Soil and Plant Interactions

fa اثر کم‌آبیاری و خاک‌پوش بر رشد، عملکرد و کیفیت میوه گیاه هندوانه The Effect of Deficit Irrigation and Mulching on The Growth, Yield and Fruit Quality of Watermelon روابط آب و گیاه Plant water relations پژوهشي Research این پژوهش با هدف بررسی اثر کم‌آبیاری و خاک‌پوش بر گیاه هندوانه با آزمایش مقدماتی به‌صورت کرت‌های خرد‌شده بر پایه طرح بلوک‌های کامل تصادفی با سه تکرار، در مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی جنوب استان کرمان، در سال 1401-1400 انجام شد. کرت اصلی، آبیاری قطره‌ای با سه سطح 100، 70 و 50 درصد نیاز آبی و کرت فرعی، خاک‌پوش با سه سطح برگ خردشده خرما، پلاستیک سیاه و بدون خاک‌پوش (شاهد) در نظر گرفته شد. بر اساس نتایج، آثار ساده و برهم‌کنش تیمارها بر طول ساقه، سطح برگ، عملکرد، بهره‌وری آب، محتوای آب نسبی، رنگیزه‌های فتوسنتزی، پرولین، فنول کل، آنزیم سوپراکسید دیسموتاز برگ و طول و عرض میوه و آثار ساده آبیاری و خاک‌پوش بر طول میان‌گره، پایداری غشاء و ویتامین ث، اثر ساده آبیاری بر درصد ماده خشک میوه، انشعابات ساقه و اثر ساده خاک‌پوش بر شکل میوه و مواد جامد محلول معنی‌دار شد. مقادیر pH و اسید کل، مزه و لیکوپن میوه تحت تأثیر تیمارها قرار نگرفت. بیش‌ترین عملکرد (ton/haو60/1) با آبیاری کامل و خاک‌پوش پلاستیک، و بیش‌ترین بهره‌وری آب (kg/m3و15/1) با آبیاری 70 درصد و خاک‌پوش پلاستیک، بدون تفاوت معنی‌دار با آبیاری کامل و خاک‌پوش‌های پلاستیک و برگ خرما حاصل شد. یافته‌ها نشان داد اثربخشی خاک‌پوش پلاستیک با آبیاری کامل و 70 درصد در مقایسه با آبیاری 50 درصد بر رشد و عملکرد بیش‌تر بود. خاک‌پوش برگ خرما با وجود برتری نسبت به شاهد در آبیاری کامل، به‌علت داشتن غلظت زیاد سدیم (mg/kgو1800) در سطوح کم‌آبیاری آثار مثبت ناچیزی داشت. Abstract This study with the aim of determining the effect of deficit irrigation and mulching on watermelon was conducted with a preliminary experiment in the form of split plots and a design of complete randomized blocks with three replications, in the Research and Education Center of Agriculture and Natural Resources in the south of Kerman province (Jiroft), in 2021‒2022. Drip irrigation as the main plot at three levels of 100, 70 and 50% of water requirement and mulching in three levels of crushed date palm leaf, black plastic and no mulch, as the sub-plot, were considered. As results demonstrate, the main and interaction effects of the treatments on stem length, leaf area, yield, water productivity, leaf relative water content, photosynthetic pigments, proline, total phenol, leaf superoxide dismutase enzyme and fruit length and width were significant. The main effects of irrigation and mulching on internode length, membrane stability index and vitamin C, and the main effect of the irrigation on the percentage of fruit dry matter, stem branches, and the main effect of mulching on fruit shape and soluble solids were significant. Fruit pH and total acidity, tasting and lycopene were not significantly affected by the treatments. The highest yield (60.1 ton/ha) was observed in the full irrigation and plastic mulch, and the highest water productivity (15.1 kg/m3) was recorded in the 70% irrigation and plastic mulch, but no significant difference with full irrigation and plastic and date palm leaves mulches. The findings showed that the effectiveness of plastic mulch on the watermelon growth and yield was higher with 100% and 70% irrigation compared to 50% irrigation. The date palm leaf mulch, despite being superior to the control in the full irrigation, had insignificant positive effects in deficit irrigation levels due to its high sodium content (1800 mg/kg). Background and Objective: Deficit irrigation has been mentioned as one of the effective techniques for increasing the water productivity of plants. Deficit irrigation of 50% caused a decrease in yield and water productivity of watermelon in Valencia region of Spain (Abdelkhalik et al., 2019). The role of mulching in compensating the negative effects of deficit irrigation has been confirmed in the literature (Diaz-Perez, 2023). This research aims at investigating the effects of deficit irrigation and mulching on the growth, yield and fruit quality of watermelon and the possibility of replacing plastic mulch with date palm leaf mulch. Methods: Irrigation as the main plot at three levels of 100, 70 and 50% of water requirement and mulching at three levels of crushed date palm leaf, black plastic and no mulch, as the sub-plot, were considered. Crimson B 34 watermelon seeds produced by Seminis company, were planted on January 2021, in plots with the size of 13.5 × 7 m, on furrows and ridges planting system (the width of furrows and ridges were 0.5 and 4 meters, respectively). After planting, bow-shaped wires were put on the planting rows and a transparent plastic was placed as a tunnel on them. Results: Analysis of variance of the plant growth, yield, water productivity, and some physiological and biological traits displayed that the main and interaction effects of treatments were significant. Some traits such as pH, titratable acidity, fruit taste and shape were not affected by the treatments. The main and interaction effects of the treatments on stem length, leaf area, yield, water productivity, leaf relative water content, photosynthetic pigments, proline, total phenol, leaf superoxide dismutase enzyme and fruit length and width were significant. The main effects of irrigation and mulching on internode length, membrane stability index and vitamin C, and the main effect of the irrigation on the percentage of fruit dry matter, stem branches, and the main effect of mulching on fruit shape and soluble solids were significant. Fruit pH and total acidity, tasting and lycopene were not significantly affected by the treatments. The highest yield (60.1 ton/ha) was observed in the full irrigation and plastic mulch, and the highest water productivity (15.1 kg/m3) was recorded in the 70% irrigation and plastic mulch, but no significant difference with full irrigation and plastic and date palm leaves mulches was obtained. Reducing the irrigation water from 100 to 70 and to 50% of crop evapotranspiration or ETc (estimated by the FAO-Penman-Monteith method) in all three types of the mulch led to a significant decreasing in yield (Y), which was caused by the occurrence of water stress. The first reduction in water use (i.e., from 100 to 70%) increased the water productivity (WP) even though not significantly, but the second reduction in water use (i.e., from 70 to 50%) significantly led to a decrease in WP. Conclusions: Overall, the 100%ETc treatment with black plastic mulch will probably have the best result in terms of watermelon yield unless water shortage, water price, and irrigation cost are noticeable compared to the crop price. In this case, 70%ETc irrigation with black plastic will be a priority in terms of WP. Of course, the cost of mulching and its possible environmental consequences should be considered. References: 1. Abdelkhalik, A., Pascual-Seva, N., Najera, I., Giner, A., Baixauli, C., Pascual, B., 2019. Yield response of seedless watermelon to different drip irrigation strategies under Mediterranean conditions. Agric. Water Manage. 212, 99–110. 2. Diaz-Perez, J.C., 2023. Plant growth and fruit yield of watermelon as influenced by colored plastic film mulch. Int. J. Veg. Sci. 29(1), 84–92. آبیاری, برگ خرما, بهره‌وری آب, تبخیر و تعرق. Date palm leaf, Evapotranspiration, Irrigation, Water productivity. 31 48 http://jspi.iut.ac.ir/browse.php?a_code=A-10-1572-1&slc_lang=fa&sid=1 N. Bahremand نادیا بهره‌مند bahremandnadia@gmail.com https://orcid.org/0009-0006-0062-7227 No Department of Horticultural Science and Landscape Architecture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. گروه علوم باغبانی و مهندسی فضای سبز، دانشکده کشاورزی، دانشگاه فردوسی مشهد H. Aroiee حسین آروئی aroiee@um.ac.ir https://orcid.org/0000000254938200 Yes Department of Horticultural Science and Landscape Architecture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. گروه علوم باغبانی و مهندسی فضای سبز، دانشکده کشاورزی، دانشگاه فردوسی مشهد A. Aien احمد آئین aien1348@yahoo.com https://orcid.org/0000000186117012 No Research Department of Agricultural and Horticultural Sciences, Research and Education Center of Agriculture and Natural Resources in The South of Kerman Province, Jiroft, Iran. گروه تحقیقات علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی جنوب استان کرمان