Effect of repeated mowing on grain yield and its components of dual-purpose barley (Hordeum vulgare L.)

Abstract

The study was conducted during the winter agricultural season 1999-2000 in a piece of land with a moderately drained silty clay texture, with a reaction degree of (pH = 7) and electrical conductivity (EC = 8.5 ds.m / m-2) within the field of field crops research station in Al-Fadhiliyah-Baghdad affiliated to the Ibaa Center for Agricultural Research, located within latitude 20-33 north and longitude 24-44 east and at an altitude of 4.1 3 m above sea level. Five genotypes of six-row barley were used in this study (B 9-12, B 22-7, B 22-24, IPA99 and Numar) for the purpose of studying the effect of repeated mowing on grain yield and its components of dual-purpose barley. The experimental land was fertilized with 400 kg of al-Dab fertilizer / ha 0:48:18:N:P:K Diammonium Phosphate added at once when preparing the land and urea fertilizer (46% N) was used at a rate of 200 kg urea / ha added to the swarming treatments. The RCBD was followed by a randomized complete block design with a split-plot arrangement and with three replications, where the main plots were allocated to genotypes and the secondary plots were allocated to the weeding treatments. The number of lines was five lines for the secondary experimental treatment, the distance between one line and the other was 30 cm, and the area of the secondary experimental unit was (4 x 1.5) m. Transactions were sown on November 21, 1999, using 140 kg seeds / ha, after measuring the germination percentage of barley genotypes included in the study, and it was (99%). The cuttings of the secondary boards were carried out when the vegetative growths reached an average height of 34 cm in order for the plant to maintain a good level of carbohydrate storage necessary for regrowth. The following characteristics were studied: Green fodder yield per bunch, number of spikes, number of grains/spike, weight of 1000 grains. (gm) and grain yield. The genotype (B9-12) excelled in the following traits: green fodder yield per weed, number of spikes/m2 and grain yield (tons/ha), giving rates of 10.577 (tons/ha), 324.7 spikes/m2 and 4.759 tons/ha. Mowing operations for four consecutive times.