نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: One of the important factors that affects the growth of plants is the amount of light in the vegetation layers, and this condition may have a destructive effect on the yield of the product. Efficient crop species can absorb a larger fraction of light and convert it into biomass with a higher conversion factor. Corn is one of the cereals that shows good tolerance to controlled defoliation. Also, researches have shown that the low light stress is one of the most important factors affecting the plant metabolism and causes a decrease in plant yield. Although there is no radiation deficiency in Iran in terms of the amount of radiation and light conditions, the density of vegetation reduces the penetration of light to the lower layers of vegetation, and this affects the yield of the crop.
Materials and Methods: The study was conducted as a factorial design based on a completely randomized blocks design in 3 replications in 2022-2023 in the agricultural fields of Zafarabad in Shiraz. In order to evaluate the effects of removing leaves and a part of the ear on the light use efficiency and yield of some corn hybrids. The treatments included detopping and removing a part of the ear at 3 levels (control, removal of half of the ear, and removal of two leaves above and below the ear) and 7 corn hybrids (SC704, Konsor, Kordona, Karaj 703, Koosha, Fajr, and Danial 690). Sampling was done once every 14 days, one month after planting, to calculate the physiological indicators of growth.
Results and Discussion: The results showed that the effect of year on CGR, remobilization, and light consumption efficiency was significant. The simple and interaction effects of detopping and hybrid on all studied traits were significant. The highest value of CGR (40.23 g/m2 per day) was obtained in the treatment of the removal of two upper and lower leaves of the ear and Danial 690 hybrid. The highest value of RGR (0.0565 g/g per day) was obtained in the treatment of removing two upper and lower leaves of the ear × hybrid SC704. The highest levels of remobilization (169.2 g/m2), the contribution of remobilization in grain (19.85 percent), light use efficiency (2.9 g dry matter per MJ), and grain yield (11260 kg/ha) were obtained in the treatment of removing the two upper and lower leaves of the ear and the Konsor hybrid. The highest value of LAI (6.05) was obtained in hybrid SC704 and the lack of detopping. Regarding remobilization, the contribution of remobilization, efficiency of light consumption, and grain yield, the Konsor hybrid had the highest value.
Conclusion: In summary, regarding physiological traits, hybrids SC704 and Karaj 703 had the highest yield. Generally, increasing light penetration into vegetation under the effect of detopping showed a positive impact on the increase of grain yield and the efficiency of light consumption in different cultivars. It is suggested that corn varieties be planted in different regions and agricultural lands of Shiraz city in such a way that there is a desirable distance for receiving light in the lower canopy layers, because at high levels, it is not possible to cut off leaves and part of the ear. This research was also conducted to investigate the light status in different canopy layers, especially the lower parts, and to investigate the yield status. It was carried out at a limited level. For higher levels, varieties with more vertical leaves and light that can reach the lower parts of the canopy can be used. Considering the nutritional value and consumption status of this plant, a higher yield can be achieved, and it is economically viable.
کلیدواژهها English
