Study of yield and physiological responses of corn 704, 705 and 706 hybrids under irrigation volumes with impacted strip method

To reduce the food insecurity, crop production will have to be doubled, and produced in more environmentally sustainable ways. This can be achieved by expanding the area of crop production, increasing per hectare yield and improving crop quality. Furthermore, during the second half of the past century, rise in per hectare crop productivity was due to improved or high yield potential. The productivity of plants are strongly influenced by environmental stresses. In the water scarcity condition, using deficit irrigation and appropriate cultivar are the most strategies to improve water productivity. Hence, the present study was to design with the following

To determine yield and WUE of forage corn varieties at different levels of irrigation. To study the effect of deficit irrigation on physiological parameters of forage corn . To identify how interaction deficit irrigation and forage corn varieties affect yield, WUE and physiological parameters.

An experiment was conducted during 2018 and 2019 in Gorgan agricultural research station to investigate the effect of deficit irrigation methods under drip irrigation condition on forage yield and physiological parameters of corn cultivars. The experiment was laid out in a randomized complete block design in form of split plot factorial experiment and replicated four times. Treatments were including three irrigation volumes [Irrigation at %100 (I1), %75 (I2) and %50 field capacity (I3)], as A factor, and varieties (SC704, SC705 and SC706) as B factor. In order to the development and management for Corn in summer season, the current study was conducted to find the effects of different varieties and irrigation on yield and physiological parameters of corn. Chlorophyll content was estimated using the method of Witham et al. (1986). Free proline concentration was determined by means of a rapid colorimetric method using an acid ninhydrin procedure developed by Bates et al. (1973). Data were analyzed using SAS. Treatment means were compared usingLSDat the 95%probability level.

Investigation of forage yield at irrigation treatment showed, the highest forage yield of I1 treatment was 50.06 ton ha-1, and reduced by %24.83 and %15.61 respectively when the irrigation interval was reduced by 75% to %50 field capacity. Comparison of fresh forage yield at varieties showed, fresh forage yield of single cross 705 with 45.65 ton ha-1 was%14.04 and %10.29 higher than single cross 704 and single cross 706 respectively. Interaction effect of irrigation value and variety showed, the most fresh forage production was belong treatment of single cross 705 and irrigation at %100 field capacity. Investigation of WUE of forage yield showed, irrigation at %75 field capacity with WUE of 7.94 kg m-3 fresh forage had the most WUE. The variety of single cross 705 with WUE of 7.38 kg m-3 fresh forage had greater WUE compared to other varieties. In the water scarcity condition, using deficit irrigation and appropriate cultivar are the most strategies to improve water productivity. The results derived from the irrigation study showed that despite the possibility of greater surface evaporation with light frequent irrigations, differentials of sorghum varieties and other indicators of plant water stress were found to be improved with low frequent irrigation. Irrespective of variety, intermediate irrigation regime had higher yield than the most frequently irrigated regime. Though, when comparing the three varieties, variety SC705 significantly produced higher dry forage in the main crop. The present findings suggest that in semiarid environments Corn should be irrigated infrequently but heavily. Therefore it is recommended to cultivate SC705 variety in the Gorgan corn farms,