The aim of this research is to study the pattern of dry matter partitioning to different above-ground plant parts during anthesis, two weeks after anthesis, and physiologic maturity among wheat cultivars and to investigate its possible relationship with grain yield. Eighteen well-watered wheat cultivars have been grown at research farm of Moghan College of Agriculture and Natural Resources based on randomized complete block design with three replications during 2014-2015 growing season. At anthesis, total dry matter accumulated in the plant, range from 1. 95 (Sumay3) to 3. 33 g (Alvand). At this time, depending on the cultivar, dry matter partitioned to the stem which differ from 31% to 41%, vary from 37% to 50% in the leaves, and from 16% to 27% in the spike. From anthesis to two weeks post-anthesis, dry weight of stem and spike increase, while those of leaves, generally, remain constant. The highest (1. 52 g) and the lowest (0. 52 g) increases in the weight of stem and spike have been observed in the case of Shirodi and Sardari, respectively. During two post-anthesis weeks to physiologic maturity, the spike has been dominant,however, the cultivar differences in the amount of allocated photoassimilates to the spike as well as stem reserves remobilization change the pattern of dry matter partitioning among wheat population again. At anthesis, there has been no clear association between cultivar height and spike weight. At physiologic maturity, however, dwarf cultivar generally has had higher weight and proportion of the spike. These results show that the pattern of dry matter partitioning is varied depending on the plant developmental stages and cultivars. Therefore, partitioning pattern of a cultivar observed at one growth stage is not necessarily similar in other growth stages. At physiologic maturity, Crossed Alborz and Pishtaz are superior with respect to dry matter partitioning and yield performance. Analysis of correlation reveals that leaves dry weight at anthesis, stem dry weight at two weeks after anthesis, and partitioned photoassimiltes to the grain are correlated positively with square grain yield. Therefore, these traits deserve further attentions in wheat programs dealing with increased grain yield.

The effect of photoperiod and growing degree days (GDD) on dry matter and dry matter partitioning in Jerusalem artichoke was investigated during 2008-09 and 2009-10. Three Jerusalem artichoke genotypes (CN-52867, JA-89 and HEL-65) were planted in 15 day-intervals between with thirteen different dates (September 20 to March 20) at Khon Kaen University, Thailand. Jerusalem artichoke genotypes responded differently to varying planting dates for harvest index, shoot dry weight, leaf area, number of tubers and tuber size. Two genotypes, CN-52867 and JA-89, were significantly more productive on the planting date of 20 September and they also performed well on planting dates of 5 October to 20 March. Plant grown in long photoperiod with a higher number of GDD produced shoot dry weight rather than greater number of harvestable tubers, while short photoperiod induced high partitioning of assimilates to harvestable tubers. Jerusalem artichoke plants grown during short photoperiod were smaller and produced larger tubers than those grown during long photoperiod. Tuber yield was relatively unchanged across planting dates. Since Jerusalem artichoke during short photoperiod had smaller plants, growing Jerusalem artichoke at higher plant population with optimum density is highly recommended to increase tuber yield. The information obtained in this study is extremely important for Jerusalem artichoke production and breeding in the tropical agro-climatic conditions such as Thailand.

Quantitative information regarding biomass partitioning in chickpea (Cicer arietinum L.) is limited or inconclusive. The objective of this study was to obtain baseline values for biomass partitioning coefficients of chickpea (cv. Hashem) crops grown under well-watered conditions. A field experiment, with 3 sowing dates and 4 plant densities, was conducted in Gorgan during 2003-2004. Crop biomass and phenological stages were measured between emergence and maturity. During growing season dry matter partitioning among different organs were described by linear relation between dry matter organs versus total dry matter. A linear relation was found for biomass partitioning between leaves and stems before podding stage (R3). Mean partitioning coefficients until R3 stage were 0.36-0.55 for leaf and 0.50-0.64 for stem. During the period from podding (R3) to first-seed (R5), 60, 27 and 13 % of produced biomass had been transferred to stems, pods and leaves respectively. During the period from first-seed (R5) to maturity, 83% of biomass was partitioned to pods. It was concluded that using fixed partitioning coefficients after first-seed (R3) are not as effective as they are before this stage. Plant density did not affect partitioning of biomass. It was concluded that the obtained coefficients could be used for chickpea growth simulation models.

There is low information regarding quantitative partition of biomass in faba (Vicia faba L. ). The purpose of this study was to obtain the values of the distribution coefficients of dry matter between different parts of faba plant under different sowing dates and densities conditions. This experiment was conducted in Gonbad Kavoos during 2012-2013 in rainfed conditions. Experimental design was a factorial arrangement of treatments based on randomized complete block design with four replications. The treatments were combinations of sowing dates (27 November 2012, 14 December 2012 and 7 January 2013) and four plant densities (8, 12, 16 and 20 plants m-2). Separately dry weight of different organs and phenological stages were measured between emergences to maturity. A linear relation was found for biomass partitioning between leaves and stems before podding stage (R3). Ratio of dry matter distribution among leaf and stem on 27November 2012, 14 December 2012 and 7 January 2013 were 62: 37, 60: 39 and 54: 40, respectively. Dry matter that was dedicated to stem more than leaf. On the other hand competition between of plants had not significant effect on dry matter distribution. Dispersion between data was more after podding stage than before it, which is probably due to translocation of dry mater. Therefore, the using of fixed partitioning coefficients isn’ t effective after podding stage. It was concluded that using fixed partitioning coefficients between leaf (0. 39) and stem (0. 58) after first-seed (R3) are not as effective as they are before this stage and using partitioning coefficients after this stage by conception of linear increase in harvest index are ideal. It was concluded that the obtained coefficients could be used for faba bean growth simulation models.

The objective of the present field experiment was to examine how plant density and enhanced source, i.e. thinning treatments, may affect grain yield and its components for a non-prolific maize hybrid, SC704. The environment of the hybrid maize crop was changed at intervals over its life cycle by removing every other plant in rows equispaced at 75 cm apart with a population of 13.34 plants m-2. The plants were grown with no water or nutrient restrictions. Results showed that earlier thinning was associated with greater stem, leaf, shoot and ear dry weight accumulation, ear kernel weight (EKW) and kernel number per ear row (KNER). In this ways the greatest of these characteristics were obtained in thinning at sowing i.e. 6.67 plants m-2 throughout. Delay in thinning until the 12-leaf stage reduced stem dry weight and EKW significantly. Thinning at tasseling also resulted in significantly lower stem dry weight accumulation compared to thinning at sowing. At final harvest, the stem dry weight of plants thinned at tasseling was 20.47% (P<0.05) lower than those thinned at sowing. Similar effects were found upon delay in thinning until tasseling on leaf, shoot, and ear dry weight accumulation. Delay in thinning until the 12-leaf stage or later, also reduced EKW significantly compared to plants thinned at sowing. This reduction was attributable to decreased KNER and 1000-kernel weight. According to these results, KNER and 1000-KW were found to be yield components sensitive to light environment.

Wheat productivity depends not only on dry matter accumulation, but also on its effective partitioning to the grains; this is a key factor to yield stability under stress. The aim of this research was to investigate the pattern of dry matter partitioning to aerial parts in 81 Iranian wheat genotypes differing in agronomic traits. Moreover, its relationship with grain yield in drought conditions was studied. The plant materials were evaluated using two simple lattice designs with two replications under irrigation and drought conditions at University of Tehran Research farm (Karaj) during 2008-2009. Drought stress was imposed by withholding irrigation at the heading stage. Samplings were carried out at an thesis as well as at physiological maturity stages. There was a significant difference between irrigated and drought stress conditions in term of grain yield. Wheat cultivars exhibited different responses to drought stress. The rate of reduction in grain yield was variable from 7 to 90 percent. At an thesis, stem, leaf and spike had the highest amount of dry matter, respectively. The effect of stress on dry matter partitioning to different plant parts was not considerable at this stage. In stress condition, a kind of remarkable correlation was observed between grain yield and dry weight of leaf at an thesis. At maturity, spike had the highest amount of dry matter and drought stress decreased dry matter partitioned into spike. But the effect of stress was not considerable on the dry weight of leaf and stem. At maturity, there was a negative correlation between dry weight of stem and grain yield under stress condition.

In this study, the effects of drought and nitrogen were analyzed on morphological traits and dry matter allocation of Isabgul (Plantago ovata) at Vali-e-Asr University of Rafsanjan in 2010. The research was conducted using factorial experiment based on RCD design with 3 replications. The factors included nitrogen (0, 60, 120 and 180 mg N.Kg-1 soil) and soil moisture (100, 80, 60, 40 % FC). Results indicated that drought, nitrogen and their interaction significantly affected seed yield and total dry weight. The highest seed yield (1.72 g.plant-1) was obtained at 120 mg N.Kg-1 soil which was 77% higher than that in control. In 80% FC treatment, using 120 mg N.Kg-1 soil caused 93% increase in total dry weight, compared to control. In addition, with increasing drought stress, dry matter partitioning benefited the root and root mass ratio (RMR) increased significantly. However, no significant changes were recorded for shoot mass ratio (SMR) and grain mass ratio (GMR). Also, with increasing nitrogen fertilizer, more dry matter was transferred to the leaves and less dry matter was transferred to the seed.

This study investigated intra-specific variation in the growth parameters and dry matter partitioning of sugar beet cultivars at different levels of salinity (0, 50, 150, 250 and 350 mM NaCL + CaCl2 in 5:1 molar ratio) using four cvs, one British (Madison) and three Iranian cvs (7233-P12, 7233-P21 and 7233-P29). The plants were grown in a controlled greenhouse environment for about 18 weeks. Although growth parameters such as leaf area and dry matter accumulation were stimulated or unaffected at a low level of salinity (50 mM), higher salt concentrations significantly decreased all growth traits. At a high level of salinity, cv P29 showed a significantly higher leaf area and total dry matter than others at 16 weeks of salt treatment, Pre-dawn leaf-water potential (Ψd and shoot water content (SWC) were decreased by salinity. Cvs Madison and P12 had significantly lower ΨL(more negative) and shoot water content at high levels of salt treatment (250 and 350 mM), while P29 and P21 showed higher ΨL (less negative) and shoot water content at the same salt concentrations. Analysis of ion accumulation revealed that Na+ and cr contents were greatly increased in leaves under saline conditions. However, salt tolerant P29 had lower Na+ and cr concentrations than other cvs at high levels of salinity. The root dry matter of sugar beet cvs at the lowest and the highest salt concentrations reduced by 23.3% and 89.8%, respectively compared to the non-stressed plants, while shoot dry matter' decreased by 1.1% and 77% at the same salt concentrations, respectively, after 16 weeks of salt treatment. The pattern of dry matter partitioning to different parts of the plant was changed by salt stress and the dry matter allocated to the storage roots was reduced by 6% and 18% at the lowest and the highest salt concentrations, respectively, at 16 weeks after salinization.  

Dry matter Partitioning in vegetative and reproductive organs and yield of 11 sunflower hybrids were evaluated in different irrigation program during 2013 and 2013 in Karaj, Iran. Three separate experiments including irrigation after 60, 120 and 180 mm evaporation from evaporation pan, Class A as base of randomized complete block design were sutdied as control, mild and severe stress conditions, respectively. The results showed the plant height was decreased by 10.1% under mild stress and 17.2% under severe stress compared to control. Although, increasing of the height had a positive effect on grain yield, but the stem weight was more effective than head weight on grain yield. In control irrigation, plants produced thicker stems that made to translocate more dry matter to the grain. But under severe stress conditions, the  head diameter decreased, and the most of the dry matters were used in the head development. The highest grain to head weight ratio was obtained from mild stress. In severe stress conditions, the grain to head weight ratio  went up and it caused to rise linear growth of grain number and weight. Grain yield was diminished on average of 18% and 33% under mild and severe stress conditions, respectively. In the stress conditions, Barzegar hybrid had the highest grain yield for maintaining the number and weight of grain in the heads. The evaluation of strees susceptibility and tolerant showed that STI, MP and GMP indices had a positive and significant correlation to yield and, Barzegar and Sunbro hybrids were superior thant Cultivars and hybrids.