IntroductionSimulation crop models are a robust tool to improve crop management and to study yield limiting and reducing factors. Crop parameters related to phenology, leaf area and dry matter production and partitioning are needed to simulate crop growth and yield. Therefore, the aim of present study is to quantify the dry matter production and to estimate dry matter partitioning coefficients to different crop parts (stem, leaf and grain).
Materials and MethodsA factorial experiment was conducted based on completely randomized block design with four replicates and three sowing dates (4 April, 25 April and 16 May) and four cultivars (411, Sina, Local Isfahan and Sofeh) in Research Farm of Rafsanjan Vali-e-Asr University in 2011. Sampling was done at an interval of 5-10 days from two weeks after planting and continued up to end of the growing season. On each sampling, the leaf, stem and grain dry matter weight were measured. The truncated expolinear model was fitted on total dry matter weight (w) data over the time (t). Coefficient of dry matter partitioning to different crop parts (leaf, stem and grain) was obtained by fitting the linear regression model on dry matter weight of each part versus total dry matter weight.
ResultsResults showed that the model well described the trend of dry matter production versus days after planting. According to the model, the maximum dry matter accumulation in all three planting dates was obtained 972-1179, 576-611 and 191-277 gm-2, respectively. Coefficient of dry matter partitioning to leaves ranged from 0.45 to 0.51 in the first planting date, 0.51 to 0.60 in the second planting date and 0.44 to 0.61 in the third planting date. There was no different between the coefficients of cultivars. Coefficient of dry matter partitioning to stem in all three planting dates were 0.35-0.49, 0.24-0.44 and 0.14-0.23, respectively. There was no significant difference among the cultivars. Partitioning coefficient to grain was between 0.16 and 0.44 for the first planting date that was lower than the second planting date. In the third planting date, the coefficient was between 0.35 and 0.76 that there was a significant difference among the cultivars.
ConclusionIt was concluded that the trend of the dry matter production and partitioning is affected by environmental condition (temperature and solar radiation) and cultivar. The results showed that with delay in planting date crop growth rate and dry matter production were decreased. In such condition, coefficient of dry matter partitioning to stem was decreased and coefficient of dry matter partitioning to leaves and grain was increased.

The vertical distribution of leaf area and dry matter is considered to be an impact factor on light absorption, evapotranspiration of canopy, dry matter accumulation and seed yield. To study the vertical distribution of leaf area and dry matter of the maize canopy in competition with weeds and cover crops, an experiment was conducted at Sari in 2011. This experiment was performed in a randomized complete block design with 8 treatments and three replications. Three cover crops, namely bean (Phaseolus vulgaris), soybean (Glycine max L.) and berseem clover (Trifolium alexandrium), were planted on two dates: simultaneous with and 21 days after maize sowing (delayed planting). In addition, maize sole crop with weed control and weed interference was added to the treatments. The results showed that dry matter and leaf area index of bean and soybean were higher than for clover. The delayed planting of bean and soybean increased the leaf area index of maize upper layer canopy rather than sole cropping of maize with weed interference: this approach caused an increase in the competitive ability of maize against weeds. The leaf area and dry matter of weeds were reduced more by bean and soybean than by berseem clover. The cover crops caused the maximum amount of weed (in particular, veveltleaf and bermuda grass) dry matter to be accumulated in the primary layer. The cover crops reduced the number of layers and dry matter of per layers in the weed canopy. For maize, the dry matter was less in the presence of berseem clover than for the two other cover crops. The maximum amount of weed dry matter was accumulated in the primary layer. Grain yield in maize was higher in simultaneous sowing than in delayed planting of cover crops, especially soybean. The cover crops’ dry matter had a positive correlation with dry matter of maize and was negatively correlated with dry matter of weeds. The yield of maize in the present of crop cover was higher than for sole cropping of maize under weed interference. The grain yield of maize with a delayed presence of cover crop was higher than at the same sowing date.

The effect of concentration and timing of application of supplementary nitrogen fertilizer on dry matter remobilization and grain yield of rapeseed (Hyola401) as a second crop following rice in paddy field, was evaluated in a field experiment conducted using complete randomized block design with three replications at Rice Research Institute of Iran, Rashat, Iran, in 2008 cropping season. Fertilizer (N from Urea source) doses at two levels (5 and 10 ppm) and timing of application at 7 levels; 1: seedling stage at 6-8 leaves (1.06-1.08 based on Sylvester-Bradley and Makepeace coding system = SBMCS), 2: commencement of stem elongation (2.01- 2.03 SBMCS), 3: prior to flowering (3.9 SBMCS), 4: 1.06-1.08 + 2.01-2.03, 5: 1.06- 1.08 + 3.9, 6: 2.01-2.03 + 3.9, 7: 1.06-1.08 + 2.01- 2.03 + 3.9, plus two control treatments a: no nitrogen b: commonly applied fertilization (180 kg.ha-1) at seed sowing, stem elongation and prior to flowering in equal rates. Plant characteristics (number of siliques, number of grain.silique-1, 1000-grain weight, dry matter remobilization, dry matter remobilization efficiency, dry matter content in 50% flowering and grain maturity stages, biological yield, grain yield, oil content and harvest index) were measured. Results showed a significant difference between concentration and timing of nitrogen spray application effect on grain yield, oil content, number of siliques, dry matter remobilization, dry matter content in 50% flowering, grain maturity stages, biological yield. Spray application of nitrogen (10 ppm) in 2.01- 2.03 + 3.9 stages (Treatment. #6) had the higest grain yield 4221.7 kg.ha-1) and number of siliques.plant-1 (219.7 siliques), dry matter remobilization (694.1 g.m-2) and dry matter content at 50% flowering stage (891.5 g.m-2). There were no significant differences between number of siliques.plant-1, dry matter remobilization, dry matter content in 50% flowering stage and grain maturity stages in concentrations (10 ppm) and times of nitrogen spray application in 2.01- 2.03 + 3.9 and 1.06- 1.08 + 2.01-2.03 treatments. Results also showed that application of supplementary nitrogen (10 ppm) at 2.01- 2.03 + 3.9 stages can increase grain yield and dry matter remobilization in rapeseed cv. Hayola401.

Kochia is a halophyte plant and is a good source of forage for livestock under saline irrigation. In order to investigate the salinity effect on morphological and forage characteristics of kochia, an experiment was conducted. Three saline waters (5.2, 10.5 and 23.1 dS m-1) and three kochia ecotypes (Birjand, Borujerd and Sabzevar) were allocated as main and sub plots, respectively, in a split plot design based on a CRBD with three replications. There were no significant effects on plant height, branch numbers, dry matter yield, forage dry matter, stem and leaves percentage and stem dry matter by increasing salinity from 5.2 to 23.1 dS-1m,. Average of dry matter yield of 9.1 ton.h-1, percentage of dry matter of 29.85 and percentage of stem and leaf of 57.94 were recorded. Fresh forage yield, stem diameter and leaf dry matter yield were reduced by increasing salinity. Birjand showed the maximum plant height, dry matter yield, dry matter percentage, leaf yield, leaf percentage, leaf dry matter percentage and leaf to stem ratio. In conclusion, Kochia had good traits such as plant height, appropriate leaf to stem ratio, large number of branches and acceptable fresh and dry matter yield in saline condition that can make Kochia a suitable candidate for forage crop.

Lipids in liver wet and dry matter، liver moist and dry matter and their relationships were investigated based on species، sex and age in cows، buffaloes، sheep and goats. Mean percentage of lipids in liver wet and dry matter and liver dry matter in cows were 3. 60%، 1. 10%، 29. 70%، and for buffaloes were 5. 30%، 1. 55%، 29. 20%، sheep 3. 00%، 0. 83%، 27. 90%، and goats 2. 910%، 1. 55% and 28. 40%، respectively. The highest and lowest percentage of lipids in liver wet and dry matter was observed in buffaloes and sheep، and for the liver dry matter was recorded in cows and sheep، respectively. Analyses showed significant differences in liver parameters among ruminants (p < 0. 01). Gender، except for goats، did not affect the animals'' liver parameters. In overall 15. 00% of buffaloes and 3. 50% of cows showed over 10. 00% lipids in liver، while none of small ruminants appeared to have over 6. 00% lipids in liver. There was no correlation between liver lipid and liver dry matter. In conclusion mean percentage of lipid in liver dry matter in small ruminants was less than large ruminants. Liver dry matter was high in cows and low in sheep. Mean differences in liver parameters was significant، while the age and sex of the animals were not. Liver lipidosis in buffaloes seems greater than in cows، and in small ruminants it was negligible. No correlation was expected between liver parameters. Finally، on the basis of liver dry matter، the liver in ruminants ranked from cows to buffaloes، goats and sheep

In order to evaluate the effects of plant density, number and stages of weed control, on weeds dry matter and seed yield of corn varieties, an experiment was conducted in 2011 on research farm, College of Agric. Univ. of Shahid Bahonar, Kerman, Iran. It was in randomized complete block (RCBD) in factorial design, with 3 replications. Weed control treatments were W1: weed control 4 times (2, 4, 6 and 8 weeks after planting), W2: weed control 3 times (2, 4 and 8 weeks after planting), W3: weed control 2 times (4 and 8 after weeks after planting) and W4: no weed control during corn growth season. Corn varieties were Single cross 704 and Maxima from FAO580, and were planted under 70,000 and 90,000 plants in hectare densities. Corn seed yield, plant leaves area, leaves dry matter, steam dry matter, total plant dry matter and weeds dry matter were calculated. The results showed that W4 treatment showed significant different in seed yield reduction compared to other weed control treatments. W1, W2 and W3 showed no significant difference between each others, so it can be concluded that W3 treatment could be used as an effective and economic weed control treatment in Kerman. Increasing weed-crop interaction time, caused low plant leaves, leaf and stem dry matter, and total plant dry matter of corn. Higher corn density produced lower total dry matter, leaf and stem dry matter and weeds dry matter. Seed yield increased with higher density. Maxima variety had higher seed yield and plant leaves area than Single cross 704. It seems that higher density caused a better ability and weed competition, and produced higher seed yield.

The percentage of fat in liver wet and dry matter، liver moist and dry matter and their relationship were investigated based on species، sex and age of 384 slaughtered animals including 114 cows، 100 buffaloes، 147 sheep and 23 goats from 2008 to 2010 in Urmia، Iran. Mean percentage of fat in liver wet and dry matter، and liver dry matter in cows were 3. 6%، 1. 1%، 29. 7%، buffaloes were 5. 3%، 1. 55%، 29. 2%، sheep were 3%، 0. 83%، 27. 9% and goats were 2. 91%، 1. 55% and 28. 4%، respectively. The highest value for fat in liver wet and dry matter was observed in buffaloes (6. 2%، 20. 5%) and the lowest value for sheep (1. 55%، 5. 14%). The highest and lowest values for liver dry matter were found in cows (38. 2%) and sheep (31. 9%)، respectively. ANOVA analysis showed significant different in liver parameters among ruminants. Variant of sex except for goats did not affect on measured parameters. In individual surveys on measured parameters، 15% of buffaloes and 3. 5% of cows showed over 10% fat in liver، while none of small ruminants appeared over 6% fat in liver. In spite of expected correlations between fat in liver wet and dry matter، liver moist and dry matter، no correlation was observed between fat liver and liver dry matter. Thus، it is concluded that mean value of fat in liver dry matter in small ruminants was less than cows and buffaloes. Maximum mean liver dry matter observed in cows and the minimum in sheep. Mean value of measured parameters among animal species was significant، while age and sex didn’t affect them. It was concluded the occurrence of liver lipidosis in buffaloes is greater than cows and in sheep and goats is so weak. No correlation was expected between fat liver and liver dry matter، and finally، based on liver dry matter، the quality of liver in ruminants sorted from cows to buffaloes، goats and sheep.

Permanent cultivation of sugarcane and harvesting without any balanced and enough fertilization and get out or burn trashes in fields causes problems in soil fertility، minerals get out from soil that influenced on yield and usage fertilizers. The green house experiment carried out for evaluation effects of crop residue on three sugarcane varieties in split plot experiment based on CRB with three replication at Karoun Agronomy and Industry Company in 2008. there were six levels of crop residue treatment including of wheat، maize، sugarcane، medicago، cowpea and mungbean as main plot and three levels of sugarcane varieties treatment including of CP57-614، CP69-1062، CP48-103 as sub plot. The results showed that there were the greatest of foliar dry matter، root dry matter، total dry matter، leaf area index and P percentage by medicago residue and the greatest N percentage and K percentage by mungbean residue. There were the lowest of variables by sugarcane residue. There were the greatest of foliar dry matter، total dry matter، leaf area index، P percentage and K percentage by CP48-103 variety and the greatest of root dry matter and N percentage by CP57-614 variety.

Efficient use of nitrogen for medicinal plants production, might increase flower dry matter, essential oil and extract yield and reduce cost of yield production. A two year (2005 and 2006) field study was conducted in Torogh region(36,10° N,59.33° E and 1300 m altitude) of Mashhad, Iran, to observe the effects of different nitrogen and densities on flower dry matter, essential oil and extract production and nitrogen use efficiency (NUE) in a multi-harvested Marigold (Calendula officinalis). The levels of Nitrogen fertilizer (N) were 0, 50, 100 and 150 kg ha-1 and levels of density were 20, 40, 60 and 80 plant m-2. The combined analysis results revealed significant effects of N and density levels on flower dry matter, essential oil and extract production and NUE of Marigold. The highest dry flower production obtained by 150 kg ha-1 N and 80 plant m-2 plant population (102.86 g m-2). The higher flower dry matter production caused more essential oil and extract production in high nitrogen and density levels. Agronomic N-use efficiency (kg flower dry matter yield per kg N applied), physiological efficiency (kg flower dry matter yield per kg N absorbed) and fertilizer N-recovery efficiency (kg N absorbed per kg N applied, expressed as %) for marigold across treatments ranged from 6.8 to14.9, 12.3 to 33.6 and 55.5 to 77.6, respectively and all were greater for N application at 50 compared with150 kg N ha-1, and under high density than low density. The amount of essential oil and extract per 100g flower dry matter decreased during the flower harvesting period. The higher amount of essential oil and extract obtained at early flowering season. The essential oil and extract ranged from 0.22 to 0.12 (ml. per 100g flower dry matter) and 2.74 to 2.13 (g per 100g flower dry matter) respectively.

In order to study the effect of strip intercropping of maize (Zea mays L.) and bean (Phaseolus vulgaris L.) on the dry matter yield and land equivalent ratio (LER) in weedy and weed free treatments, an experiment was conducted at the Agricultural Station of College of Agriculture, Ferdowsi University of Mashhad, Iran. Treatments were strip width of 2, 3, 4 and 5 rows and sole cropping of each crop. In addition two levels of weedy and weed free as strips were also included. Results indicated that treatments affected dry matter accumulation of maize and bean. The highest dry matter accumulation found in two strip widths and sole crop showed the lowest. Thus by increasing strip width dry matter was decreased. Weeds decreased dry matter accumulation by reduction of both rate and content of dry matter. Increasing of strip width reduced dry matter yield of maize and bean, and two strip widths showed the highest dry matter yield. Dry matter yield in intercropping treatments were more than sole crops in all side rows. In side rows, weeds reduced biological yield of sole stand of maize, bean and intercropped by 18.7, 23.5 and 20.3 percent compared to weed free treatments respectively. In central rows these values were 29.6, 21.3 and 27.3 percent, respectively. Land equivalent ratio in strip intercropped was more than sole crops and was reduced with increasing strip width. Intercropped LER in weedy treatment enhanced 29 percent in side rows and 21 percent in central row