Determining Weed Maps and population characteristics of Irrigated Wheat Fields for Sistan and Baluchestan Province.

Determining Weed Maps and population characteristics of

Irrigated Wheat Fields for Sistan and Baluchestan Province

H. Adim, M. Sarani, M. Minbashi Moeini*

Received date: 28 Aug 2010 Accepted date: 16 Oct

20101- Baluchestan Agricultural and Natural Resources Research Center,

Iranshahr, Iran.

- Sistan Agricultural and Natural Resources Research Center, Zabol, Iran.3- Iranian Research Institute of

Plant Protection, Tehran, Iran.

*: Corresponding author's E-mail: [email protected]

Abstract

A study was done to map weeds in irrigated wheat fields from 2001 to

2006 in Sistan and Balochistan province. In this study, 44 sample

wheat fields were selected and weed species were counted in each sampling

point and population indices were calculated. In each fields longitude, latitude and altitude were recorded

using GPS. These data were used for producing weed map using GIS.

Results showed that annual yellow sweetclover (Melilotus indicus (L.)

All.), common mallow (Malva neglecta Wallr.) and prostrate

knotweed (Polygonum aviculare L.) were dominant broadleaf species in irrigated wheat fields of Sistan and

Balochistan province. Dominant grass weed species were japanesse brome (Bromus japonicus Thunb.ex murr), winter wild oat (Avena ludoviciana L./Dur.) and Canarygrass (Phalaris minor Retz.). Hoary cress (Cardaria

draba (L.) Desv.), field bindweed (Convolvulus arvensis L.), camel’s

thorns (Alhagi pseudalhagi (M.Bieb.) Desv.) and Salsola spp. were the most

important disturbing plants prior to harvesting in irrigated wheat fields of

Sistan and Balochestan province.

• Key words: Weed mapping, geographic information system (GIS), abundance index, (AI), frequency, uniformity, mean field density.

Influence of wild mustard (Sinapis arvensis L.) different densities on

yield and yield component of winter wheat (Triticum aestivum L.)

F. Bazrafshan1*, H. Moosavinia2, A. Moezi3, A. Siadat4, R. Hamidi5

Received date: 25 May 2010 Accepted date: 16 Sep

20101- Ph.D.students of Azad university of Research and Sciences,

Khozestan.2- Associate professor, Faculty of Agriculture, Shahid Chamran

University, Ahwaz.3- Assistant professor, Faculty of Agriculture,

Shahid Chamran University, Ahwaz.4- Professor, Ramin Agricultural and

Natural Resource, University.5- Associate professor, Faculty of Agriculture, Shiraz University.*: Corresponding author's E-mail:

Abstract

A field study was conducted in Fars at Agricultural Experimental Station of Firooz Abad Islamic Azad University

in 2006 to evaluate wild mustard densities on wheat yield and yield

component. Increasing wild mustard density decreased grain yield, wheat

dry matter, spike per plant and seed per spike. Wild mustard had no effect on wheat height and wheat seed weight per 1000 seed. Reduced grain yield ranged from 3.1 to 29.9% at 1 to 16

wild mustard per m2, respectively. At 16 plant per m2 wild mustard reduced wheat spike per m2 by 16.2% and seed number per spike per m2 by 19.6%, when compared to weed free check. Results also showed

that increase in wild mustard dry weight, due to increase in mustard density, had negative

effect on wheat dry weight. Wild mustard must be

controlled either before or shortly after wheat emergence if detrimental effects on wheat

are to be minimized.

Key words: Winter wheat, wild mustard, competition, density.

Comparative evaluation of the effects of salinity and drought on

germination and seedling growth of Barnyardgrass (Echinochloa crus-galli L.) and Rice (Oryza sativa L.), and its relationship with their competition

under stress conditions.

A. Esmaili*, S.V. Eslami

Received date: 06 Mar 2009 Accepted date: 27 Jun 20101- M.Sc. Student of Weed

Science, University of Birjand. Iran.

- Assistant Professor, University of Birjand, Iran.*: Corresponding author's

E-mail:

Abstract

An experiment was conducted at Pakdasht barley fields in 2004 & 2005 growing seasons to study the effect of chemical control on weed seed bank in rotation systems. Corn-barely rotation with and without chemical application

was implemented. Method of sampling was systematic (zigzag) and the time of the sampling stages were in two dates; before sowing and after harvesting of barley. To compare the diversity between farms, Shannon-

Weiner diversity index was calculated. Weed seed bank densities in chemical managed farms (CMFs) was generally

lower than those without chemical control (NCMFs). At first sampling,

average weed seed bank populations in CMFs, were 49 and 31 seeds kg-1 of soil, and for NCMFs were 136 and 177

seeds kg-1 soil in 2004 and 2005, respectively. The weed seed bank

density in second sampling date (post harvesting of barley) for CMFs were 33 and 30.5 seeds kg-1 soil, and for NCMFs were 210 and 254 seeds kg-1 of soil in

2004 and 2005, respectively. Seed bank density decreased over sampling

times (growing season) for CMFs in 2004 as compared with NCMFs. In 2005, the NCMFs variation trend of

the seed bank densities for managed farms was constant between the two stages of sampling. But the trend of

variation in NCMFs was similar to that of previous year. Shannon-Weiner diversity index in CMFs was higher

than those of NCMFs. Herbicide application had reduced the seed

production of weeds and the ultimate seed rain into the soil seed bank.

Results of this study demonstrate the importance of weed control practices

in reducing weed seed bank size.

Key words: Rotation system, diversity index.

Study of effectiveness of different combinations of selective herbicides

for control of broadleaf weeds in Sugar beet (Beta vulgaris L.) fields

H. Najafi*, M. Bazobandi, N. Jafarzadeh

Received date: 20 Oct 2010 Accepted date: 08 Dec

20101- Iranian Research Institute of Plant Protection, Tehran, Iran.

2- Khorasan Razavi Agricultural and Natural Resources Research Center,

Iran.

3- Western Azarbayejan Agricultural and Natural Resources Research

Center, Iran*:Corresponding author's E-mail:

Abstract

Field studies were conducted in 2005 to determine the effectiveness of

different combinations of selective herbicides for control of broadleaf

weeds in sugar beet fields in Tehran (Karaj), Khorasan Razavi (Mashhad)

and Western Azarbayejan (Miandoab) provinces. Weed biomass and

frequency and visual evaluation of weed injury and Sugar beet yield were

those traits evaluated in this experiment. Weed biomass and

frequency measurements in each province indicated that

(phenmedipham + desmedipham + ethofumesate) + triflusulfuron methyl

was the best composition. triflusulfuron methyl + desmedipham

also was another composition that produced a good result. These

treatments had no good effect on bindweed. The least herbicidal effect

came from chloridazon + triflusulfuron methyl and chloridazon +

(phenmedipham + desmedipham + ethofumesate) which had little effect

on weed biomass and frequency.

Key words: Sugarbeet, weed, broadleaf herbicides, tankmixed.

– Primary growth of root and shoot of wild oat (Avena fatua L.) and wheat (Triticum aestivum L.) in competition for nitrogen

The allelochemicals or secondary plant metabolites

when are released to environment, influence the germination and seedling

growth of neighbors' weeds. The aim of this study was to investigate the effect of the extract of wormwood (Artemisia

annua) on the number and mass of weed seedlings and their

seed germination under laboratory conditions. The

Wormwood extracts were considered with different concentrations (1.25 to

20%) on the germination and seedlings growth of Zea maize, Johnsongrass

(Sorghum halepense), common lambsquarter (Chenopodium album) and redroot pigweed (Amaranthus

retroflexus) for 5 days. Results showed that with increasing concentration of wormwood extracts, their effects on

reducing seed germination and seedling growth of the above

mentioned plants was more severe. Comparison of extract effects with polyethylene glycol, revealed that

reduction of Johnsongrass and common lambsquarter seed

germination were attributed to the osmotic pressure of the extract, where as, inhibition of seed germination of redroot pigweed and corn was due to allelochemicals. Results showed the

wormwood extract was more related to the allelopathic effect.

An experiment was conducted to determine the proper time and

Atrazine dose for control of weeds in grain corn. The experiment was

conducted at the University of Shiraz Agricultural Experimental Station. Experiment was in a randomized

complete block design with factorial arrangement of treatments. The

treatments were application time (pre-planting, 10, 20, 30 and 40 days after corn emergence) and herbicide dose (0, 0.7, 1, 1.4 and 2.1 Kga.i./ha). The

carry over effects of Atrazine residues on wheat emergence were also

evaluated. The experiment results showed that only corn grain number

was affected by the time of application. Herbicide dose had

significant effect on grain weight. Both application time and herbicide doses

significantly affected dry weight of weeds. Later use of herbicide had no effect on dry weight of weeds. Due to good control of weeds by herbicide at

2.1 kg/ha, the grain yield increased significantly when compared with

weedy check. Results also indicated that rate of herbicide had more effect

on wheat germination percentage compared with application time.

Minimum and maximum germination percentage were at 2.1 Kg/ha and control treatments respectively.