The Effect of Pruning Time on the Quantitative and Qualitative Characteristics of Autumn Sugar Beet

In plants, leaves are the primary source of sunlight, and the production of photosynthetic materials. For this reason, estimating the rate of yield reduction due to leaves loss plays an important role in farm management. In order to investigate the effect of shoot removal at different stages of vegetative growth on the yield and root quality of sugar beet, a factorial experiment, in a randomized complete block design with three replications at the Agricultural Research of Gorgan-Iran (2019 and 2020) was done. The first factor included six commercial varieties of autumn sugar beet (5 foreign cultivars including Monatunno, Veles, Chimene, Jrakavas, Rosageld and Sharif domestic cultivar), and the second factor was pruning in the fourth week of May (mid-growth stage), pruning in the third week of June (final stage growth), and control treatment (no pruning). The results showed, the cuiltivar and pruning treatment had a significant effect on quality traits and root yield in both years. The pruning was more affected the yield of the sugar beet root in the fourth week of May, compared to the third week of June, by the decreasing trend. It seems, that with closing to the end of the growing and harvesting period, leaf production process in the plant decreases. Leaf removal in the final stage of growth has more negligible effect on root yield than in the middle stage of growth, becuase at the end of the growth period, the root is developed and has reached its maximum weight.