Rooting of sweet potato seedlings submitted to supplemental calcium and phosphorus nutrition on substrateABSTRACT
The objective of this study was to evaluate the rooting and growth of sweet potato seedlings in trays in response to substrate supplementation with calcium (Ca) and phosphorus (P). Two greenhouse experiments were conducted in a randomized block design with a split plot scheme and eight repetitions. In the Ca experiment, the plots were the doses of 0, 100 and 200 mg kg-1 of Ca, and in the P experiment, by the doses of 0, 150 and 300 mg kg-1 of P. In both experiments, the subplots corresponded to the sampling time of seedlings (15, 30, 45, 60 and 75 days after planting). The Ca present in the substrate was sufficient to promote the proper rooting and growth of sweet potato seedlings in the trays. The Ca supply in excess (200 mg kg-1) adversely affected the growth of seedlings that remained in the tray for more than 60 days. Although the seedlings supplied with P showed higher root growth rate after 45 days, the initial P available in the substrate was sufficient to promote the adequate growth of the seedlings in the trays until 60 days.
Key words:
Ipomoea batatas; herbaceous cutting; clod integrity; root growing; permanence time in tray
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Ca-0, Ca-100 and Ca-200 - doses of 0, 100 and 200 mg kg-1 of Ca; ♦ - average of the three Ca doses; Vertical bars represent the least significant difference at p ≤ 0.05 by LSD test; * and ** - Significant at p ≤ 0.05 and p ≤ 0.01, respectively, by F test
Ca-0, Ca-100 and Ca-200 - doses of 0, 100 and 200 mg kg-1 of Ca; ♦ - average of the three Ca doses; Vertical bars represent the least significant difference at p ≤ 0.05 by LSD test. ** - Significant at p ≤ 0.05 and p ≤ 0.01, respectively, by F test
P-0, P-150 and P-300 - Doses of 0, 150 and 300 mg kg-1 of P; ♦ - average of the three P doses; Vertical bars represent the least significant difference at p ≤ 0.05 by LSD test. * and **Significant at p ≤ 0.05 and p ≤ 0.01, respectively; by F test
P-0, P-150 and P-300 - Doses of 0, 150 and 300 mg kg-1 of P; ♦ - average of the three P doses. Vertical bars represent the least significant difference at p ≤ 0.05 by LSD test. * and ** - Significant at p ≤ 0.05 and p ≤ 0.01, respectively by F test