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Prospects of using Fungal Metabolites for the Management of Rumex dentatus, a Problematic Weed of Wheat.

Byline: Muhammad Akbar and Arshad Javaid

Abstract

Rumex dentatus L. is a very common weed of wheat (Triticum aestivum L.) in Pakistan. Present laboratory and pot trials were carried out to evaluate metabolites of Drechslera holmii, Drechslera biseptata and Drechslera australiensis as natural herbicides against R. dentatus. Fungal metabolites were prepared in M1D medium. In laboratory bioassays, original and 50% diluted metabolites of different Drechslera spp. significantly reduced seed germination, shoot biomass and root biomass of R.dentatus seedlings by 5-56%, 15-83% and 68-88%, and that of wheat seedlings by 8-20%, 16-38% and 28-38%, respectively.

Metabolites of D. biseptata and D. australiensis exhibited greater herbicidal activity than metabolites of D.holmii. In foliar spray repeated pot trials, original metabolites of the three Drechslera spp. significantly reduced shoot biomass of one- and two-week old plants of R. dentatus by 54-60% and 27-46%, respectively. By contrast, the effect of metabolites of all the three Drechslera spp. was non-significant on growth of wheat plants. Metabolites of D. australiensis showed the highest herbicidal activity in pot trials. It is concluded that metabolites of Pakistani Drechslera spp. possess herbicidal potential. (c) 2013 Friends Science Publishers

Keywords: Drechslera species; Fungal metabolites; Herbicidal activity; Rumex dentatus

Introduction

Rumex dentatus (family Polygonaceae) is native to southern and eastern Asia viz. China, India, Japan and Korea (Anonymous, 2013). Ecological surveys of various wheat growing areas of Pakistan have shown that R. dentatus is one of the most frequently occurring weeds of wheat (Qureshi et al., 2009; Qureshi and Bhatti, 2001; Siddiqui and Bajwa, 2001). It is an annual herb and is highly competitive causing remarkable reduction in yield of wheat (Siddiqui et al., 2010). Anjum and Bajwa (2010) reported 83% reduction in grain yield of wheat when crop and weed were grown in 1:1 ratio. R. dentatus is known for its inherent allelopathic activity, producing compounds that inhibit the growth of neighboring plants (Hussain et al.,1997). The weed not only reduces yield of wheat but also deteriorate quality of the produce (Memon et al., 2003).

Chemical herbicides are used to control R. dentatus. Although chemical herbicides have been proved very effective in controlling R. dentatus (Cheema et al., 2006; Usman et al., 2010; Naseer-ud-Din, 2011), However, we are now facing new challenges regarding weed control with these synthetic agro-chemicals such as emergence of weeds resistant to herbicides (Yuan et al., 2007; Llewellyn et al., 2009; Farooq et al., 2011), and concerns about herbicide effects in food, soil, ground water and atmosphere (Marin et al., 2003; Rial-Otero et al., 2005). Keeping in mind these shortcomings of herbicides and overwhelming demand for organic farming in the world, scientists are in search of alternative environmental friendly weed management strategies. In this regards use of crude and pure natural herbicidal constituents of plants and fungi has gained much attention in current years as an alternative to synthetic herbicides (Javaid and Adrees, 2009; Javaid, 2010; Javaid et al., 2013).

There are many successful stories to control weeds by the use of fungal metabolites (Evidente et al., 2008; Javaid and Ali, 2011; Vurro et al., 2012).

Many fungal species of the genus Drechslera are plant pathogen (Jorgensen and Olsen, 2007; Rabbani et al., 2011). Metabolites of some species of Drechslera have also been reported to have herbicidal effects (Evidente et al., 2005). Evidente et al. (2006) reported that Drechslera gigantea, a fungal pathogen isolated from Digitaria sanguinalis produced phytotoxins in liquid and solid cultures which were potential mycoherbicide of grassy weeds. Earlier, Shukla et al. (1990) isolated a phytotoxin Drechslerol-C that was highly effective against an invasive plant species Costus speciosus. Javaid et al. (2011) reported that metabolites of some Drechslera species from Pakistan exhibited potential herbicidal activity against noxious parthenium weed (Parthenium hysterophorus L.). Likewise, Akbar and Javaid (2012a, b) found that metabolites of Drechslera species were very effective against two problematic grassy weeds of wheat namely Avena fatua and Phalaris minor.

However, data concerning the herbicidal effect of Drechslera species against a problematic broad- leaf weed of wheat R. dentatus is lacking. Therefore, the present study was designed to evaluate herbicidal potential of metabolites of three Drechslera species from Pakistan against R. dentatus.

Materials and Methods

Preparation of Culture Filtrates of Test Fungi

Three Drechslera spp. viz. D. australiensis, D. holmii and D. biseptata were obtained from Fungal Culture Bank of Pakistan, Institute of Agricultural Sciences, Punjab University Lahore. Mineral medium (M1D) was prepared in distilled water as described by Evidente et al. (2006). This medium comprised of 1.2 mM Ca(NO3)2, 0.79 mM KNO3, 0.87 mM KCI, 3.0 mM MgSO4, 0.14 mM NaH2PO4, 87.6 mM sucrose, 27.1 mM ammonium tartrate, 7.4 mM FeC13, 30 mM MnSO4, 8.7 mM ZnSO4, 22 mM H3BO3 and 4.5 mM KI. To adjust 5.5 pH of the medium, 0.1 M HCl was used.

In each 500 mL conical flask, 200 mL M1D medium was autoclaved at 121degC for 30 min. After cooling at room temperature, flasks were inoculated with actively growing fungal discs of 5-mm diameter and incubated at 252oC for 28 days. Fungal cultures were filtered using sterilized muslin cloth, centrifuged at 4000 x g for ten minutes followed by filtration through sterilized Whatman filter paper No. 1. Dilutions of 50% were prepared by addition of sterilized distilled water to the original metabolites (100%) following Javaid et al. (2013).

Laboratory Bioassays

The effect of original and diluted metabolites of the three test Drechslera species was assessed on germination as well as on early seedling growth of R. dentatus and a wheat var. Uqab 2000 in 9-cm diameter Petri plates. Seeds of wheat and R. dentatus were surface sterilized with 1% sodium hypochlorite for 10 min. Twenty seeds of each of the test weed species and wheat were arranged on sterilized filter paper beds in Petri plates. To each Petri plate, 3 mL of fungal metabolites were poured. Treatments with 3 mL of M1D medium (Original and 50% diluted) served as positive control while distilled water was used in negative control treatment. All the treatments were performed in quadruplicate. Plates were arranged in a completely randomized design at 16degC with 10 h light period daily in a growth room. After 15 days, seed germination, and length and fresh weight of root and shoot were recorded. To determine dry biomass, materials were placed in an electric oven for 72 h at 60degC (Javaid and Ali, 2011).

Foliar Spray Pot Trials

These experiments were conducted during November- December 2010 in University of the Punjab, Lahore, Pakistan. Mean daily temperature and relative humidity in the months of November and December were 20degC and 15degC, and 62% and 67%, respectively. Plastic pots (12-cm deep, 8-cm diameter), each containing 350 g soil having sandy loam texture, 0.69% organic matter, pH 7.8, available phosphorus 6.3 mg kg-1, exchangeable potassium 100 mg kg-1 and 350 mg kg-1 nitrogen content. Seeds of wheat and R. dentatus (10 in each pot) were sown in these pots on November 20, 2010. Each treatment was replicated four times. Pots were placed in open under natural environmental conditions. Pots were divided into two groups after germination so that foliar spray can be executed on 1-week and 2-week old plants. Experiment was conducted using completely randomized design.

Experiment regarding the effect of foliar spray on R. dentatus was repeated to confirm the herbicidal potential of fungal metabolites against the target weed species.

Foliar spray with original metabolites of the three Drechslera spp. was carried out on 1-week and 2-week old weed and wheat plants four times with intervals of four days. About 5 mL of fungal metabolites were sprayed on each pot to completely moist the plants. Spray with distilled water was carried out on plants of negative control whereas M1D medium without fungal inoculation was used for spray on plants of positive control treatment. All the sprays were carried out during evening hours. After 50 days growth, weed and wheat plants were carefully uprooted and washed thoroughly under tap water to remove soil. Then these plants were allowed to remain under fan, set on a water absorbent at room temperature until excess moisture was evaporated. Various plant vegetative growth parameters viz. shoot length, and dry biomass of root and shoot were recorded (Javaid et al., 2011).

Statistical Analysis

All the data of laboratory and pot bioassays were subjected to analysis of variance (ANOVA). Treatment means were separated by applying Duncan's Multiple Range Test at 5% level of significance (Steel et al., 1997).

Results

Laboratory Bioassays

The effect of M1D broth was non-significant on germination of R. dentatus in Petri plate laboratory bioassays. Metabolites of all the three Drechslera spp. significantly reduced germination to variable extents. The highest reduction in germination was due to original metabolites (100%) of D. biseptata (up to 56% reduction) followed by those of D. australiensis and D. holmii, respectively. The original metabolites of D. australiensis and D. holmii reduced germination significantly by 12% and 40%, respectively (Table 1).

Original M1D growth medium exhibited significant effect on shoot growth of R. dentatus resulting in 15%, 17% and 15% reduction in length, and fresh and dry weight of shoot, respectively. However, the effect of diluted M1D medium was non-significant on different shoot growth parameters. Negative effect of the different fungal metabolites was significant on various shoot growth parameters as compared to control. Original metabolites of D. australiensis showed the highest toxicity and reduced shoot length and dry biomass of the weed by 85% and 88%, respectively. Similarly, original metabolites of D. biseptata caused 81% and 83% decline in shoot length and dry biomass, respectively. Metabolites of D. holmii showed the least herbicidal activity resulting in 73% and 72% reduction in length and dry weight of shoot over control, respectively (Table 1). Root growth of R. dentatus exhibited more susceptibility to fungal metabolites application than shoot growth.

There was 82-94% and 77-88% decline in root length and biomass, respectively due to various fungal metabolite treatments. Metabolites of D. australiensis showed the highest activity in inhibiting various root growth parameters of R. dentatus. This species caused 94% and 88% reduction in root length and root dry weight, respectively (Table 1).

The effect of growth medium on the germination of wheat was non-significant when compared with control. Different fungal metabolites reduced germination of wheat by 8-15% over control. However, the effect of all the metabolites except 100% metabolites of D. holmii was non- significant on germination of wheat (Table 2). Original growth medium had significant adverse effect on various shoot and root growth parameters. However, the effect was far low as compared to fungal metabolites. There was 18% and 10% suppression in shoot length and dry biomass because of original growth medium, and 30-38% and 28-38% reduction in these parameters over control due to original concentration of different fungal metabolites, respectively. Similarly, original growth medium significantly reduced root length and dry biomass by 17% and 15% while various fungal metabolites suppressed these growth parameters by 38-67% and 33-38%, respectively, over control (Table 2).

Foliar Spray Pot Trials

Data presented in Table 3 shows that foliar spray with growth medium had non-significant effect on length as well as dry biomass of R. dentatus shoot. Shoot length of 1-week old weed plants was significantly reduced by foliar spray with metabolites of each of the three fungal species. Similarly, spray with metabolites of D. australiensis and D. bisepta significantly reduced shoot length of 2-week old weed plants. Metabolites of D. australiensis caused the highest reduction in shoot length (42%) of 1-week old weed plants. Metabolites of D. holmii and D. biseptata showed comparatively less pronounced herbicidal activity against the test weed species causing 33% and 23% reduction in shoot length of 1-week old plants, respectively. In general, the adverse effect of metabolites of various test fungal species on shoot biomass was comparable to that of their effect on shoot length.

The highest decline of 60% in shoot biomass of 1-week old plants was recorded due to application of metabolites of D. australiensis followed by D. biseptata (56%) and D. holmii (54%). Negative effect of foliar spray on shoot biomass was more pronounced in 1- week than in 2-week old plants. Root biomass of the weed was significantly suppressed in 1-week old plants by 68-82% due to foliar spray of different Drechslera species.

Metabolites of D. australiensis proved to be the most effective, inhibiting root biomass by 82% followed by 74% and 68% reduction in root biomass due to metabolites of D. holmii and D. biseptata, respectively. Herbicidal activity of metabolites of various fungal species on 2-week old plants was comparatively less pronounced, where 58-73% reduction in root biomass was recorded.

The effect of all the fungal metabolite treatments on shoot and well as root biomass of wheat var. Uqab 2000 was non-significant both on 1-week and 2-week old plants (Table 4).

Discussion

In the recent years, there is a growing trend from synthetic compounds towards natural ecofriendly compounds. In search of natural herbicidal compounds based upon fungal metabolites, a number of highly successful attempts have been taken (Evidente et al., 2006; Berestetskiy, 2008). However, studies about the herbicidal activity of metabolites of Pakistani Drechslera species are scarce. The present study was, therefore, designed to investigate the herbicidal potential of metabolites of Drechslera spp. from Pakistan against a problematical weed of wheat. In general, metabolites of all the three test Drechslera spp. namely D. australiensis, D. biseptata and D. holmii, exhibited herbicidal activity to variable extent against R. dentatus.

In laboratory bioassays, generally original concentration of the M1D growth medium reduced germination, length as well as fresh and dry biomass of R. dentatus seedlings. However, this effect was far less pronounced as compared to the effect of fungal metabolites. Original growth medium reduced germination, shoot length, shoot dry biomass, root length and root biomass by 5%, 15%, 15%, 14% and 6%, respectively. On the other hand, original metabolites of various Drechslera species suppressed germination, shoot length, shoot dry biomass, root length and root biomass by 12-56%, 73-85%, 72-88%, 82-94% and 77-88%, respectively.

Although contents of the original growth medium exhibited adverse effect on germination and seedlings growth to some extent, however, it is very likely that most of the medium contents were used during the 28 days growth period of the test fungal species, and the effect of the medium components was probably negligible in the fungal metabolite treatments.

Table 1: Effect of metabolites of three Drechslera species on germination and growth of Rumex dentatus in laboratory bioassays

Fungal species###Conc. (%)###Germination###Shoot###length Shoot fresh wt.###Shoot dry wt. Root###length Root fresh wt. Root dry wt.

###(%)###(mm)###(mg)###(mg)###(mm)###(mg)###(mg)

Control###0###100 a###19.0 a###5.4 a###1.20 a###18.8 a###0.87 a###0.155 a

Growth medium###50###97 a###17.7 a###4.9 ab###1.15 ab###18.3 a###0.78 a###0.140 b

###100###95 a###16.2 b###4.5 b###1.02 b###16.1 b###0.77 a###0.145 ab

D. holmii###50###95 a###7.1 c###1.7 cd###0.47 c###5.6 c###0.25 b-d###0.050 cd

###100###88 b###5.2 de###1.2 de###0.34 c-e###3.4 d###0.36 b###0.035 de

D. biseptata###50###48 d###4.9 e###1.1 de###0.27 d-f###2.7 de###0.13 cd###0.034 de

###100###44 d###3.6 f###0.7 e###0.21 ef###1.8 ef###0.08 d###0.019 f

D. australiensis###50###59 c###6.5 cd###1.1 de###0.28 d-f###3.1 d###0.15 cd###0.032 ef

###100###60 c###2.9 f###0.7 e###0.14 f###1.2 f###0.08 d###0.019 f

Table 2: Effect of metabolites of three Drechslera species on germination and growth of wheat variety Uqab 2000 in laboratory bioassays

Fungal species###Conc. (%)###Germination Shoot###length Shoot fresh wt. Shoot dry wt. Root###length Root fresh wt. Root dry wt.

###(%)###(mm)###(mg)###(mg)###(mm)###(mg)###(mg)

Control###0###100 a###131 a###90 a###5.0 a###109 a###65 a###9.6 a

Growth medium###50###97 ab###113 b###86 ab###4.8 ab###101 a###56 b###8.9 a

###100###94 a-c###107 c###81 bc###4.5 bc###91 b###51 bc###8.1 b

D. holmii###50###90 b-d###100 d###76 c###4.0 de###81 c###42 de###6.6 cd

###100###85 de###75 h###51 e###3.1 h###49 e###36 ef###6.4 cd

D. biseptata###50###92 b-d###96 de###67 d###3.9 d-f###76 c###43 de###6.7 cd

###100###88 c-e###91 f###54 e###3.4 gh###68 d###39 ef###6.4 cd

D. australiensis###50###89 b-d###100 d###80 c###4.2 cd###82 c###48 cd###6.9 c

###100###80 f###81 g###54 e###3.6 e-g###35 f###34 f###6.0 d

Values with different letters in a column show significant difference (P 0.05) as determined by Duncan's Multiple Range Test

Note: 100% means original growth medium and fungal metabolites

Table 3: Effect of foliar spray of metabolites of three Drechslera spp. on growth of 1-week and 2-week old plants of Rumex dentatus

Rumex dentatus

Treatment time###Treatments###Shoot length (cm)###Shoot dry biomass (g)###Root dry biomass (g)

1-week old Plants###Control###6.44 a###0.072 a###0.066 a

###Growth medium###6.34 a###0.070 a###0.065 a

###D. holmii###4.30 c###0.033 e###0.017 d

###D. biseptata###4.96 c###0.032 e###0.021 cd

###D. australiensis###3.72 d###0.029 e###0.012 e

2-week old plants###Control###6.44 a###0.072 a###0.066 a

###Growth medium###6.34 a###0.070 a###0.065 a

###D. holmii###6.16 a###0.044 c###0.023 c

###D. biseptata###5.62 b###0.052 b###0.028 b

###D. australiensis###4.15 c###0.039 d###0.018 d

Table 4: Effect of foliar spray of metabolites of three Drechslera spp. on growth of 1-week and 2-week old plants of wheat

Treatment time###Treatments###Shoot length (cm)###Shoot dry biomass (g)###Root dry biomass (g)

1-week old Plants###Control###37.10 a###0.39 a###0.210 a

###Growth medium###37.08 a###0.37 a###0.202 a

###D. holmii###35.82 a###0.36 a###0.183 a

###D. biseptata###36.25 a###0.34 a###0.180 a

###D. australiensis###36.17 a###0.37 a###0.202 a

2-week old plants###Control###37.10 a###0.39 a###0.210 a

###Growth medium###37.08 a###0.37 a###0.202 a

###D. holmii###36.20 a###0.34 a###0.192 a

###D. biseptata###35.50 a###0.34 a###0.195 a

###D. australiensis###35.75 a###0.37 a###0.203 a

Values with different letters in a column show significant difference (P 0.05) as determined by Duncan's Multiple Range Test

In laboratory bioassays, metabolites of all the test Drechslera spp. reduced seed germination of R. dentatus by 12-56%. Earlier, Idrees and Javaid, (2008) have reported 23% decrease in germination of P. hysterophorus seeds due to metabolites of D. hawaiiensis. In a similar study, Javaid and Adress (2009) reported 20%, 30% and 93% decline in germination of P. hysterophorus seeds due to metabolites of D. biseptata, D. australiensis and D. rostrata, respectively.

In the present study, metabolites of D. australiensis exhibited the best herbicidal activity against shoot groth of R. dentatus. Recently, Akbar (2013) isolated a herbicidal constituent namely holadysenterine from culture filtrates of this fungal species which may be responsible for herbicidal activity against the target weed species. Other herbicidal metabolites isolated from various Drechslera spp. so far include de-O-methyldiaporthin, drazepinone, Ophiobolin E and 8-epi-ophiobolin J (Hallock et al., 1988; Evidente et al., 2005, 2006).

Earlier, Akbar and Javaid (2010) studied the herbicidal effect of metabolites of the presently tested Drechslera species using malt extract as growth medium instead of M1D medium used in the present. The results of the two studies reveal that M1D is comparatively better growth medium than malt extract for the preparation of fungal metabolites for management of weeds of wheat. Recently, Javaid et al. (2013) have also reported similar differential herbicidal effects of metabolites of Trichoderma spp. prepared in M1D and malt extract growth media against P. hysterophorus. The variable herbicidal potential of the fungal metabolites prepared in different growth media could be due to the formation of different quantities of metabolites in different growth media (Zonno et al., 2008). In the present study, seedling growth of weed species was also adversely affected by metabolites of the test Drechslera species.

Similar inhibition in seedling growth of other weed species such as P. hysterophorus has also been reported due to metabolites of Drechslera and other fungal species (Javaid and Adrees, 2009; Javaid et al., 2011). Findings of the present study reveal that metabolites of different test Drechslera spp. showed variable herbicidal activity against the germination and seedling growth of the weed. Metabolites of D. biseptata were found more effective in suppressing germination of the test weed species than the metabolites of other two fungal species. Dissimilarity in herbicidal activity of different Drechslera spp. has also been reported against growth of P. hysterophorus seeds (Javaid and Adrees 2009; Javaid et al., 2011). Differential herbicidal activity of metabolites of different Drechslera spp. could be attributed to the variation in chemical constituents of different fungal species (Evidente et al.,2005; Eneyskaya et al., 2009; Yang et al., 2009).

In general, root growth was more susceptible than shoot growth to different fungal metabolites in laboratory bioassays. It is due to the fact that roots are the first to absorb herbicidal constituents from the surrounding, thus they show greater susceptibility to the applied materials than shoots (Noor and Khan, 1994).

In pot experiments, the effect of foliar spray with M1D medium on growth of the weed as well as wheat plants was nonsignificant. Although metabolites of all the Drechslera species exhibited pronounced herbicidal activity against R. dentatus, however, D. australiensis was found to be the most effective fungal species causing 42% reduction in shoot length of 1-week old weed plants. Adverse effects of foliar spray on shoot biomass of R. dentatus were more pronounced in 1-week old than in 2-week old plants. Although roots were not directly exposed to foliar spray application, however, root biomass in R. dentatus was also severely suppressed in 1-week old plants by 68-82% due to foliar spray of different Drechslera species.

Previously, various studies conducted regarding the effect of foliar spray of metabolites of different pathogenic fungi including species of Fusarium, Alternaria and Drechslera against P. hysterophorus support the findings of the present study and suggested that fungal metabolites can be exploited as herbicides (Idrees and Javaid, 2008; Javaid and Adrees, 2009; Javaid et al., 2011).

In laboratory as well as pot trials, the effect of metabolites of various test Drechslera species was more severe on germination and growth of weed than that of wheat. Differential response of wheat and R. dentatus to the same fungal metabolites could be ascribed to different morphological and anatomical characteristic of the two plant species as wheat is monocotyledonous while R. dentatus is dicotyledonous. The differential response of R. dentatus and wheat to fungal metabolites can be best exploited in the management of R. dentatus by the metabolites of Drechslera spp.

The present investigation concludes that metabolites of all the three Drechslera species possess herbicidal potential against R. dentatus. Metabolites of D. australiensis exhibited the highest herbicidal activity. Further studies are needed to isolate and identify the effective herbicidal constituents from culture filtrates of D. australiensis to be used as structural lead for the synthesis of natural product based herbicides for management of R. dentatus.

References

Akbar, M. and A. Javaid, 2010. Management of some problematic weeds of wheat by metabolites of Drechslera sp. prepared in malt extract medium. Pak. J. Weed Sci. Res., 16: 145-151

Akbar, M. and A. Javaid, 2012a. Herbicidal activity of fungal culture filtrates against Chenopodium album L. and Avena fatua L. J. Anim. Plant Sci., 22: 977-982

Akbar, A. and A. Javaid, 2012b. Evaluation of herbicidal potential of fungal metabolites against Phalaris minor. Afr. J. Microbiol. Res., 6:4053-4057

Akbar, M., 2013. Isolation of herbicidal constituents from culture filtrates of Drechslera spp. for the management of some noxious weeds of wheat. Ph. D. Thesis University of the Punjab, Lahore, Pakistan

Anjum, T. and R. Bajwa, 2010. Competition losses caused by Rumex dentatus L. and Chenopodium album L. in wheat (Triticum aestivum L.). Philipp. Agric. Sci., 93: 365-368

Anonymous, 2013. Flora of North America. Available at: http://www.efloras.org/florataxon.aspx?flora_id=1 and taxon_id=200006747. (Accessed on 17 February 2013)

Berestetskiy, A., 2008. A review of fungal phytotoxins: from basic studies to practical use. Appl. Biochem. Microbiol., 44: 453-465

Cheema, M.S., M. Akhtar and M.S. Iqbal, 2006. Performance of different herbicides in wheat under irrigated conditions of southern Punjab, Pakistan. Pak. J. Weed Sci. Res., 12: 53-59

Eneyskaya, E.V., G. Sundqvist, A.M. Golubev, F.M. Ibatullin, D.R. Ivanen, K.A. Shabalin, H. Brumer and A.A. Kulminskaya, 2009. Transglycosylating and hydrolytic activities of the b-mannosidase from Trichoderma reesei. Biochimie, 91: 632-638

Evidente, A., A. Andolfi, M. Vurro, M. Fracchiolla, M.C. Zonno and A. Motta, 2005. Drazepinone, a trisubstituted tetrahydronaphthofuro- azepinone with herbicidal activity produced by Drechslera siccans. Phytochemistry, 66: 715-721

Evidente, A., A. Andolfi, A. Cimmino, M. Vurro, M. Fracchiolla, R. Charudattan and A. Motta, 2006. Ophiobolin E and 8-epi-ophiobolin J produced by Drechslera gigantea, a potential mycoherbicide of weedy grasses. Phytochemistry, 67: 2281-2287

Evidente, A., A. Cimmino, A. Andolfi, M. Vurro, M.C. Zonno, C.L. Cantrell and A Motta, 2008. Phyllostictines A-D, oxazatricycloalkenones produced by Phyllosticta cirsii, a potential mycoherbicide for Cirsium arvense biocontrol. Tetrahedron, 64: 1612-1619

Farooq, M., K. Jabran, Z.A. Cheema, A. Wahid and K.H.M. Siddique, 2011. The role of allelopathy in agricultural pest management. Pest Manage. Sci., 67: 494-506.

Hallock, Y.F., J. Clardy, D.S. kenfield and G. Strobel, 1988. De-O- methyldiaporthin, a phytotoxin from Drechslera siccans. Phytochemistry, 27: 3123-3125

Hussain, F. B.S. Farrukh, K. Mobeen and S. Yoo, 1997. Allelopathic suppression of wheat and mustard by Rumex dentatus ssp. klotzschianus. J. Plant Biol., 40: 120-124

Idrees, H. and A. Javaid, 2008. Screening of some pathogenic fungi for their herbicidal potential against parthenium weed. Pak. J. Phytopathol.,20: 150-155

Javaid, A., 2010. Herbicidal potential of allelopathic plants and fungi against Parthenium hysterophorus - a review. Allelopathy J., 25: 331-344

Javaid, A. and H. Adrees, 2009. Parthenium management by cultural filtrates of phytopathogenic fungi. Nat. Prod. Res., 23: 1541-1551

Javaid, A. and S. Ali, 2011. Herbicidal activity of culture filtrates of Trichoderma spp. against two problematic weeds of wheat. Nat. Prod. Res., 25: 730-740

Javaid, A., A. Javaid and M. Akbar, 2011. Herbicidal potential of Drechslera spp. culture filtrates against Parthenium hysterophorus L. Chil. J. Agric. Res., 71: 634-637

Javaid, A., G. Shafique, S. Ali and A. Shoaib, 2013. Effect of culture medium on herbicidal potential of metabolites of Trichoderma species against Parthenium hysterophorus. Int. J. Agric. Biol., 15:119-124

Jorgensen, L.N. and L.V. Olsen, 2007. Control of tan spot (Drechslera tritici-repentis) using cultivar resistance, tillage methods and fungicides. Plant Prot., 26: 1606-1616

Llewellyn, R.S., F.H. D'emden and M.J. Owen, 2009. Herbicide resistance in rigid ryegrass (Lolium rigidum) has not led to higher weed densities in western Australian cropping fields. Weed Sci., 57: 61-65

Marin, A., J., Oliva, C. Garcia, S. Navarro and A. Barba, 2003. Dissipation rates of cyprodinil and fludioxonil in lettuce and table grape in the field and under cold storage conditions. J. Agric. Food Chem., 51:4708-4711

Memon, R.A., G.R., Bhatti and S. Khalid, 2003. Weed diversity of wheat crop in khairpur district, Sindh. Pak. J. Weed Sci. Res., 9: 99-103

Naseer-ud-Din, G.M., M.A. Shehzad and H.M. Nasrullah. 2011. Efficacy of various pre and post-emergence herbicides to control weeds in wheat. Pak. J. Agric. Sci., 48: 185-190

Noor, M. and M.A. Khan, 1994. Allelopathic potential of Albizia samans Merr. Pak. J. Bot., 26: 139-147

Qureshi, R. and G.R. Bhatti, 2001. Determination of weed communities in wheat field of district Sukhur. Pak. J. Bot., 33: 109-115

Qureshi, R., A. Waheed and M. Arshad, 2009. Weed communities of wheat crop in district Toba Tek Singh, Pakistan. Pak. J. Bot., 41: 239-245

Rabbani, N., R. Bajwa and A. Javaid, 2011. Influence of culturing conditions on growth and sporulation of Drechslera hawaiiensis, the foliar blight pathogen of Marsilea minuta L. Afr. J. Biotechnol., 10:1863-1872

Rial-Otero, R., M.E. Arias-Estevez, B. Lopez-Periago, Cancho-Grande and J. Simal-Gandar, 2005. Variation in concentrations of the fungicides tebuconazole and dichlofluanid following successive applications to greenhouse-grown lettuces. J. Agric. Food Chem., 53: 4471-4475

Shukla, R.S., P.K. Agrawal, R.S. Thakur and A. Husain, 1990. Drechslerol- C, a phytotoxin produced by Drechslera maydis, the causal organism of leaf blight of Costus speciosus. Plant Sci., 66: 43-49

Siddiqui, I. and R. Bajwa, 2001. Variation in weed composition in wheat fields of Lahore and Gujranwala divisions. Pak. J. Biol. Sci., 4:492-504

Siddiqui, I., R. Bajwa, Zil-E-Huma and A. Javaid, 2010. Effect of six problematic weeds on growth and yield of wheat. Pak. J. Bot., 42:2461-2471

Steel, R.G.D., J.H. Torrie and D. Dickey, 1997. Principles and Procedures of Statistics: A Biometrical Approach, 3rd edition. McGraw Hill BookCo. Inc. New York

Usman, K., S.K. Khalil, A.Z. Khan, I.H. Khalil, M.A. Khan and Amanullah, 2010. Tillage and herbicides impact on weed control and wheat yield under rice-wheat cropping system in northwestern Pakistan. Soil Till. Res., 110: 101-107

Vurro, M., A. Andolfi, A. Boari, M.C. Zonno, S. Caretto, F. Avolio and A. Evidente, 2012. Optimization of the production of herbicidal toxins by the fungus Ascochyta caulina. Biol. Cont., 60: 192-198

Yang, H.H., S.L. Yang, K.C. Peng, C.T. Lo and S.Y. Liu, 2009. Induced proteome of Trichoderma harzianum by Botrytis cinerea. Mycol. Res., 113: 924-932

Yuan, J.S., P.J. Tranel and C.N. Stewart, 2007. Non-target-site herbicide resistance: a family business. Trends Plant Sci., 12: 6-13

Zonno, M.C., M. Vurro, S. Lucretti, A. Andolfi, C. Perrone and A.Evidente, 2008. Phyllostictine A, a potential natural herbicide produced by Phyllosticta cirsii: In vitro production and toxicity. Plant Sci., 175: 818-825

Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan

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Author:Akbar, Muhammad; Javaid, Arshad
Publication:International Journal of Agriculture and Biology
Article Type:Report
Geographic Code:9PAKI
Date:Dec 31, 2013
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