ارزیابی تأثیر احتمالی آبیاری پیش از رخداد سرما بر ویژگی‌های کمی و کیفی نیشکر

The occurrence of cold weather is one of the factors limiting the production of agricultural products such as sugarcane in most parts of the world. The severity of the cold, the duration of its occurrence and also the reaction of the sugarcane cultivars are important factors that determine the amount of damage caused by freezing so that in the constant temperature regime in the mature cane, a different reaction from chlorosis to the death of the plant can be observed in different cultivars. Understanding this phenomenon and the possible dates of its occurrence in sugarcane cultivation will help Sugarcane Agro-industries Co. in preventing and reducing damage in the plantation and ratoon fields. Therefore, it is necessary to evaluate the effect of frost on sugarcane and its management methods. In order to evaluate the possible effect of irrigation before the occurrence of cold and irrigation during the occurrence of cold and frost on the quantitative and qualitative characteristics of sugarcane, an experiment was arranged in a RCBD design using three treatments and with three replications in 2019 in Amir Kabir Agro-industry Co. Experimental treatments consisted of 1) irrigation 48 hours before the occurrence of cold, 2) Irrigation during the occurrence of cold, 3) control (irrigation according to the usual method). Using the prediction of the occurrence of cold, the time of occurrence of cold and its duration, the mentioned treatments were irrigated. In the first stage, two weeks after the occurrence of cold, the treatments were evaluated observationally. In the next step, by observing the effect of cold on the sugarcane plant, the growth status of the product or crop control program (crop logging) was studied during 12 weeks. Quantitative and qualitative traits of sugarcane including the number of internode, the diameter of the middle internode, sugarcane yield, syrup purity, sucrose percentage were evaluated. The results of the observational evaluation showed that there was a significant difference between the experimental treatments in the effect of cold on the sugarcane, so that the sugarcane in the treatment 1, irrigation 48 hours before the onset of cold had the least damage (green and fresh aerial foliage) and the other two treatments showed the most damage (aerial foliage necrosis). Crop logging program data from the first week to the twelfth week (approximately 90 days after the occurrence of cold) and the quantitative and qualitative traits of sugarcane were determined. The results of the evaluation of experimental treatments showed that 180 days after the occurrence of frost (temperature of -1.7 degrees Celsius) in terms of sugarcane growth and quantitative and qualitative traits, no significant difference was observed at the 5 percent probability level.