Problems Associated with Phalaris minor and Other Grass Weeds in India and Pakistan

1996 ◽  
Vol 32 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Rashid A. Shad ◽  
Sadar Uddin Siddiqui
Keyword(s):  
Cynodon Dactylon ◽  
Sorghum Halepense ◽  
Echinochloa Crusgalli ◽  
Phalaris Minor ◽  
Wild Oats ◽  
Perennial Weeds ◽  
Weed Flora ◽  
Annual Weeds ◽  
And Control ◽  
Grass Weed

SUMMARYThe composition and control of the grass weed flora of India and Pakistan are discussed, and the losses caused by the weeds are reviewed. The most important perennial weeds are Cynodon dactylon and Sorghum halepense and the most important annual weeds Echinochloa crusgalli and E. colona in the summer (kharif) crops and wild oats (Avena spp.) and Phalaris minor in the winter (rabi) crops. Losses caused by these weeds can be considerably reduced by the use of selective herbicides but these may be too expensive for many farmers. The problems and control of Phalaris minor are considered in detail.

Effects of Frequent Clipping on Three Perennial Weeds, Cynodon dactylon (L.) Pers., Sorghum halepense (L.) Pers. and Cyperus rotundus L.

1972 ◽  
Vol 8 (3) ◽  
pp. 225-234 ◽  
Author(s):  
Menashe Horowitz
Keyword(s):  
Dry Matter ◽  
Cynodon Dactylon ◽  
Matter Content ◽  
Cyperus Rotundus ◽  
The Other ◽  
Sorghum Halepense ◽  
Tuber Number ◽  
Dry Matter Content ◽  
Purple Nutsedge ◽  
Perennial Weeds

SUMMARYEstablished plants of bermudagrass (Cynodon dactylon (L.) Pers.), johnsongrass (Sorghum halepense (L.) Pers.) and purple nutsedge (Cyperus rotundus L.), grown in containers, were repeatedly clipped to the ground from spring to winter, at monthly and bi-weekly intervals. Regrowth of bermudagrass was markedly reduced after monthly clippings, but all plants regrew in the following March; there was no regeneration in March of bi-weekly clipped plants. Severe decrease of regrowth of clipped johnsongrass occurred after bi-weekly or monthly clippings, but a quarter of the clipped plants regenerated in the following March. Nutsedge was more resistant to clipping than the other two species and all clipped plants regrew vigorously in the following March. Repeated clipping reduced the rhizome length or tuber number and the dry matter content in the regrown plants in proportion to the frequency of clipping.

IMPACT OF WHEAT ESTABLISHMENT METHODS AND WEED MANAGEMENT PRACTICES ON WEED FLORA, YIELD AND NUTRIENT UPTAKE OF WHEAT IN RICE-WHEAT CROPPING SYSTEM

2019 ◽  
Vol 6 (02) ◽  
Author(s):  
MOHAN SINGH ◽  
OMBIR SINGH ◽  
ROHITASAV SINGH
Keyword(s):  
Nutrient Uptake ◽  
Weed Management ◽  
Conventional Tillage ◽  
Research Centre ◽  
Zero Tillage ◽  
Phalaris Minor ◽  
Weed Population ◽  
Metsulfuron Methyl ◽  
Transplanted Rice ◽  
Weed Flora

A field experiment was conducted at the Crop Research Centre of Govind Ballabh Pant University of Agriculture and Technology Pantnagar, Udham Singh Nagar during continuous two years to study the weed flora, yield and nutrient uptake of wheat (Triticum aestivum L.) under different wheat establishment methods in main plots and seven weed management in sub plots. Phalaris minor was the most dominant weed at 60 DAS contributed 55.0 per cent of total weed population. Melilotusindica was the major non grassy weeds in wheat which contributed 11 per cent to total weed population during respective years. Sowing of wheat with zero tillage significantly reduced the Phalaris minor density as compared to conventionally tilled wheat after transplanted rice, 60 per cent Phalaris minor emerged from 0-3 cm in reduced and conventional tillage where as in zero tillage after transplanted rice there was 55 per cent emergence from 0-3 cm layer.The highest grain yield was obtained in two hand weedings done at 30 and 60 DAS and was at par with Isoproturon 1.0 kg ha-1 + Metsulfuron methyl 4 g ha-1 at 30 DAS and Clodinafop – Propargyl 60 g ha-1 at 30 DAS fb. Metsulfuron methyl 4 g ha-1 at 37 DAS. Zero tillage resulted in significantly higher uptake of NPK by wheat plants as compared to conventional tillage, whereas reduced tillage recorded minimum NPK, which was significantly lower over the other treatments of wheat establishment methods.

Weed Control in a Conservation Tillage Rotation in the Texas Blacklands

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 695-699 ◽  
Author(s):  
Steven M. Brown ◽  
James M. Chandler ◽  
John E. Morrison
Keyword(s):  
Control Systems ◽  
Weed Control ◽  
Conservation Tillage ◽  
Grain Sorghum ◽  
Control Measures ◽  
Sorghum Halepense ◽  
Low Intensity ◽  
No Till ◽  
Primary Tillage ◽  
And Control

A field experiment was conducted to evaluate weed control systems in a conservation tillage rotation of grain sorghum [Sorghum bicolor(L.) Moench.] – cotton (Gossypium hirsutumL.) – wheat (Triticum aestivumL.). Herbicide systems included fall and spring/summer inputs of high and low intensity. Tillage regimes were no-till (NT) and reduced-till (RT) systems; the latter included fall primary tillage followed by spring stale seedbed planting. Both tillage systems utilized controlled traffic lanes and wide, raised beds. Effective johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control required intense herbicide inputs at one or both application periods, i.e., in the fall and/or spring/summer. Grain sorghum and cotton yields for the most intense weed control system, which included high inputs in both the fall and spring/summer, were not superior to systems that included high inputs in only one of the two application periods. Seedling johnsongrass emergence occurred before spring planting in RT (but not in NT) in 2 of 3 yr, and control measures were ineffective. After 3 yr, the predominant weeds were johnsongrass and browntop panicum (Panicum fasciculatumSw. # PANFA).

Chemical weed control in potatoes

1966 ◽  
Vol 67 (2) ◽  
pp. 239-242
Author(s):  
Maurice Eddowes
Keyword(s):  
Weed Control ◽  
Soil Type ◽  
Effective Control ◽  
Herbicide Treatment ◽  
Weed Flora ◽  
Annual Weeds

Dinoseb and TCA were successfully used to control weeds in potatoes by Robertson (1960), and Wood, Sutherland & Stephens (1960). Since then many investigations have been carried out on the use of newer herbicides including the bipyridils, triazines and substituted ureas. The results of a number of these studies, presented at the Seventh British Weed Control Conference (1964), suggested that herbicides might give effective control of annual weeds in potatoes under a range of British conditions. Yields of marketable ware following herbicide treatment were similar, in general, to those obtained following standard post-planting cultivations, but occasionally the yields after herbicide treatment were either as much as 20% higher or lower than the controls. The performance of the herbicides was related mainly to weed flora, soil type and amount and distribution of rainfall.

Pyrenophora tritici-repentis. [Descriptions of Fungi and Bacteria].

1976 ◽  
Author(s):  
M. B. Ellis
Keyword(s):  
Geographical Distribution ◽  
Cynodon Dactylon ◽  
Premature Death ◽  
Pyrenophora Tritici Repentis ◽  
Elymus Repens ◽  
Weed Hosts ◽  
Wheat Leaves ◽  
Grass Weed ◽  
Severe Leaf ◽  
Agropyron Repens

Abstract A description is provided for Pyrenophora tritici-repentis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wheat, rye, barley, Agropyrons repens, Cynodon dactylon, Elymus glaucus. DISEASES: Causes yellow leaf spot of cereals and grasses; oval to lanceolate. yellow to grey brown lesions often with a yellow halo. The lesions can be distinguished from those caused by Cochliobolus sativus because of their lighter colour. The disease results in premature death of leaves. It can also cause a seedling blight and root rot. Common and widespread on Agropyron repens[Elymus repens] and wheat, occasionally on barley and rye and recorded on many other grasses. Sometimes causes severe leaf wilt and spotting especially on durum wheat. Leaves of Agropyron repens[Elymus repens] when attacked gradually lose their colour and wither from the tips backwards; they become at first pale yellow, later grey. On wheat fusiform, oval or lanceolate spots, 0.5-2 cm long, 2-4 mm wide are formed. These are at first yellow but later turn brown or greyish brown often with a yellow halo. The leaves die prematurely from the tip backwards. GEOGRAPHICAL DISTRIBUTION: Australia; Asia (Japan, India, Nepal); Africa (Uganda, Kenya, Tanzania, Ethiopia); Europe (Britain, Germany, Czechoslovakia, Sweden, Cyprus); S. America (Bolivia); and N. America (Canada, USA). TRANSMISSION: Air-borne spores (51, 1045p), seed-borne by both external contamination and internal infection (34, 24), secondary grass weed hosts (11, 695), carryover on stubble and other crop debris (43, 1225f; 52, 685).

The Effect of Trifluralin Applied Preplant on Grass Weed Control and Establishment and Yield of Barley (Hordeum vulgare)

1997 ◽  
Vol 11 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Julio A. Scursoni ◽  
Emilio H. Satorre
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Herbicide Application ◽  
Planting Pattern ◽  
Weed Density ◽  
Time Of Application ◽  
Density And Biomass ◽  
And Control ◽  
Crop Planting ◽  
Grass Weed

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.

The effects of very deep ploughing and of subsoiling on crop yields

1956 ◽  
Vol 48 (2) ◽  
pp. 129-144 ◽  
Author(s):  
E. W. Russell
Keyword(s):  
Sugar Beet ◽  
Surface Soil ◽  
Crop Yields ◽  
Clay Soils ◽  
Deep Tillage ◽  
Perennial Weeds ◽  
The Difference ◽  
Annual Weeds ◽  
Dry Out ◽  
Complete Inversion

1. Deep tillage, namely, ploughing to a depth exceeding 12 in., or subsoiling to a depth of about 18 in., increased crop yields on about half the fields in which an experiment was made. Unfortunately, it was not possible to recognize what was the difference in soil properties between the 50% of fields that responded appreciably to deep tillage and the remainder whose yields were either unaffected or sometimes reduced by deep tillage, though, as one would expect, sands were normally less responsive to deep tillage than the heavier soils.2. On the clay soils, deep ploughing in autumn tended to give a surface soil that dried out up to several weeks earlier in the spring than land that was shallow ploughed. Subsoiling did not cause the surface soil to dry out in the same way. Only rarely did the subsoil brought up by deep ploughing give difficulty in working down to a seedbed, and probably in as high a proportion of fields the subsoil worked easier than the surface soil.3. On the clays and loams, the response of potatoes to deep tillage was more marked on fields that were heavily manured than on those lightly manured.4. Sugar beet normally gave a higher yield if its potash and phosphate was spread on the land before ploughing, even if this was in the autumn, than if it was applied in the seedbed. The exceptions to this result were for soils heavier than sandy loams if ploughing depths exceeding 12 in. were used, for the yield of beet was, on the average, depressed on these soils if the potash and phosphate was ploughed in compared with it being worked into the seedbed.5. Deep ploughing tended to give better control of many perennial weeds, and often of annual weeds than shallow ploughing. It is suggested that much of this benefit could be obtained when ploughing to 9–10 in. deep if ploughs were used that cut a furrow considerably wider than the conventional 10½–11 in. furrow, so allowing more complete inversion of the furrow slice.

Transfer of resistance alleles from herbicide-resistant to susceptible grass weeds via pollen-mediated gene flow

2021 ◽  
pp. 1-51
Author(s):  
Amit J. Jhala ◽  
Hugh J. Beckie ◽  
Carol Mallory-Smith ◽  
Marie Jasieniuk ◽  
Roberto Busi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Herbicide Resistance ◽  
Creeping Bentgrass ◽  
Agricultural Landscapes ◽  
Italian Ryegrass ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Wild Oats ◽  
Rigid Ryegrass ◽  
Grass Weed

Abstract The objective of this paper was to review the reproductive biology, herbicide-resistant (HR) biotypes, pollen-mediated gene flow (PMGF), and potential for transfer of alleles from HR to susceptible grass weeds including barnyardgrass, creeping bentgrass, Italian ryegrass, johnsongrass, rigid (annual) ryegrass, and wild oats. The widespread occurrence of HR grass weeds is at least partly due to PMGF, particularly in obligate outcrossing species such as rigid ryegrass. Creeping bentgrass, a wind-pollinated turfgrass species, can efficiently disseminate herbicide resistance alleles via PMGF and movement of seeds and stolons. The genus Agrostis contains about 200 species, many of which are sexually compatible and produce naturally occurring hybrids as well as producing hybrids with species in the genus Polypogon. The self-incompatibility, extremely high outcrossing rate, and wind pollination in Italian ryegrass clearly point to PMGF as a major mechanism by which herbicide resistance alleles can spread across agricultural landscapes, resulting in abundant genetic variation within populations and low genetic differentiation among populations. Italian ryegrass can readily hybridize with perennial ryegrass and rigid ryegrass due to their similarity in chromosome numbers (2n=14), resulting in interspecific gene exchange. Johnsongrass, barnyardgrass, and wild oats are self-pollinated species, so the potential for PMGF is relatively low and limited to short distances; however, seeds can easily shatter upon maturity before crop harvest, leading to wider dispersal. The occurrence of PMGF in reviewed grass weed species, even at a low rate is greater than that of spontaneous mutations conferring herbicide resistance in weeds and thus can contribute to the spread of herbicide resistance alleles. This review indicates that the transfer of herbicide resistance alleles occurs under field conditions at varying levels depending on the grass weed species.

scholarly journals Field study on weeds incidence in rapeseed (Brassica campestris L.).

2019 ◽  
Vol 26 ◽  
pp. 1-6
Author(s):  
MT Akhter ◽  
PB Kundu ◽  
NK Paul
Keyword(s):  
Relative Frequency ◽  
Brassica Campestris ◽  
Cynodon Dactylon ◽  
Cyperus Rotundus ◽  
Importance Value Index ◽  
Importance Value ◽  
Weed Population ◽  
Quantitative Characters ◽  
Weed Flora ◽  
Weed Infestation

A survey was conducted to highlight the weed flora infesting rapeseed in the experimental field of Rajshahi University. Frequency (F), density (D), abundance (A), relative frequency (RF), relative density (RD), relative abundance (RA) and importance value index (IVI %) of weeds were calculated in rapeseed field. The objective of the study was to study the weeds and their quantitative characters. Weed infestation was studied in three rapeseed varieties (BARI Sharisha 14, BINA Sharisha 5 and 6). The weed population was studied using quadrat. The species which had 100% frequency values were Cyperus rotundus, Cynodon dactylon, Ammania baccifera, Echinochloa crusgalli and Leucas lavendulifolia. Other species had 50% or less than 50% frequency values. The highest frequency, density, abundance and importance value index were exhibited by Cyperus rotundus. J. bio-sci. 26: 01-06, 2018

Sign in / Sign up

Export Citation Format

Share Document