تأثير تنشيط البذور المخزونة بمدد خزن مختلفة في قوة البذور ونمو وحاصل الذرة البيضاء Moench Sorghum bicolor

Effect of Seed storaged priming with different storage periods on Seed vigour, groth, and yield of Sorghum bicolor (L.) Moench

Two factorial experiments were carried out: one is laboratory in the Laboratory of Seeds Technology/Dept Field Gropes/College of Agriculture/University of Karbala, during the year 2018; the other is a field experiment, which was taken place in the field related to Abn al-Baitar Secondary School in AL-Hussainyah District, during Spring 2018 for the purpose effect of seed storage priming and storage periods  in the percentage of germination and emergence and its relation to the field establish ment, knowing the growth and yield of sorghum bicolor L., determining the best enhancing treatment, and studying the seed age of Sorghum bicolor L. The Completely Randomized Design (CRD) of factorial experiments was used in the laboratory experiment three times; and the Randomized Complete Block Design(RCBD) was used in the field experiment three times as well, with two factors: the first factor is seed enhancement by steeping the seeds for 24 hours (in mineral water and Gibberellic acid (GA₃) in several condensations (20,40,60) mg liter^-1 and dry seeds), and the other factor is seeds age(one year: seeds 2017, two years: seeds 2016, three years: seeds 2015, and four years: seeds 2014).

The results of the laboratory experiment showed the superiority of seed priming with Gibberellic acid concentration (60)mg Liter^-1 significantly by  giving the highest averages of germination speed characteristics (74.50%), the percentage of the standard laboratory germination (73.67%), root length (6.55) cm, Chlorophyll components (15.39) SPAD, dry weight of seedlings (11.40) mg,  seedling vigor in the first counting (1108), and seedling vigor in the second counting (1103) in comparison to the dry seeds which gave the lowest averages:( 57.17%),(50.67%),(2.52 cm), (12.48 SPAD), (7.95 mg),(338), and (303), respectively. Moreover, the enhancement with Gibberellic acid concentration (40) mg liter^-1 exceedingly gave the highest average of plumule length (8.13) cm in comparison to the dry seeds which gave the lowest average (3.13) cm.

The seeds that storage for one year exceeded significantly by giving the highest averages of root-length (6.38) cm, plumule-length (7.77) cm, Chlorophyll components (16.36) SPAD,  dry weight of seedlings (11.25)mg, seedling vigor in the first counting

(1245), and seedling vigor in the second counting (1202), in comparison to the dry seeds which gave the lowest averages: (3.50 cm),(4.58 cm),(10.31 SPAD), (6.66 mg), (372), and(353), respectively. The two-year storage exceedingly gave the highest averages of the germination speed (89.07%) and the percentage of the standard laboratory germination (85.07%), while the three-year storage gave the lowest averages: (42,80%) and (39.87%), respectively.

The results of the field experiment showed the superiority of seed seed priming with Gibberellic acid concentration (60) mg Liter^-1 significantly by giving the highest averages of the most characteristics: the percentage of emergence (42.66%),the number of leaves (12.97) leaf plant^-1, leaf area (5413) cm²,grain number (5819) grain, grain yield (10.74) tan h^-1; whereas enhancement with Gibberellic acid concentration (40) mg liter^-1  exceeded significantly by giving the highest averages of the two factors: plant height (148.07)cm and harvest index (38.76%); while enhancement with Gibberellic acid concentration (20) mg liter^-1exceeded significantly by giving the highest averages of the weight of 1000 grain (35.90) gm and the protein percentage in the grain (16.52%) in comparison to the dry seeds which gave the lowest averages .

The seed storage age effected all factors significantly. One-year storage exceeded significantly by giving the highest averages of most characteristics: percentage of emergence (43.91%), plant height (159.59) cm, leaf area (5308 cm²), panicle weight (12.83)tan h^-1, and grain yield (10.86)tan h^-1; whereas two-year storage exceeded in the number of tillers (1.067) tiller plant^-1, and protein percentage in the grain (15.28%) as compared to the dry seeds which gave the lowest averages.

The findings of the study showed a significant effect in the interaction between seed priming and seed storage periods on most of the studied characteristics. It can be concluded, thus, that seed enhancement with Gibberellic acid, generally, resulted in an increase in the percentage of standard laboratory germination and field emergence of all seed ages, and improving the characteristics of seedling and growth, therefore, increasing grain yield by increasing its components.