Crop establishment, Direct-seeded rice, Weed management, Weed persistence index, Zero-tillage

A field study was undertaken to evaluate the crop establishment and weed management options for direct-seeded rice (DSR) in the Institute for Agricultural Sciences, BHU, Varanasi, India during rainy season in 2008 and 2009. The weed flora were grasses as Echinochloa colona, Echinochloa crusgalli, Cynodon dactylon, Paspalum spp., sedges as Cyperus rotundus, Cyperus iria and broad-leaved weeds like Caesulia axillaris. Data were recorded on weed dynamics, crop growth and yield of the direct-seeded rice crop. Rice established by zero-till DSR with 40 cm anchored residue had minimum density of grasses, sedges and broad-leaved weeds and dry weight at 60 DAS. Among weed management methods, use of pendimethalin 1000 g/ha (pre-em) fb azimsulfuron 35 g/ha at 15-20 DAS + one HW at 40 DAS proved to be most effective in minimizing the weed density, dry weight and weed persistence index (0.08 and 0.04) and in enhancing the weed control efficiency (72.04% and 76.77%). The maximum grain yield, straw yield and biological yield was found with application of pendimethalin 1000 g/ha (pre-em) fb azimsulfuron 35 g/ha at 15-20 DAS + one HW at 40 DAS, which was significantly superior to rest of the treatments during both the years of experimentation.

Cono weeding, Conventional system, Herbicides, System of Rice Intensification, Weed management

An experiment was conducted to assess the efficacy of different weed management practices in rice grown under the System of Rice Intensification (SRI) in comparison with the conventional system. The study was carried out during 2007 and 2008 in the lateritic sandy clay loam soils at Pattambi, Kerala. Density and dry weight of weeds were higher in SRI especially when weed control was done through repeated cono weeding, while they were lower in the conventional system. Conventional system with cono weeding at 10 DAT followed by hand weeding at 30 DAT, and post-emergence herbicides alone reduced the weed dry weight significantly. Net returns and B:C ratio were also the highest in the conventional system with post-emergence application of cyhalofop-butyl  0.1 kg/ha followed by metsulfuron-methyl  + chlorimuron-ethyl. In SRI, the weed density and dry weight were the lowest with pre-emergence herbicide followed by hand weeding at 30 DAT, and cono weeding at 10 DAT followed by post-emergence herbicides. However, weed control with post-emergence application of cyhalofop-butyl, followed by metsulfuron-methyl + chlorimuron-ethyl gave higher B:C ratio in both systems. 

Direct-seeded rice, Grain yield, Row spacing, Seed rate, Weed management

Field experiment was conducted during Kharif 2009 and 2010 to study the effect of rice seed rate (20, 30, 40 and 50 kg/ha) and inter row spacing (15, 20, 25 and 30 cm) on weeds, crop growth and grain yield of direct-seeded rice. Population of Echinochloa and Cyperus was minimum when DSR was sown with seed rate of 50 kg/ha with 15-20 cm row spacing and it was maximum when lower seed rate of 20-30 kg/ha was used with wider row spacing of 30 cm. Weed biomass was significantly affected by seed rate, being maximum with lower seed rate usage of 20 kg/ha and decreased significantly with each successive increase in seed rate. With the increase in row spacing from 15 to 30 cm, weed biomass increased significantly.  Maximum number of tillers was recorded when rice was sown with seed rate of 50 kg/ha with wider row spacing of 30 cm. The seed rates and row spacings did not have any significant effect on effective tillers and grain yield of dry-drilled rice.

Conventional tillage, Isoproturon, Metsulfuron-methyl, Weed dynamics, Zero tillage

A field experiment was conducted during two consecutive Rabi season of 2005-06 and 2006-07 at NEB Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar on sandy loam soil to find out the effect of tillage and weed management practices on weeds, weed seed bank in soil and grain yield of wheat grown after rice. Zero till sown wheat had significantly lesser weed dry weight per unit area as compared to conventional sown wheat. Phalaris minor, Melilotus indica and Chenopodium album seed density in soil were significantly lower under zero tillage as compared to conventional tillage from 0 to 5, 5 to10 and 10 to 15 cm soil depths. Excellent suppression in weed density and dry weight and higher yield of wheat were obtained with two hand weeding under conventional tillage system. Under weedy situation, zero tillage was found better because of less weed emergence.

Clodinafop, Carfentrazone-ethyl, Herbicide efficiency index (HEI), Metribuzin, Weed density

On-farm trials were conducted at farmers’ fields in Ropar and Ferozpur districts of Punjab to validate, refine and popularize the technology developed by Punjab Agricultural University, Ludhiana for managing grassy and broad-leaf weeds in wheat. The objective of the study was to test the effectiveness of clodinafop 60 g/ha and carfentrazone-ethtyl 20 g/ha over farmer practice of using un-recommended herbicides and brands on the infestation of weeds and profitability of wheat in central Punjab. Recommended practice of clodinafop followed by carfentrazone-ethyl resulted in significantly higher grain yield (4.56 and 4.69 t/ha) than other treatments including farmer practice. There was 14.4 and 17.9, 3.4 and 5.7 and 3.0 and 4.3 per cent increase in grain yield with recommended practice over control, metribuzin and farmers’ practice, respectively. The population of grassy weeds was minimum with metribuzin 175 g/ha treatment, which was statistically at par with recommended practice but was significantly lower than other two treatments, whereas the number of broad-leaf weeds was significantly lower with recommended treatment. The herbicide efficiency index (HEI) was highest (16.8 and 21.8) with recommended practice indicating higher efficiency of this treatment in controlling weeds. A slight phytotoxicity was observed with metribuzin which resulted in significant reduction in effective tillers than other herbicidal treatments. Highest B: C ratio (2.45 and 2.77) and net returns (` 45.99 and 52.86 x 103 /ha) were recorded with recommended practice.

Maize, Sunflower, Tillage, Weed management, Weed density, Yield

A field experiment was conducted during Rabi and Kharif season of 2012 and 2013 at Veppantattai to study the effect of tillage and weed management methods on weeds dynamics and yield of maize–sunflower cropping system. Results revealed that conventional tillage with disc plough followed by cultivator tillage twice and pre-emergence herbicide (atrazine 0.5 kg/ha for maize and pendimethalin 1.0 kg/ha for sunflower), followed by hand weeding on 40 DAS kept the weed density and weed dry weight below the economic threshold level and increased the productivity, net returns and benefit : cost ratio of maize-sunflower cropping system in clay loam soils under irrigated condition.

Intercropping, Relative weed density, Relative dry weed weight, Weed smothering efficiency, economic returns

A field experiment consisted of four intercropping systems, viz. sole chickpea, sole mustard, chickpea + mustard (additive series) and chickpea + mustard (replacement series) and six weed management practices, viz. weedy check, weed free, pendimethalin 1 kg/ha as pre-emergence , fluchloralin 1 kg/ha as pre-plant incorporation (PPI), isoproturon 0.75 kg/ha as post-emergence and quizalofop-ethyl 50 ml/ha as post-emergence.  Results revealed that weed species, Medicago sativa, Anagallis arvensis and Cyperus rotundus with higher relative weed density and dry weed weight were observed. The values of smothering efficiency were higher in additive as compared to replacement treatment. Maximum yield loss was in weedy check in comparison to weed-free plots. Application of pendimethalin at 1 kg/ha gave higher yield of chickpea and mustard along with maximum returns.

Intercropping, Nutrient uptake, Potato, Weed management, Winter maize

A field experiment was conducted during Rabi 2009-10 and 2010-11 at research farm of Sher-e-Kashmir University of Agriculture Science and Technology, Jammu with four intercropping treatments, viz. sole maize, sole potato, maize + potato (additive Series) and maize + potato (replacement series) in main plots and six methods of weed control practices, viz. weedy check, weed free, alachlor1.5 kg/ha pre-emergence, atrazine 0.5 kg/ha pre-emergence, alachlor 2.0 kg/ha early post-emergence and atrazine 0.75 kg/ha post-emergence in sub plots to assess the productivity and profitability of winter maize + potato intercropping system.These treatments were evaluated under split plot design with three replications. Results revealed that sole stands of winter maize and potato removed highest amount of N, P and K which were followed by additive series and replacement series whereas among the weed management practices, highest amount of N, P and K was removed by weed free treatment  fb atrazine PE 0.75 kg/ha and alachlor 1.5 kg/ha while the lowest N, P and K was removed by alachlor 2.0 kg/ha early post emergence. Among the different intercropping treatments, weeds removed significantly highest N, P and K from sole crops followed by additive series and replacement series. Among weed management practices, the uptake of N, P and K in weeds was found to be significantly less in all the weed management practices as compared to weedy check treatment.

Bio-efficacy, Cyperus rotundus, Herbicide, Hoeing, Nutsedge, Spring-planted Sugarcane

Field investigion was carried out for two consecutive years 2009-10 and 2010-11 at Pantnagar (Uttarakhand) to study the bio-efficacy of ethoxysulfuron for the control of Cyperus rotundus (nutsedge) in sugarcane. Experiment consisted of six treatments, viz. doses of ethoxysulfuron 46.87, 56.25 and 60 g/ha, 2,4-D Na salt 1000 g/ha, three hoeing 30, 60 and 90 days after planting (DAP) of sugarcane and untreed control was laid out in randomized block design with three replicions. Ethoxysulfuron and 2,4-D Na salt were applied  at 3-4 leaf stage of Cyperus rotundus. Among the herbicidal treatments, the lowest weed density as well as dry weight of total weeds was observed with ethoxysulfuron 60 g/ha 3-4 leaf stage of C. rotundus  at both the stages at 30 and 60 DAA though the differences were non-significant when compared with its lower dose 56.25 g/ha, 30 and 60 DAA and 46.87 g/ha 60 DAA during both the year. Application of ethoxysulfuron 3-4 leaf stage of C. rotundus effectively controlled C. rotundus and broad-leaved weeds, viz. Trianthema monogyna, Digera arvensis, Cleome viscosa and Ipomoea spp. This herbicide any rate was not effective against grassy weeds. The highest cane yield was recorded with the execution of three hoeing at 30, 60 and 90 days after planting (DAP). Among the herbicidal trements, ethoxysulfuron 60 g/ha at 3-4 leaf stage of C. rotundus recorded maximum cane yield (82.3 and 86.8 t/ha), although it was at par with its lower dose 56.25 g/ha. The lowest cane yield was recorded with control.

Cane yield, Economics, Growth, Ratoon, Sugarcane, Weed density, Weed Management

A field experiment was conducted on ratoon crop of sugarcane to develop suitable weed management practices during spring seasons of 2008-09, 2009-10 and 2010-11 at Sugarcane Experimental Area, (Ladhowal), Punjab Agricultural University, Ludhiana. A total of fourteen treatments including weedy check was tested in randomized block design with three replication. Herbicidal treatments were applied to ratoon crop immediately after harvesting of plant crop in the Ist week of February every year under moist conditions. The highest weed dry weight of 182.7 g/m2 was recorded in weedy check. All the weed control treatments recorded significantly less weed dry weight as compared to the weedy check. The highest pooled cane yield of 74.3 t/ha was obtained with pre-emergence application of metribuzin  1.4 kg/ha fb 2,4-D 1.6 kg/ha at 45 days after ratoon initiation (DARI). The weed dry weight was significantly reduced to less than one third (54.3 g/m2) with pre-emergence application of metribuzin 1.4 kg/ha fb 2,4-D 1.6 kg/ha at 45 DARI compared to weedy check. Atrazine applied as pre-emergence at 2 kg/ha fb 2,4-D 1.0 kg/ha at 45 DARI proved equally effective as pre-emergence metribuzin 1.4 kg/ha fb 2,4-D 1.6 kg/ha at 45 DARI. In sugarcane ratoon crop, pre-emergence application of  metribuzin 1.4 kg/ha fb 2,4-D 1.6 kg/ha at 45 DARI or  atrazine 2 kg/ha fb 2,4-D 1.0 kg at 45 DARI gave net returns of ` 84,820/- and ` 84,497/- which was 61.7% and 61.1% higher over control, respectively.

Chemical control, Cropping system, Economics, French bean, Mechanical control, N uptake, Weed management 

Field experiments were conducted during Kharif 2010 and 2011 to study the effect of weed management practices on French bean in temperate region of Kashmir, India. Among different weed control treatments, pre-plant incorporation and pre-emergence application of fluchloralin and pendimethalin 1.00 kg/ha significantly reduced the population of different weeds than weedy check and other herbicide treatments.  These resulted in significant increase in growth and yield attributes, viz. plant height, number of branches, dry matter accumulation, seed and straw yield of French bean. Maximum seed yield was obtained with fluchloralin 1.00 kg/ha and pendimethalin 1.00 kg/ha treatments with a corresponding value 1.11 and 1.10     t/ha. These also increased the nutrient uptake by French bean crop at various crop growth stages over weedy check and other treatments during both the years. Application of fluchloralin 1.00 kg/ha and pendimethalin 1.00 kg/ha significantly increased the net return over weedy check, with B:C ratio of 1.18 and 1.12 during two cropping seasons.

Chemical control, Diuron, Glyphosate, Hand weeding, paraquat, Tea, Weed management

A field experiment was conducted in a permanent layout during 2009 and 2010 on farmer’s field at Palampur to evaluate BCS AA 10717 – 2% + glyphosate 40 – 42% SC in tea (Camellia sinensis [L.] Kuntze) crop. Ageratum conyzoides and A. houstonianum (17 and 25.9%, during 2009 and 2010, respectively), Bidens pilosa (19 and 13%), Erigeron canadensis (2 and 16.2%) and Chromolaena adenophorum (9.1 and 9.7%) were the major weeds found infesting tea crop during both the years. BCS AA 10717 + glyphosate, glyphosate and diuron + glyphosate effectively reduced the infestation of Ageratum sp, B. pilosa, and E. canadensis. BCSAA 10717 and hand weeding were not effective against E. canadensis and B. pilosa and paraquat against B. pilosa. Hackelia uncinata was completely eliminated under BCS AA 10717 + glyphosate, glyphosate and diuron + glyphosate. Wild strawberry (Fragaria vesca) was completely eliminated under all the treatments. BCSAA 10717 + glyphosate at higher dose (> 50+1000 g/ha) and diuron + glyphosate were found effective against Cynodon dactylon. All treatments except hand weeding and BCSAA10717  37.5 + glyphosate 750 g/ha had significantly lower count of local grass than untreated check. BCSAA 10717  37.5-140 + glyphosate 750-2800 g/ha, glyphosate alone and diuron + glyphosate effectively reduced the count of C. adenophorum. Total weed count and total weed dry weight were significantly reduced under BCSAA10717  50-140 + glyphosate 1000-2800 g/ha, glyphosate and diuron + glyphosate. BCSAA10717  50-140 + glyphosate 1000-2800 g/ha, glyphosate and diuron + glyphosate had higher weed control efficiency than the hand weeding treatment. There were no phytotoxicity symptoms of BCS AA 10717 + glyphosate on tea. The tea green leaf yield was not influenced by the weed control treatments.

Glyphosate, Roundup ready cotton, Seed cotton yield, Weeds, Weed  management

A field experiment was conducted to evaluate potassium salt of glyphosate (MON 76366) in Roundup Ready Bt cotton hybrid at PAU, Ludhiana during 2009 and 2010. Potassium salt of glyphosate 50 EC at 900, 1350, 1800, 2700, 3600 and 5400 g/ha was applied twice (after one and three months of sowing) as post-emergence. All the treatments except glyphosate 900 g/ha and weedy check gave effective control of weeds. Application of K salt of glyphosate at 1350 to 5400 g/ha recorded the weed control efficiency (WCE) ranging from 96.8 -99.8%, and produced higher seed cotton yield. The performance of succeeding crops of wheat, barley and raya sown after cotton was not affected, indicating no residual toxicity of K-salt of glyphosate. 

Alternanthera philoxeroides, Cadmium, Eichhornia crassipes, Heavy metals, Iron, Manganese, Nickel

The various ponds receive untreated sewage effluents from residential areas in Jabalpur city affecting water quality of the ponds. The very survival of aquatic weed species in contaminated water is testimony of ability of accumulating heavy metals. A survey was made to identify weed species grown in various ponds of Jabalpur  for assessing their heavy metal potential. The heavy metals exhibited the sequence of their concentration in pond water as Fe > Cd > Mn >Ni >Cu. Among the weeds, Eichhornia crassipes accumulated higher concentration of cadmium, nickel, iron and manganese in their roots than shoots whereas Alternanathera philoxeroides accumulated higher metals in shoots than its root parts. Except nickel, higher bioaccumulation factor of Fe, Cd, Mn, Ni, Cu  was exhibited by Alternanthera philoxeroides followed by Eichhornia crassipes. These observations may be exploited while selecting plant species for removal of heavy metals from contaminated water in an artificial wetland system.

Bacteria, Diazotrophs, Phosphate solubilising microbes, Weedy grasses

The present investigation hypothesizes that the weedy grass species grown in different physiographic regions do harbour potential microbes and shows lot of scope for the identification of novel functional microbes. In the present study, diazotrophic bacteria were isolated from rhizosphere of ten selected grass species and identified using 16S rRNA gene sequencing. The isolates were belonging to the members of alpha Proteobacteria and Firmicutes. Phosphorus solubilizing traits of all the selected diazotrophic isolates were analysed and results revealed that all the diazotrophs were found to solubilise phosphorous in qualitative assay. Influence of phosphorus solubilizing organisms on the pH, titrable acidity, available phosphorus and phosphatase enzyme production were studied. Maximum amount of available phosphorus and phosphatase activity was observed in Klebsiella sp. (OR7) (0.96 ± 0.09 µg/ml) and Staphylococcus saprophyticus (OR5) (12.9 ±0.10 µg of PNP released/ml/day) respectively. The present compilation of diverse diazotrophs along with phosphorous solubilisation potential suggests that these particular organisms can promote plant growth by more than one mechanism and that these traits could be better exploited as bio-inoculants.

Bacteria, Free living nitrogen fixers, Fungi, Herbicide, Lablab bean, Phosphate solubilzers, Tillage

A long term field study was conducted at the Agronomy Farm, Department of Agronomy, Dr. B.S. KKV, Dapoli (Maharashtra) in Rabi season lablab bean crop to evaluate the effect of different tillage systems vis-à-vis different weed control measures on the survival and growth of total bacteria, total fungi, total free living nitrogen fixers and total phosphate solubilizers in rhizosphere soil. Four types of tillage systems were evaluated, viz. (i) Conventional-conventional (ii) Conventional-zero (iii) Zero-conventional and (iv) Zero-zero tillage systems. Among weed control measures, comparative effects of hand weeding and recommended herbicides application (oxadiargyl as pre-emergence) were tested along with weedy check. The results of the investigation revealed that tillage systems didnot significantly influence microbial population. The marginal growth of different microorganisms was observed in conventional-conventional tillage system, whereas minimum was in zero-tillage system. There were no adverse effects of herbicide use on all the estimated microbial population at all the stages of the crop. In short use of recommended herbicide oxadiargyl at 0.12 kg/ha had no long term adverse effects on rhizosphere microflora of lablab bean crop.

Garlic, Pendimethalin, Persistence, Residues

A field experiment was conducted  to study the persistence and accumulation of pendimethalin residues in garlic. Pendimethalin was applied as pre-emergence treatment at three different doses, viz. 0.75, 1.5 and 3.0 kg/ha. Mature garlic bulbs were collected at crop harvest and soil samples were collected at 0, 15, 30, 45, 60, 75, 90, 120 days after herbicide application and at crop harvest. These samples were analyzed for pendimethalin residues by a validated Gas Liquid Chromatography (GLC) method with an accepted recovery of 79.1–88.2%. The analysis showed that pendimethalin did not leave any residues in soil beyond harvest of the crop at any of the applied dose. On the other hand, garlic bulbs collected at harvest showed 0.004 µg/g pendimethalin residues at a dose of 3.0 kg/ha and below detectable limit (BDL) at 0.75 and 1.5 kg/ha.

Bispyribac-sodium, Ethoxysulfuron, Herbicide mixure, Transplanted rice, Weed, Yield

Different herbicides alone and in combination were tested for the control of complex weed flora in transplanted rice during Kharif season 2013 at Crop Research Centre (CRC) of G.B Pant University of Agriculture and Technology, Pantnagar, District, Udham Singh Nagar (Uttarakhand). The experiment was laid out in randomized block design with three replications to evaluate twelve treatments. The major weeds were Echinochloa colona, E. crusgalli, Ischaemum rugosum, Caesulia axillaris, Ammania baccifera, Alternanthera sessilis and Cyperus iria. Combination of post-emergence application of bispyribac-sodium at 25 g/ha + ethoxysulfuron at 18.75 g /ha was most effective in controlling weed species and yielded maximum grain yield (6.51 t/ha) among the herbicidal treatments after weed free (6.74 t/ha).

Chemical control, Post-emergence, Transplanted rice, Weed management

The experiment was conducted at the Students’ Farm of College of Agriculture, CCS Haryana Agricultural University, Kaul (Kaithal) during Kharif 2008. The experiment consisted of fifteen treatments in block design with three replications. Thirty days old seedlings were transplanted on 3rd July, 2008 manually at a spacing of 20 x 15 cm with two seedlings per hill. The crop was raised with recommended fertilizer dose. Pre-emergence application of butachlor at 1500 g/ha, pretilachlor 750 g/ha,  pyrazosulfuron at 20 g/ha  or  post-emergence herbicide bispyribac-sodium at the rate of 25 g/ha at 20 DAT could be suitable and economical herbicidal weed management option for transplanted rice to achive higher productivity.

Adoption, Economics, Grain yield, Mechanical weeding, Rotary weeder, SRI

Eighteen on-farm demonstrations on System of Rice Intensification (SRI) were carried out in  ten  hectares of farmers fields in Sivagangai and Madurai districts of Tamil Nadu from October 2010 to February 2011 under Tamil Nadu-Irrigated Agriculture Modernization and Water Bodies Restoration and Management Project  (TN–IAMWARM) to study the effect and adoption level of rotary weeding on yield of rice under SRI. The results revealed that SRI registered a mean grain yield of 6.06 t /ha against 54.2 t /ha under conventional method of rice cultivation. SRI yielded 11.06 per cent higher grain yield than conventional method. The number of rotary weeding also decides the rate of yield increase in SRI. The average yield increment by four, thrice and twice rotary weeding under SRI over conventional method were 24.1, 15.4 and 8.5 per cent, respectively. Among the total farmers,  only 11.1 per cent farmers perfectly carried out four times rotary weeding as per recommendation. The percentage of farmers adopted thrice, twice and single rotary weeding were 44.5, 33.3 and 11.1 per cent, respectively. Adoption of SRI drastically reduced the cost of weeding as evident due to Rs 2, 534 /ha lesser weed management cost  under SRI  (Rs 2989 /ha) than conventional method of rice cultivation (Rs 5, 523/ha). The cost of cultivation was comparatively lesser in SRI which resulted in gaining an additional net profit of ` 11, 021 /ha as compared to conventional method of rice cultivation.

Herbicides, Wheat, Yield, Yield attributes

A field experiment was conducted during Rabi season of 2010-11 at College of Agriculture, Pune to study the effect post-emergence herbicides on weeds and productivity of wheat. Among the weed control treatments, application of sulfosulfuron 16.5 g/ha + 2,4-D  563 g/ha registered significantly lower weed population (7.6/m2), dry matter of weeds (3.1 g/m2)   and significantly more weed control efficiency of  81.27% than rest of the treatments. The same treatment recorded lowest value of weed index. The values of yield attributes were higher in magnitude in weed free check treatment. Among the herbicide treatments, post-emergence application of sulfosulfuron 16.5 g/ha + 2,4-D  563 g/ha  recorded higher values of yield attributes, viz. length of spike, number of spikelets/spike, number of grains/spike, grain weight/plant and thousand seed weight.  Amongst the weed control treatments, application of sulfosulfuron 16.5 g/ha + 2,4-D  563 g/ha  recorded maximum grain and straw yield of 4.4 and 5.9 t/ha, respectively as compared to other treatments.

Chemical control, Groundnut, Post-emergence herbicides, Yield

A field experiment was conducted at Norman E. Borlaug, Crop Research Center GBPUA&T, Pantnagar to evaluate the efficacy of quizalofop-ethyl market sample (MS) and sponsor sample (SS) in managing grassy weed flora in groundnut. Result revealed that that application of quizalofop-ethyl 5% EC (SS) at 50 g/ha resulted in significantly higher kernel yield (0.98 t/ha) which was at par with its market sample applied at the same dose. Density and dry matter accumulation of weeds was also minimum by the application of these herbicides. However the highest kernel yield was obtained under the weed free situation. Lower weed density, weed dry weight, weed persistence index and weed index in the plots where quizalofop-ethyl (SS) at 50 g/ha was applied. Higher weed control efficiency and herbicidal efficiency index, economic return were recorded under quizalofop-ethyl 5% EC (SS) at 50 g/ha as compared to standard check imazethapyr 150 g/ha. Thus, the post-emergence application of quizalofop-ethyl 5% EC (SS) at 50g/ha seemed to be more beneficial with high productivity and economic return owing to effective weed control.

Herbicides, Microbial population, Phytotoxicity, Post-emergence, Pre-emergence

Mungbean is recommended for cultivation mainly in Kharif season under Vidarbha condition in Maharastra, India. Weed management is an important factor for enhancing the productivity of mungbean as weeds compete for nutrients, water, light and space with crop during early growth period. Yield losses in mungbean due to weeds have been estimated to range between 30-50% (Kumar et al. 2004). Mechanical practices such as hand weeding and inter -culturing are effective but unavailability of labour and incessant rains during the early crop season normally limit the weeding operations. Therefore, chemical weeding  under such circumstances become indispensible and can be the excellent alternate. Pendimethalin is only recommended pre-emergence herbicides in mungbean, however, peasants could not find time to apply it during the same day or next day due to busy shedule in sowing operation. This warrants the use of pre- and post-emergence herbicides for weed control. The present study was, therefore, conducted to evaluate the effect of different herbicides for mungbean, which can be cost effective and acceptable to the growers of this crop.

Chemical control, Chrysanthemum, Weed management

A field experiment was laid out in randomized block design  with eleven treatments comprising of  ifferent pre-emergence herbicides, viz. butachlor  1.0 kg/ha, butachlor  1.0 kg/ha + 2 hand weedings, butachlor  1.5 kg/ha, pendimethalin  0.75 kg/ha, pendimethalin  0.75 kg/ha + 2 hand weedings, pendimethalin  1.0 kg/ha and atrazine  1.0 kg/ha, atrazine  1.0 kg/ha  + 2 hand weedings, atrazine  1.5 kg/ha besides weed-free (where plots were kept weed free with regular hand weeding) and weedy check (where no cultural practices were followed to control weeds) as control. Results revealed a significant enhancement in flower yield with weed free and butachlor  1.0 kg/ha + 2 hand weedings which were superior over weedy check. The highest weed control efficiency (100%) was also observed in weed free treatment, followed by butachlor  1.0 kg/ha + 2 hand weedings (84.5%) and atrazine  1.0 kg/ha + 2 hand weedings (80.1%). Application of butachlor 1.0 kg/ha along with hand weedings proved to be economical.

Fennel, Glyphosate, Fenoxaprop-ethyl, Quizalofop-ethyl, Oxadiargyl, Weed seed bank

A field experiment was conducted during Rabi season of 2011-12 at Junagadh (Gujarat) to find out most effective and economical method of weed control in Rabi fennel (Foeniculum vulgare). Results revealed that besides weed free treatment, significantly higher plant height, seed and stover yields of fennel were recorded with pre-emergence application of pendimethalin at 0.90 kg/ha + post-emergence application of fenoxaprop-ethyl at 75 g/ha at 45 DAS, which was at par with pendimethalin at 0.90 kg/ha PRE + hand weeding (HW) at 45 DAS and HW twice at 15 and 45 DAS. These treatments also recorded lower weed density and dry weight of weeds along with higher net returns and B:C ratio owing to lower weed index and higher weed control efficiency. The highest depletion of weed seed bank was observed with pendimethalin at 0.90 kg/ha PRE + HW at 45 DAS.

Surfactants, Non edible oil, Herbicidal activity, Pongamia pinnata

Surface active formulation from non edible oil was evaluated for herbicidal activity against weeds, Checorium intybus and Medicago denticulata under in vitro conditions.  Different dilutions of formulation exhibited markedly variable herbicidal activities against germination and seedling growth of the target weed species. Different concentrations (1.0 – 7.5%)  inhibited the growth of shoot and root of C. intybus and M.denticulata  by 71.7 – 100, 83.3 – 97.7% and 51.17 – 100, 24 – 100%, respectively. No shoot formation was recorded in 5.0 and 7.5% dilution against C. intybus and  M. denticulate. The present study concluded that the surfactant formulations from non edible oil of Pongamia pinnata possess potential herbicidal activities against weeds. Pollution of the environment is now a major concern. Therefore, utilization of plant product based surfactant as herbicide will pave a way for possible exploitation of surfactants in weed management.