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Background. Organic agriculture has grown rapidly in recent years due to its environmental friendliness, sustainability, and improved farm profitability. Transplants are commonly used for fruits and vegetables to achieve consistent quality, uniformity, and easy field spacing control. The efficacy and optimal amounts of fertilizers for organic transplant production need to be investigated. Methods. The effects of three organic fertilizers (Sustane 4-6-4, Nature Safe 7-7-7, and Dramatic 2-4-1) and one conventional fertilizer Peters Professional 20-20-20 (Conventional) with four doses (nitrogen (N) content was matched among fertilizers in each level, as 0.14 g/L, 0.28 g/L, 0.56 g/L, and 0.84 g/L N, respectively) on watermelon seedlings were compared in this study. Results. The results showed that all organic fertilizer treatments were not significantly different from the Conventional group in terms of watermelon germination. The only exception was the highest dose of Sustane 4-6-4 (0.84 g/L N) which decreased the germination rate and relative emergence index. Generally, growth index, shoot fresh and dry weights, true leaf number, and stem diameter increased as the amount of N increased within each fertilizer type. The best shoot growth was observed in the highest doses of Conventional and Dramatic 2-4-1 treatments (0.84 g/L N). However, Dramatic 2-4-1 treatments resulted in the lowest root growth when compared to other fertilizers at the same N dose. The second highest fertilization dose (0.56 g/L N) of Sustane 4-6-4 had the best root growth according to root fresh weight, root volume, root area, total root length, as well as the numbers of root tip and crossing when compared to other treatments. For seedlings, a well-developed root system can ensure a good seedling establishment and high survival rate under stressful field conditions after transplanting. Thus, Sustane 4-6-4 at 14 g/L (0.56 g/L N) is recommended to produce high-quality organic watermelon seedlings among the treatments applied in this study. [ABSTRACT FROM AUTHOR]

Background: Organic agriculture has grown rapidly in recent years due to its environmental friendliness, sustainability, and improved farm profitability. Transplants are commonly used for fruits and vegetables to achieve consistent quality, uniformity, and easy field spacing control. The efficacy and optimal amounts of fertilizers for organic transplant production need to be investigated., Methods: The effects of three organic fertilizers (Sustane 4-6-4, Nature Safe 7-7-7, and Dramatic 2-4-1) and one conventional fertilizer Peters Professional 20-20-20 (Conventional) with four doses (nitrogen (N) content was matched among fertilizers in each level, as 0.14 g/L, 0.28 g/L, 0.56 g/L, and 0.84 g/L N, respectively) on watermelon seedlings were compared in this study., Results: The results showed that all organic fertilizer treatments were not significantly different from the Conventional group in terms of watermelon germination. The only exception was the highest dose of Sustane 4-6-4 (0.84 g/L N) which decreased the germination rate and relative emergence index. Generally, growth index, shoot fresh and dry weights, true leaf number, and stem diameter increased as the amount of N increased within each fertilizer type. The best shoot growth was observed in the highest doses of Conventional and Dramatic 2-4-1 treatments (0.84 g/L N). However, Dramatic 2-4-1 treatments resulted in the lowest root growth when compared to other fertilizers at the same N dose. The second highest fertilization dose (0.56 g/L N) of Sustane 4-6-4 had the best root growth according to root fresh weight, root volume, root area, total root length, as well as the numbers of root tip and crossing when compared to other treatments. For seedlings, a well-developed root system can ensure a good seedling establishment and high survival rate under stressful field conditions after transplanting. Thus, Sustane 4-6-4 at 14 g/L (0.56 g/L N) is recommended to produce high-quality organic watermelon seedlings among the treatments applied in this study., Competing Interests: Qianwen Zhang is an Academic Editor for PeerJ., (©2024 Zhang et al.)

به منظور بررسی اثر سطوح مختلف شوری بر عملکرد و اجزای عملکرد، خصوصیات مورفولوژیک و تغییرات عدد کلروفیل متر برگ گیاه کنجد، تحقیقی در گلخانة تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد به‌صورت آزمایش فاکتوریل بر پایه طرح کاملاً تصادفی با 3 تکرار به اجرا درآمد. تیمارهای آزمایش شامل ترکیبی از پنج سطح مختلف شوری (2/4، 4/4، 6/4، 8/4 و 10/4 دسی‌زیمنس‌برمتر) و چهار ژنوتیپ کنجد (جیرفت، دزفول، مغان و برازجان) بود. نتایج نشان داد که شوری اثر معنی­ داری بر خصوصیات مرفولوژیک و محتوی کلروفیل برگ داشت. خصوصیات مرفولوژیک همچنین تفاوت معنی­ داری را در بین ژنوتیپ­ های کنجد نشان دادند. تنش شوری باعث کاهش معنی داری در میزان دانه و اجزای عملکرد تک بوته، وزن کل، ارتفاع، نسبت وزن خشک ریشه به اندام هوائی گیاه گردید. کمترین مقدار دانه در بوته در سطح شوری 4/10 دسی زیمنس بر متر مشاهده شد. عدد کلروفیل متر نیز متأثر ازتنش شوری بوده و با افزایش شوری تا سطح 6/4 دسی‌زیمنس‌برمتر، افزایش عدد کلروفیل مترمشاهده گردید، البته با افزایش سن، از مقدارکلروفیل برگ و درنتیجه عدد کلروفیل‌متر قرائت شده کاسته شد. نتایج نشان داد که در غلظت‌های بالای نمک، نسبت وزن خشک ریشه به اندام هوائی در ژنوتیپ مغان از سایر ژنوتیپ‌ها بالاتر بود. با افزایش شوری، میزان افزایش عددکلروفیل‌متر ژنوتیپ‌ مغان بسیار بیشتر از سایر ژنوتیپ‌ها بوده و افزایش مقدار شوری در این ژنوتیپ کمترین تغییرات در وزن دانه تک بوته و اجزای عملکرد را نشان داد. بنابراین به نظرمی‌رسد که در میان ژنوتیپ‌های مورد بررسی، ژنوتیپ مغان می‌تواند به عنوان ژنوتیپ مقاوم به شوری مورد بررسی میدانی قرار گیرد.

Studies on root and shoot morphology, endogenous hormones and water use efficiency in five grape rootstocks namely Dogridge, 1613 C, Salt Creek, St. George and Vitis champinii clone (VC Clone) at three levels of moisture stress viz., no stress (100% irrigation), 50% stress (50% irrigation) and 100% stress (without irrigation) for 14 days revealed that Dogridge and Salt Creek rootstocks maintained the highest ratios of root to shoot length and root to shoot dry weight as compared to other rootstocks. Water use efficiency increased with increased soil moisture stress and was the highest in Dogridge and Salt Creek. The abscisic acid content in the leaves of Dogridge was maximum at 50% stress followed by that of Salt Creek. Similarly the cytokinin content (both t-ZR and DHZR) was minimum in Dogridge and Salt Creek at 50% stress while it was maximum in 1613 C and St.George. The root to shoot length ratio was positively correlated with ABA content under moisture stress conditions. The higher levels of abscisic acid content in Dogridge and Salt Creek under soil moisture stress suggested their better drought tolerance capacity through a reduction of stomatal conductance and increased water use efficiency.