Medicinal Plants
Seyyed Amir Hossein Mousavi; F. Nekounam; Taher Barzegar; Zahra Ghahremani; Jafar Nikbakht
Abstract
Introduction
Physalis peruviana L. is a short perennial shrub that is a member of the Solanaceae family. These fruits have many benefits for human health because of their nutritional and bioactive compounds (vitamins (A, B, C and K), essential fats and etc.) and reduced the risk of diseases such as ...
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Introduction
Physalis peruviana L. is a short perennial shrub that is a member of the Solanaceae family. These fruits have many benefits for human health because of their nutritional and bioactive compounds (vitamins (A, B, C and K), essential fats and etc.) and reduced the risk of diseases such as cancer, malaria, asthma, hepatitis, dermatitis and rheumatism. Therefore, it has received special attention for cultivation all over the world. Increasing crop production and mitigating abiotic stresses are major challenges under extreme climatic environments and intense farming activities. Crop management strategies such as deficit irrigation can decrease soil evaporation, runoff, and plant transpiration, and increase water use efficiency (WUE) and water conservation. In addition to these practices, organic input, which includes the application of organic materials such as compost and humic substances, is an additional strategy that increases soil water retention and can potentially improve plant WUE. Water is crucial for agriculture and needs to be used effectively due to climate change and drought in Iran. For this reason, to adapt to water deficit scenarios, deficit irrigation applications are increasing in importance. Water availability is expected to be a growth limiting factor that would affect fruit yield in Physalis peruviana due to reduced flower set and elevated floral abscission rate.
Materials and Methods
In order to investigate the effect of humic acid on physiological characteristics, yield and fruit quality of Physalis peruviana under deficit irrigation conditions, a split plot experiment based on randomized complete block design with three replications was conducted during 2021. Treatments consisted arrangement of three levels of irrigation (starting irrigation at 100, 80 and 60% ETc (crop evapotranspiration)) and three levels of humic acid (0, 1.5 and 3 kg ha-1). The seeds of Physalis peruviana were sown in seedling trays contain peat moss. The seedlings were grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). Plant height, total chlorophyll, fruit yield per plant, total soluble solid content, titratable acidity, vitamin C content and water use efficiency were measured. Statistical analyses were performed with SAS V9.3, and means comparison were separated by Duncan’s multiple range tests at p < 0.05.
Results and Discussion
The results showed that deficit irrigation significantly reduced growth, fruit yield, vitamin C and increased water use efficiency (WUE) and Total soluble solid content of Physalis peruviana. The soil application of humic acid significantly increased total chlorophyll, fruit quality and yield, and decreased leaf electrolyte leakage under normal and deficit irrigation, thus, the deficit irrigation 60 ETc% decreased the plant height by 18.6% and the fruit yield by 22.2% compared to irrigation 100 ETc%. The maximum plant length (200.3 cm), total chlorophyll content (2.42 mg g-1FW) and fruit yield (4793.3 kg ha-1) were observed in plants treated with 3 kg ha-1 humic acid under 100% ETc irrigation. The highest value of total soluble solid (12.6 B°), antioxidant activity (90.06 %) and WUE (1.23 kg m-3) were obtained with 3 kg ha-1 soil application of humic acid under deficit irrigation 60% ETc. The application of 3 kg ha-1 humic acid under 100 and 80 %ETc irrigation increased the fruit yield by 25% and 4%, respectively, compared to the control plants (non treated with humic acid) under irrigation100 ETc% and under deficit irrigation 60 ETc%, with decreasing 11% fruit yield, water consumption was saved by 40%. Soil and crop management practices that alter plant water and nutrient availability could affect the processes of crop evapotranspiration and WUE, which can influence the yield and fruit quality by changing the internal nutrient and water balance. Incorporating organic matter within a crop growth system either as leaf spray or soil mix is a complementary strategy to improve crop growth and WUE. By inducing antioxidant enzyme activities, HS could assist plants in stomata functioning, thereby closing stomata more efficiently under drought stress, which results in plant water conservation. The reason of the difference between WUE values probably appeared due to the differences on Physalis peruviana yield. WUE showed an upward trend with an increasing in irrigation.
Conclusion
Study results suggest that soil application of humic acid with increasing vitamin C, TSS and TA, improved fruit quality. According to the results, application of 3 kg ha-1 humic acid is suggested to improve fruit yield and quality of Physalis peruviana under normal and deficit irrigation conditions.
Growing vegetables
Moslem Ghoreyshi; Fatemeh Nekounam; Taher Barzegar; Jafar Nikbakht
Abstract
Introduction
Water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. Deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. Growth and development ...
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Introduction
Water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. Deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. Growth and development of plants is influenced by reduction in turgor that results in decreased nutrient acquisition from dry soil. When water supply is limited, plant growth and yield is reduced and plant structure is modified by decreasing in leaf size. The effect of deficit irrigation on fruit yield and quality has been reported by numerous researchers with different results. In melon, deficit irrigation reduced marketable fruit number and yield, average fruit weight, fruit diameter and did not affect rind thickness and seed cavity, but increased total soluble solids content. Although the effects of water stress have been studied on growth and yield of different crops during the last years, recent information on the response of African horned cucumber yield and quality to deficit irrigation remains limited, particularly about the results of restricted water distributions in arid and sub-arid environments. The main goal of this study was to evaluate the effect of controlled deficit irrigation on growth, physiological parameters and yield and fruit quality of African horned cucumber.
Material and Methods
Field experiment was performed based on a completely randomized block design with three irrigation regimes (60, 80 and 100 %ETc), whit three replications at Research Farm of University of Zanjan during the 2019. The African horned cucumber seeds were sown on 1th July 2020 at recommended spacing of 50 cm in row with 120 cm between rows. The irrigation system consisted of one drip line every crop row. The three irrigation levels were calculated based on actual evapotranspiration (ETc): (1) control, irrigated 100% crop water requirement, (2) deficit irrigation 80% ETc and (3) deficit irrigation 60% ETc. The Water requirement of the plant for control treatment was estimated using long-term average daily data of meteorological parameters recorded at Zanjan Meteorological Station and following relation. Before starting the differential irrigation at five-leaf stage, all treatments were supplied with similar amount of water to maximize stands and uniform crop establishment. During plant growth, the relative water content, proline content, electrolyte leakage, chlorophyll and carotenoids, P and K contents were measured. After fruit harvest, vine length of each plant, leaf dry weight and stem diameter were measured. The fruits were harvested when color changed from green to yellow. Fruit weight, fruit number per plant and fruit yield per plant was measured. Immediately after harvest, fruit firmness, total soluble solid, total phenols content, antioxidant capacity and vitamin C were determined.
Results and Discussion
As the results showed water deficit stress significantly reduced plant length, chlorophyll content, and increased carotenoids content. Based on the findings, deficit irrigation caused a significant reduction in leaf relative water content. According to the results, phosphorus and potassium contents in African horned cucumber leaves decreased with deficit irrigation treatments. The highest P and K contents were found under irrigation 100 %ETc treatment. Drought stress and associated reduction in soil moisture can decrease plant nutrient uptake by reducing nutrient supply through mineralization. The proline content increased with the deficit irrigation treatments; in particular with sever deficit irrigation (60 %ETc). Mean comparisons of data showed that deficit irrigation led to a significant increase in electrolyte leakage compared to control.
Water deficit stress caused significant reductions in yield. The highest fruit number per plant and yield were obtained under irrigation 100% ETc. The average fruit weigh significantly increased in response to increase water deficit stress. Deficit irrigation treatments significantly decreased vitamin C and fruit firmness. Significant differences among irrigation treatments were observed for total phenols and total soluble solid contents. The phenols and total soluble solid contents increased with the decrease of irrigation water applied. Antioxidant capacity was affected significantly by the irrigation treatments, and water deficit stress increased antioxidant capacity, which no significant difference was observed between irrigation 100 and 80 %ETc.
Conclusion
Water deficit has been shown to adversely affect plant growth, fruit yield, and leaf water status of African horned cucumber, but led to increase the TSS and antioxidant capacity. According to the results, fruit yield reduced 13.9 % under irrigation 80% ETc compared to irrigation 100% ETc, However, water consumption was saved by 20% and improved fruit weight and fruit quality with increasing soluble solids and antioxidant capacity.
