تاثیر تعدادی از گیاهان پوششی و وجین دستی علف‌های‌هرز بر عملکرد اسفناج (spinacia oleracea l.)

علف های هرز یکی از مهم ترین چالش های تولید سبزیجات برگی مانند اسفناج هستند. بروز مقاومت نسبت به علفکش ها در مزارع اسفناج موجب توجه به استفاده از روش های سازگار با محیط زیست به جهت کنترل علف های هرز شده است. به منظور ارزیابی تیمارهای مدیریت علف های هرز در اسفناج آزمایشی در سال های زراعی 1400-1399 و 1401-1400 در مزرعه تحقیقاتی دانشکده کشاورزی و منابع طبیعی دانشگاه محقق اردبیلی به صورت فاکتوریل بر پایه طرح بلوک های کامل تصادفی با سه تکرار اجرا شد. تیمارهای آزمایشی شامل گیاهان پوششی یولاف زراعی (.avena sativa l)، ترب سفید (raphanus sativus var. longipinnatus)، کشت مخلوط آن ها و شاهد بدون گیاه پوششی و سطوح وجین دستی (وجین و عدم وجین دستی) بود. نتایج جداگانه سال ها نشان داد بیشترین زیست توده گیاهان پوششی (538/83 گرم در متر مربع) از تک کشتی یولاف زراعی حاصل شد. همچنین بیشترین درصد کاهش زیست توده کل، تراکم علف های هرز و  شاخص کارایی کنترل علف‌های هرز در دو مرحله نمونه برداری متعلق به تک کشتی یولاف زراعی (57/21 و 53/69درصد) و وجین دستی علف‌های‌هرز (55/06 و 51/47) بود. بیشترین شاخص های شانون وینر، سیمپسون از شاهد و تک کشتی ترب سفید (0/47، 0/79) و کمترین این شاخص ها (0/46، 0/75 و 0/76) از تک کشتی یولاف زراعی و کشت مخلوط حاصل شد. بیشترین عملکرد اسفناج ریز و عملکرد نهایی در دو مرحله از نمونه برداری در دو سال زراعی از تک کشتی یولاف زراعی (به ترتیب 567/05و 944/83گرم در متر مربع) حاصل شد. براساس نتایج این مطالعه، استفاده از تک کشتی یولاف زراعی و وجین دستی علف‌های‌هرز بر کاهش تراکم، زیست توده کل علف های هرز و بهبود عملکرد و اجزای عملکرد اسفناج مناسب می باشد.

impact of some cover crops and hand weeding on the yield of spinach (spinacia oleracea l.)

extended abstract introduction: spinach (spinacia oleracea l.) belongs to chenopodiaceae and is one of the most important leafy vegetables in the world. spinach is a valuable human food source because its leaves are rich in minerals, vitamins, antioxidants, and phenolic compounds. weeds are one of the significant challenges for spinach production. they can lead to a decrease in commercial biomass and spinach quality. the incidence of herbicide resistance in spinach fields has led to the use of environmentally friendly methods such as cover crops. these plants can cause physical suppression of the weeds by creating adequate biomass and developing a canopy. the aim of this study was to provide a quantitative study of the interactions of the cover crops (such as oat and daikon radish) and hand weeding treatments on the suppression of the weeds and their effect on the vegetative growth and yield of spinach.materials and methods: the experiment was conducted in the crop years of 2020 2021 and 2021 2022 at the research farm of the faculty of agriculture and natural resources of the university of mohaghegh ardabili with 1350 meters above sea level and geographical coordinates 38˚ 19´ east and 48˚ 20´ north with cold and semi arid climates. the experiment was performed as a randomized complete block design with three repetitions. experimental treatments included the first factor of oat (avena sativa l.), daikon radish (raphanus sativus var. longipinnatus), their intercropping (with 50 % seed ratio), and control treatment (without cover crops). the second factor consisted of hand weeding and non weeding. the seed rate of oat and daikon radish was 100 and 20 kg per ha, respectively, and were planted manually at a 3×4 meter plots. in this experiment, the seeds of spinach viroflay were used. seeds were sowed manually among the residues of cover crops at 1.5 cm depth. due to the amount of precipitation in two years, irrigation was performed if needed. the inter and intra row spacing was 20 and 10 cm. hand weeding was done from the planting date to the final harvest of spinach. the investigated traits included dried biomass of cover crops, the density of dominant weeds, and simpson, shannon weaner, and margalef indices.results and discussion: the biomass of cover crops was significantly affected by planting systems, seed density, and year (p ≤1 %). the results showed that the highest biomass of cover crops (538.83 gm 2) was obtained from oats. also, the lowest biomass (325.83 g.m2) belonged to daikon radish. the dominant weeds were consisted of three species such as lamb’s quarters (chenopodium album), italian bugloss (anchusa italica retz), and common fumitory (fumaria officinalis). the results showed that oat in two years had the lowest weed biomass (10.64 g.m2) and density of lamb’s quarters, italian bugloss, and common fumitory (4.33, 5.00, and 4.25 number/m2). the maximum weed control efficiency index (57.67 %) was obtained from the oat monoculture. also, the highest weed control efficiency index (51.47 %) was obtained from the hand weeding. margalef’s index decreased in the first and second sampling times compared to 5.55 % and 9.85 % relative to the first year. the highest index of shannon weaner’s diversity belonged to control and daikon radish (0.47 and 0.47). the highest baby spinach yield and final yield in the first and second phases of sampling in two years were obtained from oats treatment (with 567.05 and 944 g.m2, respectively) and then from their intercropping (390.04 and 786.33 g.m2).conclusion: the results showed that oat and its combination with daikon radish had the highest biomass compared to daikon monoculture. the effect of oat biomass on the decrease in density and biomass of the total weeds was significant, which was due to the amount of oat seeds consumed compared to daikon radish. in addition, hand weeding reduced the density and biomass of the weeds more than non weeding. hand weeding led to the lack of opportunity for weeds’ growth. as such, the improvement of the baby spinach and the final yield was due to the hand weeding of the weeds and the presence of the cover crops biomass in the experiment. the results of are inferred that oat monoculture is suitable both in terms of reducing physical competition of horticultural plants with weeds and improving spinach yield.