The present study aimed to investigate the impact of salinity on vegetative growth, chemical constituents, and yields of cowpeas (Vigna unguiculata) and the possible benefits of salicylic acid (SA) on these plants after damage from salinity. To achieve these objectives, two pot experiments were carried out at the Faculty of Agriculture, Al-Azhar University, Egypt, during the two growing seasons of 2019 and 2020. The results revealed that salinity significantly decreased, and SA treatment substantially increased the plant height, number of compound leaves, number of internodes per plant, fresh weights of leaves and stems, productivity, photosynthetic pigments content, and concentrations of nitrogen (N), phosphorus (P), and potassium (K) of the cowpea plants compared with the control. The anatomical structure of stems and leaves of the plants were also investigated, and it was found that positive variations in the anatomical structure of the median portion of the main stems and blades of mature foliage leaves were detected in the stressed and SA-treated plants. In conclusion, SA treatment increased the salt stress tolerance of cowpea plants by improving the morphological and physiological attributes of the plants.

Drought stress has become more common in recent years as a result of climate change impacts on the production of banana crops and other fruit trees. The growth and productivity of Musa spp are severely impacted by the gradual degradation of water resources and the erratic distribution pattern of annual precipitation amount. The aim of the work includes increased drought tolerance in light of water scarcity in the world as a result of the bananas’ being gluttonous for water needs. This investigation was carried out from 2019 to 2020 to study the effect of potassium silicate on morphological growth and biochemical parameters of Musa acuminata L under drought stress by PEG. As a result, drought stress reduced the morphological characteristics such as shoots number, shoot length, roots number, and survival percentage and biochemical characteristics such as chlorophyll a, b, carotenoids, stomatal status, and RWC. While proline content increased in the leaf of M. acuminata L. Media complemented with K2SiO3 (2 to 6 mM) either individually or in combination with PEG led to an improvement in all morphological and biochemical characteristics. The activities of CAT, POD, and PPO enzymes increased signifi- cantly compared to control. Furthermore, the lowest PPO, CAT, and POD activity were achieved. Additionally, K2SiO3 treatments under drought stress successfully enhanced the leaf stomatal behavior. Our results suggest that K2SiO3 can help to maintain plant integrity in the tested cultivar under drought stress.

The investigation focused on the impacts of specific nutrients as calcium chloride (CaCl2) at 0.4 and 0.6%, zinc sulfate (ZnSO4) at 0.4 and 0.5% and boric acid (B(OH)3) at 50 and100 ppm one and two sprays on delay senescence of leaves and fruit quality of guava yield in eleven years old guava at the Qalyub area, Qalyubeia Governorate, Egypt, under randomized block design with factorial approach.‎ It was discovered in this study that there had been considerable improvements in the foliar application of CaCl2, ZnSO4 and B(OH)3 on physiological and biochemical characteristics in leaves led to an increasing in the pigments of photosynthesis, proline (Pro), total sugars content (TSC), total phenolic content (TPC) and NPK contents and a decreasing in anthocyanin (ACY), poly-phenol oxidase (PPO) and peroxidase (POD) activity which reflected positively on the quality of guava fruits and led to an increase in firmness and total soluble solids (TSS) and decrease in respiration coefficient compared with the control. . In all, the single spray was better compared to the two sprays, although the two sprays were distinguished in some cases from the single spray.

The Cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an important insect pest that attacks many economically important plants. The present study monitored the population dynamics of cotton mealybugs P. solenopsis on eggplant, okra, cotton and molokheya plants by conducting weekly sampling during 2022 and 2023 seasons. The results indicated that nymphs and adults of P. solenopsis attacked eggplants more than the other three host plants. The mealybug population was showing significant effect with max. temperature and predatory insects on eggplant during 2022 season. In 2023, a significant positive correlation was found with R.H, (r =0.551) and predators (r =0.811) with an Explained Variance (EV) of 44.5 % in 1st season and 68% in 2nd season. For okra plants, P. solenopsis showed significant positive correlation with R.H and predators. The highest infestation of P. solenopsis on eggplant plant was associated with highest total protein (18.73 mg/100 mg FW) and total carbohydrates (40.53mg/100mg FW). Whereas, the least infestation on cotton and molokheya plants was associated with least total protein 6.40 and 8.62 mg/100 mg FW respectively. The data included in this study lead to decide suitable management practices during effective period for P. solenopsis on the four tested host plants.