In Experiment 2, the most critical stage for tuber bulking was the last 10 days of May (Fig. 5). Treatment M50 had its plastic mulch removed just before this stage. However, the difference in bulking rates among the three mulching treatments was not significant (F-test, P > 0.05), suggesting that removal of the plastic mulch had little effect on tuber bulking. After early June, the potatoes in the three-mulched treatments seemed to stop bulking, but the potatoes without mulch (M0)
continued bulking.
In the end, the difference in tuber mass per plant for the mulched treatments was not significant (F-test, P > 0.05). The treatment without mulch had the highest tuber mass per plant among treatments, but the difference was not significant (F-test, P > 0.05).