The study objective was to evaluate the effects of reducing dietary starch content in fresh cow diets while maintaining NDF levels by substituting barley grain (BG), corn silage (CS), or both with beet pulp (BP) on DMI, lactation performance, serum mineral and metabolites concentrations, liver enzymes and liver functionality index (LFI), serum insulin and revised quantitative insulin sensitivity check index (RQUICKI). Thirty-six multiparous cows were randomly assigned to 1 of 4 experimental diets from calving to 21 days in lactation. Experimental diets were a high-starch diet with ground BG (CO; 24.9% starch; 0% BP) and 3 low-starch diets where BP substituted for either BG (BB; 19.6% starch; 7% BP), CS (BC; 20.6% starch; 12% BP) or CS and BG (BCB; 20.3% starch; 12% BP). Relative to CO cows (16.50 kg/d), DMI was greater for BC (17.70 kg/d) and BCB (17.50 kg/d) cows, but it was lesser in BB (15.60 kg/d) cows. Similar to DMI results, milk yields tended to be greater for BC (37.89 kg/d) and BCB cows (37.81 kg/d) compared to CO cows (35.41 kg/d), but BB cows (33.05 kg/d) tended to produce less milk than CO cows. Relative to CO, cows fed BB had lower serum glucose concentrations, whereas cows fed BC and BCB had higher serum glucose. Serum insulin concentrations were lower for BB cows than for other exprimental groups. Relative to CO, serum NEFA and BHB concentrations were lower for BC and BCB, but was similar between BB and CO. The RQUICKI was lower for CO, BC cows than BB cows, and cows in BCB tended to have less RQUICKI compared to BB during postpartum. The concentrations of gamma glutamyl transferase were lower in BC and BCB cows relative to CO and BB cows. The cows fed CO and BB had higher serum bilirubin relative to cows fed BC and BCB diets. Although, LFI for CO cows was similar to cows on BB, BC and BCB, BC cows had higher LFI than BB cows and tended to have greater LFI than CO cows. Overall, reducing dietary starch by replacing CS (BC) or a mix of CS and BG (BCB) with BP positively affected DMI and milk yield and indicated improved energy metabolism and liver function during the first 21 d of lactation compared to when BP was fed instead of BG to reduce starch (BB).

Background and Objective: The present study was performed to determine the effect of planting arrangement and plant density in transplanting method on forage corn yield and yield components and water consumption indicators for delayed cultivation in Hamadan province. Materials and Methods: This study was carried out as split-plot factorial based on randomized complete block design at the Ekbatan station of Agriculture and Natural Resources Research and Education Center of Hamedan. The planting arrangement in three levels including a one-row with spacing of 70 cm, two-row with spacing of 70 cm and two-row with spacing of 140 cm as the main factor and plant density in three levels including 85000, 110000 and 135000 plants per hectar, along with the planting method in two levels, including direct seed cultivation and transplanting were considered as secondary factors. Results: The highest yield of fresh forage with 75661 and 72359 kg. ha-1 belonged to the planting arrangments of two-row with spacing of 70 and 140 cm, respectively. However, the highest values of protein yield (2694. 78 kg. ha-1 ), ear to fresh forage weight ratio (33. 53 %), as well as water use efficiency and economic water productivity (22. 33 kg. m-3 and 10048. 9 toman. m-3 of water) were belonged to the planting arrangement of tworow with spacing of 140 cm. Among the different plant densities, the density of 110000 plants per hectar, despite the relatively lower values of fresh and dry forage compared to the density of 135000 plants, in terms of the ear to fresh forage weight ratio and protein content (32. 80 and 12. 54 %, respectively) and protein yield (2789. 86 kg. ha-1 ) was superior to the density of 135000 plants which indicated its high nutritional value for livestock. Appropriate values of height and diameter of stem (273. 13 and 2. 65 cm, respectively) in the density of 110000 plants can maintain plant resistance against lodging. The transplanting showed higher quantities of fresh and dry forage and protein yield (72160, 22066 and 2585 kg. ha-1, respectively) compared to direct seeding, also, it improved the amount of water use efficiency (WUE) and economic water productivity by 19. 3 and 19. 2 %, respectively. Conclusion: In the conditions of delayed cultivation of forage corn, transplanting under the density of 110000 plants per hectar in the planting arrangement of two-row with spacing of 140 cm, in addition to maintaining the resistance of plants against lodging, caused harvesting forage with high yield and optimal nutritional value before the autumn cold and significantly increased the water use efficiency.

Application of plant hormones in the development of sustainable agriculture in recent decades has been considered therefore it should be investigated in integrated crop management (ICM). To evaluate the effects of plant hormones (auxin and gibberellin) a factorial experiment in randomized complete block design with three replications was carried out in Marvdasht city. The first factor was four levels of auxin (zero, 50, 100 and 150 ppm) and the second factor consisted of four levels of gibberellin (zero, 50, 100 and 150 ppm). ANOVA of Measurement traits showed the effect of auxin on quantitative traits in maize (Plant height, ear length, leaf fresh weight, fresh weight per ear and weight of forage kg/ha in level of probability 99 % was significant and was not significant for stem fresh weight. The effects of hormone gibberellin on trait (fresh weight of leaf, stem fresh weight, plant height, fresh weight forage, per hectare, and ear length) were significant at level of probability 99 %. And stem diameter was not significant. The results of the interaction were significant for forage yield (kg/ha) and fresh weight per plant but were not significant for other traits. Mean comparisons of auxin hormone showed that most quantitative traits (leaf fresh weight, stem fresh weight, fresh forage weight and fresh weight per plant) related to hormone auxin application of 100 and 150 ppm which are not statistically different. Mean comparisons showed that hormone gibberellin greatest attributes related to the application of 100 and 150 ppm. Results for quality traits (protein and carbohydrate ear stems and leaves) showed that increasing concentrations of the hormone increases the amount of quality traits.

To examine the effects of sowing date and water stress on yield and some agronomic traits of three sweet corn hybrids, an experiment was carried out as a strip split-plot design with three replications, at College of Agriculture, Shiraz University, during 2013 and 2014 growing seasons. The main plots composed of two sowing dates (4 and 25 June considered as the optimum and late planting date, respectively) and two levels of water stress (Normal irrigation and withholding irrigation at early silking). Three sweet corn hybrids including KSC403su, Passion, and Signet were considered as sub-plots. Delay in sowing date and water stress significantly reduced fresh ear yield and its components, plant height, ear length, and fresh forage yield in all three hybrids. The KSC403su hybrid showed superiority and the highest fresh ear, kernel, and forage yields when seeds were planted on time and irrigated normally. Under withholding irrigation at early silking and planting on time, yield reduced the most by 45% in KSC403su. Under late planting date and water stress condition, the highest yield reduction was observed in Signet by 44% whereas, the lowest yield reduction was observed in Passion. Therefore, it seems that under recent water shortage of Fars Province, planting of Passion can be recommended as a suitable hybrid in such a region to save water.

To study the effect of anti-transpiration application on forage corn in water deficit condition, an experiment was conducted during the 2013 in Khoy Agricultural Research Center; therefore, a Split Plot on the base of Randomized Complete Block Design was used in 3 replications. Main factors were irrigations in 2 levels including: irrigation after 75 mm evaporation (control) and irrigation after 150 mm evaporation from pan A. Sub factors were anti-transpiration in 7 levels including: Ascorbic acid application amount of 100, 200 and 300 ppm, Salicylic acid, application of 100, 200 and 300 ppm and control (non-application). Drought stress had significant effect on plant height, ear length, leaf fresh weight and forage fresh weight. Irrigation after 75 mm evaporation with the average of 76219.0 kg/ha had the most fresh forage and irrigation after 150 mm evaporation with average of 57490.6 kg/ha had the least fresh forage. Anti-transpiration materials had significant effect on leaf fresh weight and forage fresh weight. Salicylic acid foliar applications treatments of 100 and 300 ppm with average of 74463.7 and 60613.0 kg/ha were the maximum and minimum of fresh forage yield, respectively. Interaction of these factors had significant effect on the corn ear length.

In order to investigate the agro-morphological and physiologic characteristics of different silage corn genotypes, an experiment was carried out at Agricultural and Natural Resource Research Center of Tehran Province during 2009-2010. In this experiment, twenty genotypes of silage corn were compared in the form of Randomized Complete Blocks Design with four replications. Evaluated traits were growth period, number of leaf, plant height, stem diameter, dry and fresh weight of leaf, stem, sheath, ear as well as dry and fresh forage yield and its quality. Correlation among studied treats showed, dried weight of stem, ear and sheath had the highest correlation with forage yield. The genotype No.2 (K3547.4×MO17) had the highest correlation in the most of investigated characteristics such as number of leaf, stem diameter, dry and fresh weight of sheath and ear, growth period and dried forage yield, but didn’t showed appropriate quality. In respect to forage quality, the genotypes of No.16 (KLM76004.2-1-7-2-1-1-1-1 ×K19.1) and No.18 (KSC670 (K3653.2×K19)) showed the highest percent of dry matter digestibility and the genotype No.2 pointed out the highest percent of crude protein, percent of dissolved fiber and ash percent. The genotype No.18 allocated the highest percent of metabolizable energy. So, it seems that the genotype No.16 with middle height but folious, middle stem weight and relatively high ear weight and produced forage quality is of particular importance and can be a suitable option for the region.

In this study 18 forage corn (Zea mays L.) hybrid varieties were evaluated based on RCBD with four replications in Khorasan Razavi Agricultural and Natural Resources Research Centre, Iran, on 2008-2009. Result of analysis of variance showed that there was significantly difference between hybrids in forage yield, ear weight and ear to biomass ratio. Results of hybrids mean comparison with Duncan’s multiple range test showed that SC700 was higher than other investigated hybrids in forage yield trait. But hybrid 3 with 85.31 forage yield was the best hybrid in weight of ear and ear to biomass ratio. Though the SC704 hybrid was better than others for stem dry weight, ear dry weight and leaf area but there was not any significant difference between this hybrid and hybrid 3.

In order to evaluate the effects of plant density and nitrogen on quantity and quality of forage corn an experiment was conducted in Daregaz region in cropping season 2008–2009. The experimental design was a split–plot based on randomized complete block with three replications. The main plots were four levels of nitrogen (0, 75, 150 and 225 kg/ha) and sub plots were three levels of plant density (75000, 100000 and 125000 plant/ha). The results showed that increasing nitrogen levels and plant density, plant height, percentage crude protein and total protein production (ton/ha) were increased. By increasing plant density, stem diameter, leaf and ear weight decreased while they increased with increased nitrogen levels. The highest forage yield obtained at nitrogen level 150 kg/ha (46 ton/ha) and 100000 plant per hectare (40.27 ton/ha). The highest total protein production (7 ton/ha) obtained at nitrogen level of 150 kg/ha and plant density of 125000 plant/ha.

In order to study the influence of municipal solid waste compost and nitrogen fertilizer on grain and forage yield of sweet corn an experiment was conducted at Marvdasht during 2009. The experiment was arranged in split plots based on randomized complete block design with two factors and three replications. Main plot included 5 levels of nitrogen fertilizer (100, 150, 200, 250, 300 Kg N ha-1) and sub plots included 4 levels of municipal solid waste compost (10, 20, 30, 40 ton ha-1). Results showed that nitrogen, compost and interactions between them had significant effect on fresh ear yield, grain yield, 1000 grain weight and fresh ear and grain harvest index. The highest fresh ear and grain yield, 1000 grain weight and fresh ear and grain harvest index equal 2387 and 1233 gr m-2, 237 gr, 51.53 and 51.73 persent belong to application of 200 kg N ha-1 and 40 ton ha-1 compost respectively. Nitrogen had significant effect only on row number per ear, grain number per row and ear and ear number.m-2. The highest fresh and dry forage yield equal 2356 and 584 gr m-2 belonged to application of 300 kg N ha-1 and equal 2298 and 618 gr m-2 for 40 ton ha-1 compost, respectively. Generally, it seems that using of 30 ton ha-1 compost by 23.5% increase in 1000 grain weight lead to 30% increase in grain yield of sweet corn. Also, application of 200 Kg N ha-1 (decline of chemical fertilizer) and 40 ton ha-1 compost suggest for high sweet corn yield in the same environmental conditions.