نشریه پژوهش های کاربردی زراعی
پیاپی 134 (بهار 1401)

Pearl millets are commonly cross-pollination and constitute different cultivars and hybrids. Pearl millets can be used for dry forage, pasture, silage, seed production and human nutrition (Lee et al., 2004). According to the reports of Jahad Ministry, the global surface area dedicated to the cultivation of pearl millets is estimated to be 10 million hectares and the reports demonstrate that the growing of this cultivar has increased in the recent years (Statistical report of Jahad Agricultural Ministry, 2017). More than 70% of the total cultivated millet in India are pearl millets. American Agricultural Department also recommend different pearl millet cultivars to the farmers who seek the cultivation of forages with high economic and biological performance in dry and semi dry areas of this country (Lee et al., 2004) . Due to its high production potential, optimum nutritional value, and the ability to be preserved as dry hay and silage, millets can be grown in many areas of Iran with different climate conditions for forage production (Mehrani et al., 2017). A maximum of 10,000 ha of millets are cultivated in the country. Works in the late 1980s demonstrated that yields can be raised two to three-fold by using available improved varieties and appropriate agronomic techniques. But, these findings need to be refined, improved and tested for local climatic, soil and crop conditions. In order to release new pearl millet lines for summer cropping season, this research was conducted in Golestan province during the 2017 growing season. The experiment consisted of two new pearl millet lines (Pennisetum americanum) and Bastan cultivar, which is grown in the fields of Golestan province. The number of planting lines was 60 with a length of 66.66 meters and 50 cm interval between the lines. To measure traits such as plant height, number of tiller, stem diameter and number of node etc, 10 bushes were randomly harvested by using quadrate. Also, the total surface area under cultivation was measured. The results were compared using t-test.The mean comparison of yield and morphological parameters of two new pearl millet lines (Pennisetum americanum) and Bastan cultivar showed that KPM4, new pearl millet line in Gomishan had a plant height of 138.8 cm, which was 18.94% and 28.45% taller than KPM1 and Bastan cultivar, respectively. KPM4 produced greater stem diameter (7.13 mm), number of leaf (9.6) and number of node as compared to the check cultivar Bastan. The mean comparison of fresh yield of two new pearl millet lines and Bastan cultivar showed significant differences among the varities. Fresh forage production of KPM1 with a yield of 25.04 ton ha-1 was 2.24% greater compared to Bastan cultivar, which gave a yield of 24.46 ton ha-1. Also, the mean comparison of dry yield showed significant differences among the varietries. Dry forage production of KPM1 (6.68 ton ha-1) was 17.51% higher than the check cultivar, which produced a dry forage yield of 5.01 ton ha-1). There was an increase of 15% and 32% in fresh forage (28.63 ton ha-1)and dry forage (7.41 ton ha-1) production of KPM4 compared to Bastan cultivar. Meanwhile, no significant difference was found between the grain yield production of new pearl millet lines and the check cultivar (Bastan). Alos, the new pearl millet lines were superior in terms of morphological parameters as compared to the check cultivar. It indicates that the new millet plants grow better and produce higher yield components. Overall, the findings of the study showed that KPM4 line performed better relative to KPM1. The fresh forage and dry forage production of the new lines were greater than those of Bastan cultivar. It could be concluded that, by using new pearl millet lines during summer cropping season, higher yield per surface area might be attained.Keywords: Forage and grain yield, morphological traits, t-test ReferencesLee, D.W., Hanna, G., Buntin, D., Dozier, W., Timper, P., and Wilson, J.P. 2004 . Pearl millet for grain, University of Georgia, USA.Mehrani, A., Azari, A., Zand, A., Saberi, A.R., Tabatbaie, A., Miri, Kh., Abadooz, M., and Chabook, Kh. 2017. Quantitative and qualitative yield comparison of Pearl millet lines (Pennisetum americanum). Final report of seed and plant improvement institute. (In Persian). 53 pages

Oilseed rape (Brassica napus L.) is a traditional oil crop in Iran. Conventional oilseed rape production during the past decades has been performed through manual sowing, transplanting, and harvesting. In cold and temperate regions of the Iran, due to delays in harvesting the previous crop, it is not possible to planting oilseed rape seeds directly. Delayed planting of oilseed rape can reduce grain yield. Therefore, oilseed rape seedling transplanting can be one of the appropriate solutions. On the other hand, seedling quality is an essential indicator for grain yield in oilseed rape, which is affected by many factors, including seedling age. In addition, the time of seedling transplanting is also very important. Therefore, transplanting is also more advantageous than direct sowing in terms of time management. Although there are many benefits of transplanting in oilseed rape production systems, the optimal age of oilseed rape seedling for transplanting remains unknown. Furthermore, inappropriate seedling age is always misleading in terms of whether older or younger seedlings are employed for transplanting in practice. Thus, it necessitates seeking an optimal seedling age and evaluating its effect on grain yield.

Two field experiments was conducted as randomized complete block design with three replications at research field of Seed and Plant Improvement Institute (SPII) in 2017-2018 and 2018-2019 growing season. There 7 treatments including seed planting on 7 October (control), transplanting of two-leaf seedlings and four-leaf seedlings on 17 October, 1 November and 11 November. The genotype used in this study was Ahmadi as a winter cultivar. The measured traits included days to flowering, flowering period, growth period, plant height, number of branches, grain per silique, silique per plant, silique length, 1000-grain weight and grain yield. SAS statistical software was used for data analysis and means were compared with LSD test.

The results of variance analysis indicated that days to flowering, flowering period, silique per plant and grain yield (P≤0.05) and grain per silique (P≤0.01) was significantly affected by the seedling and seed planting treatments. Results of this study showed that in two-leaf seedling transplanting treatments at different times of seedling transplanting, delay in flowering was observed, but the duration of flowering period was shorter in these treatments. Also, in the transplanting treatments at the two-leaf seedling, silique per plant and grain per silique were less than them in other treatments. The highest grain yield and net income observed in seed planting treatment (3495 kg ha-1 and 61.1 Iranian million rials ha-1). Higher grain yield components such as silique per plant and grain per silique due to early flowering caused higher grain yield in seed planting treatment. In contrast, grain yield was lower in transplanting treatments compared to seed planting method. However, among the transplanting treatments, the highest grain yield was observed in the four-leaf seedling transplanting on 17 October as 3332 kg ha-1.

The results of this study showed that transplanting of winter oilseed rape cultivar is not suitable in the two-leaf seedling stage and winter oilseed rape seedling should have at least four-leaf stage. In general, it seems that the late transplanting of oilseed rape seedlings to the farm in semi cold regions will significantly reduce grain yield compared to oilseed rape seed planting method.

Meta-analysis is a method that summarizes and combines independent results from the number of different articles, which can be used to determine the results of a series of studies. Meta-analysis is a method for statistically comparing the results of independent studies on a subject. Meta-analysis is a type of research on other research. It can be used to re-examine the various studies that have been done on a particular topic and to compare them statistically. This approach is an independent study in itself.

For this purpose, this study was conducted as a meta-analysis of the effect of drought stress on corn yield. The sample of the study included collecting articles from the Sid site, which selected a total of 13 papers and theses from among 61 articles. The first step in performing the meta-analysis is to calculate the standard difference between the mean of the control and experimental treatments (the stress treatment), which is called effect size (d). Therefore, a value of d is calculated for each of the 13 independent experiments examined in this meta-analysis. At first, the remote and asymmetric part of the funnel diagram was removed after estimating the number of studies in this part. Were replaced with their missing symmetric part around the center. Finally, the estimate of the total mean as well as the corresponding variance was obtained based on the completed Funnel diagram. In meta-analysis, it should be considered which studies agree with the null hypothesis and which oppose it; for this purpose, the accumulation or Forrest diagram was used. All calculations and charts were performed in Excel.

In this study, four traits were studied. The standardized values for the effect of drought stress on biological yield were significant in all four treatments (P <0.001). It should be noted that the effect size for each trait is the difference between the mean drought modulus of the control treatment (without stress), so the positive values indicate the higher mean of drought stress treatment than the control treatment. Based on effect size chart, standardized size values were significant for drought stress on grain yield in all 4 treatments compared with control. From the collection of d collected studies, the accumulation diagram related to the study of the effectiveness of grain yield against drought stress was drawn. The research used in this trait shows the estimation of the effect of the treatments very close to zero and with a low confidence interval. Among the high-weight researches, we can refer to the articles of Khadem et al. (2011). Regarding the funnel diagram, the articles are in the range of 95% and the amount of bias is less and its bias is more, which is considered a positive thing as a result of research. In the above diagram, T is an exact experiment that has less standard deviation and has a smaller number on the x-axis and is located at the top of the diagram and close to the vertical zero-axis. Only 5 studies on the effect of drought stress on grain yield were not significant and were excluded from the funnel.

The results of this study showed that, despite numerous studies on the effect of drought stress on yield and yield components of maize in the country, the results are very diverse and have high dispersion. This issue has not yet determined the exact effect of drought stress, especially on yield and yield components of maize. As a robust statistical method, the meta-analysis provided a proper and accurate tool for combining the results of independent experiments and established specific ranges for the effects of drought stress, especially on the corn counts.

In order to investigate the effect of deficit irrigation on vegetative growth characteristics and potato tuber and the effect of foliar application of chitosan and salicylic acid on yield and physiological characteristics of experimental potatoes as a split plot in a randomized complete block design with three replications in 2019 at an agricultural reaearch station in the city of Fariman. Experimental treatments included irrigation levels (60, 80 and 100% water requirement) and foliar application of chitosan and salicylic acid (control treatment, 2 g/l chitosan, 0.5 g/l salicylic acid and combined treatment with chitosan and salicylic acids). Irrigation levels in main plots and foliar spraying treatments were included in sub-treatments. Deficit irrigation treatments were applied 20 days after after plant emergence and at each irrigation period, and foliar application of chitosan and salicylic acid was performed in two stages during the growing season: at the flowering stage (beginning of tuber development), and at the mid-growth stage of tubers. The results showed that by reducing the irrigation volume by 20%, the same performance can be achieved with the performance in full irrigation conditions. Foliar application chitosan and salicylic acid also yielded different results. Foliar application of chitosan prevented a decrease in chlorophyll a concentration as the most important leaf photosynthetic pigment in 80% irrigation treatment. Other pigments showed similar behavior to chlorophyll a in solutions sprayed with chitosan or a combination of chitosan with salicylic acid. Proline, free phenols and soluble carbohydrates as secondary metabolites that undergo stress-induced osmotic regulation of leaf cells also had higher concentrations in chitosan foliar application at 80% irrigation treatment than their control treatment. Foliar application of chitosan and salicylic acid separately or in combination in treatments that were irrigated at 20 and 40% also maintained the concentration of glutathione peroxidase. Despite the above effects, foliar treatments could not clearly have a significant effect on glandular function.It does this by playing an important role in counteracting oxidative stress and balancing oxygen free radicals, as well as its role in protecting cell membranes, especially under stress conditions. According to the results of this experiment, it can be concluded that although these compounds have a significant role in the interaction of potato plant with deficit irrigation conditions, but the time and dose of its use requires more detailed research. Time and dose used that can compensate for the effects of stress and improve yield in deficit irrigation treatments. 

In recent years, due to climate change, the planting of millets has become of particular importance, necessitating conducting further research on their quantitative and qualitative attributes. Pearl millet (Pennisetum glaucum L.) is widely known as a multipurpose crop in many regions of the world. It provides nutritious food for humans, feeds for poultry, and fodder for ruminants. About 20 different species of millet have been cultivated throughout the world at different points in time. Commonly cultivated millet species include proso millet (Panicum miliaceum L.), pearl millet (Pennisetum glaucum L.R. Br.), finger millet (Eleusine coracana), Kodo millet (Paspalum setaceum), foxtail millet (Setaria italica L. Beauv.). Little millet provides excellent support for nervous system health by helping to restore nerve cell function, regenerate myelin fiber, and intensify brain cell metabolism. Millets are also rich in micronutrients such as niacin, B-complex vitamins, Vitamin B6, and folic acid. Millets generally contain significant amounts of essential amino acids, particularly those containing sulfur (methionine and cysteine) ( Torabi, 2015). Plant density is among the agricultural practices that greatly influences grain yield and yield components of pearl millet as it determines the inter-and intra-plant competition for groundwater and soil nutrients during the growing season. Due to the development of human societies, food security has become a priority(Khajeh pour, 2012). Technological advancements and the introduction of chemical fertilizers and pesticides have provided sufficient quantities of food in recent decades, but food quality is questioned. Fertilizers from natural sources might be a practical solution. Coastal farmers in various countries have been applying seaweed for crop growth and development for many years. Nowadays, with technological development, some species of seaweed such as Ascophyllum nodosum are cultivated and processed as seaweed extract alone or mixed with other fertilizers to be used by farmers) Manea and Abbas, 2018.)

To investigate the effects of different densities of millet and bio-fertilizer application on morphological and physiological yield and yield components of three millet cultivars, a factorial experiment in a randomized complete block design with three replications was conducted in Mashhad in 2021. In the experiment, three density levels of millet (300,000, 400,000, and 500,000 plants per hectare), and two levels of seaweed (Ascophyllum nodosum) bio-fertilizer in quantity of 0 and 1 L per hectare, as well as three cultivars of millet (Bastan, Pishahang, and Mehran) were applied. In this experiment, grain yield, biomass yield, harvest index, 1000-seed weight, plant height and protein percentage were measured.

The analysis of variance showed that the effects of cultivar and density on grain yield were significant at the probability of 1% where the highest grain yield with an average of 4444.1 kg/ha was obtained from Mehran cultivar at a density of 400 thousand plants per hectare. The lowest was related to Pishahang cultivar at a density of 400,000 plants per hectare with an average yield of 2321.5 kg per hectare. The effect of bio-fertilizer application was also significant on the yield and yield components at the probability of 1%. The highest harvest index value (0.29) was obtained from the Mehran cultivar at a density of 400,000 plants per hectare. The examination of the trend of change in the biological yield and harvest index of this cultivar also indicated that with increasing density, the biological yield increased and the harvest index decreased. Additionally, the highest biomass yield (7629/6 kg/ha) was observed in Pishahang cultivar at a density of 400,000 plants per hectare, both by bio-fertilizer application.

Maize (Zea mays L.) has high yield potential and suitable ensiling properties and is a valuable source of energy and nutrients for cattle (Johnson et al., 1999). Timely planting is critical for maximizing yield for both grain and biomass in maize and therefore, growers are concerned about the yield response of maize to planting date. However, optimum planting date may vary from area to area due to differences in climate and the length of the growing season where the crop is produced (Maresma et al., 2019). The cultivation of maize hybrids in Hamedan is done regardless of their growth period. So, the present study was conducted to determine the appropriate date for planting the hybrids of silage maize in the different maturity groups in Hamedan region.

A two-year experiment (2017 and 2018) was conducted at Ekbatan station of Agriculture and Natural Resources Research and Education Center in Hamedan province, Iran. The statistical design of experiment was a split plot, where planting dates (22 May, 10 June, 1 July and 21 July) were used as the main plot, and the hybrids with different maturity time (KSC201, KSC260, KSC400, KSC647, BC678, KSC703 and KSC70) as the subplots. Ten plants were randomly selected from each plot and plant height, stem diameter and fresh weight ratios of ear, stem and leaf to plant aerial parts were measured. To determine the fresh forage yield, a sample of 4 square meters was taken from each plot and weighed. Then, the samples were placed in an oven at 70 °C for 48 hours and after drying, they were weighed again to estimate the dry forage yield. The percentage of crude protein in dry forage was measured by Kajeldal method. Considering the occurrence of severe autumn cold in early of November that prevented the timely harvesting of hybrids with long growth period of KSC703 and KSC704 cultivated on the forth planting date, only the data obtained from the first to third planting dates was subjected to statistical analysis. Analysis of variance and comparisons of the mean effect of planting date and hybrid and their interactions were performed based on the least significant difference test (LSD) at a 5% probability level.

The results of compound analysis indicated that different planting dates differed in terms of all traits, except protein yield, and the highest amounts of fresh and dry forage yields (60008 and 18595 kg.ha-1, respectively) were for the first planting date and the lowest amounts of the mentioned traits (50643 and 14672 kg.ha-1, respectively) were for the third planting date. It seems that the high forage yields on the first planting date were due to the suitable temperature conditions that allowed the plant completed its growth period and increased the accumulation of photosynthetic materials. The effect of hybrid on all the traits was significant and KSC703 and KSC704 hybrids gave the highest values of fresh (71322 and 68443 kg.ha-1, respectively) and dry matter (21527 and 20197 kg.ha-1, respectively). The superiority of late (and medium) maturing hybrids over early maturing hybrids in terms of fresh and dry yields, may be due to the longer growth period. Despite KSC201, KSC260 and KSC400 hybrids gave the lowest amounts of growth period (78.06, 89.61 and 97.22 days), fresh yield (37469, 40499 and 45732 kg.ha-1, respectively) and dry yield (11620, 12395 and 14720 kg.ha-1, respectively), these hybrids showed the highest values of crude protein (14.63, 14.09 and 14.04%, respectively) and ear to plant weight ratio (38.44, 35.97 and 34.95%, respectively). Therefore, cultivation of the early maturing hybrids is recommended if high quality forage is targeted. Also, it is not recommended to delay the planting FAO maturity groups 700 and 600 maize to early summer season, due to excessive delay in land preparation for the cultivation of autumn crops.

Due to the possibility of timely harvest, acceptable yield and suitable forage quality of early maturing hybrids on the last planting date, in case of delay in planting date to late July in Hamedan region and areas with similar climate, planting early maturing hybrids (especially KSC400) is recommended.