Agricultural Research Communication Centre, Sadar Bazar, Post Office Marg, KARNAL-132001, Haryana, India

 Journal

 Manual Determination Of Leaf Area Coefficient In Two Tropical Weeds.

 Smith, M.A.K.

 2002

Leaf area coefficients were determined manually from linear leaf measurements (X) and leaf dry weight (L) of non-senescent fully- expanded leaves of 10-week old giant blue-stem (A. tectorum) and sicklepod (Cassia obtusifolia) plants in the screenhouse. Estimated leaf area or leaf dry weight can be converted to actual leaf area from the equations Y= 0.6.3X and Y= 3.02 +411.89 L in A. tectorum and Y= 0.76X and Y= 0.62+215.34L in C.obtusifolia. 

 School Of Agriculture & Agricultural Technology, The Federal University Of Technology, Akure, Nigeria

 Journal

 Effects Of Population Source And Rhizome Length On Growth And Development Of Speargrass (Imperata Cylindrica (L.) Raeuschel).

 Smith, M.A.K. And Ayeni, A.O.

 2002

The growth patterns of speargrass (Imperata cylindrica (L.) Raeuschel) from 2 cm and 5 cm rhizome sections obtained from populations originating from the derived (DS), southern Guinea (SGS) and northern Guinea (NGS) savanna agro-ecozones were studied in a screenhouse. Speargrass grown for 14 weeks from 2 cm rhizome sections produced significantly more efficient roots and topgrowth, total dry matter and indeterminate rhizomes than that grown from 5 cm sections. The latter was more efficient in allocating plant dry matter into leaf, shoot, and rhizome production and produced more determinate rhizomes and dry weight per cm rhizome length (rhizome unit dry weight) than the former. Regardless of rhizome propagule length, speargrass from DS was significantly shorter and produced lighter rhizomes than those from both SGS and NGS, which had narrower leaves and shorter rhizomes. Speargrass from both DS and NGS produced more leaf area, total dry matter and rhizomes than that from SGS. Total leaf number and leaves/shoot were higher in speargrass from NGS than in those from both DS and SGS. Differences in speargrass shoot growth pattern, dry matter production and partitioning and rhizome production were primarily attributed to plant vigour, rates of leaf production and leaf expansion, leaf area duration (LAD), specific leaf weight (SLW) and leaf area ratio (LAR) 

 Agricultural Research Communication Centre, Sadar Bazar, Post Office Marg, KARNAL-132001, Haryana, India

 Journal

 : Comparative Response Of Chromolaena Odorata And Corchorus Olitorius To Intraspecific Competition

 Smith, M.A.K.

 2000

Chromoleana odorata and Corchorus olitorius were grown at 5, 10, 15 and 20 plants/pot to evaluate the response of individual plants to intraspecific competition after 10 weeks. Both species showed considerable plasticity in plant height, root dry matter production and biomass partitioning but competitive effects were significant in respect of leaf production, leaf area and photosynthetic efficiency (as indicated by LAR). Competitive effects were also significant with respect to shoot and total dry weights and individual plant weight (weight per plant) in C. olitorius. The reduction in leaf area was greater with increasing plant density in C. odorata while C. olitorius showed greater reductions in leaf production and LAR. Weight per plant was reduced significantly by 0.56 g for each unit increase in plant density for both species. Differences in plant response to intraspecific competition were due to growth habit and physiology. These differences have practical implications on population regulation and relative competitive ability of these two weeds in cropping situations 

 The Israeli Journal Of Aquaculture- Bamidgeh

 Journal

 Acha (Digitaria ExilisStapf) Meal Compared With Maize And Sorghum Meals As A Dietary Carbohydrate Source For Nile Tilapia (Oreochromis Niloticus L.).

 Fagbenro, O.A., Smith, M.A.K. And Amoo, A.I.

 2000

This study evaluated the nutritive potential of Acha (Digitaria exilis) meal as compared with maize and sorghum meals in Nile tilapia (Oreochromis niloticus) diets. In a preliminary digestibility experiment, acha meal showed similar protein digestibility to maize and sorghum meal but its digestible energy was lower (p 

 Development Africa Consortium, Port Harcourt, Nigeria. ISSN: 978-35066-4-1

 Journal

 Influence Of Germination Media On Germination Characteristics Of Selected Tropical Broadleaf Weeds.

 Smith, M.A.K. And Sawyerr, O.

 2000

Laboratory tests were carried out to examine effects of some germination media (potassium nitrate, ethanol, distilled water control) on seed germination and seedling growth in hairy beggarticks (Bidens pilosa, BIPIL), siam weed (Chromolaena odorata, SYNOD) and Mexican sunflower (Tithonia diversifolia, TIDIV). Seeds were germinated under natural day/night and ambient temperature and humidity conditions for 7 days. Weed seed germination, except in TIDIV, was influenced by germination medium, and more prominently over time. Each weed exhibited consistently peculiar seed germinability in specific medium; maximum germination of BIPIL, CHROD and EUHET occurred in potassium nitrate of pH 6.0 to 7.1, while both SYNOD and TIDIV germinated most in ethanol of pH 7.1 to 8.3. Seedling growth in all weeds was best in potassium nitrate. BIPIL, CHROD and EUHET seedlings had the best radicle growth in ethanol compared to SYNOD and TIDIV which produced the best seedling growth in water. Initial germination in water was best in SYNOD (45.0%, 58.9%). Initial plumule and radicle growth were best in EUHET. The least germination and seedling growth were obtained in EUHET and CHROD respectively. On average, CHROD seed germination responded most to germination media followed by EUHET, SYNOD and BIPIL. The differential seed germination and seedling growth responses to selected germination media were primarily due to seed dormancy characteristics and the dormancy-breaking activity of the germination media used in this study 

 Agricultural Research Communication Centre, Sadar Bazar, Post Office Marg, KARNAL-132001, Haryana, India

 Journal

 Influence Of Weed Type On Weed Interference In Cowpea (Vigna Unguiculata (L.) Walp.).

 Smith, M.A.K. And Ayeni, A.O.

 1999

Cowpea [Vigna ungulculata (L.) Walp.cv. VITA-5] was subjected to the influence of Rottboellia cochinchinensis, Euphorbia heterophylla, Cyperus tuberosus, and a mixture of three weeds and weed-interference durations of 0, 15, 20, 25, 30 and 60 days after planting (DAP). Average yield reductions in cowpea were 63.3% and 28.5% in the dry and wet seasons, respectively. In the dry season, C. tuberosus caused 82.9% yield reduction. In the wet season, R. cochinchinensis and weed mixture caused 59.6% and 34.6% yield reductions respectively, whereas C. tuberosus caused 25.9% yield increase in cowpea. E. heterophylla caused 31.9% and 46.7 % yield reductions in the dry and wet seasons, respectively. Cowpea tolerated weed interference for four weeks at 15:1 weed/crop population, irrespective of weed species and season. Adverse effect of weed interference for 25-30 DAP was less in terms of yield and pod number than other weed interference durations 

 Agricultural Research Communication Centre, Sadar Bazar, Post Office Marg, KARNAL-132001, Haryana, India

 Journal

 Rhizome Bud Distribution In Three Speargrass (Imperata Cylindrica (L.) Raeuschel) Populations In Nigeria.

 Smith, M.A.K.

 1999

Speargrass populations from the forest/savanna transition (DS; Ibadan), southern Guinea savanna (SGS; Ilora) and northern Guinea savanna (NGS; Bida) agro-ecozones exhibited ecotypic variations in rhizome bud distribution. Rhizomes from Ibadan were longer but had less visible buds, most of which occurred within the apical region, than those from both Ilora and Bida which had more and regularly distributed visible buds, and by implication, greater regenerative potential, aggressiveness and persistence 

 Weed Science Society Of Nigeria, WSSN; ISSN 0794 4950

 Journal

 Effect Of Sampling Time And Location On Rhizome Features In Speargrass (Imperata Cylindrica (L.) Raeuschel).

 Smith, M.A.K.

 1999

The effects of sampling time and location of length, dry weight per cm length (rhizome unit dry weight, and moisture content of single-node speargrass, Imperata cylindrica (L.) Raeuschel) rhizome segments sampled from the upper (0-10 cm), middle (10- 20 cm), and lower (20-30 cm) soil depths in the derived savanna (DS), Southern Guinea Savanna (SGS), and Northern Guinea Savanna (NGS) agro-ecozones of Nigeria were assessed. Across agro-ecozones, sampling time did not significantly influence rhizome feature at 0-10 cm soil depth. Rhizomes form the 10-20 cm soil depths had similar dry weight but significantly more moisture in May and September than in July. At 20-30 cm soil depth, rhizomes sampled in May and September had more dry weight than those sampled in July. In addition, rhizomes in NGS were longer and had more dry weight at this soil depth than in SGS. Regardless of sample time and soil depth, rhizomes in SGS and NGS were longer and had more dry weight than those in DS. Differences in rhizome features were due to seasonal changes in rainfall, plant growth and soil characteristics 

 Klobex Academic Publishers, Nigeria. BRC 9737/10106

 Journal

 Early Development Of Speargrass (Imperata Cylindrica (L.) Raeuschel) From Three Ecological Zones In Nigeria.

 Smith, M.A.K.

 1998

Screenhouse studies were conducted to assess the pattern of early development of speargrass form the forest/savana transition (Ibadan), southern Guinea savanna (Ilora), and northern Guinea savanna (Bida) agro-ecozones of Nigeria. Speargrass was transplanted from 2cm single- node rhizome sections from different locations and grown for 8 weeks. Speargrass from both Ibadan and Bida produced significantly more main-shoot leaves and wider leaves during sprout establishment than speargrass from Ilora. On the other hand, shoot dry weigh was higher in speargrass from Bida than in speargrass from both Ibadan and Ilora. On the average, speargrass from Ibadan grew significantly more than speargrass from both Ilora and Bida due primarily to differences in rhizome propagule dry weight and leaf area ratio. 

 Klobex Academic Publishers, Nigeria. BRC 9824/10201

 Journal

 Cowpea Performance Under Interference From Common Weed Associates.

 Smith, M.A.K. And Ayeni, A.O.

 1998

Cowpea performance (dry matter) under weed interference and common weed associates Rothboelia cochinchinensis, Euphorbia heterophylla, Cyperus tuberosus and weed mixture were compared at 1:15 crop-weed ratio in dry and wet season pot experiments. Weed growth and dry weight production were slow during the first 15 days after planting (DAP) but increased sharply after establishment. Wet-season weed growth was slower than dry-season weed growth but established wet-season plants grew better. Cowpea performed better than each weed associate during the first 20 and 25 DAP in the dry wet seasons respectively. However, the crop was considerably less productive than C. tuberosus and weed mixture in the dry season, and the latter in the wet season. Crop and weed productivity were smaller under full-season weed interference in the dry season than in the wet season, and vice versa for weed free crop. In the wet season, crop performance reduced more under shading from E. heterophylla (r = 0.85**) than from R. cochinchinnensis (r= -0.75**), weed mixture (r= 0.58**) and C. tuberosus (r= 0.10). Shading from weed associates reduced crop performance as early as 20 DAP for C. tuberosus and 25 DAP for other weed species. Full-season crop association with R. cochinchinensis and weed mixture caused the greatest reduction in crop performance. Differences in crop and weed productivity were due to soil moisture, growth habit and probably, resource-use efficiency. The implication of weed association with cowpea beyond the first 20-25 DAP and influence on weed species on its productivity are indicated.