واکنش رشد، عملکرد و کیفیت علوفه و شاخص‌های سودمندی و رقابت به تلقیح مایکوریزایی در کشت مخلوط گوار و آفتابگردان

به‌منظور بررسی اثر الگو‌های کشت مخلوط و تلقیح مایکوریزا بر عملکرد و شاخص‌های سودمندی آفتابگردان (helianthus annus l.) و گوار (cyamopsis tetragonoloba l.)، یک آزمایش فاکتوریل در بهار 1397 در مزرعه دانشگاه علوم کشاورزی و منابع طبیعی خوزستان در قالب بلوک‌های کامل تصادفی با چهار تکرار اجرا گردید. عوامل آزمایشی شامل سطوح مایکوریزا (تلقیح و عدم تلقیح) و نسبت‌های کاشت (100 درصد آفتابگردان)، (100 درصد گوار)، (75 درصد آفتابگردان + 25 درصد گوار)، (25 درصد آفتابگردان + 75 درصد گوار) و (50 درصد آفتابگردان + 50 درصد گوار) بودند. اثر نسبت‌های کشت و تلقیح مایکوریزا بر صفات مورد‌بررسی معنی‌دار بود. بالاترین نسبت برابری زمین (1.34) به تیمار 50 درصد آفتابگردان + 50 درصد گوار تعلق داشت. ترکیب 75 درصد آفتابگردان + 25 درصد گوار پایین‌ترین شاخص رقابت برای آفتابگردان، و در نسبت 75 درصد گوار + 25 درصد آفتابگردان پایین‌ترین شاخص رقابت برای گوار به‌دست آمد. بالاترین درصد نیتروژن علوفه (2.34 درصد) از تیمار 25 درصد آفتابگردان + 75 درصد گوار و عدم تلقیح مایکوریزا به‌دست آمد. بیش‌ترین درصد فیبرخام آفتابگردان از تیمار عدم تلقیح مایکوریزا از نسبت 50 درصد آفتابگردان + 50 درصد گوار با میانگین 0.45 حاصل شد. بیش‌ترین و کم‌ترین عملکرد علوفه خشک به‌ترتیب از تیمار 75 درصد آفتابگردان + 25 درصد گوار (2699 کیلوگرم در هکتار) و تیمار 100 درصد گوار (827 کیلوگرم در هکتار) حاصل شد. به‌طورکلی، به‌نظر می‌رسد کشت مخلوط آفتابگردان و گوار می‌تواند سبب افزایش کمیت و کیفیت علوفه تولیدی شود که در صورت تکرار نتایج می‌توان از نسبت 75 درصد آفتابگردان همراه با 25 درصد گوار در این زمینه استفاده نمود.

response of growth, yield and forage quality and indices of effectiveness and competitiveness to mycorrhizal inoculation in mixed intercropping of sunflower and guar

introduction mixed cropping is one of the ways to increase the crop yield in the form of multiculturalism on a farm in one crop season. this method of cultivation improves the efficiency of the use of environmental resources such as light, water and nutrients by plants. guar (cyamopsis tetragonoloba l.) is a plant of the legume family and is compatible with tropical regions, which due to its coexistence with nitrogen-fixing bacteria, can be an effective plant in mixing crops in warm regions. sunflower (helianthus annus l.) is an important oil crop that is also grown as a forage crop in some areas and seasons. biological fertilizers, eco-friendly fertilizers, have beneficial effects on plant growth characteristics as well as the physical, chemical and biological characteristics of the soil. mycorrhizal fungi increase the uptake of water and nutrients by increasing the level of adsorption of the plant’s root system, and ultimately increase the growth and yield of the crop. in the present study, the cultivation of sunflower mixed with guar was investigated under the influence of mycorrhizal inoculation. materials and methods in order to evaluate the effect of planting proportions and mycorrhizal inoculation on sunflower (helianthus annus l.) and guar (cyamopsis tetragonoloba l.) yield and effectiveness indices, an experiment was conducted at khuzestan university of agricultural sciences and natural resources in the spring of 2018 using a factorial trial in randomized complete blocks (rcbd) with four replications. experimental factors included five ratios of mixed planting of guar and sunflower as alternate series in inoculation conditions and non-inoculation of mycorrhiza. mixed culture ratios included i. pure sunflower cultivation, ii. 75 percent sunflower + 25 percent guar, iii. 50 percent sunflower + 50 percent guar, iv. 25 percent sunflower + 75 percent guar, and pure guar cultivation. the studied traits included plant height, number of branches, stem and leaves weight, number of leaves, dry and fresh forage yield, as well as effectiveness and competiveness indices. the land equality ratio (ler) and competitiveness ratio (cr) were evaluated as indicators of the usefulness assessment of mixed cultivation. both sunflower and guar plants were planted on march 15, 2018. harvesting of sunflower and guar plants took place on june 1 and june 23, 2018, respectively. results and discussionthe results of statistical analysis showed that the growth, yield and efficiency indices of mixed cropping of sunflower and guar were significantly affected. the height of the plant, the number of leaves, the weight of the leaves and stems, as well as the number of branches were significantly affected by the experimental factors, especially the planting proportions. the highest yield of fresh forage (21391 kg.ha-1) was obtained in the treatment of pure sunflower cultivation and the highest yield of dry forage (2618 kg.ha-1) was obtained from the treatment of 75 percent sunflower  + 25 percent guar. the highest ler (1.34) was obtained from the treatment of 75 percent sunflower + 25 percent guar. the combination of 75 percent sunflower + 25 percent guar caused the lowest competition ratio for sunflower, and the combination of 75 percent guar + 25 percent sunflower caused the lowest competition ratio for guar. conclusionas mentioned, the highest yield of mixed cropping was obtained when the planting composition included 75 percent sunflower and 25 percent guar. under the conditions of this experiment, the growth of guar plants was significantly affected by the ability of the sunflower to compete. as a result, due to the lower competitiveness of guar against sunflower, it is necessary to consider other methods of mixed cropping. including delayed mixed cropping. in general, mixed cropping flattered different growth factors and the accumulation of dry matter significantly changed forage yield and morphological traits.