JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2003 | Volume:12 | Issue:4|Papers Count:12

In this experiment, 11 combinations of sugar beet tops and crown (SBTC) were ensiled for 2 months as: l-SBTC, 2- Chopped SBTC, 3- Chopped SBTC + %5 molasses, 4- treatment no. 3 + %2 urea, 5- Chopped SBTC + %10 molasses, 6- treatment no. 5+ %2 urea, 7- Chopped SBTC + wheat straw to give %35 dry matter (DM), 8- SBTC + wheat straw to give %35 DM + %10 molasses, 9- treatment 8+ %2 urea, 10Copped SBTC + wheat straw to give %40 DM + %10 molasses, 11- treatment no. 10 + %2 urea, 12- Dried sugar beets and crown alone (control). At first physical and chemical characteristics of silage such as pH, DM, organic matter (OM), ammonia nitrogen (N-NID), total nitrogen (N), non protein nitrogen (NPN), true protein nitrogen (TPN), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of treatments were determined. Addition of molasses to silages significantly (P<0.05) decreased pH and increased NPN. Addition of urea to silages significantly increased pH and N-NH3. Using of wheat straw in the silage significantly (P<0.05) increased silages DM and pH. In situ degradability of DM and crude protein of treatments. 1, 2, 3, 4,5,6,8 and 12 were determined by using 2 fistulated sheep. The results were analyzed by Fig-P. Software and the coefficients of a, band c were calculated. The results indicated that addition of molasses and urea to silage increased quickly degradable portion (a) of DM and crude protein and decreased slowly degradable portion (b) of dry matter and increased coefficient of (c) for DM.

The genetic changes in Holstein dairy cattle of Moghan Co. farm iscure estimated and milk records during years 1987-1988 and fat records from 1992 to 1998 were collected for statistical analysis and estimation of (co) variance components and genetic parameters. Three models including single- trait, two-traits (first lactation records) and repeatability (first three lactation records) were applied, using DFREML software. Estimated heritability of milk and fat yield traits with three models were 0.254, 0.255; 0.245, 0.25; 0.234 and 0.204, respectively. Repeatability of these traits were estimated as 0.501 and 0.361, respectively. To calculate the genetic trend of production traits, regression of mean predicted breeding value on year of calving in cows and first calving of daughter in sires were used. To estimate phenotypic trend, regression of mean phenotypic records on first calving of cows was determined. Genetic trend of sires for milk production during 1990-1998 years and for fat yield during 1992-1998 years were 2.22 and -0.179 kg per years, respectively. Dam’s genetic and phenotypic trend for milk production during 1987-1998 years and for fat yield during 1992-1998 years were 13.26 and 44.23; -0.0003 and 2.23 kg per year, respectively.

Seven tobacco cultivars of Burley type (Burley 21, Burley CDL 28, Burley Banket, Burley Resistant, Burley 14, Burley 26 and Burley m 86) were intercrossed in the year of 2000 in Tobacco Research Center in Rasht, Iran, using a randomized complete block design with 3 replications and several of their quantitative and qualitative characteristic were investigated. The results of analysis of variance with regard to the traits such as plant height, leaves per plant, days to flowering, leaf area index (LAT), resistance to blue mold (Peronospora tabacina) and root knot nematodes (Meloidogyne incognita), Green and dry yields showed significant differences among genotypes. Thus, diallel data were analysed and results were interpreted by using Hayman’s graphical method. Since plant height, green leaf yield and resistance to Poronospora are controlled mainly by additive gene effects, therefore, selection for these traits with relatively higher heritabilities would be promising. It was also revealed that leaf area index and resistance to nematode were controlled by non- additive gene effects. Thus, selection for these two traits will not be quite successful. Dry leaf yield is controlled by over- dominance genes effect. The graphical analysis of results showed that cultivars B. 21 and B Blanket had both the maximum dominant genes, cultivars, B. CDL 28, B. 26 and B. Resis had the maximum recessive genes and B. 14 and B. m 26 were intermediate for dominant and recessive genes. Heritability estimates (narrow sense), using Griffing and Hayman methods, ranged 25 to 52%. Thus, probability of selection for high yielding lines would be intermediate.

In order to determine the effect of different electrolytes supplements during heat stress on broilers performance, four electrolytes: KCl, Na2CO3, NK4Cl and K2CO3 with four levels 0.0%, 0.15%, 0.3% and 0.45% were used in drinking water. The study was conducted by using of 780 day old chicks (Arian). They were reared under normal condition till 36 days of ages. Then they were exposed on heat stress (35°C, 4 hours per 24h) until 56 days of age. Results of the present study indicated that generally electrolytes had a beneficial effects on broiler performance and mortality rate in compared to control group. However, the best level for KCl, Na2CO3, NH4Cl and K2CO3 on feed conversion ratio were, 0.15%, 0.15%, 0.45% and 0.3%, respectively. Feed conversion ratio were improved to 20.1%, 18.8%, 13.6% and 18.07% by using 0.15% KCl, 0.15% Na2CO3, 0.45% NH4Cl and 0.3% K2CO3, respectively. Using 0.15% KCl, 0.15% Na2CO3, 0.45% NH4Cl and 0.45% K2CO3 resulted to decrease mortality rate as compared to control group by 40%, 24%, 51.5% and 64.9% respectively.

To study the effects of different concentrations of calcium chloride and the number of its foliar application on quality and storage life of red apple, an experiment was carried out in 1998-1999 in Orumia. This experiment consisted of apple trees on seedling stocks, treated with 2, 4 or 6 foliar spraY8 of calcium chloride at 0, 0.5, 1 and 1.5% concentrations in weekly intervals. The experiment was based on a randomized complete block design with four replications. The stored fruits were sampled and analyzed for the quality parameters and weight loss at 45-day intervals. The results indicated that foliar application of CaCl2 reduced the amount of TSS compared to control but did not affect the acidity and pH. Effect of CaCl2 on firmness was significant at 1% level and maximum firmness was observed in 1% of CaCl2. Foliar application with CaCl2 had a significant effect on weight loss at 5% level in storage. The most decrease in weight was observed in control and the least decrease was in 1.5%, respectively. The calcium content of the fruits was increased due to the foliar sprays in all calcium treatments as compared to control. The effects of number of foliar application was not significant on quality parameters, but the interaction of CaCl2 concentration and the number of it’s foliar application was significant on TSS at 1% level and on firmness at 5% level.

In order to investigate the effect of two herbicides: ioxinil (Totril) and oxadiazon (Ronstar) and their mixture effect on weed control and yield of onion (Azarshahr red onion C.V.) an experiment was carried out in Agricultural Research field of Azarbaijan Tarbiat - Moallem University located in 35 km Tabriz - Marageh road in years 2000-2001. The experiment was planned in a randomized complete block design with 7 treatments and 3 replications. The results indicated that ioxinil (0.7 and 0.6 kg/ha) controlled the broad leaf weeds such as Chenopodium album, Convolulus arvensis and Amaranthus spp. This herbicide didn’t control grass weeds such as Setaria viridis. The application of oxadiazon (0.36 kg/ha.) controlled grass weeds well and suppressed the growth of broad leaf weeds. The onion yield in the oxadiazon plots was usual like ioxinil. The application of oxadiazon (0.36 kg/ha.) along with ioxinil (0.7 kg/ha.) controlled both the broad leaf and grass weeds. In this case both weed density and dry weed biomass were also reduced. The onion yield was highest in this treatment and in hand weed control. It was shown that in control treatment plots didn’t produce any suitable onion due to competition.

The mortalities occurred on various developmental stages of apple leaf miner [Leucoptera scitella (Zell)] on Goldend and Red Delicious varieties grown on trellis at Khalatpoushan Experimental Station were studied from late in 1992 and during 1993. The mortality rates of over wintering pupae as well as various developmental stages of the first and second generations was determined estimating the relevant k-values. The percentage mortality of over wintering pupae appeared to be 7.17%, of which 1.83% was due to the parasitism whilst the other control agents had caused 5.34% mortalities. 2.64% and 1.73% egg mortalities were calculated for the two generations. Mortality rates due to the natural control agents at 4 larval instars and pupal stage during the 1st generation appeared to be 7.4%, 1.58%, 13.74%, 22.2% and 12.16% respectively. Whlilst estimates of such mortality rates during the 2nd generation were as 6.7%, 11.29%, 42.59%, 32.16% and 2.60%, respectively. The highest mortality rates within the two generations were associated with parasitism and the main parasitoides collected from different developmental stages belonged to the genus Baryscapus in the family Eulophidae.

In order to study the effect of defoliation and stand reduction on grain yield and yield components in sunflower, an experiment was conducted in Agricultural Research Station, Faculty of Agriculture, University of Tabriz in 2000. Two varieties namely Azargol (CMS19x R46) and Golshid (CMS31 xR46) were used in this study. The leaves were removed at the time of beginning of anthesis (R5) and the treatments consisted of five levels including check (no leaves removed), removal of one third upper leaves, removal of one third middle leaves, removal of one third lower leaves, and removal of all leaves of the plant. The experiment was carried out in randomized complete block design with three replications. Each plot consisted four 4 m long rows spaced 0.75m apart with 25cm between plants on each row. With the exception of plant height and stem diameter, head diameter, filled achene percent, 1000 grain weight, harvest index and grain yield was reduced as a result of partial or complete leaf excision when compared with the undefoliated check. Middle leaves showed maximum effect on filling of grains due to their largest surface and more photosynthetic activity. Grain yield was minimum at treatment with all leaves removal as reflected by less 1000 grain weight and filled achene percent.

In a survey conducted on hoverflies (Dip.: Syrphidae), in Marand during 1997-99, 9 indentified species belonged to 3 genera: Eristalis, Eristalinus and Scaeva. In the genus Eristalis 2 species: Eristalis arbostorum (L.) and E. tenax (L.) and in the genus Eristalinus 3 species: E. taeniops (Wiedemann), E. megacephalus (Rossi) and E. aeneus (Wiedemann), and in the genus Scaeva: 4 species, Scaeva pyrastri (L.), S. albomaculata (Brunetti), S. latimaculata (Mac quart) S. rossica (Kuznetsov) were identified, respectively. The collecting was done using sweepnet, whilst insects in immature stages, were hand collected and reared under laboratory conditions of 25±2, 60±5 R.H, and 12L: 12D regime and resulting adults were then identified. The most common species appeared to be Eristalis tenax and E. arbostorum. A simple identification key to the species and the relevant figures are provided as a further aid in recognition of the presented species.