To evaluate the effect of nitrogen and water withholding in vegetative growth stage of corn on efficacy of nicosulfuron and 2,4-D+ MCPA an experiment was conducted as a factorial arrangement in a randomized complete block design with three replications at Tarbiat Modares University in 2017. The first factor contained four treatments including application of nicosulfuron, 2,4-D+ MCPA, weed free and weed infested as control. The second factor consisted of normal irrigation and water withholding from 4 to 8 leaf stage. Third factor contained either urea application or no fertilizer application. Normal irrigation and nitrogen fertilizer application significantly increased nicosulfuron and 2,4-D+ MCPA efficacy in weed control and total weed dry weight decreased to 341 and 361 g.m-2 respectively compared 1370 g.m-2 as weed infested. Nicosulfuron and 2,4-D+ MCPA reduced weed total dry weight significantly under irrigation withholding. Grain Yield increased with application of nitrogen and nicosulfuron. Grain Yield was higher with application of 2,4-D+ MCPA than nicosulfuron without nitrogen application under irrigation withholding. Application of nicosulfuron with nitrogen application provided satisfactory weed control and increased grain Yield.

Modification of soil temperature and canopy microclimate of potato is an appropriate factor, where soil temperature during the growing season is high. Using a shade crop such as corn has been proved to be a proper tool to overcome this problem. An attempt was made to evaluate the potato/corn intercropping under climatic conditions of Mashhad. An experiment was conducted with different combination of corn and potato: MC (corn monoculture), MP (potato monoculture), S (strip intercropping), I 25%, I 50%, I 75% (with the potato/corn rows overlapping of 25%, 50% and 75% in the strip treatment) and R(row intercropping), in a randomized complete block design with three replications. The results showed that shading caused to an increase in specific leaf area of potato in such a way that the maximum and minimum value of this variable was related to R and MP treatments, respectively. With the gradual overlapping of the potato/corn rows in strip treatment (i.e I 25%, I 50%, I 75% and R, respectively), the corn Yield increased as the result of higher rows distance than sole crop, in contrast potato Yield decreased as the result of corn over shading. Consequently there was no significant difference between the experimental treatments LER. Therefore according to the results of this experiment the simultaneous planting of corn and potato with their sole crop density is not recommended, and in order to achieve better results, the corn density most be decreased, or alternatively relay intercropping systems could be used.

This survey was done to assessment Yield and Yield component of fall Rapeseed cultivars (Brassica napus) in climatic conditions of Arak was conducted cropping season 2004-2005. The experiments were arrange in Split Plot design and were compared in a CRBD with three replications. In this design, planting date treatment assumed as the main factor in two levels (usual planting date and delayed planting dates) and autumn rapeseed cultivars in eleven levels were assumed as subplot. The considered cultivars in this research were Dexter, Celsius, ARC91004, Sahara, ARC5, Orient, Sinotra, Talent, Talaye, ARC2 Geronima and Talaye variety was considered as control. The results of experiments showed that in usual planting date condition and delayed planting dates cultivars in adjectives like the number of pods in plant, number of grains per pod, the weight of thousand seeds and seed Yield had significant difference in level %1 probability. The highest Yield of seed was related to Talaye variety with average 3463. 5 kg/ha and the least Yield rate of seed was related to Geronima variety with average 2651.8 kg/ha. Usual planting date in terms of Yield performance of seed, Talaye variety has been the best, and after it, also the cultivars as Talent, Sahara and Celsius had the highest level respectively. In terms of seed thousand weight, Talaye and Talent variety, and in terms of the number of seed in pod, ARC2 and Talaye variety in usual planting date, the number of pods in plant Talaye and Celsius variety in usual planting date were better than others.

Experiments were performed with 49 soybean genotypes from I II and III maturity groups on base of lattice 7*7 designs at two replications and two levels normal (60 mm) and stress (150mm) in field of seed and plant breeding research institute in karaj in summer of 1383. At duration of the experiments were took notes from phenologic traits and were took notes from Yield, Yield components, oil and protein percents after field harvest, too.Results of analysis of variance indicated a good diversity between genotypes for almost traits. Path and stepwise regression analysis showed seed number in plant and biomass have most effects on Yield in normal and stress conditions, respectively. Factor analysis indicated 5 affected factors in normal condition and 4 affected factors in stress conditions.Traits such as pod on reproductive nodules, plant seed number associated with Yield in normal conditions and characters such as 100seed weight, root weight and biomass associated with Yield in stress conditions, too. Calculation of resistance indices and biplot analysis divided genotypes to 4 groups and indices such as MP, STI, GMP and Harm were recognized as best drought indices in soybean. Obtained results of biplot analysis and drought resistance indices recognized genotypes such as Maccon, cysen, L.D.8149 have high Yield and drought resistance and genotypes such as Korona, Hadgson and Enterprise have low Yield and susceptible to drought.

In order to evaluate the effects of methanol on Yield and Yield components in chickpea, a study was conducted in 2008 in Mahdasht (Karaj, Iran). Aqueous solutions 0 (control), 5, 10, 15, 20, 25% (v/v) methanol and each solution contained 0.2% glycine. These solutions were sprayed over head 3 times in one weeks intervals after flowering. This experiment was carried out based on randomized block design with 3 replication. Results showed that there was significant differences between different levels of methanol and control on plant height, biological Yield, weight of 100 grain and grain Yield, whereas 10% (v/v) had highest on plant height, biological Yield, weight of 100 grain and grain Yield. Also effect of foliar application of methanol was notable in growth indices and growth indices in 10% (v/v) were higher than the some of levels and control.

In order to study the effects of leaf clipping on Yield and Yield component of three seed corn varieties a field experiment was conducted as factorial laid out in complete block design with three replications in 2005. Three varieties (700, 604 and 301) and four leaf defoliation levels (without defoliation, ear leaf clipping. Above ear leaf clipping, and below ear leaf clipping) were used in this experiment. The result showed that defoliation, varieties and their interaction significantly affected on ear length, seed abortion, ear seed row number and grain Yield. Varieties had different seed number in row and also defoliation affected on it. 1000-grian weight was not affected by any of defoliation treatments. On the whole, without defoliation, ear leaf clipping, and below ear leaf clipping treatments had the same ear length. Above ear leaf clipping reduced ear length. Ear length reduction, seed abortion, seed number in row, and grain Yield was observed in 700, 604 and 301 in descending order respectively. The most ear seed row number, seed number per row and grain Yield was obtained from without defoliation treatment. Ear and below ear leaf clipping was rank in second order in aspect of three former traits. Above ear leaf clipping produced the lowest ear seed row number, seed number in row and grain Yield. Below ear leaf clipping and without defoliation produced the same grain Yield in early maturity variety, but grain Yield was more in without leaf clipping than other treatments in medium and late maturity variety. Response of early maturity variety to leaf clipping was severely more than late maturity variety (700). Low and non-significant effects of below ear leaf clipping on corn grain Yield show that medium and early maturity varieties can be cultivated in higher density than 7plant/m2. These two former varieties also can be used in intercropping (with legumes).