ارزیابی شاخص‌های کیفی شربت در برداشت سبز و سوخته نیشکر

تعهدات بین‌المللی و فشار افکار عمومی برای جلوگیری از آلودگی محیط‌زیست موجب‌گذار از برداشت سوخته نیشکر به برداشت سبز در مناطق نیشکر کاری دنیا شده است. به منظور مقایسه شاخص‌های کیفی شربت نیشکر در دو روش برداشت سبز و سوخته تحقیقی در سال زراعی 95-1394 در کشت و صنعت نیشکر امام خمینی (ره) واقع در شمال خوزستان به‌صورت آزمایش کرت‌های یک‌بار خرد‌شده بر پایه بلوک‌های کامل تصادفی در چهار تکرار اجراء شد. عامل اصلی سه واریته نیشکر با دوره رسیدگی متفاوت و عامل فرعی پنج روش برداشت و راتونینگ بودند. شاخص‌های کیفی مورد ارزیابی شامل درصد خاشاک ساقه، درصد وزنی شربت قابل استخراج‌، کل مواد جامد حل‌شده در شربت، میزان ساکارز در شربت، درجه خلوص شربت، قند قابل استحصال درکارخانه (r.s) و عملکرد ساقه بودند. نتایج نشان داد واریته نیشکر در خصوص همه صفات مورد ارزیابی به جز درصد وزنی شربت قابل استخراج اختلاف معنی‌دار داشتند. روش‌های برداشت و راتونینگ در مورد درصد خاشاک همراه‌ نی، قند قابل استحصال در کارخانه، عملکرد نی و کل مواد جامد حل‌شده در شربت اختلاف معنی‌دار داشتند. خاشاک همراه‌نی در مجموع روش‌های برداشت سبز حدود 7 درصد و در برداشت سوخته 4 درصد بود. میانگین عملکرد برداشت سوخته 83 تن در هکتار و برداشت سبز 74 تن در هکتار بود. به‌طورکلی برداشت سبز نیشکر موجب افزایش درجه خلوص شربت نسبت به برداشت سوخته شد.

Evaluating Quality Indices of Extracts in Green and Burnt Sugarcane Harvesting

Abstract   Background and Objectives International forces and public pressure to prevent environmental pollution have changed burnt sugarcane harvesting to green sugarcane harvesting in most important sugarcaneproducing regions of the world. In the major countries that produce sugarcane, sufficient research has been done on green sugarcane harvesting. Due to climate difference between Iran and other countries, it is essential to investigate all the aspects of green cane harvesting such as the quality indices of extracts in Khuzestan, Iran.   Materials and Methods To compare extract quality in burnt and green sugarcane harvesting, a test was performed in 20152016 at Emam Khomeini Agro industry company (latitude 31,44o N, longitude 48,44o E and 24 m asl). A spilet plot design was used. Three sugarcane varieties with different ripeness durations were considered as the main plot and five harvesting methods and ratooning including burnt harvesting, green cane harvesting without rationing, green cane harvesting with rationing, green cane harvesting with one reshape replication and green cane harvesting with two reshape replications with four replications were considered as the sub plot. Trash percent, extraction percent (Ex), total solid material solute in extract (Brix), sugar percent in extract (Pol), extract purity degree (Pty), recovery sugar percent in factory (R.S) and the yield were studied.   Results Results showed the varieties had a significant difference regarding all the parameters except Ex. Maximum Ex (%41.863), and the yield (93 t/ha) belonging to Cp691062 varieties. Cp7321 had the maximum Brix (%20.35) and Pol (%18.16). Methods of harvesting and ratooning caused a significant difference as to the trash percent, R.S, the yield and Brix. The mean of trash in green harvesting was 7 %but it was 4% in burnt harvesting. Maximum Brix belonged to the burnt but had no significant difference with that of the green harvesting. Pol percent in the burnt was not significantly different from the two green harvesting methods. The average yields of burnt and green harvestings were 83 t/ha and 74 t/ha respectively. Finally, green harvesting increased Pty.   Discussion The results of this study show that in green cane harvesting, as compared with burnt cane harvesting, the trash is increased and the yield is decrease. Because the trash prevents the recovery sugar, we expected that quality indices in green cane harvesting to be worse than burnt cane harvesting. However, due to having fresh cane in green cane harvesting, the parameters of quality, especially the purity, were higher than those in burnt cane harvesting. In the executive phase, the difference between the green and burnt harvesting is more than this experiment because a cane field that has been burnt for harvesting is usually detained for more than 12 hours for transporting the cane to the factory, resulting in much lower quality. The benefits of green cane harvesting will better be understood now if the trash is decreased in green cane harvesting by setting and changing the harvesters.