تحسين خصائص الانبات والبزوغ الحقلي والنمو والحاصل بإستخذام البراسينولايذ في بعض اصناف الذرة البيضاء

Abstract

Two Factorial experiments were carried out, one of which was in the seed technology laboratory affiliated to the Department of Field Crops - College of Agriculture - University of Anbar during the year 2022, and the second field experiment was conducted in the field belonging to the College of Agriculture in Al Buaitha area of AL Ramadi city during the autumn season 2021. The objective was to study the stimulating seeds with the growth regulator Brassinolide and its role in the viability and activity of the seedling and field establishment of some cultivars of sorghum ( Sorghum bicolor L. Moench) to determine the best stimulating concentration for the best variety. Complete randomized design (CRD) was used for the laboratory factorial experiment with four replications, the randomized complete block design (RCBD) was used in the field factorial experiment with three replications, for two factors the first was the seed soaking treatment for (12) hour in distilled water solution with the growth regulator Brassinolide concentrations (0.2, 0.4 and 0.6 mg L-1) in addition to the control treatment (soaking with distilled water only), and the second factor three varieties of sorghum (Enqad, Rabeh and Lilo). The results of the laboratory experiment showed a significant superiority by using growth regulator Brassinolide at a concentration of 0.6 mg L-1 that giving highest averages for most of the studied traits as follows:- germination speed (73.33%), standard laboratory germination rate (94.43%), radicle length (16.08 cm) and length of plumule (15.36 cm), seedling vigor (2968.2) and the dry weight of seedling (0.0545 mg) in comparison with the control treatment (soaking with distilled water only), which gave the lowest averages B for the studied traits. As for the cultivars, cultivar (Rabeh) showed a significant superiority for most of the studied traits than the rest of the cultivars as follow: speed of germination (67.72%), percentage of germination (87.67%), length of the plumule (13.21 cm), seedling vigor (2371.1), and the dry weight of seedling (0.0513 mg). As well the cultivar ( Enqad) which gave the superior significant rate for radicle length with 13.90 cm . The results of the field experiment showed a significant superiority by using growth regulator Brassinolide at concentration of 0.6 mg L -1 to stimulate seed by showing the highest averages in most of the studied traits as followed :- emergence speed (75.44%), percentage of emergence (90.00%), plant height (165.14 cm) chlorophyll content of the leaves ( 62.09 spad), flag leaf area (610.49 cm2), number of grains per panicle (3119.7 grains), the weight of 500 grains (13.47 g), grain yield of single plant (83.13 g), total grain yield (6.650 tons h-1) and biological yield (21.37 tons h-1). As for the character of the number of days from planting up to 75% of flowering, the same above mentioned concentration gave it the least number of days average, which amounted to (61.11 days), as compared to the rest of study treatments, as concerning the harvest index character , using growth regulator Brassinolide at 0.4 mgL -1 showed the highest average of this character with 31.70% which was significantly higher than rest of concentrations. The results of the statistical analysis showed that there were significant differences between the cultivars in some of the studied traits of the field experiment, the cultivar Rabeh gave the highest average for the field emergence speed with 69.58%, percentage of emergence 86.58%, plant height 161.96 cm, chlorophyll content of C leaves 57.80 spad, the number of grains per panicle 3376.1 grains per panicle ,and biological yield 23.11 tons h-1. The same variety gave the best average in terms of number of days from planting up to 75% of flowering by recording the lowest number of days with 63.00 days. The same cultivar was superior in terms of total yield ,harvest index averages, which were 6.676 tons h- 1, and 34.39% respectively . The cultivar Lilo showed highest averages for area of the flag leaf with 600.85 cm2, and weight of 500 grains with 14.15 g. The results showed a significant effect of the interaction between the two study factors in most of the studied traits . We conclude from the results of the present study that stimulating the seeds with the growth regulator Brassinolide in general, led to an improve in the germination performances ,field emergence, and gives best seedlings for the studies cultivars, in addition to an increase in total yield due to an increase in yield components.