Glasshouse experiments were conducted from March to July 2003 to determine the effects of sowing depth, and the time, duration, and depth of flooding on the emergence, survival, and growth of Fimbristylis miliacea (L.) Vahl. The treatments that were evaluated in the first experiment were three seeding depths (0, 0.5, and 1.0 cm), while in the second experiment, three flooding depths (saturated soil with no standing water and soil with water depths of 5 and 10 cm) and three flooding durations (7, 14, and 21 days from sowing) were evaluated. In the third experiment, three flooding depths (saturated soil with no standing water, and soil with water depths of 5 and 10 cm) and four flooding regimes (7, 14, 21 or 28 days after sowing [DAS]) were evaluated. Surface seeding gave the highest emergence rate compared to the 0.5 cm and 1.0 cm soil depths. A significantly higher emergence rate was recorded with the saturated conditions than with the flooded conditions. A flooding duration of ≥ 14 days showed a clear trend of reduced emergence with increasing flooding depth. A significantly higher survival rate, plant height, root length, number of leaves, and dry matter were recorded at soil saturation followed by the 5 cm and 10 cm flooding depths when flooding was simulated at 7 and 14 DAS. When the flooding was delayed to 21 and 28 DAS, the 10 cm flooding depth was required to suppress this weed. The results provide sufficient evidence to confirm that from deeper seed burial (1 cm sowing depth), flooding depths of ≥ 5 cm of durations of 14 and 21 days and at the onset of flooding within 14 DAS were effective in suppressing the emergence and growth of F. miliacea. 1995;Begum et al. 1999) and one of the principal weeds in the Philippines, Mashhor

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A glasshouse experiment was conducted at University Putra Malaysia, Serdang, to study the growth pattern of itchgrass collected from 13 locations. The itchgrass was either associated with crops or found along roadsides in six infested estates located in Johor, Kedah, Pahang, Perak, Perlis and Selangor. Significant differences between populations were observed in all variables except in time to seedling emergence. Cluster analysis of the data classified the populations into three major groups. The first group comprised populations from Johor, Pahang and Perak found in association with banana, cocoa and oil palm plantations, or along the roadsides. The second group comprised populations from Kedah, Perlis and Selangor found in association with maize, upland rice, rubber, sugar cane and tobacco plantations. The third group was a distinct population found only along roadsides at Padang Kartong, Perlis. Principal component analysis was performed to determine the growth characteristics that separated the groups. The results showed that plant height, number of leaves, number of seeds/plant, secondary culm diameter and the weight of 100 intact or dehulled seeds were the most significant characteristics that differentiated the groups. The study provided strong evidence of the existence of three itchgrass groups in Peninsular Malaysia.

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Direct seeding has some advantages compared to transplanting system in rice, however there are some constraints need to be addressed. One  constraint generally faced in the wet seeded rice is poor stand  establishment. The experiment was conducted to improve seedling  establishment by using selected growth regulators. Seeds of four rice  cultivars, i.e. Memberamo, Widas, MR 84, and MR 219 were treated with  GA3 (gibberellic acid-3) of 25, 50, and 100 mg 1-1, and IBA (indole-3  butyric acid) of 10, 20, and 40 mg l-1. Results showed that cultivar  response to GA3 was similar in all parameters observed, however the response of cultivars to IBA was different at the initial stage. In Indonesian cultivars (Memberamo and Widas), shoot length of IBA treated seedlings was comparable to the control, but the IBA treated seedlings of  Malaysian cultivars (MR 84 and MR 219) had slightly shorter shoots   compared to the control. GA3 as seed treatment induced favorable early emergence and shoot growth in the initial stage, but the shoots were  etiolated and resulted in susceptible to lodging even in the vegetative  stage. In comparison, exogenous application of IBA resulted in high number of adventitious roots contributing towards better establishment of seedling with broader and greener leaves. The growth regulator was lost its  effect by 2 or 3 weeks after sowing. All IBA concentrations also did not  show any significant differences on growth parameters or have any detrimental effect on grain yield in all cultivar tested. IBA 10 mg l-1 was  sufficient in providing the required improvement in the rice seedlings.

Tlie experiment was conducted in the glasshouse of UPM from March 2003 to June 2004 to determine the soil seedbank in the ricefields ot'Muda rice granary area in Peninsular Malaysia. Six soil cores of 5 cm in diameter and 10 cm depth were sampled from each of 24 fields. All samples from each individual field were bulked and placed in plastic trays of 38 x 25 x 10 cm. Soil was moistened as required and emergence of weed seedlings were recorded over period of one year. After one year, remaining seeds were separated, removed and identified. The total seed bank was estimated at 1136.48 million/ha of which 62.35% (708.60 million seedlings ha" 1) germinated within 12 months and 37.65% (427.88 million seeds ha" 1) remained ungerminated. Total of 20 taxa were recognized. Based on importance value (I.V.) the five most dominant species in terms of emerged seedling were Fimbristylis miliacea, Leplochloa chinensis, LitJwigia hyssopifolia, Cyperus difformii and C. iria. Of the remaining seeds the five dominant species with decreasing trend in ranking were F. miliacea, Scirpus lateriflonis, Monochoria vagina/is, L. hyssopifolia and L. chinensis. Ranking of total seed reserves (seedlings+ remaining seeds) were similar to emerged seedling indicating that emerged seedlings reflect the actual weed flora in the Muda area. Among the dominant species F. miliacea accounted for 58.07% of emerged seedlings, 79.31% of remaining seeds and 66.07% of total seed bank. Total seedling emergence of all species was higher in the first observation in April 2003 and cumulative seedling emergence showed no clear peaks.

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Direct seeding has some advantages compared to transplanting system in rice, however there are some constraints need to be addressed. One constraint generally faced in the wet seeded rice is poor stand establishment. The experiment was conducted to improve seedling establishment by using selected growth regulators. Seeds of four rice cultivars, i.e. Memberamo, Widas, MR 84, and MR 219 were treated with GA 3 (gibberellic acid-3) of 25, 50, and 100 mg 1 -1 , and IBA (indole-3 butyric acid) of 10, 20, and 40 mg l -1 . Results showed that cultivar response to GA 3 was similar in all parameters observed, however the response of cultivars to IBA was different at the initial stage. In Indonesian cultivars (Memberamo and Widas), shoot length of IBA treated seedlings was comparable to the control, but the IBA treated seedlings of Malaysian cultivars (MR 84 and MR 219) had slightly shorter shoots compared to the control. GA 3 as seed treatment induced favorable early emergence and shoot growth in the initial stage, but the shoots were etiolated and resulted in susceptible to lodging even in the vegetative stage. In comparison, exogenous application of IBA resulted in high number of adventitious roots contributing towards better establishment of seedling with broader and greener leaves. The growth regulator was lost its effect by 2 or 3 weeks after sowing. All IBA concentrations also did not show any significant differences on growth parameters or have any detrimental effect on grain yield in all cultivar tested. IBA 10 mg l -1 was sufficient in providing the required improvement in the rice seedlings.