scholarly journals Yield loss prediction for integrated weed management in direct‐seeded rice

1993 ◽  
Vol 39 (2) ◽  
pp. 175-180 ◽  
Author(s):  
A. J. Fischer ◽  
J. Lozano ◽  
A. Ramirez ◽  
L. R. Sanint
Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 99 ◽  
Author(s):  
Gulshan Mahajan ◽  
Lee Hickey ◽  
Bhagirath Singh Chauhan

Weed-competitive genotypes could be an important tool in integrated weed management (IWM) practices. However, weed competitiveness is often not considered a priority for breeding high-yielding cultivars. Weed-competitive ability is often evaluated based on weed-suppressive ability (WSA) and weed-tolerance ability (WTA) parameters; however, there is little information on these aspects for barley genotypes in Australia. In this study, the effects of weed interference on eight barley genotypes were assessed. Two years of field experiments were performed in a split-plot design with three replications. Yield loss due to weed interference ranged from 43% to 78%. The weed yield amongst genotypes varied from 0.5 to 1.7 Mg ha−1. Relative yield loss due to weed interference was negatively correlated with WTA and WSA. A negative correlation was also found between WSA and weed seed production (r = −0.72). Similarly, a negative correlation was found between WTA and barley yield in the weedy environment (r = −0.91). The results suggest that a high tillering ability and plant height are desirable attributes for weed competitiveness in the barley genotypes. These results also demonstrated that among the eight barley genotypes, Commander exhibited superior WSA and WTA parameters and therefore, could be used in both low- and high-production systems for weed management. Westminster had a superior WSA parameter. Therefore, it could be used for weed management in organic production systems. These results also implied that genotypic ranking on the basis of WSA and WTA could be used as an important tool in strengthening IWM programs for barley.


Author(s):  
Suryakanta Kashyap ◽  
V.P. Singh ◽  
S.K. Guru ◽  
Tej Pratap ◽  
S.P. Singh ◽  
...  

Background: Weeds are the major threat to direct seeded rice and a single strategy of weed control may not be effective for season-long weed control. Intending to accomplish the long-term and sustainable weed management of direct seeded rice, the integration approach of weed management strategies seems a better alternative. The current field study was aimed to evaluate the impact of integration of different weed control methods on direct seeded rice under irrigated ecosystem on weed growth and rice yield. Methods: The experiment was laid out in randomized block design with three replications and twelve treatments during 2017 at G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India. The twelve treatments included the combination of cultural, mechanical, physical and chemical weed management methods. Result: Combination of stale seedbed technique integrated with pre-emergence application of pendimethalin with mechanical weeding at 25 DAS followed by 1 hand weeding at 45 DAS, Sesbania (line sowing) fb application of pendimethalin (PE) fb 1 mechanical weeding at 25 DAS fb 1 hand weeding at 45 DAS, stale seedbed with application of pendimethalin (PE) with Sesbania brown manuring supplemented with mechanical weeding (25 DAS) fb hand weeding at 45 DAS, mulching with wheat straw mulch along with post-emergence application of penoxsulam (20 DAS) fb 1 hand weeding at 45 DAS and application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with a row spacing of 25 cm found to be similar in the suppression of weed population and weed density at 40 and 60 DAS and crop yields (4.3, 4.1, 4.2, 4.0 and 4.2 t/ha, respectively) were on par with weed free plot i.e. 4.4t/ha. Application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with row spacing of 25cm recorded 93.7%, 90.6% and 4.5% weed control efficiency, weed control index and weed index respectively, which was similar with above integrated weed management treatments. A negative correlation of the weed density and dry matter with the yield of rice was recorded.


2021 ◽  
Vol 53 (3) ◽  
pp. 230-237
Author(s):  
Buta Singh Dhillon ◽  
Tanu Bansal ◽  
Pardeep-Sagwal ◽  
Virender Kumar ◽  
Makhan S Bhullar ◽  
...  

2017 ◽  
Vol 31 (6) ◽  
pp. 897-902 ◽  
Author(s):  
Jed B. Colquhoun ◽  
Richard A. Rittmeyer ◽  
Daniel J. Heider

Slow carrot emergence and canopy development render the crop a poor competitor with weeds. In this study, the ability to suppress weeds and maintain yield in the presence of weeds was compared among nine carrot varieties that included those selected by plant breeders for rapid vegetative canopy development compared to traditional varieties. Two weed management treatments were compared: handweeding for 21 d after carrot seeding versus handweeding for the entire carrot season. In years and locations with low to moderate weed pressure, such as in the 2014 study, differences among carrot varieties in weed competitiveness or tolerance were less apparent and therefore less relevant. Maximum carrot yield loss to weed competition among varieties was 28% in 2014. Yield loss in the presence of weeds was 15% or less with six of the nine carrot varieties. However, when weed pressure was intense in the 2015 study, both carrot plant density and carrot canopy development were inversely related to weed biomass. Carrot yield loss in the presence of weeds ranged from 38 to 87%. Despite correcting seeding populations for differences in germination among carrot varieties, carrot stand establishment varied greatly and would likely affect subsequent weed control measures such as timely cultivation or herbicide application. Future research efforts are warranted that consider carrot stand establishment factors and their relationship with integrated weed management programs.


2014 ◽  
Vol 14 (2) ◽  
pp. 33-42 ◽  
Author(s):  
KP Bhurer ◽  
DN Yadav ◽  
JK Ladha ◽  
RB Thapa ◽  
KR Pandey

Field experiment under dry direct seeded rice(Oryza sativa L.) was conducted during rainy season of 2010 and 2011 at Regional Agriculture Research Station (RARS), Parwanipur, Bara to develop appropriate weed management practices for dry direct- seeded rice. The trial was laid-out in randomized complete block design (RCBD) and replicated thrice. Observations were taken on weed, plant growth and yield attributing, yield, and socio-economic parameters. The weed density, dry weed weight and weed control efficiency resulted significantly different as influenced by integrated weed management practices. Low weed population density, low weed index and highest weed control efficiency resulted by pendimethalin followed by 2, 4- D followed by one hand weeding were at par with weed free check. Highest yield resulted from weed free plot followed by pendimethalin followed by two hand weeding and pendimethalin followed by 2, 4- D followed by one hand weeding. However, the net return per unit investment resulted highest in pendimethalin followed by 2, 4- D followed by one hand weeding. This proved that amid increasing wage rate and labour scarcity integrated weed management through pendimethalin 30 EC (Stomp) @1 kg a. i. /ha as pre- emergence herbicide application followed by 2, 4- D sodium salt 80 WP @ 0.5 kg a. i. /ha followed by one hand weeding or stale seed bed followed by pendimethalin 30 EC (Stomp) @1 kg a. i. /ha followed by bispyribac (Nominee gold) @25 g a. i. /ha 10% @200 ml/ha at 20 days of seeding resulted best alternative for manual hand weeding practices giving higher net return per unit investment. DOI: http://dx.doi.org/10.3126/njst.v14i2.10413   Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 33-42


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1557
Author(s):  
Robert Martin ◽  
Bunna Som ◽  
Joel Janiya ◽  
Ratha Rien ◽  
Sophea Yous ◽  
...  

The objective of this work was to determine the value of improved establishment methods and herbicide applications as alternatives to high seeding rates to improve weed suppression in rice. Field experiments were carried out in 2010 and 2011 to determine optimal seeding rates and seeding methods with and without weed competition in wet-seeded rice. Under wet seeding conditions, drum seeding at 80 kg ha−1 was the most profitable treatment for both weed-free and unweeded rice. Although pre-emergence herbicides are beginning to be adopted in wet-seeded rice, they are seldom used in dry direct-seeded rice in Cambodia. Experiments were carried out in 2018 and 2019 to test crop tolerance and the efficacy of butachlor, oxadiazon, pendimethalin and pretilachlor applied post-sowing and pre-emergence to dry direct-seeded rice. Oxadiazon and butachlor, with the option for a post-emergence herbicide, provided effective weed control and a high grain yield in dry direct-seeded rice. Pretilachlor did not effectively control weeds under dry seeding conditions. Although pendimethalin exhibited good weed control, crop damage was a risk in poorly prepared seedbeds which typify Cambodian rice systems. With an effective integrated weed management strategy, it might be possible to safely reduce seeding rates below 80 kg ha−1 using drum or drill seeding machines.


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