Gulshan Mahajan - Academia.edu (original) (raw)
Papers by Gulshan Mahajan
Weed Technology
Australian grain growers are showing interest in winter-planted sorghum to avoid heat and water s... more Australian grain growers are showing interest in winter-planted sorghum to avoid heat and water stress during the grain-filling stage. Winter-planted sorghum may face competition from winter weeds, including sterile oats, and no herbicides are registered for controlling winter weeds in winter-planted sorghum. The objectives of this study were to (1) identify alternate herbicide options for sterile oats control in winter-sown imidazolinone (IMI)-resistant sorghum and (2) assess the crop injury levels due to herbicides. Sterile oats control with pendimethalin at 0.59 kg ai ha−1, trifluralin at 0.38 kg ai ha−1, and prosulfocarb + S-metolachlor at 2.3 kg ai ha−1 was poor (<30%). Atrazine at 2.7 kg ai ha−1, imazamox + imazapyr at 0.048 kg ai ha−1, and atrazine at 2.7 kg ai ha−1 followed by imazamox + imazapyr at 0.048 kg ai ha−1 reduced the sterile oats biomass by 93%, 96%, and 100% and increased yields by 116%, 136%, and 140%, respectively, compared with nontreated control. Pendimeth...
Cotton Production
Australia is known worldwide for producing cotton of the finest quality. Cotton production has an... more Australia is known worldwide for producing cotton of the finest quality. Cotton production has an important position in the economy of Australia, earning foreign exchange of two billion dollars annually. Australian cotton production is highly mechanized, and its production systems are quite specialized with emphasis on more crops per drop. However, several factors are making Australian cotton production challengeable, such as climate change, water scarcity, emergence of new insects, diseases and weeds, waterlogged soils and rising production cost. Australian cotton growers, as well as cotton scientists, put sincere efforts to cope up with these issues. New agronomic tools, for example, the skip‐row technique for water saving in the dry land area, timely planting, and use of glyphosate‐tolerant and Helicoverpa ‐resistant cultivars, were adopted to increase the yield potential. Synergy among weather forecasting, fertilizer, water, and pest management in the integrated crop management mode is being considered for high efficiency of cotton production systems. This book chapter explores current issues of Australian cotton production systems and opportunities to solve these issues
Best Management Practices for Drip Irrigated Crops, 2015
Peas occupy an important place among vegetable crops in the submountainous region of India. Being... more Peas occupy an important place among vegetable crops in the submountainous region of India. Being a cool weather-loving crop, it occupies a place of prominence among winter vegetables in kandi area, because the kandi area is cooler as compared to other pea-growing regions of Punjab. But, due to various physiographic constraints, existing legal constraints and the present method of utilization, the utilizable water for irrigation is very limited. In the present day context, improvements in irrigation practices are needed to increase crop production and to sustain the productivity level. Therefore, drip irrigation is a most efficient method of irrigation, which optimizes the use of irrigation water by providing it uniformly and directly to the roots of the plants. Drip irrigation can be helpful in kandi area where water is scarce and very expensive to pump and the fields have uneven topography. Irrigation with drip may be more efficient in kandi area due to precise application of water because evaporation is reduced, runoff is reduced or eliminated, deep percolation is reduced, and irrigation uniformity is improved so it is no longer necessary to “over water” parts of a field to adequately irrigate the more difficult parts. The major drawback of the drip irrigation system is its high initial investment; however, cost can be recovered in a short span if proper water and nutrient management and design principles are followed. Among the various components of the drip irrigation system, the cost of the lateral is a major factor, which influence the total system cost. Any effort made to reduce the length of lateral per unit area will result in reduction of system cost. Many scientists reported that drip irrigation in vegetable crops is very economical by reducing the cost and water use by 50%, when these crops were planted in paired row patterns [1, 3]. With drip irrigation, precise application of nutrients is possible. Fertilizer costs and nitrate losses can be reduced and nutrient applications can be better timed to needs of a crop. The response of pea to the combined effect of drip with different levels of irrigation in conjunction with different nitrogen levels and their economic feasibility are not well known. The information on seasonal water requirement of pea crop under drip irrigation is not available.
Weed Science, 2021
Prevalence of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu)... more Prevalence of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet & Magne; referred to as A. sterilis hereafter], winter-season weeds, is increasing in the eastern grain region of Australia. Biological attributes of these weeds enable them to survive in a wide range of environments and under different weed infestation levels. The interference of A. fatua and A. sterilis in a wheat (Triticum aestivum L.) crop was examined in southeast Queensland, Australia, through field studies in 2019 and 2020. Different infestation levels (0, 3, 6, 12, 24, and 48 plants m−2) of A. fatua and A. sterilis were evaluated for their potential to cause yield losses in wheat. Based on a three-parameter logarithmic model, the A. fatua and A. sterilis infestation levels corresponding to 50% wheat yield loss were 15 and 16 plants m−2, respectively. The yield reduction was due to a reduced spike number per unit area because of an increased weed infestation level. At the ...
Weed Science, 2021
African mustard (Brassica tournefortii Gouan) is a problematic winter annual weed in Australia. G... more African mustard (Brassica tournefortii Gouan) is a problematic winter annual weed in Australia. Germination ecology of B. tournefortii may change in response to the maternal environments or habitats in which the plants grow. A study was conducted to evaluate the effect of environmental factors on germination and emergence of four populations of B. tournefortii that were collected from different fields. Averaged over populations, germination was stimulated by dark and was higher at 25/15 C (92%) compared with 15/5 C (76%) and 35/25 C (45%). Averaged over light/dark regimes, at the lowest temperature regime (15/5 C), population A had higher germination than population D; however, at the highest temperature regime (35/25 C), population D had higher germination than population A. Populations B and C had higher germination in the temperature range of 25/15 C and 30/20 C compared with 15/5 C, 20/10 C, and 35/25 C. Seeds germinated at a wide range of alternating day/night temperatures (15/...
Weed Science, 2021
Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropp... more Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropping region. Populations resistant to glyphosate have evolved in Australia, creating the demand for information regarding the seed germination ecology of glyphosate-resistant (R) and glyphosate-susceptible (S) populations of C. sumatrensis. A study was conducted to examine the effects of temperature, light intensity, salt stress, osmotic stress, and burial depth on the germination and emergence of two populations (R and S) of C. sumatrensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C). In light/dark conditions, the R population had higher germination than the S population at 20/10 and 35/25 C. In the dark, the R population had higher germination than the S population at 25/15 C. In the dark, germination was inhibited at 30/20 C and above. Averaged over populations, seed germination of C. sumatrensis was reduced by 97% a...
Weed Technology, 2019
In Australia, junglerice and feather fingergrass are problematic weeds in sorghum. The high seed ... more In Australia, junglerice and feather fingergrass are problematic weeds in sorghum. The high seed production potential of these weeds increases their seedbank in the soil and makes weed control practices more difficult and expensive, particularly when weeds have evolved resistance to herbicides. A study was conducted to evaluate the seed production and seed retention behavior of junglerice and feather fingergrass at sorghum crop maturity following four transplanting times: 0, 2, 4, and 6 wk after sorghum emergence. Averaged across years, junglerice and feather fingergrass produced 4,060 and 5,740 seeds plant-1, respectively,when they were transplanted with the emergence of a sorghum crop. Seed retention ranged from 42% to 56% for junglerice and 67% to 75% for feather fingergrass when these weeds were transplanted from 0 to 4 wk after crop emergence. A positive correlation (r = 0.75 for junglerice; r = 0.44 for feather fingergrass) was found between seed production and weed biomass in...
Weed Science, 2019
Junglerice [Echinochloa colona (L.) Link] is a problematic weed in the northern grain region of A... more Junglerice [Echinochloa colona (L.) Link] is a problematic weed in the northern grain region of Australia. Two pot experiments (Experiment 1 and Experiment 2) were conducted in a screen house to evaluate the growth and reproductive behavior of two biotypes (A, collected from a cotton (Gossypium hirsutum L.)–fallow; B, collected from a fence near a water channel) of E. colona in response to water stress (100%, 75%, 50%, and 25% water holding capacity [WHC]). Averaged across both biotypes, the plant height, biomass, and seed production of E. colona were reduced at 25% WHC compared with 100% WHC. However, E. colona still produced a considerable amount of seeds at 25% WHC (at least 365 seeds plant−1). Biotype A produced more seeds in the second experiment, while biotype B produced more seeds in the first experiment. In Experiment 2, at 100% WHC, biotype A produced more seeds (17,618 seeds plant−1) than biotype B (4,378 seeds plant−1), and similar observations were noticed for root bioma...
Crop Protection, 2017
Weeds represent a significant challenge to successful crop production. Highly effective and susta... more Weeds represent a significant challenge to successful crop production. Highly effective and sustainable weed control is required in order to meet global food demand. In this context, excessive use of herbicides has resulted in serious environmental and ecological issues. There are several weed control options which neither harm the environment nor require a significant increase in cost of production. Improving crop competition is particularly important and attractive among such options, which can be achieved by using crop cultivars possessing a competitive advantage over weeds, and manipulating the seed rate and direction of crop rows. Crop cultivars possessing traits such as fast germination, quick growth, high biomass, and large leaf area have a competitive advantage over weeds. Sowing such cultivars has been shown to suppress weeds in various crops. The use of high seed rates and narrow row spacing, if properly manipulated, can cause a significant decrease in weed proliferation in the crops. These techniques (cultivar, seed rate, row spacing, and row direction) are under-exploited as weed control methods, and offer considerable potential for achieving environmentally benign weed management. This special issue on "Eco-friendly Weed Management" will address the role of crop competition in managing weeds in different crops as well as in different countries.
Agronomy Journal, 2015
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or b... more All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
For short-duration cultivar 'PR 115', grain yield remained same when N was applied in eit... more For short-duration cultivar 'PR 115', grain yield remained same when N was applied in either 2 (at tillering and panicle initiation) or 3 splits (basal, at tillering and panicle initiation). However, with 3 splits including N applied at flowering stage resulted in 7.3% reduction in grain yield. In medium and longer duration cultivars, N application in 3 splits resulted in more grain yield than 2 splits. So, for medium and longer duration cultivars, if N application is omitted at tillering stage, the same yield can be obtained by applying that amount at flowering stage.
Twenty-seven rice (Oryza sativa L.) genotypes were evaluated in two planting systems, viz. aerobi... more Twenty-seven rice (Oryza sativa L.) genotypes were evaluated in two planting systems, viz. aerobic (dry direct seeded) and conventional flood irrigated transplanting under puddle conditions. There was a significant change in yield and morpho-physicochemical grain quality traits when grown under aerobic system of planting. Per cent yield reduction was varying between 2.45% in IR 71703-587-1-3 and 79.44% in IR 73435-8-2-2-1. Differences for days to 50% flowering, plant height and effective tillers/m2 were also observed over the planting systems. Planting systems significantly affected total rice recovery, head rice recovery, test weight of paddy, brown rice and milled rice, alkali spreading value and amylose content. However, grain length, grain breadth and L:B ratio were not affected. Genotypic differences over planting method for susceptibility index (SI) and mean relative performance were also observed. Genotypes which are suitable in flooded system may not be suitable for aerobic system. However, among these genotypes IR 73944-143-3-2-3-3, IR 71701-28-1- 4, PAU 201, IR 71703-587-1-3 and IR 72158-11-5-3-2 were found to be better candidates for the aerobic system. Possibility of improving rice yield and quality using genotypes suitable for aerobic system in the breeding programmes was explored.
Weed Technology, 2011
Weeds are a major biotic constraint to aerobic rice production in Asia. Research is needed on the... more Weeds are a major biotic constraint to aerobic rice production in Asia. Research is needed on the effects of cultural practices on weed management in aerobic rice, including techniques such as planting pattern and competitive cultivars. Field experiments were conducted in Punjab, India, in the wet seasons of 2008 and 2009 to study the growth of weeds and two rice cultivars [PR 115 and Punjab (P.) Mehak 1] in relation to planting pattern (uniform rows [23-cm row spacing] and paired rows [15-, 30-, and 15-cm row spacings]) under aerobic conditions. Junglerice and rice flatsedge were the dominant weed species during the early stages of the crop, while Chinese sprangletop and large crabgrass were the predominant species during flowering stage of the crop. Weed dry matter was not affected by planting pattern of P. Mehak 1; however, for PR 115, weed dry matter was greater in rice grown in uniform rows (244 g m−2) than in paired rows (183 g m−2). Planting patterns did not affect weed-free ...
Journal of Crop Improvement, 2011
... 1990. Rules for testing seed. J. Seed Technol., 12: 1112. 3. Basra, SMA, Farooq, M. andTabas... more ... 1990. Rules for testing seed. J. Seed Technol., 12: 1112. 3. Basra, SMA, Farooq, M. andTabassum, R. 2005. ... Adv. Agron., 101: 351388. [CrossRef], [Web of Science ®]; 9. Hira, GS 2009. Water management in northern states and the food security of India. ...
Field Crops Research, 2013
Dry-seeded rice (DSR) is an emerging production system in Asia in the face of looming water scarc... more Dry-seeded rice (DSR) is an emerging production system in Asia in the face of looming water scarcity, labor scarcity, and the energy crisis. The rice yield in this production system is highly variable. A survey was conducted during the kharif seasons of 2011 and 2012, comprising 320 randomly selected farmers covering all the major agroclimatic regions of Punjab State of India to understand the cultural practices, farmers' perceptions, and reasons for the yield gap in DSR. Farmers used seeding rates from 15 to 40 kg ha −1 , depending upon the type of seed drill used and agroecological conditions. About 65% of the farmers used drills with inclined plates, a seed-metering device, and on a "custom hiring" basis. More than 90% of the farmers chose cultivars for dry seeding by considering their yield potential, suitability to agroecological zones, and being easy to sell. Among the farmers surveyed, about 45% of them adhered to recommended practices of fertilizer application. Weeds were reported as the main biological constraints in DSR culture. Only 46% of the farmers applied both pre-and postemergence herbicides for weed control. About 67% of the farmers used flood jet or cone-type nozzles for herbicide spray, resulting in additional hand-weeding by 42% of the farmers due to poor weed control. The survey revealed that non-adherence to a recommended fertilizer schedule and weed control package (appropriate herbicides, optimum application time of herbicides, optimum volume of water for spraying, and selection of the right nozzles) is one of the reasons for the existing yield gap. Site-specific agrotechnologies for DSR need to be developed and transferred to farmers to achieve high yield. The survey also revealed that tailoring cultivars for dry-seeding conditions is needed for further productivity gains in DSR.
Asian Journal of Plant Sciences, 2007
Field Crops Research, 2017
The aims of the present study were to determine the optimum sowing time of newly developed rice g... more The aims of the present study were to determine the optimum sowing time of newly developed rice genotypes for high crop water productivity in non-flooded dry-seeded rice (DSR) in northwest India, and to identify the factors underlying high yielding genotypes by comparing their sink production in DSR. We evaluated differences in dry matter, nitrogen accumulation, translocation, yield formation and evapo-transpiration requirement of the selected genotypes developed for DSR (two cultivars; PR-115 and PR-121, two recombinant inbred lines; RIL-367 and RIL-1649) under three sowing dates (1, 10, and 20 June), for two years in the rainy seasons of 2014 and 2015 in northwest India. RIL-1649 sown on 1 June had higher grain yield (9.4 t ha −1) and similar or higher water productivity (1.3 kg m −3) than the other sowing date x genotype combinations. Delaying sowing from 1 to 10 June reduced yield of all genotypes except PR-121, and there was no further decrease in yield with delay to 20 June of PR-115 and RIL-1649. The yield of RIL-1649 sown on 20 June (7.9 t ha −1) was similar to that of PR-115 sown on 1 June.The high grain yield of RIL-1649 (7.9 t ha −1) for the late sowing was due to high pre-and post-anthesis dry matter accumulation, coupled with greater contribution of dry matter translocation to grain yield. RIL-367 not only produced similar yield (8.5 t ha −1) to the check variety PR-115 (8.3 t ha −1) for the 1 June sowing, but also matured 13 days earlier than PR-115.These results suggest that RIL-367 could be useful for DSR-based intensive cropping systems in northwest India, and with higher crop water productivity (1.32 kg m −3) than PR-115 (1.20 kg m −3). In the late sown condition, grain yield had a positive relationship with harvest index, leaf area index at flowering, preanthesis dry-matter accumulation, and dry matter translocation. A greater amount of dry matter and nitrogen uptake at anthesis, in combination with an increased harvest index, resulted in a greater amount of translocated material during the grain filling period. This, in turn, contributed to higher grain yield during late sowing. This study suggests that, for widening the sowing window, and for sustained yields of DSR in northwest India, high dry matter and nitrogen accumulation at anthesis, together with high harvest index, are useful selection traits.
Weed Technology
Australian grain growers are showing interest in winter-planted sorghum to avoid heat and water s... more Australian grain growers are showing interest in winter-planted sorghum to avoid heat and water stress during the grain-filling stage. Winter-planted sorghum may face competition from winter weeds, including sterile oats, and no herbicides are registered for controlling winter weeds in winter-planted sorghum. The objectives of this study were to (1) identify alternate herbicide options for sterile oats control in winter-sown imidazolinone (IMI)-resistant sorghum and (2) assess the crop injury levels due to herbicides. Sterile oats control with pendimethalin at 0.59 kg ai ha−1, trifluralin at 0.38 kg ai ha−1, and prosulfocarb + S-metolachlor at 2.3 kg ai ha−1 was poor (<30%). Atrazine at 2.7 kg ai ha−1, imazamox + imazapyr at 0.048 kg ai ha−1, and atrazine at 2.7 kg ai ha−1 followed by imazamox + imazapyr at 0.048 kg ai ha−1 reduced the sterile oats biomass by 93%, 96%, and 100% and increased yields by 116%, 136%, and 140%, respectively, compared with nontreated control. Pendimeth...
Cotton Production
Australia is known worldwide for producing cotton of the finest quality. Cotton production has an... more Australia is known worldwide for producing cotton of the finest quality. Cotton production has an important position in the economy of Australia, earning foreign exchange of two billion dollars annually. Australian cotton production is highly mechanized, and its production systems are quite specialized with emphasis on more crops per drop. However, several factors are making Australian cotton production challengeable, such as climate change, water scarcity, emergence of new insects, diseases and weeds, waterlogged soils and rising production cost. Australian cotton growers, as well as cotton scientists, put sincere efforts to cope up with these issues. New agronomic tools, for example, the skip‐row technique for water saving in the dry land area, timely planting, and use of glyphosate‐tolerant and Helicoverpa ‐resistant cultivars, were adopted to increase the yield potential. Synergy among weather forecasting, fertilizer, water, and pest management in the integrated crop management mode is being considered for high efficiency of cotton production systems. This book chapter explores current issues of Australian cotton production systems and opportunities to solve these issues
Best Management Practices for Drip Irrigated Crops, 2015
Peas occupy an important place among vegetable crops in the submountainous region of India. Being... more Peas occupy an important place among vegetable crops in the submountainous region of India. Being a cool weather-loving crop, it occupies a place of prominence among winter vegetables in kandi area, because the kandi area is cooler as compared to other pea-growing regions of Punjab. But, due to various physiographic constraints, existing legal constraints and the present method of utilization, the utilizable water for irrigation is very limited. In the present day context, improvements in irrigation practices are needed to increase crop production and to sustain the productivity level. Therefore, drip irrigation is a most efficient method of irrigation, which optimizes the use of irrigation water by providing it uniformly and directly to the roots of the plants. Drip irrigation can be helpful in kandi area where water is scarce and very expensive to pump and the fields have uneven topography. Irrigation with drip may be more efficient in kandi area due to precise application of water because evaporation is reduced, runoff is reduced or eliminated, deep percolation is reduced, and irrigation uniformity is improved so it is no longer necessary to “over water” parts of a field to adequately irrigate the more difficult parts. The major drawback of the drip irrigation system is its high initial investment; however, cost can be recovered in a short span if proper water and nutrient management and design principles are followed. Among the various components of the drip irrigation system, the cost of the lateral is a major factor, which influence the total system cost. Any effort made to reduce the length of lateral per unit area will result in reduction of system cost. Many scientists reported that drip irrigation in vegetable crops is very economical by reducing the cost and water use by 50%, when these crops were planted in paired row patterns [1, 3]. With drip irrigation, precise application of nutrients is possible. Fertilizer costs and nitrate losses can be reduced and nutrient applications can be better timed to needs of a crop. The response of pea to the combined effect of drip with different levels of irrigation in conjunction with different nitrogen levels and their economic feasibility are not well known. The information on seasonal water requirement of pea crop under drip irrigation is not available.
Weed Science, 2021
Prevalence of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu)... more Prevalence of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet & Magne; referred to as A. sterilis hereafter], winter-season weeds, is increasing in the eastern grain region of Australia. Biological attributes of these weeds enable them to survive in a wide range of environments and under different weed infestation levels. The interference of A. fatua and A. sterilis in a wheat (Triticum aestivum L.) crop was examined in southeast Queensland, Australia, through field studies in 2019 and 2020. Different infestation levels (0, 3, 6, 12, 24, and 48 plants m−2) of A. fatua and A. sterilis were evaluated for their potential to cause yield losses in wheat. Based on a three-parameter logarithmic model, the A. fatua and A. sterilis infestation levels corresponding to 50% wheat yield loss were 15 and 16 plants m−2, respectively. The yield reduction was due to a reduced spike number per unit area because of an increased weed infestation level. At the ...
Weed Science, 2021
African mustard (Brassica tournefortii Gouan) is a problematic winter annual weed in Australia. G... more African mustard (Brassica tournefortii Gouan) is a problematic winter annual weed in Australia. Germination ecology of B. tournefortii may change in response to the maternal environments or habitats in which the plants grow. A study was conducted to evaluate the effect of environmental factors on germination and emergence of four populations of B. tournefortii that were collected from different fields. Averaged over populations, germination was stimulated by dark and was higher at 25/15 C (92%) compared with 15/5 C (76%) and 35/25 C (45%). Averaged over light/dark regimes, at the lowest temperature regime (15/5 C), population A had higher germination than population D; however, at the highest temperature regime (35/25 C), population D had higher germination than population A. Populations B and C had higher germination in the temperature range of 25/15 C and 30/20 C compared with 15/5 C, 20/10 C, and 35/25 C. Seeds germinated at a wide range of alternating day/night temperatures (15/...
Weed Science, 2021
Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropp... more Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropping region. Populations resistant to glyphosate have evolved in Australia, creating the demand for information regarding the seed germination ecology of glyphosate-resistant (R) and glyphosate-susceptible (S) populations of C. sumatrensis. A study was conducted to examine the effects of temperature, light intensity, salt stress, osmotic stress, and burial depth on the germination and emergence of two populations (R and S) of C. sumatrensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C). In light/dark conditions, the R population had higher germination than the S population at 20/10 and 35/25 C. In the dark, the R population had higher germination than the S population at 25/15 C. In the dark, germination was inhibited at 30/20 C and above. Averaged over populations, seed germination of C. sumatrensis was reduced by 97% a...
Weed Technology, 2019
In Australia, junglerice and feather fingergrass are problematic weeds in sorghum. The high seed ... more In Australia, junglerice and feather fingergrass are problematic weeds in sorghum. The high seed production potential of these weeds increases their seedbank in the soil and makes weed control practices more difficult and expensive, particularly when weeds have evolved resistance to herbicides. A study was conducted to evaluate the seed production and seed retention behavior of junglerice and feather fingergrass at sorghum crop maturity following four transplanting times: 0, 2, 4, and 6 wk after sorghum emergence. Averaged across years, junglerice and feather fingergrass produced 4,060 and 5,740 seeds plant-1, respectively,when they were transplanted with the emergence of a sorghum crop. Seed retention ranged from 42% to 56% for junglerice and 67% to 75% for feather fingergrass when these weeds were transplanted from 0 to 4 wk after crop emergence. A positive correlation (r = 0.75 for junglerice; r = 0.44 for feather fingergrass) was found between seed production and weed biomass in...
Weed Science, 2019
Junglerice [Echinochloa colona (L.) Link] is a problematic weed in the northern grain region of A... more Junglerice [Echinochloa colona (L.) Link] is a problematic weed in the northern grain region of Australia. Two pot experiments (Experiment 1 and Experiment 2) were conducted in a screen house to evaluate the growth and reproductive behavior of two biotypes (A, collected from a cotton (Gossypium hirsutum L.)–fallow; B, collected from a fence near a water channel) of E. colona in response to water stress (100%, 75%, 50%, and 25% water holding capacity [WHC]). Averaged across both biotypes, the plant height, biomass, and seed production of E. colona were reduced at 25% WHC compared with 100% WHC. However, E. colona still produced a considerable amount of seeds at 25% WHC (at least 365 seeds plant−1). Biotype A produced more seeds in the second experiment, while biotype B produced more seeds in the first experiment. In Experiment 2, at 100% WHC, biotype A produced more seeds (17,618 seeds plant−1) than biotype B (4,378 seeds plant−1), and similar observations were noticed for root bioma...
Crop Protection, 2017
Weeds represent a significant challenge to successful crop production. Highly effective and susta... more Weeds represent a significant challenge to successful crop production. Highly effective and sustainable weed control is required in order to meet global food demand. In this context, excessive use of herbicides has resulted in serious environmental and ecological issues. There are several weed control options which neither harm the environment nor require a significant increase in cost of production. Improving crop competition is particularly important and attractive among such options, which can be achieved by using crop cultivars possessing a competitive advantage over weeds, and manipulating the seed rate and direction of crop rows. Crop cultivars possessing traits such as fast germination, quick growth, high biomass, and large leaf area have a competitive advantage over weeds. Sowing such cultivars has been shown to suppress weeds in various crops. The use of high seed rates and narrow row spacing, if properly manipulated, can cause a significant decrease in weed proliferation in the crops. These techniques (cultivar, seed rate, row spacing, and row direction) are under-exploited as weed control methods, and offer considerable potential for achieving environmentally benign weed management. This special issue on "Eco-friendly Weed Management" will address the role of crop competition in managing weeds in different crops as well as in different countries.
Agronomy Journal, 2015
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or b... more All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
For short-duration cultivar 'PR 115', grain yield remained same when N was applied in eit... more For short-duration cultivar 'PR 115', grain yield remained same when N was applied in either 2 (at tillering and panicle initiation) or 3 splits (basal, at tillering and panicle initiation). However, with 3 splits including N applied at flowering stage resulted in 7.3% reduction in grain yield. In medium and longer duration cultivars, N application in 3 splits resulted in more grain yield than 2 splits. So, for medium and longer duration cultivars, if N application is omitted at tillering stage, the same yield can be obtained by applying that amount at flowering stage.
Twenty-seven rice (Oryza sativa L.) genotypes were evaluated in two planting systems, viz. aerobi... more Twenty-seven rice (Oryza sativa L.) genotypes were evaluated in two planting systems, viz. aerobic (dry direct seeded) and conventional flood irrigated transplanting under puddle conditions. There was a significant change in yield and morpho-physicochemical grain quality traits when grown under aerobic system of planting. Per cent yield reduction was varying between 2.45% in IR 71703-587-1-3 and 79.44% in IR 73435-8-2-2-1. Differences for days to 50% flowering, plant height and effective tillers/m2 were also observed over the planting systems. Planting systems significantly affected total rice recovery, head rice recovery, test weight of paddy, brown rice and milled rice, alkali spreading value and amylose content. However, grain length, grain breadth and L:B ratio were not affected. Genotypic differences over planting method for susceptibility index (SI) and mean relative performance were also observed. Genotypes which are suitable in flooded system may not be suitable for aerobic system. However, among these genotypes IR 73944-143-3-2-3-3, IR 71701-28-1- 4, PAU 201, IR 71703-587-1-3 and IR 72158-11-5-3-2 were found to be better candidates for the aerobic system. Possibility of improving rice yield and quality using genotypes suitable for aerobic system in the breeding programmes was explored.
Weed Technology, 2011
Weeds are a major biotic constraint to aerobic rice production in Asia. Research is needed on the... more Weeds are a major biotic constraint to aerobic rice production in Asia. Research is needed on the effects of cultural practices on weed management in aerobic rice, including techniques such as planting pattern and competitive cultivars. Field experiments were conducted in Punjab, India, in the wet seasons of 2008 and 2009 to study the growth of weeds and two rice cultivars [PR 115 and Punjab (P.) Mehak 1] in relation to planting pattern (uniform rows [23-cm row spacing] and paired rows [15-, 30-, and 15-cm row spacings]) under aerobic conditions. Junglerice and rice flatsedge were the dominant weed species during the early stages of the crop, while Chinese sprangletop and large crabgrass were the predominant species during flowering stage of the crop. Weed dry matter was not affected by planting pattern of P. Mehak 1; however, for PR 115, weed dry matter was greater in rice grown in uniform rows (244 g m−2) than in paired rows (183 g m−2). Planting patterns did not affect weed-free ...
Journal of Crop Improvement, 2011
... 1990. Rules for testing seed. J. Seed Technol., 12: 1112. 3. Basra, SMA, Farooq, M. andTabas... more ... 1990. Rules for testing seed. J. Seed Technol., 12: 1112. 3. Basra, SMA, Farooq, M. andTabassum, R. 2005. ... Adv. Agron., 101: 351388. [CrossRef], [Web of Science ®]; 9. Hira, GS 2009. Water management in northern states and the food security of India. ...
Field Crops Research, 2013
Dry-seeded rice (DSR) is an emerging production system in Asia in the face of looming water scarc... more Dry-seeded rice (DSR) is an emerging production system in Asia in the face of looming water scarcity, labor scarcity, and the energy crisis. The rice yield in this production system is highly variable. A survey was conducted during the kharif seasons of 2011 and 2012, comprising 320 randomly selected farmers covering all the major agroclimatic regions of Punjab State of India to understand the cultural practices, farmers' perceptions, and reasons for the yield gap in DSR. Farmers used seeding rates from 15 to 40 kg ha −1 , depending upon the type of seed drill used and agroecological conditions. About 65% of the farmers used drills with inclined plates, a seed-metering device, and on a "custom hiring" basis. More than 90% of the farmers chose cultivars for dry seeding by considering their yield potential, suitability to agroecological zones, and being easy to sell. Among the farmers surveyed, about 45% of them adhered to recommended practices of fertilizer application. Weeds were reported as the main biological constraints in DSR culture. Only 46% of the farmers applied both pre-and postemergence herbicides for weed control. About 67% of the farmers used flood jet or cone-type nozzles for herbicide spray, resulting in additional hand-weeding by 42% of the farmers due to poor weed control. The survey revealed that non-adherence to a recommended fertilizer schedule and weed control package (appropriate herbicides, optimum application time of herbicides, optimum volume of water for spraying, and selection of the right nozzles) is one of the reasons for the existing yield gap. Site-specific agrotechnologies for DSR need to be developed and transferred to farmers to achieve high yield. The survey also revealed that tailoring cultivars for dry-seeding conditions is needed for further productivity gains in DSR.
Asian Journal of Plant Sciences, 2007
Field Crops Research, 2017
The aims of the present study were to determine the optimum sowing time of newly developed rice g... more The aims of the present study were to determine the optimum sowing time of newly developed rice genotypes for high crop water productivity in non-flooded dry-seeded rice (DSR) in northwest India, and to identify the factors underlying high yielding genotypes by comparing their sink production in DSR. We evaluated differences in dry matter, nitrogen accumulation, translocation, yield formation and evapo-transpiration requirement of the selected genotypes developed for DSR (two cultivars; PR-115 and PR-121, two recombinant inbred lines; RIL-367 and RIL-1649) under three sowing dates (1, 10, and 20 June), for two years in the rainy seasons of 2014 and 2015 in northwest India. RIL-1649 sown on 1 June had higher grain yield (9.4 t ha −1) and similar or higher water productivity (1.3 kg m −3) than the other sowing date x genotype combinations. Delaying sowing from 1 to 10 June reduced yield of all genotypes except PR-121, and there was no further decrease in yield with delay to 20 June of PR-115 and RIL-1649. The yield of RIL-1649 sown on 20 June (7.9 t ha −1) was similar to that of PR-115 sown on 1 June.The high grain yield of RIL-1649 (7.9 t ha −1) for the late sowing was due to high pre-and post-anthesis dry matter accumulation, coupled with greater contribution of dry matter translocation to grain yield. RIL-367 not only produced similar yield (8.5 t ha −1) to the check variety PR-115 (8.3 t ha −1) for the 1 June sowing, but also matured 13 days earlier than PR-115.These results suggest that RIL-367 could be useful for DSR-based intensive cropping systems in northwest India, and with higher crop water productivity (1.32 kg m −3) than PR-115 (1.20 kg m −3). In the late sown condition, grain yield had a positive relationship with harvest index, leaf area index at flowering, preanthesis dry-matter accumulation, and dry matter translocation. A greater amount of dry matter and nitrogen uptake at anthesis, in combination with an increased harvest index, resulted in a greater amount of translocated material during the grain filling period. This, in turn, contributed to higher grain yield during late sowing. This study suggests that, for widening the sowing window, and for sustained yields of DSR in northwest India, high dry matter and nitrogen accumulation at anthesis, together with high harvest index, are useful selection traits.