Agrotechniques in Industrial Crops
Volume:2 Issue: 1, Winter 2022

Many studies have focused on the cardinal temperatures and thermal time requirements of seed germination, but how seed size and color affect germination rate and thermal thresholds is poorly understood. In this study, nonlinear regression models were used to examine the relationships among seed size, seed color, and germination rate, and assess the extent to which these seed traits influence cardinal temperature and thermal time requirements for seed germination. The beta-modified model was found to be the best model for predicting the required time to reach 50% germination. Based on the model output, the base, optimum, and maximum temperatures were 4.49-8.59, 19.76-21.88 and 34.12-41.68 ○C, respectively. Larger seeds have a higher base and ceiling temperatures compared to smaller seeds. The thermal time of 50% germination was 1890, 954, 1551, and 1188 degree-hours for small and large greenish-gay and reddish-brown seeds, respectively. The lower germination rate in greenish-gray seeds compared with reddish-brown colored seeds could be due to the lower seed vigor or viability. Not all castor seeds are produced at the same time during the growing season. Therefore, the last produced grains lose ideal grain filling conditions, which cause them to be smaller, less dense, and have low vigor.

This study aimed to determine the effect of cutting the aerial part of Jerusalem artichoke at different growth stages, as forage, on tuber yield. Tubers were planted in a randomized complete block design in 16 plots with dimensions of 3 m × 4 m (4 plots in 4 blocks). Treatments with different dates of the harvest of the aerial part were: 1) first cut at stem elongation stage, BBCH-39 and second cut at inflorescence emergence stage, BBCH-59 (66 and 138 days after planting, respectively), 2) first and second cuts at stem elongation stage, BBCH-39 (100 and 173 days after planting, respectively), 3) one cut at inflorescence emergence stage, BBCH-59 (132 days after planting) with no regrowth of the aerial part, and 4) no aerial part cut. Tubers were harvested with approaching the cold season when the aerial part stopped growing. Treatment 1 and 2 resulted in lower total fresh and dry matter yield than treatment 3. The amount of water-soluble carbohydrates and crude protein in second cuts were numerically higher and fiber fractions lower than the first cuts. The highest fresh and dry tuber yield in treatment 4 was 63.3 and 14.8 t/ha, respectively, which was significantly higher than the mean of fresh (25.4-29.5 t/ha) and dry (4.6-6.1 t/ha) tuber yield in the other treatments. An increase in tuber organic matter was observed in treatment 4 with a significant increase in soluble carbohydrate contents. The results showed that an extra cut of the aerial part of Jerusalem artichoke during the vegetative stage did not increase the aboveground biomass yield compared to the treatment in which the only harvest was made just before the flowering stage. Yield of tubers was also negatively affected by regrowth of the aerial part.

From 2016 to 2017, an experiment was conducted at Razi University Organic Farming to identify the best organic fertilizers for organic sesame production. The research was carried out in the split-plot design based on a randomized complete block design with three replications. Comparison of soil nitrate in the post-planting stage of sesame with soil before the experiment shows that organic nitrate storage with an application of treatments of 10 and 20 t ha-1 of animal manure is 36 and 63% and green manure of fenugreek, berseem clover, and hairy vetch is 63, 54, and 23%, respectively. The reason for improving grain yield is the positive role of animal manure and green manure in the fertility and balance of soil elements. The plant doesn’t face a lack of nutrients and increases the concentration of essential growth elements in the leaves, which increases grain yield. Fenugreek and berseem clover were higher than hairy vetch due to higher nitrogen yield. In the post-harvesting stage of sesame, soil experiments revealed that approximately 24% organic carbon, 58% phosphorus, 16% nitrogen, 63% nitrate, and 50% ammonium were stored in the soil. Potassium content was 13% lower than in soil before the experiment. In general, this study showed that the application of animal and green manure by providing physical and chemical properties of soil in organic field conditions leads to improved traits associated with sesame growth and, ultimately, grain yield.

The seeds of most medicinal plants have a variety of dormancy. Therefore, it is necessary to know the effective methods of breaking the seed dormancy for their production and cultivation. In this study, to determine the best method of breaking dormancy and increasing the germination percentage of tattoo seeds, various factors have been investigated. Different treatments, scratching with sandpaper, embryo culture, GA treatment (100, 150 and 200 PPM) and sulfuric acid treatment (50, 75 and 100%) with filter paper or on MS medium containing BAP (0.5, 1 and 1.5 mg/l) was applied with untreated samples (control). Embryo culture was performed only on MS medium containing BAP hormone. The analysis of variance showed that all interactions with the studied treatments were significantly different in terms of germination percentage, fresh and dry weight of roots and stems (P <0.01). It was observed that the use of benzyl aminopurine (1.5 mg/l) with gibberellic acid (200 ppm) increased the seed germination percentage compared to the control. The use of benzylaminopurine (1.5 mg/l) and sulfuric acid (50%) significantly increased seed germination compared to the control. It was concluded that the effect of GA with BAP on seed germination was greater than sulfuric acid with BAP.

In order to investigate the effect of different phosphorus and radiation treatments on Azolla growth and water use efficiency (WUE), an experiment was carried out at the Agricultural Research Greenhouse of Razi University, Kermanshah, Iran. The experiment was a factorial with three factors based on a completely randomized design with three replications. The first factor was cultivation dates (4 May and 4 June), the second was radiation levels (0, 50 and 100% of full sunlight) and the third was phosphorus treatments including control (without fertilizer), chemical fertilizer and chicken manure. Results indicated that the highest dry matter produced and water use efficiency occurred at the 100% level of full sunlight. At the higher radiation levels (50 and 100% of full sunlight) chicken manure performed better as compared with the other phosphorus treatments. Moreover, at the 100% of full sunlight, there was no significant difference between the two cultivation dates in terms of WUE.

Medicinal-oil plant Camelina is a plant that has attracted a lot of attention in recent years. Because its most important advantage is excellent resistance to drought and cold as well. Therefore, in this study, in order to determine the best cultivation areas of Camelina in Kurdistan province based on a number of main parameters affecting the growth of this plant, statistics and daily meteorological information for 19 years in different meteorological stations of the province from 2000 to 2019 were used. Statistics and information from14 stations in neighboring provinces were also used to increase the accuracy of the created zoning maps. To create a spatial database for the study area, the required maps were entered into the ArcGIS 10.3 software and environment and descriptive map information was added to them. Finally, based on the requirements for each of the parameters, the classification of the maps was done according to the resources used. Krigink's method was used to prepare temperature, precipitation and altitude maps. The final results showed that for Camelina cultivation, in 26259 and 7059 square kilometers, equal to 75 and 25% of the total area of the province was suitable and unsuitable respectively. In addition, Camelina susceptible areas were often located in the southern parts of the province.