Effect of harvesting dates on the yield and tuber quality of processing potatoes

An experiment was conducted to study the effect of harvesting dates and variety on the yield and processing quality of potato tuber. Three processing potato varieties (BARI Alu-25, Asterix; BARI Alu-28, Lady Rosetta and BARI Alu-29, Courage) were used as test crops and they were harvested at different days after planting [80, 90, and 100 days after planting (DAP)]. The three processing potato varieties showed higher tuber yield of Grade A (9.12 t ha-1) and B (13.64 t ha-1). The highest tuber yield (Grade A+B) [29.62 t ha-1] and total tuber yield (35.97 t ha-1) was found in Courage at 90 and 100 DAP harvest, respectively. The variety Lady Rosetta attained the highest percent of processable tuber yield (86.8% of the total tuber yield), the maximum dry matter content (26.37%), specific gravity (1.102) at 90 DAP harvest and this variety also contained the highest mean starch content (111.75 mg g-1 FW) followed by Courage (111.17 mg g-1 FW) and Asterix (103.95 mg g-1 FW). Optimum dry matter content (24.07%), specific gravity (1.091), starch content (110.15 mg g-1 FW), processable tuber yield (26.62 t ha-1) and total tuber yield (32.76 t ha-1) was found at 90 DAP harvest and therefore, it could be mentioned as suitable harvesting date for processing purposes. Among the varieties, Lady Rosetta and Courage were found preferable potato varieties that could be used for processing of potato products