تأثیر سطوح مختلف کنسانتره کود مرغی بر صفات رویشی و شاخص‌های فتوسنتزی زعفران (Crocus sativus L.)

چکیده: به منظور بررسی اثر کنسانتره کود مرغی بر خصوصیات رویشی و زایشی گیاه دارویی زعفران (Crocus sativus L.)، آزمایشی در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در سال زراعی 94-1393 در مزرعه تحقیقاتی دانشگاه بیرجند اجرا شد. تیمارهای آزمایشی شامل سطوح صفر، 5، 10 و 15 تن در هکتار کنسانتره کود مرغی بود. نتایج نشان داد که کنسانتره کود مرغی بر عملکرد گل تر، وزن خشک کلاله و وزن بنه‌ها تأثیر معنی‌دار داشت. بیشترین عملکرد گل تر و وزن خشک کلاله از تیمار 5 تن در هکتار به دست آمد. همچنین، کنسانتره کود مرغی بر اجزای برگ (طول، وزن خشک و تعداد) و رنگدانه‌های فتوسنتزی آن اثر معنی‌دار داشت، به‌طوری‌که بیشترین طول و وزن خشک برگ و کلروفیل در تیمار 15 تن در هکتار مشاهده شد، اما بین تیمارهای 5، 10 و 15 تن در هکتار تفاوت معنی‌داری نبود. به طور کلی، نتایج نشان داد که تیمار 5 تن در هکتار کنسانتره کود مرغی تأثیر بسزایی بر رشد رویشی و زایشی زعفران در شرایط مزرعه دارد.

Introduction: The most expensive medicinal spicy plant in the Middle East countries is saffron (Crocus sativus L.). Today, Iran is the major supplier of saffron to the world market, and it is a strategic plant in the south of Khorasan region. This crop has a very low harvested yield (stigmas biomass). Saffron is a perennial crop (at least 4 to 5 years) and requires adequate amount of nutrients. Nutritional management is one of the main factors affecting qualitative properties and yield of saffron. Chicken manure is organic manure which improves the physical, chemical and biological properties of soil and adds organic matter and increases the water holding capacity and beneficial biota in soil. Therefore, the aim of this research was to investigate the effects of different rates of chicken manure on vegetative and reproductive characteristics of saffron. Materials and Methods: This experiment was carried out based on randomized completely block design with three replications in research farm of Birjand University, Iran, during growing season 2015. Experimental factor was consisted of Chicken manure (0, 5, 10 and 15 t.h.a-1). Mother corn planting was in early October, 2015 with 10×20 cm corms distances and planting depth of 15 cm. Flower of saffron wase measured during autumn of 2015. Chl content (chl a,b, total and cartenoid) was determined by method of Arnon (1967). Chl content was assessed using a chl meter (SPAD-502; MINOLTA-JAPAN). Chl fluorescence was measured using chl fluorometer (MINI-PAM). Measurements for minimal (F0) and maximal (Fm) fluorescence yields were made on dark-adapted (20 min) leaves and the variable fluorescence (Fv) were calculated as (Fm-F0). Finally, data analysis was done using SAS 9.1 and means were compared by LSD test at 5% level of probability. Results and Discussion: yield of fresh flower, dry weight of stigma and corn weight with scale were influenced by chiken manure treatments. The highest yield of fresh flower (19.26 g/m2) and dry weight of stigma (0.58 g/m2) were obtained in plants treated with 5 t/ ha chicken manure while the lowest values (13.93 and 0.26 g/m2) was recorded in the control. Results showed that chiken manure improved the leaf growth indices (length, dry weight of leaf and number of leaf) and photosynthetic pigments (chl a, chl b, total chl and cartenoid). The highest length, dry weight of leaf and photosynthetic pigments (chl a and chl b) were obtained in plants treated with 15 t/ha chicken manure. But, not significance difference between treatments 5, 10 and 15 t/ha and the lowest values were recorded in the control. Application of organic fertilizers, as soil amendments or surface mulches, have been advocated as compatible with IAP (Integrated Agricultural Production) since fertilizer inputs can be reduced. It can be inferred that saffron nutrient demands could be supplied by application of enough animal manures. Evidences showed that application of 40 to 60 t/ha animal manure supplied not only nutrient requirements of plant, but also improved soil fertility. This lead to the minimizing of the use of chemical fertilizers (organic system), and consistently affected quantity and quality of saffron yield. These basic nitrogen sources are considered to be important for saffron production since they not only provide nutrients for plant growth, but also improve soil structure which increases corn multiplication, increasing saffron yield. Conclusion: Findings revealed that the use of 5 t/ha chicken manure had strong impact on vegetative and reproductive characteristics of saffron in this study.