-.), shoot diameter (-7.7), root length (-.87), root fresh weight (-9.9), root dry weight (-9.3), shoot fresh weight (- 37.9), shoot dry weight (-3.), total dry matter (-.7) were otained in the treatment T (soil watered with aqueous leaf extracts). There were promotory effects were recorded in the treatment T (root zone soil). 8 J. Innov. Dev. Strategy (): April

9 Effects of leafs and Leucaenea leucocephala different tree depth soil on the allelopathy of agricultural crops Leucaena leucocephala: T (soil watered with aqueous leaf extract) > T (topsoil) > T 3 (soil mulched with dry leaf) >T (control/fresh garden soil)>t (root zone soil). REFERENCES Bansal GL (99) The Science of Allelopathy: Prolems and Prospects. In: Allelopathy in Agriculture and Forestry. eds S.S. Narwal and P. Tauro. pp Scientific Pulishers, Jodhpur, India. Bene JG, Beall HG, Cote A (977) Trees, Food and People: Land Management in the Tropics. International Development Research Center, Ottawa. Chou CH (98) The role of allelopathy in sutropical agroecosystems in Taiwan. In the Science of Allelopathy, eds. A. R. Putnam and C.S. Tang, pp New York: Wiley Interscience. Gomez KA, Gomez AA (98) Statistical procedures for Agricultural Res. nd edn. John Wiley and Sons, New York. p. 8. Hale MG, Orcutt DM (987) Physiology of plants under stress. pp Hossain MK, Dhali MAH, Hossain MS () Effects of forest soil and leaf-litter on germination and initial seedling growth of Leucaena leucocephala. Allelopathy-Journal. (), 3-. Khan MS, Alam MK (99) Homestead flora of Bangladesh. BARC, IDRC, SDC., Dhaka Bangladesh. Miller NA (983) Allelopathic effects of alfalfa. J. Chem. Ecol. 9, 9-7. Neelam-Khare, Bisaria AK () The allelopathic effect on Triticum aestivum of different extracts of Leucaena leucocephala. Indian-Journal-of-Agroforestry. (), 3-. Pires N, de M, Souza IRP, Prates HT, Faria TCLde, Pereira-Filho IA, Magalhaes PC () Effect of Leucaena aqueous extract on the development, mitotic index and peroxidase activity in maize seedlings. Revista- Brasileira-de-Fisiologia-Vegetal. 3(), -. Sahoo UK, Upadhyaya K, Meitei CB (7) Allelopathic effects of Leucaena leucocephala and Tectona grandis on germination and growth of maize. Allelopathy-Journal. (), J. Innov. Dev. Strategy (): April