Mehdi Mehdi; Alireza Yazdanpanah
Abstract
Introduction
The super sweet corn produced of Hamedan province is one of the most suitable super sweet corn in Iran for industrial processing (canning or freezing of grain). This ...
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Introduction
The super sweet corn produced of Hamedan province is one of the most suitable super sweet corn in Iran for industrial processing (canning or freezing of grain). This is because the favorable temperature conditions in the province during summer (warm days and moderate nights) which causes the high percentage of grain extraction of green ear. The planting date of super sweet corn effects all the plant's phenological stages and changes the final yields of the grain and green ear by affecting the grain yield components. The purpose of this study was to compare the impact of planting dates of super sweet corn cultivars on phenological and agricultural traits, the yields of grain and green ear and the product processing for food industries.
Materials and Methods
A two-year experiment (2020-2021 and 2021-2022) 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 (9 May, 4 and 30 June) were used as the main plot, and the cultivars (Basin, Messenger, Sheba, Passion and Shaker) as the subplots. In harvesting time (milky grain stage), the yield of green ear in area was determined. After separating the grain from the cob, the grain yield (canned grain) and the ratio of grain weight to green ear weight (percentage of grain extraction of ear) was determined. Also, the percentage of Total Soluble Solids (TSS) of grain was determined by refractometer. After the compound variance analysis, the effects of planting date and cultivar on the mean of each trait were compared with the LSD test at 5 % probability level.
Results and Discussion
According to the results, the highest values of Growth Degree Day (GDD) to pollination among the studied cultivars were belonged to Shaker, Messenger and Basin with 713.4, 698.2 and 688.7 Celsius, respectively; also, the planting date of 9 May with 708.5 Celsius, showed the highest value among the planting dates. However, the highest values of GDD to ear harvest were observed on the planting date of 4 June and Messenger, Shakar and Basin cultivars with 1212, 1195 and 1162.4 Celsius were superior to other cultivars in the second time of planting. In terms of the number rows of ear, the second time of planting with 15.17 units showed significant superiority to other times of planting and Messenger, Shakar and Basin cultivares with 14.95, 14.74 and 14.59 units, respectively, were superior to other cultivares. In terms of the number of grains per row, all cultivars showes the highest values in the second time of planting, and the Basin cultivar with 44.58 units, was significantly superior to other cultivars . The High values of the number rows of ear and the number of grains per row (as the components of grain yield) caused Basin cultivar acquired the highest yields of green ear and grain (with 38854 and 15922 kg/ha, respectively) among different cultivares in the second time of planting. Also, the highest TSS with 23.11% was observed in the third time of planting, which showed a non-significant advantage compared to the second time of planting (22.32%). The Messenger, Sheba and Basin with 24.37, 22.38 and 22.17%, respectively, showed a significant superiority over other cultivars in terms of the TSS parameter.
Conclusion
According to the results, the most suitable planting date for super sweet corn in Hamedan province is the first decade of June and delaying planting to the third decade of June is not recommended due to a significant decrease in the yields of green ear and grain. Also, because of the high yields of green ear and grain (along with the acceptable values of TSS content) of the Basin cultivar, its cultivation is recommended in Hamedan and areas with similar climate.
