@article{ author = {}, title = {Assessment of Irrigated Cotton Seedling Emergence in Flatland Mechanized Planting Systems}, abstract ={The nonuniform emergence of cotton seedlings in the flatland mechanical planting method is a major problem in cotton production areas with crust-forming soil and saline soil and irrigation water. A field study was conducted in central Iran within Isfahan Prov-ince to assess the effects of four types of planting equipment and three crust breaking methods on cotton (Varamin cultivar) emergence on a clay loam soil. Four items of plant-ing equipment were used, consisting of: a cotton planter with runner opener and its smooth-crown zero pressure pneumatic press wheels positioned along or away from the seed row; a cotton planter with runner opener and open-center concave steel press wheels; and a grain drill with disk opener and without covering device. Three crust breaking methods were employed, including rolling cultivator, rolling-type crust breaker (two spike-tooth drums in tandem) and no crust breaking. The crust breaking operations were done one week after the first irrigation when the first seedlings had emerged. Final emergence, planting depth, plant height and soil strength were measured.The choice of planting equipment had significant effects on planting depth, final emergence and plant height. The cotton planter with its press wheels positioned along the seed row had the greatest level of seedling emergence in a non-crust breaking treatment. This is because, during the planting operation, the soil was very dry and the press wheels were firming the soil above or around the seed to the degree that enough seed-soil contact was provided and the seeding depth was decreased. In non crust-breaking treatments, the emergence was less than 50%. The difference in emergence for the rolling cultivator and the rolling-type crust breaker was not significant. However, the rolling cultivator could be recom-mended due to its availability in the region. Results indicated that the grain drill (with acid delinted cotton seed) or alternatively the cotton planter with open-center press wheels (with undelinted seed) could be used with the rolling cultivator as a crust breaker as a mechanized cotton dry flatland planting system in this region.}, Keywords = {Planter,Cotton emergence,Crust breaker,Drill,Rotary hoe}, volume = {5}, Number = {3}, pages = {87-98}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-2198-en.html}, eprint = {http://jast.modares.ac.ir/article-23-2198-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Study of the Strength Properties of Pistachio Nuts and Cluster Stem Joints for the Design and Development of a Harvesting Machine}, abstract ={A consideration of the design and development of any harvesting machine is required to determine the physical and biomechanical properties of the tree and its fruit. Biome-chanical properties such as pull, bending and torsion strengths must be determined. In the field experiments, trees were selected from an orchard in Rafsanjan, Kerman Prov-ince, Iran. Parameters related to fruit properties were measured using load cells. In Raf-sanjan’s Pistachio Research Institute laboratory, subsequent measurements were made using similar instrumentation. In a randomized design layout, 18 tree cultivars with five replications were selected. The maximum pull, bending, and torsion strengths were found respectively for Badami Ravar, Momtaze Tajabadi and Italiaee cultivar clusters. Mini-mum pull, bending, and torsional strengths were obtained for Ghazvini, Louk and Kalleh Ghoochi clusters. The cultivars Kalleh Ghoochi, Rezaee Zoodras and Khanjari Damghan were found to have fruit with the highest pull, bending, and torsional strengths, with the lowest strengths belonging to the Italiaee cultivar.}, Keywords = {Pistachio,Bending,Harvest,Pull,Strength,Torsion}, volume = {5}, Number = {3}, pages = {99-104}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-316-en.html}, eprint = {http://jast.modares.ac.ir/article-23-316-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Effect of NSP Degrading Enzyme Supplement on the Nutrient Digestibility of Young Chickens Fed Wheat with Different Viscosities and Triticale}, abstract ={To study the effect of cell-wall degrading enzymes on the nutrient efficiency of young chickens fed different grains, an in vitro experiment was conducted to determine the range of viscosities of seven local wheat varieties. From these, the highest (Flaat) and the lowest (Ghods) were selected for an in vivo study. 288 day-old Arian chickens were kept in cages and fed one of four grains (Flaat, Ghods, Triticale, and Corn) with or without a die-tary NSP degrading enzyme in a 4×2 factorial arrangement with six replicates per treat-ment. An indigestible marker (chromic oxide) was used for digestibility measurements. Feed and water were provided ad libitum. Excreta samples were collected from 18-21 days of the experiment. Apparent metabolizable energy corrected for nitrogen (AMEn) was improved (P<0.05) in all diets by enzyme supplementation except the corn diet. The ap-parent lipid digestibility (ALD) and apparent crude carbohydrate digestibility (ACCD) of all treatments were significantly improved by adding an enzyme (P<0.01). This improve-ment was highest in the Flaat variety (highest viscosity) of wheat. The results of this ex-periment clearly indicate the positive effects of supplemental NSP degrading enzymes on nutrient digestibilities and on AMEn especially for the grains with the highest viscosity (wheat cultivar Flaat and triticale).}, Keywords = {Broilers,NSP degrading enzymes,Nutrient digestibility,Viscosity}, volume = {5}, Number = {3}, pages = {105-112}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10746-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10746-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Effect of Various Maturity Stages at Harvest on Storability of Persimmon Fruits (Diospyros kaki L.)}, abstract ={Fruits of a commercial cultivar of sweet persimmon (Diospyros kaki L.) were harvested at four stages of maturity to evaluate the practical maximum postharvest storage during 1998 and 1990. Fruits were harvested at four stages of maturity which corresponded to 6th October, 19th October, 4th November, 29th November in 1998 and 1st October, 15th Oc-tober and 29th October in 1999, respectively. Fruits were held at 2 1oC and 95 % relative humidity for a period of twenty weeks. Fruit firmness, titrable acidity (TA), soluble tan-nin and vitamin C content significantly decreased with increasing maturity, while pH and soluble solid concentrations (SSC) increased. After storage, fruit harvested at all stages of maturity had higher pH, SSC, weight loss, and breakdown, but lower TA, firmness, vi-tamin C and soluble tannins as compared with their quality attributes at harvest. The least weight loss (less than 10 percent) during twenty weeks storage occurred in fruits harvested at the early stage of maturity (first harvest ), compared to other harvest dates. Fruit firmness, SSC and vitamin C content were also best in the same order for the first harvest. However, at the end of storage period, total soluble tannins were remarkably high in fruit harvested at the early stage of maturity. In contrast, harvesting fruit at early maturity stage (i.e., SSC around 13 % and fruit firmness of 15 kg/cm2) was found to be the best stage for minimising a postharvest loss and maintaining a marketable persim-mon fruit quality product for short term storage.}, Keywords = {Persimmon,harvest date,maturity and storage}, volume = {5}, Number = {3}, pages = {113-123}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10842-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10842-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Application of Mathematical Modeling to Determine The Size of On-Site Grass Filters for Reducing Farm Pesticide Pollution}, abstract ={This paper presents a mathematical approach for estimating the size of a grass filter area for removing pesticide residues from agricultural drainage waters. The method util-izes a water table management model, DRAINMOD, for simulating drainage waters from agricultural land and then a solute transport model, PRZM2, for simulating pesticide concentrations in drain effluent discharging from grass filters. DRAINMOD was used to estimate daily drain outflows that occurred in a 100 ha subsurface drained field in the Ot-tawa-St. Lawrence lowlands by running the model for a one-in-twenty year annual rain-fall period. Atrazine (AZ), metolachlor (MT) and metribuzin (MZ) are the most common herbicides that are found in drainage waters. The simulated drain outflows were as-sumed to contain 50 µg/l of AZ, MT and MZ residues, and simulations were carried out with PRZM2 to determine the required size of grass filter area to make drainage waters safer for aquatic life and a marine habitat. It was found that no more than 6% of the farm area could be used to reduce the concentrations in drainage waters from 50 µg/l to less than 1 µg/l for the three herbicides.}, Keywords = {Atrazine,DRAINMOD,Grass strips,Metolachlor,Metribuzin,PRZM2,Subsurface drainage}, volume = {5}, Number = {3}, pages = {125-134}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-285-en.html}, eprint = {http://jast.modares.ac.ir/article-23-285-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Further Investigation on the Orange Cotyledons in Pea (Pisum sativum L.)}, abstract ={Pea (Pisum sativum L.) is an important model plant for genetic as well as biochemical and physiological studies. A well-saturated map of pea consisting several morphological, biochemical and molecular markers has been constructed to date. Nevertheless, there are still several genes whose inheritance and map positions are not well understood. Orange cotyledon color in pea is an interesting characteristic whose precise nature of gene interactions is unknown. Genetic analysis using crosses between lines having orange cotyledon color and lines with yellow or green cotyledons revealed that the character is controlled by a single gene. It was also found that the gene i (producing green cotyledon color) shows an epistatic effect on the gene Orc (orange cotyledon color). Incomplete dominance and dominance were revealed in the loci Orc and I, respectively. Mapping analysis revealed that the gene Orc is located on linkage group 1 and 28.5 crossover units away from the gene Ans and 31.3 map units away from Idh. In addition, a significant linkage was detected between two genes Pur and Ans with an estimated distance of 9.9 map units. The distance between Orc and Pur was estimated as 38 map units.}, Keywords = {Epistasis,Incomplete dominance,Isocitrate dehydrogenase,Linkage}, volume = {5}, Number = {3}, pages = {135-141}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-536-en.html}, eprint = {http://jast.modares.ac.ir/article-23-536-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {Estimation of Genetic Parameters for Yield, Yield Components and Glucosinolate in Rapeseed (Brassica napus L.)}, abstract ={Eight genotypes of rapeseed (Brassica napus L.), including six cultivars and two breed-ing lines, were used to determine the genetic parameters for number of pods per main axis (NPM), number of pods per plant (NPP), length of pod (LOP), number of seeds per pods (NSP), 1000-seed weight , seed yield, and total glucosinolate. Analysis of variance based on Hayman’s method revealed significant general (a) and specific (b) combining ability mean squares for all traits except for 1000-seed weight, which indicated the impor-tance of additive and non-additive genetic effects. For 1000-seed weight, only the general combining ability mean square was statistically significant. Significant ratios of a to b mean squares and high narrow-sense heritability estimates were observed for 1000-seed weight and total glucosinolate, which indicated the importance of additive genetic effects for these traits. Therefore, the efficiency of selection for improving these traits will be high. The significant b1 (mean deviation of F1’s from their mid-parental values) mean squares for all of the studied traits except LOP and 1000-seed weight, exhibited direc-tional dominance and subsequently significant average heterosis. Significant maternal (c) mean squares were observed for all of traits, except LOP. Among yield components, NPM and NPP had a significant correlation with seed yield and can therefore be used as good criteria for improving seed yield. The correlation between seed yield and total glucosi-nolate was not significant, and so reducing this antiquality trait without any considerable changes in seed yield is possible. In general, the parents PF7045/91 and BL1 were good combiners and the crosses BL1×PF7045/91, BL1×BL2 and PF7045/91×Shiralee were good combinations for improving seed yield and total glucosinolate, simultaneously.}, Keywords = {Rapeseed,Yield components,Genetic parameters,Glucosinolate}, volume = {5}, Number = {3}, pages = {143-151}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-5486-en.html}, eprint = {http://jast.modares.ac.ir/article-23-5486-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} } @article{ author = {}, title = {The Agha Jari Formation: A Potential Source of Ammonium and Nitrate Nitrogen Fertilizers}, abstract ={Nitrogen deficiency ranks right behind water shortage as the second-most constraint to crop production in the coarse-loamy sand of the Gareh Bygone Plain (GBP) in southern Iran. Since better resource utilization is essential for wise energy management, contrary to reported cases, surface water pollution by N maybe a boon in the GBP. The Agha Jari Formation (AJF), in which the Bisheh Zard Basin (BZB) has been formed, contains an-omalously high concentrations of NO3 and NH4+ in its calcareous sandstone, siltstone and marl components. As about 60% of our irrigation water is supplied through under-ground resources and are heavily over-exploited, the artificial recharge of groundwater (ARG) is actively pursued in Iran. Therefore, a major proportion of the ephemeral dis-charge of the BZB is spread over 1365 hectares of sedimentation basins and recharge ponds of the ARG system in the GBP. These basins and ponds are covered with improved rangeland, and eucalyptus (Eucalyptus spp.) and acacia (Acacia spp.) plantations. There-fore, it is expected that some of the geological-N dissolved in floodwater, and also carried by the suspended load, will reach the groundwater and supply the plants coming in con-tact with the water and/or sediment. Moreover, as both NO3 and NH4+ are considered pollutants of groundwater, the relative abundance of each should be determined, so that possible remedial measures can be designed and implemented. To study the origin of N in the BZB, and to investigate the fate of the dissolved and adsorbed N as it travels from the watershed to the root zone, 13 rock samples, 5 floodwater samples and 81 soil samples were collected and analyzed for NO3and NH4+. The NO3-N concentration was lower than that of NH4+-N in most of the samples: 5.1 vs. 9.6 mg kg-1 in rocks, 13.4 vs.17.4 mg L-1 dis-solved in floodwater, 1.3 vs.4.3 mg kg-1 carried by the suspended load, and 10.6 vs.15.5 mg kg-1 in the 0-125 cm soil profile. Assuming that the mean annual inflow of the GBP-ARG system is 7 million m3 ,we receive 89.4±52.4 kg ha-1 yr-1 of NH4+-N and 68.7± 24.6 kg ha-1 yr-1 of NO3-N, of which some furnishes the vegetative cover with N. A part of what remains may reach the watertable after passing through the vadose zone.}, Keywords = {AJF, Agha Jari Formation,ARG, Artificial recharge of groundwater,BZB, Bisheh Zard Basin, GBP, Gareh Bygone Plain,MRT, Multiple Range Test}, volume = {5}, Number = {3}, pages = {153-163}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-11875-en.html}, eprint = {http://jast.modares.ac.ir/article-23-11875-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2003} }