Document Type: Original Article


1 Department of Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Weed Research, Plant Protection Research Institute


To assess the effect of non chemical management of weed control on forage Sorghum (Sorghum bicolor) a field study was conducted in Varamin, Iran during 2010 crop year in a three- replicated- split factorial experiment laid out in randomized complete block design with four weeding levels (W1= one time cultivation at 3-leaf stage using a duck foot cultivator, W2= two times cultivation at 3 and 5-leaf stages using a duck foot cultivator, W3= hand weeding throughout growing season and W4= without weeding) as main plots, and two plant density levels (D1= 190000, and D2= 266000 plant ha-1) and two plant pattern levels (P1= one-row and P2= two-row) as sub plots. Weed density, weed biomass, number of leaves (NL), stem diameter (SD), number of tillers (NT), plant height (PH), leaf area index (LAI), dry matter yield (DM yield), dry matter digestibility (DMD), water soluble carbohydrates (WSC), crude protein (CP), acid detergent fiber (ADF), total ash (ASH), and crude fiber (CF) where measured. The results revealed that the highest weed density and biomass observed in not weeding treatment. There was not significant difference among one time cultivation at 3-leaf stage and two times cultivation at 3 and 5-leaf stages from the weed density and biomass point of view. The lowest NL, SD, and NT observed in not weeding treatment. Increasing plant density decreased DM yield, PH, SD and NL of sorghum. Two-row plant pattern showed a significant preference in comparison to one-row plant pattern from the DM yield point of view although the highest CP obtained in one-row plant pattern. The highest DMD obtained in P2D2. The highest ASH obtained in W2D2 and W2P2


Balkcom K. S., J. L. Satterwhite, F. J. Arriaga, A. J. Price, and E. Van Santen (2011) Conventional and glyphosate-resistant maize yields across plant densities in single- and twinrow configurations, Field crop research, 120(3): 330-337.
Ballare C. L., A. L. Scopel, and R. A. Sanchez (1990) Far-red radiation reflected from adjacent leaves: an early signal of competition in plant canopies, Science, 247: 329-331.
Baumhardt R. L., J. A. Tolk, and S. R. (2005) Winter Seeding Practices and Cultivar Maturity Effects on Simulated Dryland Grain Sorghum Yield, Agron. J., 97: 935-942.
Bello I. A., M.D.K. Owen, and H. M. Hatterman-Valenti (1995) Effect of shade on velvetleaf (Abutilon theophrasti) growth, seed production, and dormancy, Weed Technol., 9: 452-455.
Berenguer M. J., J. M Faci (2001) Sorghum (Sorghum Bicolor L. Moench) yield
compensation processes under different plant densities and variable water supply European journal of agronomy 15(1): 43-55.
Blackshaw, R. E (1993) Safflower (Carthamustinctorius) density and row spacing effects on competition with green foxtail (Setariaviridis), Weed Sci., 41: 403-408.
Carmi A., Y. Aharoni, M. Edelstein, N. Umiel, A. Hagiladi, E. Yosef, M. Nikbachat, A. Zenou,. and J. Miron (2006) Effects of irrigation and plant density on yield, composition and in vitro digestibility of a new forage sorghum variety, Tal, at two maturity stages, Animal feed science and technology, 131(1-2): 121-133.
Carruthers K., Q. Fe, D. Cloutier, and D. L. Smith (1998) Intercropping corn with soybean, lupin and forages: weed control by intercrops combined with interrow cultivation, European journal of agronomy, 8(3-4): 225-238.
Deregibus V. A., R. A. Sanchez, J. J. Casal, and M. J. Trlica (1985) Tillering responses to enrichment of red light beneath the canopy in humid natural grassland, Journal of Applied Ecology, 22: 199-206.
El-henawy S. E., E. A. Abd El-Lattief, M. S. Ahmad, and U. Schmidhalter (2008) Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn, Agricultural water management, 95(7): 836-844.
Forcella, F. (1987) Tolerance of weed competition associated with high leaf area expansion rate in tall fescue, Crop Sci., 27: 146-147.
Forcella, F., M. E. Westgate, and D. D. Warnes (1992) Effect of row width on herbicide and cultivation requirements in row crops, Am. J. Altern. Agric., 7: 161-167.
Gressel, J. (1992) Addressing real weed science needs with innovations, Weed Technol., 6:509-525.
Guatier H., C. V. Grancher, and L. Hazard (1999) Tillering responses to the light environment andto defoliation in populations of Perennial ryegrass (LoliumperenneL.) selected for contrasting leaf length, Ann. Bot., 83: 423-429.
Habyarimana E., P. Bonardi, D. Laureti, V. Di Bari, S. Cosentino, and C. lorenzoni (2004) Multilocational evaluation of biomass sorghum hybrids under two stand densities and variable water supply in Italy, Industrial crops and products, 20(1): 3-9.
Hunt P. G., M. J. Kasperbauer, and T. A. Matheny (1989) Soybean seedling growth responses to light reflected from different coloured soil surfaces Crop Sci., 29:130-133.
Jones A. C. (1985) C4 grasses and cereals, Growth, development and stress responses. p. 80-82.
Jones O. R., and G.L. Johnson (1991) Row width and plant density effects on Texas High Plains sorghum, J. Prod. Agric, 4: 613-619.
Kasperbauer M. J. and P. G. Hunt (1998) Far-red light affects photosynthate allocation and yield of tomato over red mulch, Crop Sci. 38: 970–974.
Lafarge T. A., I. J. Broad, and G. L. Hammer (2002) Tillering in grain sorghum over a wide range of population densities: Identification of a common hierarchy of tiller emergence, leaf area development and fertility, Ann. Bot., 90: 87-98.
Lanning S. P., L. E. Talbert, J. M. Martin, T. K. Blake, and P. L. Bruckner (1997) Genotype of wheat and barley affects light penetration and wild oat growth, Agron. J., 89: 100-103.
Marsalis M. A., S. V. Angadi, and F. E. Contreras-Govea (2010) Dry matter yield and nutritive value of corn, forage sorghum, and BMR forage sorghum at different plant populations and nitrogen rates, Field crop research, 116(1-2): 52-57.
Rajcan I. and C. J. Swanton (2001) Understanding maize–weed competition: resource competition, light quality and the whole plant, Field crop research, 71(2): 139-150.
Snider J. L., R. L. Raper, and E. B. Schwab (2012) The effect of row spacing and seeding rate on biomass production and plant stand characteristics of non-irrigated photoperiod-sensitive sorghum (Sorghum bicolor (L.) Moench), Industrial crops and products, 37(1): 527-535.
Staggenborg S. A., D. L. Fjell, D. L. Devlin, W. B. Gordon, and B. H. Marsh (1999) Grain sorghum response to row spacings and seeding rates in Kansas, J. Prod. Agric., 12: 390-395.
Wyse, D. L. (1992) Future of weed science research, Weed Technol., 6:162-165.
Zimdahl, R. L. (1999) Harmful aspects of weeds. Pages 13-40 in Fundamentals of Weed Science. San Diego, CA: Academic.