Nitrogen Fertilization of Sweet Potato and Its Effect on Hoot Set and Yield

Mulkey, W.A.; McLemore, W.B.; Talbot, T.

doi:10.21273/hortsci.29.7.726d

Cited by 1 publication

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results from our work coincide with field plot data regarding N rate effects on SR yield in 'Beauregard,' particularly in the southeastern U.S. production regions. Mulkey at al. (1994) reported that the maximum yield of 'Beauregard' U.S. No.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Variation in Nitrogen Rate and Local Availability Alter Root Architecture Attributes at the Onset of Storage Root Initiation in ‘Beauregard’ Sweetpotato

Villordon

LaBonte²,

Firon³

et al. 2013

horts

View full text Add to dashboard Cite

This study characterized the influence of nitrogen (N) rates and variation in local availability on root architecture as measured by lateral root (LR) development attributes during the onset of the storage root (SR) initiation stage in ‘Beauregard’ sweetpotato adventitious roots (ARs). In N rate experiments, plants grown without fertilizer N showed significantly lower values for all measured LR attributes compared with fertilized plants. Total first- (1LR) and second-order LR (2LR) length increased by 78% and 2873%, respectively, as N was increased from 0 to 50 kg·ha−1. Total 1LR and 2LR number increased by 32% and 1465%, respectively. Increasing the N rates to 100 and 200 kg·ha−1 did not result in further increases for all LR attributes measured. There were no differences in AR number between untreated controls and plants fertilized with 50 kg N/ha. However, the number of ARs increased by 65% when fertilizer N was increased from 50 to 100 kg·ha−1. Increasing the rate to 200 kg·ha−1 did not result in further increases in AR number. In split-root experiments, roots grown in the compartment with 50 kg N/ha had 135% and 2916% increase in total 1LR and 2LR length, respectively, compared with roots grown in the compartment without fertilizer N. Total 1LR and 2LR number increased by 110% and 2114%, respectively. There were 111% more ARs in the fertilized compartment relative to the unfertilized compartment. There were no differences in LR attributes and AR number between compartments that received similar fertilizer N rates. In fertilizer placement experiments, there were no differences in LR attributes between pre-mixing fertilizer N and placement of fertilizer ≈4 cm below the surface of the growth substrate. There were also no differences between the unfertilized control and placement of fertilizer ≈4 cm from the bottom of the pot. Plants grown in substrate with pre-mixed N showed 38% and 342% increase in 1LR and 2LR length, respectively, relative to the bottom placement of N. Total number of 1LR and 2LR in the growth substrate with pre-mixed N increased by 30% and 312%, respectively, relative to the bottom placement of N. These results represent the first evidence for the association between sweetpotato root architectural attributes and variation in N rate and localized availability. These results are also consistent with findings in model systems in which local N presence is necessary for LR development. This information can be used to further optimize SR yield by helping to ensure the availability of N at the optimum rate across time and space.

show abstract

Section: Discussionmentioning

confidence: 99%

“…In Louisiana, sweetpotato growers commonly use urea or urea-containing fertilizers (Cannon, personal communication). The N rate of 50 kg · ha -1 has been documented by previous work as optimum for 'Beauregard' in Louisiana (Mulkey et al, 1994). The second set of experiments used a split-root culture system (SPLIT ROOT) ( Fig.…”

Section: Methodsmentioning

confidence: 99%