مقایسه شاخص‌های کمی و کیفی برداشت سبز و سوخته ارقام نیشکر

Abstract

Background and objectives: Increase in global warming and environmental issues, public opinion pressure, especially in urban areas near cane fields, the necessity of replacing green harvesting sugarcane (Saccharum Officinarum) instead of burning up is increasing. To set on fire cane fields also due to lose about 20 T ha-1 herbaceous (Trash blanket) remains can change to organic matter and help to soil fertility and sustainable production of sugarcane in Khuzestan.

Materials and methods: To evaluation quantity and quality indices at harvesting time in green harvesting method and comparison with burnt harvesting losses a test performed in 2015-2016 growing season at Imam Khomeini Agro Industry Company. The experiment design was a split plot based on complete randomized block with four replications. Three sugarcane cultivars were as main plots and five harvesting methods and ratooning after harvesting were as sub plots considered. Infield losses such as complete cane, chopper cane, unravel cane, uncut cane, total losses, pol percent and cane yield was studied in test units. A SAS (v 9.2) software was used for accounts statistical and LSD test for means comparison.

Results and Discussion: The results showed that cultivars had significant effect on all of measured characteristics. The highest and lowest unravel cane loses was observed in cultivar of CP73-21 (2.65 T ha-1) and CP48-103 (1.23Tha-1), respectively. Maximum total of losses belong CP73-21 cultivar (12.14Tha-1) and minimum (4.46Tha-1) belong CP48 cultivar. Because of difference between sugarcane cultivars in terms of cane length, leaf numbers, maturation stage period and tolerance to logging, these characteristics have important role in field losses. The highest unravel cane losses belong whole of green harvesting methods (without significant different between themselves) with nearly (2Tha-1) and the lowest unravel cane was observed burnt harvesting (1.35Tha-1). Green harvesting methods had more losses than burnt harvesting method. Because leaves and top are green at harvesting time in green harvesting method so losses amount in green harvesting method is higher than burnt method. The highest pol percent belong pre and middle mature cultivar. Method harvesting had not significant different on pol percent .The highest cane yield was observed in CP69-1062 cultivar (92.87Tha-1) and the lowest cane yield was observed in CP73-21 cultivar (65.4Tha-1). Average yield of burnt harvesting was 83.19Tha-1 and average yield of total green harvesting methods was 73.68T ha-1. Generally, yield of green harvesting methods had yield about 11% lower than burnt harvesting methods.

Conclusion: Because researches about green harvesting sugarcane start lately in Iran and because infield losses is higher in early maturity cultivar than other cultivars and need to technical changes about sugarcane harvesters for field losses decrease, current green cane harvesting must be start with middle maturity and late maturity cultivars.