Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition

Two field experiments were conducted at MARDI station, Seberang Perai, Penang. The experiments were: 1) Critical period in saturated and flooded field (off season 2005 and main season 2005/2006); 2) Chemical weed control in saturated field (main season 2005/2006 and off season 2006). The objectiv...

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Main Author: Mohd Yusof, Mohamad Najib
Format: Thesis
Language:English
English
Published: 2009
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/10704/1/FP_2009_27_A.pdf
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spelling my-upm-ir.107042013-05-27T07:46:48Z Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition 2009-08 Mohd Yusof, Mohamad Najib Two field experiments were conducted at MARDI station, Seberang Perai, Penang. The experiments were: 1) Critical period in saturated and flooded field (off season 2005 and main season 2005/2006); 2) Chemical weed control in saturated field (main season 2005/2006 and off season 2006). The objectives of the study were: a) to determine the critical period of weed competition under saturated and flooded field conditions; b) to determine the efficacy of herbicides in controlling weed and their subsequent effect on rice productivity under saturated field. The first study consisted of different weeding periods under saturated and flooded field conditions. Meanwhile, the second experiment evaluated ten widely used herbicides which were available in the market either individually or as mixture, and sequentially applied in direct seeded rice fields during the critical period of weed competition under saturated field condition. Results from the first experiment indicated that Summed Dominance Ratio (SDR) of weed composition was different under saturated condition compared with flooded condition for both seasons. The dominance ranking of weed groups in off season 2005 under saturated condition was sedges followed by grasses and broadleaved weeds, while in main season 2005/2006, grassy weeds was the most dominant followed by sedges and broadleaved weeds. Under flooded condition the dominance ranking of weed groups was broadleaved followed by grasses and sedges where the trend was the same in both seasons. The numbers of tillers, along with rice grain yield were significantly affected by weed competition in both saturated and flooded condition. Yield loss due to weed competition was higher in saturated condition (54.5%) than in flooded condition (35.2%). Based on the 5% level of yield loss, the critical period in off season 2005 was at 2-71days after sowing (DAS) under saturated condition, and 15-73 DAS under flooded condition. In the main season 2005/2006, the critical periods were at 1-72 DAS in saturated condition and 2-98 DAS in flooded condition. Weeds - Control Rice - Weed control - Case studies 2009-08 Thesis http://psasir.upm.edu.my/id/eprint/10704/ http://psasir.upm.edu.my/id/eprint/10704/1/FP_2009_27_A.pdf application/pdf en public masters Universiti Putra Malaysia Weeds - Control Rice - Weed control - Case studies Faculty of Agriculture English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
topic Weeds - Control
Rice - Weed control - Case studies

spellingShingle Weeds - Control
Rice - Weed control - Case studies

Mohd Yusof, Mohamad Najib
Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
description Two field experiments were conducted at MARDI station, Seberang Perai, Penang. The experiments were: 1) Critical period in saturated and flooded field (off season 2005 and main season 2005/2006); 2) Chemical weed control in saturated field (main season 2005/2006 and off season 2006). The objectives of the study were: a) to determine the critical period of weed competition under saturated and flooded field conditions; b) to determine the efficacy of herbicides in controlling weed and their subsequent effect on rice productivity under saturated field. The first study consisted of different weeding periods under saturated and flooded field conditions. Meanwhile, the second experiment evaluated ten widely used herbicides which were available in the market either individually or as mixture, and sequentially applied in direct seeded rice fields during the critical period of weed competition under saturated field condition. Results from the first experiment indicated that Summed Dominance Ratio (SDR) of weed composition was different under saturated condition compared with flooded condition for both seasons. The dominance ranking of weed groups in off season 2005 under saturated condition was sedges followed by grasses and broadleaved weeds, while in main season 2005/2006, grassy weeds was the most dominant followed by sedges and broadleaved weeds. Under flooded condition the dominance ranking of weed groups was broadleaved followed by grasses and sedges where the trend was the same in both seasons. The numbers of tillers, along with rice grain yield were significantly affected by weed competition in both saturated and flooded condition. Yield loss due to weed competition was higher in saturated condition (54.5%) than in flooded condition (35.2%). Based on the 5% level of yield loss, the critical period in off season 2005 was at 2-71days after sowing (DAS) under saturated condition, and 15-73 DAS under flooded condition. In the main season 2005/2006, the critical periods were at 1-72 DAS in saturated condition and 2-98 DAS in flooded condition.
format Thesis
qualification_level Master's degree
author Mohd Yusof, Mohamad Najib
author_facet Mohd Yusof, Mohamad Najib
author_sort Mohd Yusof, Mohamad Najib
title Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
title_short Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
title_full Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
title_fullStr Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
title_full_unstemmed Critical Period for Weed Control in Saturated and Flooded Field, and Chemical Weed Control in Direct Seeded Rice Under Saturated Condition
title_sort critical period for weed control in saturated and flooded field, and chemical weed control in direct seeded rice under saturated condition
granting_institution Universiti Putra Malaysia
granting_department Faculty of Agriculture
publishDate 2009
url http://psasir.upm.edu.my/id/eprint/10704/1/FP_2009_27_A.pdf
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