INTRODUCTION Sweet potato (Ipomoea batatas L.) is popularly known as sarkarkand it originated from Central America belong to family convolvulaceae. Approximately 900 different species of Convolvulaceae in 400 genera have been identified around the world. Yen (1974); Austin (1978, 1988) recognized 11 species in the section batatas, which includes sweet potato. The closest relative of the sweet potato appears to be Ipomoea trifida that is found wild in Mexico, and Ipomoea tabascana. It is hexaploid species with chromosome number 2n = 90. Sweet potato is a dicotyledonous plant with tubers derived from swollen roots. It is an important starchy food crop grown in the world’s tropical and sub-tropical regions. It is a perennial herbaceous plant planted as an annual vine. Sweet potato, after rice, wheat, potato, maize and cassava, is the sixth most important food crop Worldwide. Among different vegetables; after cereals and grain legumes, tuber plant are the most important food crops. In tropical, subtropical and temperate areas, it serves as staple food for millions of individuals. These crops are known for their high calorific value and their ability to resist adverse soil and climatic conditions (Saravaiya and Patel 2005). The main feature of tuber crops is that these crops have high production per unit area per unit time and is expected to bridge the food shortages and malnutrition. They are tolerant to drought and can be grown even on undulated and unfertile soil. The crop has the additional advantage that due to rapid soil coverage and good rooting characteristics, it helps to reduce soil erosion. Thus, sweet potato is a particularly valuable crop for poorer farmers. The area under Sweet potato cultivation in India is 134.88 thousand ha with a production of 1638.8 thousand MT and productivity 12.2 MT ha respectively. Odisha is leading state with area 40.80 thousand ha and production 384.51 thousand tonne. It is an important tubers crop in tribal dominant Chhattisgarh state. The underground root as well as leaves of which are consumed as vegetable. The tubers and vine is used as feed for cattle. In Chhattisgarh state, Sweet potato is cultivated in an area 5.57 thousand ha with production 200.03 thousand MT. Major growing belts in Chhattisgarh are Sarguja, Kondagaon, Balrampur, Korba, Raigarh, Kanker, Bilaspur and Kabirdham districts (Anon., 2017). Shoot pruning, particularly the quality and quantity of Sweet potato tubers, increases tuber formation. The timing of shoot pruning influences the growth of the plant, especially the Sweet potato. The vegetative organs will increase if shoot pruning occurs during the late vegetative phase, whereas if shoot pruning occurs during the late vegetative phase, the development of generative organs may accelerate, while it will be spread to the tubers. If the balance of vegetative and reproductive phases is established, photosynthate accumulation will also be balanced. The plants with medium vegetative growth have more tubers. Sweet potato topping raises the yield and starch content of root tubers (Villareal and Griggs 1982). To identify the best variety suited combination of topping treatments and growth retardant concentration for improving quality attributes. MATERIALS AND METHODS A Field Experiment was conducted at Horticulture Research cum Instructional Farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur situated at latitude 21°16’ N, 81°36’ E and 289.56 m above mean sea level. The experiment was carried out during rabi seasons of 2018-19 and 2019-20. The soil is a predominantly light-textured Clay loam with a pH of 7.12.The organic matter content of the soil ranges between 0.49 to 0.60% at 0 to 20 cm soil depth. The experiment was laid out in Factorial Randomized Block Design with 24 treatment combinations which were replicated three times. The treatments included: four varieties (i) Indira Madhur (ii) Indira Nandani (iii) Sree Rethna (iv) Chhattisgarh Sarkark and Priya, 3 levels of topping (i) Control (No topping) (ii) Topping 30cm from top at 60DAP iii) Topping 30cm from top at 80DAP and 2 levels plant growth retardant treatments (i) Control (P0), (ii) foliar spray of Cycocel 500ppm after 60 and 80 DAP (P1). The treatments were randomly allotted in each replication in a total 72 plots of 2 m × 1.8 m size in each accommodating 30 plants. The cutting was planted at 20 cm distance on ridges spaced at 60 cm. The crop was applied @75:50:75 NPK kg/ha in the form of urea, single super phosphate and muriate of potash, respectively. Urea was applied in two split doses, first as basal and second after the 45 days of vine planting in main field as top dressing. Full dose of phosphorus and potassium along with FYM 10 t/ha were applied as basal dose. The vine was turned and lifted during the growth period of 45 and 75 days after planting to prevent rooting from nodes. RESULTS AND DISCUSSION Starch recovery in root tubers (%). The data starch recovery in root tubers (%) as influenced by varieties, topping and plant growth retardant are presented in Table 1. The variety Chhattisgarh Sarkarkand Priya (V4) showed maximum starch recovery of root tuber (7.79 %) followed by V3- Sree Rethna (7.49 %). Among topping, treatments during the investigation significant maximum starch recovery percent was recorded in T1 i.e topping at 60 DAP (6.99 %) which was found statistically at par with treatment T0i.e control. The minimum starch recovery percent was noticed in T2 i.e topping at 80 DAP (6.50 %). These results are supported by the findings of earlier workers reported that topping of sweet potato increased starch content of the roots because it minimized the competition between shoots and roots in drawing photosynthates (Griggs and Villareal 1982). The results indicated that P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP significantly maximum starch recovery of root tuber was recorded (7.26 %). The minimum starch recovery of root tuber was noticed in P0 i.e control (6.20 %). The interactions among varieties, topping and growth retardant treatment showed non-significant impact on starch recovery of root tuber are presented in Table 2. The interactions between V4T1 P1 i.e when topping at 60 DAP and cycocel 500ppm as foliar spray at 60 and 80 DAP produced maximum starch recovery (9.05 %) followed by V4 T0 P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP (8.83 %) among different treatment combination. The significant improvement in starch recovery of root tuber under different treatment combinations were noticed over control treatment i.e. when no topping and cycocel 500ppm was applied at 60 and 80 DAP foliar spray was done. Total soluble solids (oBrix). The data on Total soluble solids in tubers as influenced by varieties, topping and plant growth retardant are presented in Table 1.The variety Chhattisgarh Sarkarkand Priya (V4 ) showed maximum total soluble solids (12.04 Brixo) followed by Indira Madhur (V1) (10.17 Brixo). However minimum total soluble solids was noticed in Sree Rethna (V3) (8.96 Brix0). The higher total soluble solids due to varietal characteristic. Among topping, treatments during the investigation significant maximum total soluble solids in root tuber was recorded in T2 i.e topping at 80 DAP (10.66 Brixo ) followed by T1 i.e topping at 60 DAP. The minimum total soluble solids in root tuber was noticed in T0 i.e control. The results indicated that P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP significantly maximum total soluble solids in root tuber was recorded (10.54 Brixo). The minimum total soluble solids in root tuber was noticed in P0 i.e control (9.95Brixo). The interaction between varieties, topping and growth retardant treatments exhibited significant impact on total soluble solids in root tuber are presented in Table 2. The data indicated that maximum values of total soluble solids in root tuber in V4 –Chhattisgarh Sarkarkand Priya in combination with different topping and plant growth retardant treatments over rest of the counter parts. The interactions between V4T0P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP recorded higher total soluble solids in root tuber (12.89Brixo) which was found statistically at par with treatment of same variety. The minimum total soluble solids in root tuber was recorded in V3 T0 P0 i.e control (8.64 Brixo). The higher total soluble solids due to varietal characteristic. Similar results are recorded that total soluble solids in root tuber of sweet potato by Slosar et al. (2019). Moisture content (%). The data on moisture content (%) in tubers as influenced by varieties, topping and plant growth retardant are presented in Table 1. The variety Indira Nandani (V2) showed maximum moisture content (78.54%) followed by Indira Madhur (V1) (70.67%). However minimum moisture content was noticed in Chhattisgarh Sarkarkand Priya (V4) (64.65%). Among Topping, treatments T1 i.e topping at 60 DAP obtained higher moisture content in root tuber (72.09 %) in comparison to rest of the treatments and while the lower moisture content was noted under treatment T2 i.e topping at 80 DAP (69.11 %). As regards, plant growth retardant, perusal of data indicated that treatment P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP recorded significantly maximum moisture content of root tuber (72.89%) as compare to control treatment (P0). The interactions among varieties, topping and growth retardant treatments exhibited non-significant impact on moisture content during are presented in Table 2. The interactions of data between V2T0P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP produced maximum moisture content (86.21 %) followed by V2T1 P1 i.e when topping at 60 DAP and Cycocel 500ppm as foliar spray at 60 and 80 DAP among different treatments. Similar results are recorded that moisture content in the Sweet potato varieties by Rose and Vasanthakaalam (2011); Kamal et al. (2013). Protein in root tubers (%). The data protein in root tubers (%) as influenced by varieties, topping and plant growth retardant are presented in Table 1. The variety Chhattisgarh Sarkarkand Priya (V4) showed maximum of protein content in root tubers (3.95 %) followed by Indira Madhur (V1) (3.47%). However protein content in root tuber was noticed in Indira Nandini (V2) (2.68 %). Among topping, treatments during the investigation significant maximum protein content was recorded in T1i.e topping at 60 DAP (3.45 %) followed by T0 i.e control. The minimum protein content was noticed in T2i.e topping at 80 DAP (3.05 %). As regards, plant growth retardant, perusal of data indicated that treatment P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP recorded significantly maximum protein content in root tuber (3.52 %) as compare to control treatment (P0). The interaction between varieties, topping and growth retardant treatments exhibited non-significant impact on protein content in root tuber are presented in Table 2. The data indicated that maximum values of protein content in root tubers in V4 – Chhattisgarh Sarkarkand Priya in combination with different topping and plant growth retardant treatments over rest of the combinations. The interaction among V4T0 P1i.e when cycocel 500ppm was applied at 60 and 80 DAP as foliar spray (4.67 %) followed by V4 T1 P1 i.e when topping at 60 DAP and cycocel 500ppm as foliar spray at 60 and 80 DAP. The minimum protein content in root tubers was recorded in V2 T0 P0 i.e when no topping and without cycocel 500ppm as foliar spray at 60 and 80 DAP. The increment in protein content due to plant growth retardant. Similar results are observed by Rodrigues et al. (2016); Samy et al. (2014); Kamal et al. (2013). Vitamin ‘C’ in root tuber (mg/100 g). The data vitamin ‘C’ in root tuber as influenced by varieties, topping and plant growth retardant are presented in Table 1. The variety Sree Rethna (V3) showed maximum of vitamin ‘C’ content in root tubers (26.49 mg 100 g-1) followed by Indira Nandani (V2) (18.00 mg 100 g-1). However minimum value of vitamin ‘C’ content in root tubers was noticed in Chhattisgarh Sarkarkand Priya (V4) (11.23 mg 100 g-1) .Topping among, T0 i.e control (No topping) obtained higher vitamin ‘C’ content in root tuber (.43 mg 100 g-1) followed by T2 i.e topping at 80 DAP while the lower vitamin ‘C’ content in root tuber was noted under treatment T1i.e topping at 60 DAP (17.88mg 100 g-1). As regards, plant growth retardant, perusal of data indicated that treatment P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP recorded significantly maximum vitamin ‘C’ content in root tuber (18.59mg 100 g-1) as compare to control treatment (P0). The interactions among varieties, topping and growth retardant treatments exhibited non-significant impact on vitamin ‘C’ content are presented in Table 2. The interactions between V3T0 P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP produced maximum vitamin ‘C’ content (28.32mg 100 g-1) followed by V3T1 P1 i.e when topping at 60 DAP and cycocel 500ppm as foliar spray at 60 and 80 DAP among different treatments. The significant improvement in ascorbic acid content due varieties, topping and plant growth retardant may be attributed to combine effect of treatments. Similar observation was documented by Mitra (2012); Yildirim et al. (2011). Total sugar content in root tuber (%). The data on total sugar content in root tuber as influenced by varieties, topping and plant growth retardant treatments are presented in Table 1. The variety Chhattisgarh Sarkarkand Priya (V4) showed maximum of total sugar content in root tuber (4.97 %) followed by Indira Madhur (V1) (3.47%). However protein content in root tuber was noticed in Indira Nandini (V2) (2.68 %). Among topping, treatments during the investigation significant maximum total sugar content was recorded in T1 i.e topping at 60 DAP (4.24 %) followed by T2 i.e topping at 80 DAP. The minimum total sugar content was noticed in T0 i.e control (No topping) (3.49 %). As regards, plant growth retardant, perusal of data indicated that treatment P1 i.e cycocel 500ppm as foliar spray at 60 and 80 DAP recorded Significantly maximum sugar content in root tuber (4.18 %) as compare to control treatment (P0). The interaction between varieties, topping and growth retardant treatments exhibited non-significant impact on protein content in root tuber are presented in Table 2. The data indicated that maximum values of protein content in root tubersin V4 – Chhattisgarh Sarkarkand Priya in combination with different topping and plant growth retardant treatments over rest of the combinations. The interaction among V4T0 P1 i.e when cycocel 500ppm was applied at 60 and 80 DAP as foliar spray (4.67 %) followed by V4 T1 P1 i.e when topping at 60 DAP and cycocel 500ppm as foliar spray at 60 and 80 DAP. The minimum protein content in root tubers was recorded in V2 T0 P0 i.e when no topping and without cycocel 500ppm as foliar spray at 60 and 80 DAP. The improvement in total sugar content may be due to combine effect of varieties, topping and plant growth retardant treatments. Similar results are obtained by Lai et al. (2014); Kamal et al. (2013); Rose and Vasanthakaalam (2011); Suraji et al. (2013).