مجله تولید و فرآوری محصولات زراعی و باغی
سال سیزدهم شماره 4 (پیاپی 100، زمستان 1402)

Mexican yam plant (Pachyrhizus erosus (L.) Urban) is a new and hence less-known crop plant in Iran, with potential applicationes in food and pest control industries. Therefore, the present study was conducted to determine the best fertilizer treatments and its effect on the morphological characteristics and grain yield of Mexican yam bean plant in a semi-arid region. The experiment was carried out as a randomized complete block design with six replications in Kazeron, Fars province, south of Iran. The treatments included the control, EM biofertilizer (40 L/ha), Vinas organic fertilizer (80 L/ha), and the combination of bio-organic fertilizer (the optimum level of fertilizer was determined based on the results of previous experiments). Fertilizer treatments had a significant effect (at 1% probability level) on plant height, plant fresh and dry weight, pods/plant, grains/pod, stem diameter, grain and biological yield and harvest index, photosynthetic pigments concentration and grain protein content. The mean comparison showed that in the combined treatment of Vinas organic fertilizer and EM, the fresh and dry weight of the plant (67.6 grams and 26.8 g, respectively), the height of the plant (56.1 cm), grains/pod (6.4), pods/plant (6.3), biological yield (4929 kg/ha), grain yield (527 kg/ha), harvest index (10.7%), concentration of chlorophyll a, b, and total chlorophyll and carotenoid concentration (9.83, 3.43, 13.5 and 3.28 mg/g fresh weight, respectively), grain protein (34.1%) were more than control. Also, the stem diameter showed the greatest increase compared to the control. The results suggested the superiority of the bio-organic fertilizer treatment at the optimal level (40 and 80 L/ha) and the positive response of Mexican yam bean plant to these fertilizers.

Two species of common cocklebur (Xanthium strumarium L.) and spiny cocklebur (X. spinosum) are common annual summer weeds in soybean fields and other summer crops. The current research was carried out with the aim of determining the cardinal temperatures of germination and determining the phenology stages of these two species in Sari University of Agricultural Sciences and Natural Resources. In order to determine the cardinal temperatures of germination of seeds of two weed species, the seeds were examined at constant temperatures of 5 to 45 °C in a completely randomized design in 4 replications in a laboratory experiment. Also, the phenology stages of two weed species were investigated in a field experiment. The highest germination% was observed for the spiny cocklebur (51.3%) and the common cocklebur (58.1%) at temperatures of 25 and 35 °C, respectively. According to the different parameters of segmented model, the base temperature, lower optimum temperature and ceiling temperature for spiny cocklebur are 1.4, 23.2 and 54.7 °C, and for common cocklebur are 4.8, 34.6 and 48.4 °C, respectively. Time from emergence to physiological maturity for the spiny cocklebur and common cocklebur were 136 and 128 days, respectively. The results suggested that seed germination of the two weed species occurs in a wide range of temperatures, i.e. of 5 to 45 °C, and the best time to control this weed is late summer (before the beginning of the flowering stage).

In order to investigate the profile of saturated and unsaturated fatty acids of camellia oil in response to salinity stress and polyamines, an experiment was conducted in March 2022 in a factorial layout based on a completely randomized design as pot culture (open air) with 12 treatments and 3 replications. The salinity stress treatment applied using Urmia Lake water at three levels (0, 15, 30 dS/m). Foliar treatment carried out in 4 levels, including 1- Foliar spraying with Spermine, 2- Foliar spraying with Spermidine, 3- Foliar spraying with Putrescine and control (no foliar spraying). The results showed that with the increase of salinity stress level, the percentage of saturated fatty acids increased but the unsaturated fatty acids of grain oil decreased. Also, the salinity stress of 30 and 15 dS/m increased the saturated fatty acids (6 and 4%, respectively) and the ratio of saturated to unsaturated fatty acids (9 and 6%, respectively), but decreased the percentage of oil (17 and 9%, respectively), monounsaturated fatty acids (4 and 2%, respectively), polyunsaturated fatty acids (3 and 1%, respectively), reduced oil yield (62 and 21%, respectively) and grain yield (52 and 10%, respectively) compared to the control. Foliar spraying with polyamines decreased the percentage of saturated fatty acids and increased the percentage of unsaturated fatty acids, unsaturated index, oil stability percentage, oil percentage, oil yield and grain yield. Therefore, foliar-applied polyamines are proven suitable to mitigate the salinity stress and improve oil composition and increase the quantity and quality of camellia grain yield.

The study aimed to investigate the response of bean yield and yield components to  the application of growth stimulants under different irrigation levels. A field experiment was conducted in the Khoy, Northwest of Iran. The experiment was conducted as a split-plot design using a randomized complete block design (RCBD) in three replications. Irrigation was the main factor in three levels, including once every 8, 11, and 14 days and growth stimulating compounds as subfactors in 5 levels, including the use of humic acid with irrigation water, amino acid foliar spraying, rooting stimulant, potassium, and no growth stimulants (control). Drought stress (irrigating once every 14 days) led to the reduction of the absorption of essential plant elements such as nitrogen, potassium, and phosphorus, as well as decrease in the lateral branches/plant, grains/pod, hundred-seed weight (HSW), harvest index (HI), leaf area index (LAI), protein yield, and grain yield. Application of growth stimulants both under normal irrigation conditions and under drought stress increased the examined traits, compared to the control treatment. The results indicated that the impact of mild drought stress during the pod development and grain filling stages has a more pronounced effect on the yield and yield components of red kidney beans. Application of growth stimulants, particularly humic acid, during these stages mitigates the adverse effects of stress and leads to a notably higher grain yield compared to other growth stimulants. The highest grain yield (3076 kg/ha) and protein yield (746 kg/ha) were achieved at the presence of irrigating every 8 days and the application of humic acid. It appears that the use of humic acid can be highly effective in enhancing the agronomic, qualitative, and physiological attributes of red kidney beans, contributing up to 95% improvement under both normal irrigation and stress conditions.

Today, agroforestry production systems as viable strategy for sustainable agriculture, is appreciated by both researchers and farmers, as it increases the efficiency of natural resources uses and may enhance the combined production of wood and crop products and hence income of the rural communities. In order to investigate the benefits of the agroforestry system of Euramerican poplar (Populus euramericana clone of 92/40) and alfalfa fodder plant (Medicago sativa), an experiment was carried out in the form of Randomized Complete Block Design (RCBD) with three replications at the Alborz Research Station in the south of Karaj, Iran. The treatments included poplar pure culture, alfalfa pure culture, and poplar-alfalfa mixed culture. Alfalfa plants were planted between the rows of poplar (Populus euramericana clone of 92/40) which were planted in March 2015 at a distance of 3 × 4 m, in late autumn 2016. The height and diameter at breast height (DBH) of the poplar trees were measured at the end of each growing season for three consecutive years, and then the annual increment in growth of height, diameter and stem volume (m3/ha) were calculated and evaluated using the T-Test. The plant height and dry weight of alfalfa were measured for the three years and its total annual fodder dry mass yield was obtained. Competitive and economic evaluation of each of the pure and agroforestry cultivations was done based on the indices of land equality ratio (LER), relative value total (RVT) and advantage index (IA). In 2019 and 2020, there was a statistically significant difference in the DBH and stem volume in pure and agroforestry cultivations, indicating the highest values for both parameters in pure poplar culture. In 2018, the highest alfalfa fodder dry mass yield was obtained in agroforestry cultivation with 11320 kg ha-1 but the highest alfalfa fodder dry mass in 2019 (with 10928 kg ha-1) belonged to its pure cultivation. In all the studied years, LER was greater than one and ranged from 1.27 to 2.39, with the three-year average being 1.78. The values for RVT in 2018, 2019, and 2020 were 1.6, 0.69 and 0.41 and those for IA were 6.53, 4, and 2.81, respectively. Therefore, adopting agroforestry by cultivation of poplar and alfalfa will enable the farmers to receive 160%, 69%, and 41% increases in income compared to the income from pure cultivation of poplar and alfalfa for the years 2018, 2019 and 2020, respectively.

In order to study the effects of nitrogen and phosphorus biofertilizers on photosynthetic pigments, grain yield, yield components and grain protein content of two pea (Pisum sativum L.) varieties under different irrigation regimes; a split-split plot experiment was conducted based on a randomized complete block design with three replications at a field in Farsan, southwestern Iran, in 2021. The main plots were allocated to irrigation treatments including: irrigation after 50, 75 and 100 mm (I1, I2 and I3, respectively) cumulative evaporation from class A evaporation pan and the sub plots were allocated to different sources of biofertilizers treatments including: control (no biofertilizer application), Azotobarvar-1(nitrogen), Phosphatebarvar-2 (phosphorus) and Azotobarvar-1 + Phosphatebarvar-2 (nitrogen + phosphorus). Sub-sub plots were allocated to two varieties of peas (Majarestani and Wolfholland). Results showed that in Majarestani variety mild drought stress increased chlorophyll a and b contents, but severe drought stress decreased them. In Wolfholland variety, both mild and severe drought stress decreased chlorophyll a and b contents. In both varieties, mild drought stress increased carotenoid contents, but severe drought stress decreased them. Biofertilizers were effective in improving chlorophyll a, b and carotenoid contents, particularly under drought stress conditions. The drought stress reduced the grain yield and yield components of both pea varieties but application of biofertilizers moderated the effects of drought stress. The highest value of grain yield was obtained from the Majarestani variety when grown under full irrigation conditions (I1) and nitrogen biofertilizer application. Under the mild and severe drought stress (I2 and I3), the highest value of grain yield was obtained from Majarestani variety in the presence of phosphorus and nitrogen + phosphorus biofertilizer application, respectively. Majarestani variety outranked the Wolfholland in terms of  pods/plant, grain/pod and grain yield under both stress and normal conditions, but the latter variety indicated a greater 1000-grain weight. Therefore, Majarestani variety is a more suitable cultivar, particularly under drought stress conditions. Grain protein percentage was not affected by variety. The highest percentage of grain protein content was achieved with I2 irrigation and nitrogen + phosphorus biofertilizer treatments, averaged over the examined varieties. To conclude, given the prevalence of water scarcity in the semi-arid regions of Iran’s type, further examinations of more drought resistant varieties such as Majarestani and application of biofertilizers may prove suitable for reducing the adverse effects of drought stress.

Wheat has an important role in food production of the world and Iran as well. It provides around 40 percent of energy and protein intake of Iran’s people. Closing yield gap can increase wheat production. The first step of closing yield gap is to quantify the yield gap at a given region or country. The objective of this research was to determine wheat (Triticum spp. L.) yields and production during the two cropping years (2013-2015) in the Parsabad Moghan in Ardabil province, northwest of Iran. To calculate the actual yield, a 22-year of official data and 460 farms under the management of farmers during 2014-2016 were used. The average and maximum attainable yield was estimated using field experiment results (FLD), comparative performance analysis (CPA) and the 90th percentile of record yield distribution. Based on the results of this research, a significant management yield gap was observed between attainable and actual yield (22%). In addition; genetic (i.e., gaps due to genetic selection) and total gaps in wheat were 11% and 36%, respectively. The increase in wheat production with the genetic selection and optimal crop management for the studied 28154 ha was estimated to be approximately 59000 tons with an economic value of 2.59 million dollars. Based on the results of this research, the yield potential of wheat genotypes can be achieved by closing yield gaps in the study area.