In this study, the effects of the extracts obtained from flower, stem, leaf, branch and their mixture of Nerium oleander L. on the seed germination and seedling growth of four Pistacia species (Pistacia terebinthus L., P. vera L., P. khinjuk Stocks., P. atlantica Desf. and P. terebinthus L.) were investigated. Five hundred grams of N. oleander was taken from the plant parts and the extracts were mixed with distilled water (1.5 L). The extracts were applied to Pistacia species for 24 and 48 hours. The results showed that the extract had positive effects on their germination and growths of the species mentioned above. The highest germination rate for all the Pistacia species was obtained from the extracts of flower, while the lowest germination rate was recorded in the mixture of all parts of N. oleander mentioned above. Moreover, the treatment time was found to reduce the germination ratio. It was also found that the extracts from the stem of N. oleander were the most effective on the stem height of the Pistacia species studied. It was followed by the extracts from branches, leaves and flower, respectively. Furthermore, the findings indicated that the extracts from the stem of N. oleander had pronounced effect on the stem diameter of the Pistacia species studied. It was followed by the extracts from flower, leaves, and branches, respectively. In general, the effects of the extracts from several parts of N. oleander on the germination and other growing parameters were found to be almost comparable to those of synthetic promoter, Gibberellic Acid (GA3).

An efficient plant regeneration protocol was developed from in vitro germinated seeds of Petunia hybrida an ornamentally important plant in the family Solanaceae. Shoot tip and node explants of Petunia hybrida were cultured on MS basal medium supplemented with different concentrations and combinations of Benzyl amino purine (BAP), 1-Naphthaleneacetic acid (NAA), Indole-3-butyric acid (IBA) and Gibberellic acid (GA3). The highest shoot length was obtained from MS medium supplemented with 1 mg/l BAP + 1 mg/l NAA. The highest shoot number (3 shoots/explant) were obtained from MS medium supplemented with 0.6 mg/l BAP + 0.5 mg/l IBA. The isolated shoots were transferred to MS basal medium supplemented with different concentrations of GA3 ranging from 0.05, 0.2, 0.5 and 1 mg/l for shoot elongation. The highest shoot length (5.75 cm) was recorded from the MS medium supplemented with 0.2 mg/l GA3 +0.2 mg/l BAP. Rooting of regenerated shoots were achieved on MS medium supplemented with 0.1-1 mg/1 IBA and NAA. The regenerated shoots with well developed roots were successfully acclimatized and established in pots containing sterilized peat moss and grown under laboratory conditions with 70% survival rates.

Two plant growth regulators: β-NOA (50 and 80 ppm) and GA (200 and 250 ppm) were applied to emasculated flowers at anthesis to set parthenocarpic fruit, while in the control treatment fruit set was achieved by natural pollination. The application of β-NOA found ineffective in setting parthenocarpic guava. No significant differences were observed in the length and diameter of fruit between parthenocarpic and naturally pollinated seeded fruit at different days after anthesis. The mean fruit weight, TSS and ascorbic acid content of parthenocarpic fruit were similar to that of seeded fruit. Significant higher amount of total polyphenol was detected in the seeded fruit than the parthenocarpic fruit. Although 200 ppm GA showed comparatively better response to fruit growth, TSS and ascorbic acid content than 250 ppm GA but not in a statistical level.

The utilization of Nigella sativa L., commonly known as black cumin, in traditional and medicinal practices is well-documented, attributing to its wide-ranging biological activities. Given its significance, this study explores the efficacy of various seed priming treatments (control, distilled water, potassium humate, and gibberellic acid) under laboratory and field conditions to enhance the early growth stages of Nigella sativa L. Priming treatments aimed to improve germination rates, plant height, and other growth parameters, potentially translating into increased agricultural productivity. According to results plant height ranged from 52.38 to 58.91 cm, number of branches between 3.76 and 3.98 (branch plant-1). The number of capsules varied from 4.93 to 6.81 (capsule plant-1),  capsule seed weight was between 0.19 and 0.22 (gram capsule-1 ), and the thousand-seed weight ranged from 2.26 to 2.39 grams. The germination rate ranged from 78% to 93%, germination index 4.22-5.83 and mean germination time was observed from 4.27 to 4.82 days. Our findings reveal significant effects of priming on germination parameters and  plant height, this offering insights into the potential of these treatments to optimize crop growth. However, the transition of these benefits to field conditions, particularly yield-related parameters, appeared limited, suggesting the complex nature of growth enhancement strategies and their implications for agricultural practices.