الفهرس 
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Abstract
This study was carried out during the two growing seasons 2020/2021 and 2021/2022, at the Agronomy Experimental Farm, Faculty of Agriculture, Assiut University, to study the response of faba bean seed yield and its components to foliar spray by some growth regulators. The soil structure of the experimental site is clay, comprising 42.60% clay, 30.40% silt, and 27% sand, with a pH of 8.02 and EC 0.74 dsm -1. This experiment consists of two factors, i.e.
1. Foliar application with growth regulators (salicylic acid, Indole acetic acid, and gibberellic acid) at 200 ppm in addition to control (distilled water was used as a solvent).
2. Number of application times:
i. One time at 30 days after sowing (DAS).
ii. Two times at 30 and 60 (DAS), respectively.
iii. Three times at 30, 60, and 90 (DAS), respectively.
The experiment was carried out in randomized complete block design (RCBD) with three replications utilizing a strip plot configuration. Foliar applications were organized vertically, but application numbers were assigned horizontally. Faba bean cultivar Giza 843 was sowed on October 20th and 25th of each growing season. The experimental unit area was 10.5 m2 and was made up of 6 rows 3 m long and 60 cm apart, with plant-to-plant (on the row) intervals of 25 cm. At the time of planting, two or three seeds were dribbled into each hill to promote better emergence and a uniform stand of plants. To eliminate weeds from the experimental plots, hoeing was done twice during the growing season. Maize was the preceding summer crop in both seasons. All other suggested faba bean crop cultural techniques were carried out in both seasons. All foliar sprays were carried out after daybreak using a 5-liter pressure garden sprayer at a rate of 200 liters/fed.
Measurement traits:
At harvest, the average number of pods per plant, 100-seed weight (g), and seed weight plant -1 (g) were calculated for ten guarded plants that were randomly selected from the middle rows of each experimental unit. Each experimental unit’s whole plant population was also collected, air-dried, and threshed before being weighed and converted to a seed yield measurement in kilograms (kg).
The result obtained from this study could be summarized as follows:
1- Plant height in cm
The faba bean plants exposed to gibberellic acid at a rate of 200 ppm outperformed other spray treatments using other growth regulators and obtained the highest mean values in this regard. Furthermore, growth regulator application timing had a highly substantial impact on the faba bean plant height throughout the course of the two growing seasons. The highest average values of the plant height were obtained by applying growth regulators three times at 30, 60, and 90 days after sowing (DAS). Regarding the interaction effect in this regard, there were highly significant differences in the plant height trait were significant at the 1% level of probability.
2- Number of branches per plant
The number of branches per plant of the faba bean was significantly affected by the growth regulators that were evaluated. According to data, growth regulator application time treatments had a highly substantial impact on the faba bean plant-1 number of branches per plant throughout the course of the two growing seasons. Regarding the interaction effect in this regard, only the first season’s differences in the number of branches per plant plant-1 were significant at the 5% level of probability.
3-Number of pods plant-1:
The tested growth regulators significantly affected the quantity of faba bean pods on plant-1 throughout the course of two growing seasons. In this way, the faba bean plants that were sprayed with salicylic acid (SA) at a rate of 200 ppm outperformed the other spray treatments with other growth regulators and obtained the highest mean values in this regard. Additionally, the quantity of pods produced by faba bean plants throughout the two growing seasons was significantly influenced by the growth regulators’ application times. Growth regulators applied three times at 30, 60, and 90 days after sowing (DAS) produced the highest mean values number of pods per plant. Here again, the number of pods plant-1 in both seasons was significantly impacted by the interplay between growth regulators and treatment periods. Thus, in the first season, faba bean plants sprayed with salicylic acid three times at 30, 60, and 90 DAS, followed by plants sprayed with gibberellic acid three times at 30, 60, and 90 DAS, recorded the highest average values of pods number plant-1, with no discernible difference between them.
4- Seeds number per pod
Seeds number per pod weight plant-1 of the faba bean was significantly affected by the growth regulators that were evaluated. The largest mean values in this regard were found in faba bean plants that were sprayed with salicylic acid or gibberellic acid in both seasons. Growth regulator application time treatments had a highly substantial impact on the faba bean plant-1 seed weight throughout the course of the two growing seasons. Regarding the interaction effect in this regard, only the first or season’s differences in the seed weight plant-1 were significant at the 5% or 1% level of probability.
5- Seeds weight per pod in gm
The tested growth regulators significantly affected the quantity of seeds weight per pod in gm of faba bean pods on plant-1 throughout the course of two growing seasons. In this way, the faba bean plants that were sprayed with salicylic acid (SA) at a rate of 200 ppm outperformed the other spray treatments with other growth regulators and obtained the highest mean values in this regard. Additionally, the seed weight per pod in gm by faba bean plants throughout the two growing seasons was significantly influenced by the growth regulators’ application times. Growth regulators applied three times at 30, 60, and 90 days after sowing (DAS) produced the highest mean seed weight per pod in gm in the first and second seasons, respectively. Here again, the number of pods plant-1 in both seasons was significantly impacted by the interplay between growth regulators and treatment periods. Thus, in the first season, faba bean plants sprayed with salicylic acid three times at 30, 60, and 90 DAS, followed by plants sprayed with gibberellic acid three times at 30, 60, and 90 DAS, recorded the highest average values of seed weight per pod in gm.
6- Seed index (g):
Growth regulators significantly affected the weight of 100 faba bean seeds over the course of two growing seasons. As a result, the faba bean plants exposed to gibberellic acid at a rate of 200 ppm outperformed other spray treatments using other growth regulators. They obtained the highest mean values in this regard, with no discernible differences between gibberellic acid and salicylic acid in the second season. Furthermore, growth regulator application timing had a highly substantial impact on the faba bean 100 seed weight throughout the course of the two growing seasons. The highest average values of the seed index trait were obtained by applying growth regulators three times at 30, 60, and 90 days after sowing (DAS). In contrast. Regarding the interaction effect in this respect, only the first season’s differences on the seed index trait were highly significant at the 1% level of probability, whereas the interaction between growth regulators and application times was not. Thus, the largest average values of the seed index characteristic were reported in the first season by faba bean plants that received three sprays of gibberellic acid at 30, 60, and 90 DAS.
7- Seeds weight per plant (g)
Seed weight plant-1 of the faba bean was significantly affected by the growth regulators that were evaluated. The largest mean values in this regard were found in faba bean plants that were sprayed with salicylic acid or gibberellic acid in both seasons. As a result, the application of any growth regulators to faba bean plants at a rate of 200 ppm outperformed the control-treated plants. Since the number of plant-1 pods and 100 seed weight characteristics, which were thought to be the key contributors to the seed weight plant-1 trait, showed the same trend, this seems logical. Growth regulator application time treatments had a highly substantial impact on the faba bean plant-1 Plant-1’s seed weight throughout the course of the two growing seasons. The highest average seed weight plant-1 values were obtained by applying growth regulators three times at 30, 60, and 90 days after sowing (DAS).
In contrast, the lowest mean values in this regard were obtained by applying growth regulators only once at 30 DAS (39.71 and 38.30 g in the two corresponding seasons). Regarding the interaction effect in this regard, the data show that only the first season’s differences in the seed weight plant-1 were highly significant (P≤ 0.01), whereas the interactions between growth regulators and application times were not. As a result, in the first season, faba bean plants treated with three applications of gibberellic acid at 30, 60, and 90 DAS recorded the highest average values of seed weight plant-1 (52.92 g), with no discernible difference between those treated with three applications of salicylic acid (52.47 g).
8- Biological yield feddan-1 (kg).
The average biological yield of feddan-1 reacted highly significantly to the growth regulators in the two growing seasons. Growth regulators significantly affected the biological yield feddan-1 of faba bean over the course of two growing seasons. As a result, the faba bean plants exposed to Salicylic acid at a rate of 200 ppm outperformed other spray treatments using other growth regulators. They obtained the highest mean values in this regard (3150.39 and 3359.28 kg per feddan in the two different seasons). The highest average values of the biological yield feddan-1 were obtained by applying growth regulators three times at 30, 60, and 90 days after sowing (2851.42 and 2987.79 kg in the two respective seasons). In contrast, the lowest mean values in this regard were obtained by applying growth regulators only once at 30 DAS (2534.88 and 2579.79 kg per feddan in the two respective seasons). Regarding the interaction effect in this respect, Data illustrated there were no significant differences in biological yield feddan-1 in the two respective seasons.
9- Seed yield feddan-1 (kg).
The tested growth regulators had a highly significant effect (P≤ 0.01) on seed yield feddan-1 of faba bean in the two growing seasons. Thus, the application of any growth regulators to faba bean plants at the rate of 200 ppm surpassed the control-treated plants. Furthermore, the maximum mean values of seed yield faddan-1 were detected from faba bean plants, which were sprayed with gibberellic or salicylic acid in both seasons. The application timing of growth regulators had a highly substantial impact on the faba bean seed yield faddan-1 in the two growing seasons. The greatest average values of faddan-1 trait seed yield were obtained by applying growth regulators three times at 30, 60, and 90 days after sowing (DAS) (1365.64 and 1373.87 kg in the first and second seasons, respectively). Otherwise, growth regulators were sprayed once at 30 DAS, which resulted in the lowest mean values of seed yield faddan-1 (1191.22 and 1119.15 kg for the two corresponding seasons). This makes sense because the seed yield plant-1 characteristic showed a similar pattern. Regarding the interaction effect between growth regulators*Spray numbers were significant in the 1st season, whereas the interaction between growth regulators and application times was not. Therefore, in the first season, faba bean plants that received three applications of gibberellic acid at 30, 60, and 90 DAS recorded the highest average values of seed yield feddan-1 trait (1587.59 kg), with no discernible difference from faba bean plants that received three applications of salicylic acid (1574.10 kg) per feddan.
On the other hand, the control treatment (without growth regulators) had the lowest seed yield mean value (961.31k g in the first season) when faba bean plants were sprayed with distilled water. Given that the same interaction and similar trend were seen in relation to seed weight plant-1, this is to be expected.
10- Protein percentage (%)
Both spray numbers and growth regulators’ main effects failed to achieve any significant effect on protein percentage in both growing seasons. On the other hand, the interaction between growth regulators × spray numbers achieved a significant effect in the 1st season. The highest values of protein percentages were obtained from spraying with gibberellic acid twice on faba bean plants (26.65%), while the effect of the interaction was highly significant in the second year, and the highest protein percentage was obtained from the same treatment as well as in the first year, and this percentage was 26.66% superior to the rest the treatments.