A study was conducted to investigate some biological aspects of the weed species Amaranthus viridis L. and Sinapis arvensis L. Seeds were sown in field plots on 3 November 2003 at Dongla area, Northern State. At flowering plant height, root length and days to 50% flowering were recorded. At maturity number of seeds/plant was counted. Laboratory experiments included the effects of constant temperature (5 - 45°C) and alternating temperature of 30/20 °C, simulated drought (0 to -15 bar) and sowing depth (0 - 5 cm) on seed germination and seedling emergence. Germination of both species commenced within 24 h, rapidly increased after 3 days and reached a maximum with 3 _ 9 days. Both species are annual herbs 90 -92 cm high, with 22 - 30 cm root length, reached 50% flowering within 52 _ 54 days and completed their life span after 99 -101 days. A. viridis produced 1050000 seeds/plant, while that for S. arvensis produced only 650. Seed germination of both species, was inhibited at 5 and 45 °C. Germination of A. viridis occurred at 15 °C, while that for S. arvensis commenced at 10 °C. The optimum temperature for germination of A. viridis was at 30 or 30/20 °C, while that for S. arvensis was 20 °C. The maximum temperature in both species was 40°C. Germination decreased with increased osmotic pressure. In A. viridis seeds it took place at _3 and _6 bar, while that of S. arvensis was displayed up to _12 bar. Germination was considerable (94-99%) at sowing depths of 0 - 2 cm, moderate (70-88%) at 3 cm depth and was significantly reduced at 4 and 5 cm depth. Seedlings failed to emerge at 4 or 5 cm depth. Maximum emergence was attained at 0 - 0.50 cm depth. Emergence of A. viridis was generally higher than S. arvensis

Objective of this research was to compare the two evaluation methods of S2 line per se (S2) and S2 testcross (TC) for line evaluation in two subpopulations of Suwan 5(S)C3 (AB), Suwan 5(S)C3(F) (A) and Suwan 5(S)C3(SF) (B). The inbred testers of the TC method were Ki 45 in A and Ki 46 in B subpopulations, respectively. A hundred progenies from each method in both subpopulations (A-S2 x Ki 45 เนเธฅเธฐ B-S2 x Ki 46) were evaluated in the 2000 early rainy season at the National Corn and Sorghum Research Center, Nakhon Ratchasima. The results of genetic variability among progenies evaluated over both subpopulations showed that the S2 method (22.38 percent) was 1.84 times greater than the TC method (12.15 percent) for all of 15 agronomic characters measured, and 4.35 times for grain yield. Correlation coefficient (r) between the two methods for grain yield was 0.069. Total number of common S2 lines of the two methods for the 10-highest and 10 lowest-yielding groups in both subpopulations were the two lines.

Objective of this research was to compare the 2 evaluation methods of S2 line per se (S2) and S2 testcross (TC) for inbred and hybrid development in 2 subpopulations of Suwan 5(S)C3(ABC0), Suwan 5(S)C3(F) (AC0) and Suwan 5(S)C3(SF) (BC0). The inbred testers of the TC method were Ki 45 in AC0 and Ki 46 in BC0 subpopulations, respectively. The 10 S5 lines from highest yield selection of each the method of AC0 and BC0 were testcrossed with Ki 45 and Ki 46, respectively. The 20 hybrids of the 2 subpopulations and 4 hybrid checks were evaluated in the 2001 late rainy season at the National Corn and Sorghum Research Center, Nakhon Ratchasima. The S6 lines from the 2 methods of both subpopulations and 4 inbred checks were also evaluated in the same season. In conclusion, both methods were not different in selecting for high-yielding inbreds and hybrids.

Objective of this research was to compare the two evaluation methods of S2 line per se (S2) and S2 testcross (TC) for population improvement in two subpopulations of Suwan 5(S)C3 (ABC0), Suwan 5(S)C3(F) (AC0) and Suwan 5(S)C3(SF) (BC0). The inbred testers of the TC method were Ki 45 in AC0 and Ki 46 in BC0 subpopulations, respectively. Ten entries selected from each of the highest yield of each method in the two subpopulations were pollinated by using their S2 seeds to form 4 synthetics (A(S2)C1, A(TC)C1, B(S2)C1 and B(TC)C1). The 4 synthetics and 3 original 2 populations were testcrossed with Ki 45 and Ki 46, 21 population crosses of the 7 populations, and the 7 populations per se were evaluated in the 2001 late rainy season at the National Corn and Sorghum Research Center, Nakhon Ratchasima. In conclusion, the S2 method was more efficient in improving yields of populations per se and populations topcrossed with unrelated inbreds. However, the TC method was more efficient in improving yields of related population crosses.

Background: Both sorghum (Sorghum bicolor) and sugarcane (Saccharum officinarum) are members of the Andropogoneae tribe in the Poaceae and are each other's closest relatives amongst cultivated plants. Both are relatively recent domesticates and comparatively little of the genetic potential of these taxa and their wild relatives has been captured by breeding programmes to date. This review assesses the genetic gains made by plant breeders since domestication and the progress in the characterization of genetic resources and their utilization in crop improvement for these two related species. Genetic Resources: The genome of sorghum has recently been sequenced providing a great boost to our knowledge of the evolution of grass genomes and the wealth of diversity within S. bicolor taxa. Molecular analysis of the Sorghum genus has identified close relatives of S. bicolor with novel traits, endosperm structure and composition that may be used to expand the cultivated gene pool. Mutant populations (including TILLING populations) provide a useful addition to genetic resources for this species. Sugarcane is a complex polyploid with a large and variable number of copies of each gene. The wild relatives of sugarcane represent a reservoir of genetic diversity for use in sugarcane improvement. Techniques for quantitative molecular analysis of gene or allele copy number in this genetically complex crop have been developed. SNP discovery and mapping in sugarcane has been advanced by the development of high-throughput techniques for ecoTILLING in sugarcane. Genetic linkage maps of the sugarcane genome are being improved for use in breeding selection. The improvement of both sorghum and sugarcane will be accelerated by the incorporation of more diverse germplasm into the domesticated gene pools using molecular tools and the improved knowledge of these genomes.

Effects of weed densities on fresh ear yield of sweet corn and waxy corn were conducted at the National Corn and Sorghum Research Center during April-June 2005. The RCBD with 3 replications, 10 treatments, includingweed densities of 10 20 40 60 80 100 120 140 and 160 plants/square m were employed. The results showed that most of weeds were nutsedge (Cyperus rotundus), synedrella (Synedrella nodifora) itchgrass (Rottboellia cochinchinensis), painted spurge (Euphorbia heterophylla), tropical spiderwort (Commelina benghalensis), running grass (Brachiaria reptans ) and goose grass (Eleusine indica). Weed densities of 10-160 plants/square m gave higher weed dry weight than Hand weeding (494-963 percent), and reduced fresh corn yield, i.e. yield with husk (20-53 percent), standard yield without husk (30-83 percent), number of standard ear and number of large ear. Moreover, weed densities of 10-160 plants/square m increased total weight of undergrade ear and number of undergrade ears.

Striga hermonthica (L) Moench, a parasitic weed species, is a major constraint to sorghum production in the savanna zones of north-eastern Nigeria. The aim of this study was to assess the influence of farmer practices on Striga infestation of sorghum fields in the region. Random sampling technique and semi-structured questionnaires were used to sample 54 sorghum fields and assess farmer-practices in nine communities of Borno State in north-eastern Nigeria. About 39% of the farmers had continuously cultivated their fannlands for more than 10 years, 60% planted in June, and 41 % practiced sorghum-legume rotation, 45% practiced sorghum+legumes relay intercropping, 58% applied nitrogen fertilizer and 43% conducted hoe-weeding three times . In northern and southern Guinea savannas, prolonged period of land cultivation, early planting, and inadequate nitrogen fertilization promoted Slriga infestation as these practices were positively associated with Slriga counts. However, late planting, sorghum-cowpea or groundnut rotation, and increased weeding frequency reduced infestation as these were negatively correlated with Strigo counts . Relay intercropping reduced grain yield ha-1 (r = -0.52*) in· northern Guinea savanna, but sorghum-legume rotation, weeding frequency, and increased nitrogen fertilizer rate increased grain yield as these were positively associated with grain yield ha-1 in both zones. In Sudan savanna, Slriga counts were reduced by relay intercropping of sorghum with legumes, as the practice was negatively associated with Striga count, while inadequate weeding promoted infestation (r = 0.44*). However, grain yield ha-I was positively associated with nitrogen fertilizer rate and weeding frequency. Thus prolonged period of land use, continuous cropping of sorghum, inadequate nitrogen fertilization and early planting or less than 3 hoe-weedings promote Striga infestation, while sorghum-legume rotation, sorghum + legume intercropping or 3 hoe-weeding reduced infestation and increased grain yield of sorghum in the three zones.

Striga hermonthica (Scrophulariaceae), a root parasitic weed, is a major constraint to cereal production in Sudan. Available control measures are relatively expensive. An integration of simple cultural practices was thought to give an economically acceptable solution under subsistence farming conditions. The aim of this work was to evaluate the efficiency of intercropping sorghum with hyacinth bean on Striga control and sorghum growth and yield. Under field conditions, sowing of hyacinth bean, in alternating holes with sorghum on the same day, reduced Striga population density, biomass and number of capsules per plant by 88, 83 and 52% in comparison to sole sorghum, respectively. Sowing of hyacinth bean on the same day as sorghum was more effective in suppressing the parasite than delayed planting for one or two weeks. Urea at 190 kg/ha applied to sole sorghum reduced Striga population density, Striga biomass and number of capsules per plant by 57, 73 and 94%, respectively. Unrestricted Striga parasitism reduced number of heads, straw and grain yield of sorghum significantly. Urea applied to sole sorghum increased the number of heads and straw yield by more than 2-folds. Intercropping, without urea, increased straw yield by over 100% and number of sorghum heads by 55 -170 %. Urea, at 190 kg/ha, applied to intercropped sorghum increased straw yield by 24-100% and grain yield by 38-200% in comparison to the respective intercropping treatment without urea. Laboratory observations on the subterranean stages of Striga growth in root chambers revealed that hyacinth bean sown alone or in mixture with sorghum induced 40 _ 47% Striga seed germination in comparison to 55% germination on sole sorghum. Attachment of Striga seed was high on sole sorghum (14.9%) but low (2.6%) on intercropped sorghum. Intercropping sorghum with hyacinth bean reduced Striga attachment to sorghum, Striga growth, seed production and ability to debilitate the host. Delayed intercropping reduced efficiency of controlling the parasite, but decreased competition between hyacinth bean and sorghum. Intercropping technique is suitable for subsistent farming especially on localized infestations

Research of cotton improvement for yield and fiber quality are not only just studied in the field of cotton planting but also have to studied on fiber quality especially in fiber length, fiber strength and fiber fineness, in order to develop cotton varieties which are suitable for using as raw materials in textile industry. In this research, the cotton fiber samples of 5 white cotton trials set which are dora11*c118, dora11(3)*c118, dora11(5)*bio-7, takfha2 and SSR60 and 4 brown cotton trials set which are B624, B651, B661 and dora41. Those samples were tested physical properties by HVI instrument and then analyzed by using statistic comparison of the length of each cotton trials set. It can concluded that the white cotton trial set there is Takfha2 was significantly different from SSR60 (checked variety) in the white cotton trial set. And there is insufficient data to conclude that there is different in fiber length on the brown cotton trial.