Relationship of relative maturity and storage temperatures to weight loss of potatoes in storage

Harvest date had no significant influence on weight loss in storage of tubers which were grown under a low fertilizer regime (vines died prematurely). However under a higher fertilizer regime, tubers harvested 21–45 days after vine kill lost significantly less weight than those harvested 2–13 days after vine kill. An average of 4 years’ data indicates that tubers stored continuously at 45 F (7.2 C) lost significantly less weight than those stored at 42 F (5.5 C) or 48 F (8.9 C). This is attributed to lack of suberization and delayed maturation of tubers at 42 F resulting in increased weight loss and to higher respiration at 48 F in comparison to tubers held at 45 F storage. Considerable seasonal differences in weight loss were recorded. The 1971 growing season which was characterized by a prolonged period of extremely high temperatures resulted in tubers which lost significantly more weight during storage than was the case in the other seasons. Air ventilization rates from 20 to 80 cfm/T were used to cool potatoes from 60 F to ambient temperatures of 48 F. No significant differences in weight loss were obtained after 3 week’s continuous cooling with air at 93–95% R. H. regardless of air ventilation rate.     

The influence of physiological age,stem numbers and fertility on yield and grade of Russet Burbank potatoes

The present study was initiated to determine if increased stem numbers produced by physiologically older seed can be compensated for by increased fertilizer rate. Seed tubers held for 2 months at 16 C (physiological older seed) which averaged 3.7 main stems were compared in yield parameters to physiologically younger seed kept at 4 C (average 2.4 stems). The comparison was made at three levels of fertilizer 0, 140, and 280 kg/ha of nitrogen applied in a 16:16:16 (N-P²O⁵-K²O) formulation. Seed size and spacing were equal. Total and U.S. No. 1 yield were significantly higher for the younger seed. The greatest difference was that the younger seed at 140 kg/ha fertilizer yielded significantly more large size (over 280 g size) tubers than the older seed at equal to or double (280 kg/ha) the fertilizer rate indicating that additional fertilizer was not sufficient to overcome the effects of higher stem numbers from older seed. On the other hand, the older seed produced significantly higher yield of the undesirable small sizes.