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A study on allelopathic effect of Pinus roxburghii bark extract on a common weedPhalaris minor was conducted. The aqueous extracts of different concentrations were prepared and tested for germination and seedling growth of P.minor. The bark extracts showed inhibitory effect on germination and seedling growth of test plant in concentration dependent manner. The role of active principle (s) of allelopathy has been suggested. Allelopathic Effect of Pinus Roxburghii Bark Extract on Phalaris Minor

The ACIAR-managed project CS1/1996/013, Herbicide-resistant weeds of wheat in India and Australia: integrated management, was designed to find a long-term method of control of Phalaris minor, a problem weed of the rice–wheat cropping system of north-western India. By 1993, the weed had developed resistance to isoproturon, a herbicide which had delivered effective weed control for 15 years. The short-term solution, implemented before the ACIAR project commenced, involved identification and registration of a new set of herbicides. But these new herbicides were expensive. To ensure high adoption they needed to be combined with changes in wheat-growing techniques that would provide cost savings to help farmers pay for them. And to avoid the re-emergence of chemical resistance, they needed to be used sparingly as one element in a broader approach to weed management. The project team used these circumstances to field-test and encourage adoption of zero tillage, a technology that agronomists had been advocating for many years, but which had failed to capture the interest of Indian farmers. Zero tillage has the potential to deliver big cost savings. In addition, it provides prospects for yield increases by allowing early sowing of wheat and avoiding soil degradation. Project research established that zero tillage also provided effective weed control with only a moderate reliance on chemicals, making the re-emergence of herbicide resistance remote. We calculate a gain to the Indian economy of around $1800 million in net present value terms over the next 30 years from the adoption of zero tillage to control Phalaris minor infestation in the rice–wheat areas of north-western India. This leads to an extremely high ratio of benefits to project costs. Zero tillage by itself is clearly a profitable technology. It does not need a weed problem to justify its introduction. Without the ACIAR project, zero tillage would have been introduced to the region, though somewhat later than what has occurred. On the assumption that the ACIAR project has advanced the adoption profile of zero tillage by 3 years, we calculate gains that can be attributed to ACIAR’s role of $238 million in net present value terms over the next 30 years. This gain has been achieved with total expenditures on the ACIAR-managed project amounting to only $1.3 million in present values.

The field experiment was conducted at Students’ Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana during rabi 2013–14 to study the bio-efficacy of two new brand formulations-Penda 30 EC and Markpendi 30 EC for control of Phalaris minor in wheat. New brand formulations of pendimethalin (Penda 30 EC and Markpendi 30 EC) @ 2.5 l/ha were tested against recommended brand formulation (Stomp 30 EC) @ 2.5 l/ha and unsprayed check in randomized block design in three replications. The tested new brand formulations of pendimethalin (Markpendi 30 EC and Penda 30 EC) were at par to earlier recommended brand (Stomp 30 EC) with respect to weed population, dry matter accumulation and wheat grain yield.

Two field experiments were conducted to determine the economic threshold level of C. album and P. minor in wheat. Different densities viz., check (weed free). 50. 100. 150. 200. 250. 300. 350. 400. 450 and 500 m-2 of each weed species were maintained separately. Grain yield obtained from plots having C, album densities up to 250 m-2 was not statistically different from that obtained from weed free plots (check). In P. minor, minimum grain yield was obtained at the highest weed density of 500 m-2 as compared with that in the absence of weeds.

A field experiment was conducted to estimate nutrient losses by Phalaris minor Retz, in wheat under different fertilizer application methods and competition periods. The study consisted of a Side-placement and a broadcast incorporate method of fertilizer application, and competition periods of O, 3, 4, 5, 6, 7 and 8 wk after emergence (WAE) and full season competition. Nitrogen, P, K, uptake by Phalaris minor Retz, was 11.33, 1.20 and 8.34 kg.ha-1 respectively, using the broadcast incorporate method whereas full season competition resulted in a maximum uptake of 28.41 kg.ha-1, N and 3.13 kg.ha-1 P by Phalaris minor Retz. Potassium uptake by Phalaris minor Retz, reached a maximum (17.45 kg.ha -1) at 8 wk competition. Nitrogen, P, and K concentrations in wheat were higher in Side-placement than in the broadcast incorporate method of fertilizer application. Wheat under zero competition showed higher N, P, and K concentrations than that of the different competition periods.

Cytological studies in 49 taxa belonging to 27 genera and 39 species of grasses from the plains and hills of North India have been carried out. One species Agropyron striatum has been cytologically investigated for the first time and new chromosome numbers have been made available for 8 more species. These species are: Agrostis semiverticillata (n=21), Helictotrichon virescens (n=21), Dactyloctenium aristatum (n=20), D. sindicum (n=10), Festuca modesta (n=7), Sporobolus.fimbriatus (n=27), Oryzopsis munroi (n=12), and Paspalidium flavidum (2n=44). Accessory chromosomes have been reported for the first time in Phleum himalaicum, Agropyron striatum, Polypogon fugax and phalaris minor.

Loss in activity of foliar-applied methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} occurred under low soil moisture conditions. A loss in control of yellow foxtail [Setaria lutescens(Weigel) Hubb.], wild oats (Avena fatuaL.), little-seed canarygrass (Phalaris minorRetz.), and barnyardgrass [Echinochloa crus-galli(L.) Beauv.], was observed under greenhouse and growth chamber conditions. When soil was maintained at 2 to 3% above wilting point as compared to near field capacity, herbicide activity was decreased by 15 to 50%. High soil moisture (at or above 67% of field capacity) for at least 2 to 4 days following treatment was needed to achieve maximum effectiveness of the herbicide. Daily furrow irrigations for a period of 10 days following treatment of barnyardgrass in the field resulted in highest activity as compared to that under single irrigation regimes within the 10-day period. The effect of low soil moisture was minimized by increased rates of herbicide application. Hoe-29152 {methyl-2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoate} showed similar losses in activity associated with low soil moisture. No consistent changes in uptake or translocation of14C-labeled diclofop could be detected in association with altered soil moisture status.

Results of field experiments, with sodium, amine and ester formulations of 2,4-D, terbutryne, hand weeding and unweeded controls, with and without post sowing planking, showed that terbutryne applied post-emergence almost completely eliminated weed competition from wheat on a clay loam soil notorious for weed growth, and gave a significantly higher grain yield when compared with the standard 2,4-D treatments. As a result of terbutryne applied post-emergence mean increases in grain yield over the unweeded control, 2,4-D sodium, 2,4-D amine, 2,4-D ester and hand weeding were 14.53, 6.94, 9.54, 7.26 and 8.77 quintals (q)/ha; 41.70, 16.30 23.90, 17.20 and 29.06% respectively. Weed dry matter was reduced by 18.57, 6.26, 6.36, 6.31 and 5.87 q/ha respectively. Terbutryne also reduced difficult to control weeds like Phalaris minor and Avena fatua. The use of terbutryne was shown to be economically sound. Post sowing planking seemed to reduce seedling emergence, increase weed dry matter and slightly reduc...

The receptive surfaces of the stigma papillae of Phalaris minor (Gramineae) bear a superficial proteinaceous layer outside of the cuticle. Using the peroxidase labelling technique, it has been shown that this surface layer or pellicle binds the lectin concanavalin A. Glycoproteins in the pellicle may play a part in pollen adhesion as well as in pollen-stigma recognition.

We report here the discovery and characterization of a fibrous mineral contaminant of the diet in that area of north-east Iran where oesophageal cancer has a very high incidence. This contaminant has a smoothly tapering shape and is between 50 and 150 micrometers long. The greatest diameter is between 1 and 10 micrometers and this decreases to a sharply pointed tip with a radius of curvature of between 0.25 and 0.60 micrometers. Electron microscope X-ray analysis shows that this fibre consists almost entirely of silica. It is free from alkali metals, aluminium and iron, and therefore differs from other known natural or manmade mineral fibres. Examination of the seeds of more than sixty different species of weed know to contaminate the wheat in this area of the Middle East shows that the fibre originates from the seeds of the common Mediterranean grass Phalaris minor. This seed bears fibres of the same dimensions, composition and birefringence, borne upon the inflorescence bracts which envelop the pericarp of the seeds of this and other members of the phalaris genus. They are broken off from the seed when the wheat is milled but persist in the flour, where up to 3,000 are found in each gram. Similar fibres can be isolated in quantity from the seeds of related species which are grown commercially, and they have a similar size and composition. When cells of the 3T3 mouse fibroblast line are exposed to these fibres in semi-solid suspension culture, their proliferation is stimulated more than 100-fold. We present an hypothesis for the involvement of these plant mineral fibres in the aetiology of oesophageal cancer in Iran and in other areas of high incidence.

In field experiments conducted at the Punjab Agricultural University, Ludhiana during 1973–74 and 1974–75, pre-emergence application (one day after sowing) of methabenzthiazuron (1.05 kg a.i./ha), metoxuron (1.6 kg a.i./ha) and chlortoluron (0.75 kg a.i./ha) gave effective control of Phalaris minor and Avena ludoviciana in wheat without any phytotoxic effect on the crop. Methabenzthiazuron, metoxuron and chlortoluron gave 1410, 1420 and 1090 kg/ha, respectively, more grain than the unweeded crop and 590, 600 and 270 kg/ha more than the crop hand-weeded twice. Nitrofen (1.25 kg a.i./ha) applied pre-emergence was effective against P. minor only and gave substantial increase in grain yield. Terbutryne, dichlormate and linuron, while effective against P. minor, also had a phytotoxic effect on the crop.

Field investigations were conducted at the Punjab Agricultural University, Ludhiana, India, during 1980–81 and 1981–82 to study the influence of selective broad‐spectrum herbicides (isoproturon, metoxuron and methabenzthiazuron) applied post‐emergence in improving the utilization of applied nitrogen (40, 80, 120 and 160 kg N/ha). Phalaris minor Retz, was the dominant weed in the field. On average (mean of two crops), the herbicide treated crop gave 42.2% higher grain yields than the crop given two hand‐weedings (hoeing). Isoproturon and metoxuron were more effective than methabenzthiazuron. The interaction for nitrogen x weed control treatments was significant for both crop seasons. The isoproturon (0.94 kg/ha) and metoxuron (1.5 kg/ha) treated crop under N80 gave significantly higher grain yield than the hand‐weeded crop given 120 and 160 kg N/ha during both crop seasons. Methabenzthiazuron (1.3 kg/ha) induced a similar response during 1980–81 only.

The selective action of MSMA, benzoylprop-ethyl, nitrofen, dichlormate, terbutryne and methabenzthiazuron and their combinations with 2, 4-D for control of grass weeds in spring wheat (Triticum aestivum L.) was studied in two field experiments at Haryana Agricultural University, Hissar, India, during 1975–76 and 1976–77. The differences in response among wheat, wild canarygrass, wild oats and broadleaved weeds to post-emergence herbicides were very variable. Methabenzthiazuron at 1.75 and 2.0 kg/ha and terbutryne at 0.60 to 0.75 kg/ha sprayed in the wheat crop at maximum tillering stage killed more than 70% of wild canarygrass (Phalaris spp.) and wild oats (Avena spp.) with no injury to the crop plants, resulting in the highest grain yield. The application of 2, 4-D (0.50 kg/ha) controlled only 55% wild canarygrass and 40% wild oats but significantly increased the wheat yields over the unweeded control. The other post-emergence herbicides were not effective in controlling both weeds selectively. ...

Control of littleseed canarygrass (Phalaris minor Retz.), wild oat (Avena fatua L.), common lambsquarters (Chenopodium album L.), and field bindweed (Convolvulus arvensis L.) in dwarf wheat (Triticum aestivum L.) fields was studied with five herbicides and hand weeding. Terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] and 1-benzthiazol-2-yl-1,3-dimethylurea controlled the weeds more effectively than did two hand weedings. Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], nitrofen (2,4-dichlorophenyl p-nitrophenyl ether), and dichlormate (3,4-dichlorobenzyl methylcarbamate), proved only partially effective against weeds, and were therefore significantly inferior to two hand weedings. Spikes per meter of row length and test weight of wheat were increased significantly by 1-benzthiazol-2-yl-1,3-dimethylurea (1.5 to 2 kg/ha), terbutryn (0.5 kg/ha), and two hand weedings over the yields of the weedy check. The 1-benzthiazol-2-yl-1,3-dimethylurea showed a high degree of selectivity in the wheat crop at 2 kg/ha and increased yields to those of weed-free plots. Terbutryn was almost as effective as 1-benzthiazol-2-yl-1,3-dimethylurea, which increased the wheat yields over those of the weedy check by 19.8 and 42.4% during the 1974/75 and 1975/76 seasons, respectively. Tolerance of dwarf wheat to terbutryn at 0.75 kg/ha was variable, resulting in significant decreases in yield components and grain yield. Dry-matter yield of wheat was negatively correlated with the dry matter production of weeds.

In field experiments carried out at the Punjab Agricultural University, Ludhiana (India) during 1971–72 and 1972–73, methabenzthiazuron (70% a.i. w.p.) and nitrofen (24% wt/vol a.i.) applied pre-emergence gave remarkable control (90%) of Phalaris minor L. (canary grass) in wheat. This work on the successful control of this obnoxious grassy annual weed in wheat is the first of its kind in the country. For these light textured soils (0.21% organic carbon and 75% sand), the effective dose of nitrofen was 1.20 kg a.i./ha and for methabenzthiazuron 0.70–1.05 kg a.i./ha. Nitrofen was specific for Phalaris only, whereas methabenzthiazuron controlled Phalaris, Avena fatua L. and Chenopodium sp. as well. These herbicides exhibited good selectivity to the crop. The maximum gains in grain yield due to herbicidal treatment over the weedy control were 1790 and 2510 kg/ha respectively for nitrofen and methabenzthiazuron.

Field investigations on a moderately fertile silty clay loam soil in the northwestern Himalayas revealed that the weed flora in wheat crops in this zone comprised mainly of three grassy weeds: Phalaris minor Retz., Avena fatua L. and Lolium temu‐lentum L. Cultural manipulations such as closer spaced rows, i.e. 15 cm spacing between rows, and/or cross row sowing in combination with the application of isoproturon at 0.50 kg a.i./ha applied 2 weeks after sowing significantly reduced the density of Phalaris minor and Avena fatua weeds. The dry weight of these grassy weed species was significantly lowered with the application of isoproturon irrespective of its rate and time of application. Isoproturon application at a rate of 1 kg a.i./ha or 0.50 kg a.i./ha in combination with cross row sowing, normal row spacing of 22.5 cm or closer spaced rows of 15 cm reduced the weed competition and resulted in positive advantages in yield attributes and increased the grain yield of wheat.

Fusariella hughesii sp. n. is described and illustrated. The fungus was isolated from the dispersal units of Phalaris minor Retz. and Trigonella arabica Del.

Allelopathic potentiality of hexane, ethyl acetate and methanol extracts of the Himalyan lichen, Parmelia reticulate Taylor, at different concentrations (50, 25 and 12.5 μg ml -1 ) was studied on germination and early seedling growth of highly devastating weed Phalaris minor . The experiments were carried out in portray maintained in natural environment. Current investigation has revealed concentration dependent allelopathic phenomenon of the lichen extracts on P. minor . Hexane and ethyl acetate extracts at 50 μg ml -1 exhibited maximum detrimental effect on seed germination (56% as compared to control i.e. 90%). Hexane extract at 50 μg ml -1 showed maximum inhibition of early seedling growths, determined in terms of shoot and root lengths of the test weed. It reduced shoot and root lengths to 2.5cm (control 10.7 cm) and 0.9 cm (control 3.4cm) respectively, indicating semipolar nature of constituents responsible for bioactivity.

The effect of cold and hot aqueous leaf extracts of Lantana camara L. on the germination and seedling growth of Phalaris minor Retz. and Sorghum bicolor L. (Moench) was evaluated. Bioassays indicated that the inhibitory effect of the allelopathic plant on the germination percentage (GP), inhibition percentage (IP) and seed germination index (SGI) of the two recipient weed species was proportional to the concentration of the extract. High concentrations had stronger inhibitory effect than low concentrations that showed no stimulatory effect on both species. Both plumule (PL) and radicle (RL) lengths of the recipient species were affected negatively due to the addition of L. camara extracts and this effect was directly proportional to the concentration and more significant in the case of the radicle of P. minor compared with S. bicolor. Our results suggested that L. camara aqueous extract could be used as a potential allelopathic substance for some weed bio-control.

Littleseed canarygrass (Phalaris minor Retz.) is one of the most common and troublesome weeds infesting wheat crop in India. Repeated use during the last two decades of the ACCase-inhibiting herbicide (clodinafop) to control this weed has resulted in the occurrence of resistance. Fifty-three P. minor populations were collected from wheat fields in Haryana and Punjab states of India. The dose–response assays indicated that 29 populations were resistant, 23 populations were susceptible and one population was moderately resistant to clodinafop. Sequence analysis of the CT domain of ACCase gene among resistant and susceptible populations revealed two non-synonymous mutations, Trp2027 to Cys and Ile2041 to Asn in the resistant populations. Allele-specific PCR markers were developed to differentiate between wild-type and resistant codons at positions 2027 and 2041 of ACCase in P. minor which enables molecular assays for rapid detection and resistance diagnosis for efficient weed management in wheat. This is the first report from India of a target site mutation corresponding to resistance to clodinafop in P. minor.

Chlorophyll fluorescence measurement is a precise research technique that can be used for studying the effect of herbicides with different modes of action on photosynthetic apparatus. The aim of the present project was to study the variation of the fluorescence induction curve (Kautsky curve) and its variables affected by pinoxaden (ACCase inhibitor) and mesosulfuron-methyl + iodosulfuron herbicide (ALS inhibitor) in littleseed canarygrass (Phalaris minor Retz.) and wild oat (Avena ludoviciana Durieu). This study was carried out at the Greenhouse of Collage of Agriculture at Ferdowsi University of Mashhad, during 2013. Experiments were performed based on a completely randomized design in form of a dose-response test with six doses of each herbicide plus an untreated control. The maximum quantum efficiency of photosystem II (PSII) was measured 1, 2, 3, 5 and 7 days after spraying (DAS). The results obtained in the study indicated that the estimated EDs parameters differed based on herbicide types or weed species. For example, ED90 varied from 11.67 to 28.61 g active ingredient (a.i.) ha-1. Moreover, the results showed that application of mesosulfuron-methyl + iodosulfuron at doses higher than 9 g a.i. ha-1 changed the shape of the chlorophyll fluorescence induction curve (Kautsky curve) in littleseed canarygrass at 7 DAS while herbicide doses of mesosulfuron-methyl + iodosulfuron did not change the shape of the Kautsky curve in wild oat. In addition, the Kautsky curve was observed to have an approximate permanent drop for littleseed canarygrass species at 2 DAS by pinoxaden. Comparing the fluorescence parameters in wild oat and littleseed canarygrass treated with two herbicides showed that Fv/Fm, the maximum quantum efficiency of PSII and Fvj, variable fluorescence at the J step of littleseed canarygrass decreased more than the mentioned parameters in wild oat. Furthermore, there was a strong relationship ranging from 0.53 to 0.79 between dry weights after 4 weeks and fluorescence parameters at 7 DAS depending on the herbicide type and weed species. Applying fluorescence parameters a few days after treatment to predict biomass production can be a defining criterion in research and development stages of herbicides to eliminate the need for whole plant bioassay. This method can also be applied to shorten the bioassay screening period and function as a suitable and cost effective indicator for monitoring of ACCase and ALS inhibitors. This approach also demonstrates serious damages to plant photosynthesis apparatus on crop during herbicide misapplication. RESUMO: A medição da fluorescência da clorofila é uma técnica de pesquisa precisa que pode ser usada para o estudo do efeito de herbicidas com diferentes modos de ação no aparato fotossintético. O objetivo deste projeto foi estudar a variação da curva de indução de fluorescência (curva de Kautsky) e suas variáveis afetadas pelos herbicidas pinoxaden (inibidor da ACCase) e mesosulfuron-methyl + iodosulfuron (inibidores da ALS) na erva-cabecinha (Phalaris minor Retz.) e no aveião (Avena ludoviciana Durieu). Este estudo foi realizado na casa de vegetação do College of Agriculture, Ferdowsi University of Mashhad, durante o ano de 2013. Os experimentos foram feitos em delineamento inteiramente casualizado, na forma de avaliação dose-resposta, com seis doses de cada herbicida e um controle não tratado. A eficiência quântica máxima do fotossistema II (PSII) foi medida 1, 2, 3, 5 e 7 dias após a pulverização (DAS). Os resultados indicaram que houve diferenças nos parâmetros estimados de DE, de acordo com os tipos de herbicidas ou espécies de plantas daninhas. Por exemplo, a DE90 variou de 11,67 a 28,61 g de ingrediente ativo (i.a.) ha-1. Além disso, os resultados mostraram que a aplicação de mesosulfuron-methyl + iodosulfuron em doses superiores a 9 g i.a. ha-1 modificou a forma da curva de indução da fluorescência da clorofila (curva de Kautsky) na erva-cabecinha aos 7 DAS, enquanto as doses dos herbicidas mesosulfuron-methyl + iodosulfuron não alteraram a forma da curva de Kautsky no aveião. Além disso, observou-se queda permanente aproximada na curva de Kautsky para a espécie erva-cabecinha aos 2 DAS, em função do pinoxaden. A comparação dos parâmetros de fluorescência no aveião e na erva-cabecinha, tratados com dois herbicidas, mostrou que Fv/Fm, eficiência quântica máxima do PSII e Fvj e fluorescência variável no passo J da erva-cabecinha tiveram maior redução do que os mesmos parâmetros para o aveião. Além disso, houve forte relação (com variação de 0,53 a 0,79) entre os pesos secos após quatro semanas e os parâmetros de fluorescência aos 7 DAS, dependendo do tipo de herbicida e da espécie de planta daninha. A aplicação de parâmetros de fluorescência alguns dias após o tratamento para prever a produção de biomassa pode ser um critério de definição em estádios de pesquisa e desenvolvimento de herbicidas para eliminar a necessidade de bioensaio com a planta inteira. Esse método também pode ser aplicado para encurtar o período de rastreio do bioensaio e funcionar como um indicador adequado e rentável para o monitoramento dos inibidores da ACCase e da ALS. Essa abordagem também demonstra sérios danos ao aparato fotossintético das plantas na cultura durante a aplicação incorreta do herbicida.

Cross-inoculation tests with urediniospores of Puccinia striiformis , between wheat and different grass species, established that Bromus mollis, B. unioloides, Hordeum hystrix, H. leporinum, H. marinum, H. vulgare, Phalaris minor, P. paradoxa and Triticosecale were accessory hosts to P. striiformis f.sp. tritici in Victoria.