UVM Theses and Dissertations
Format:
Print
Author:
Menasha, Sandra Robin
Dept./Program:
Plant and Soil Science
Year:
2005
Degree:
MS
Abstract:
Despite reduced yields, growers are transplanting sweet corn to hasten maturity time to target profitable early markets in the Northeast. Researchers have ascribed some negative impacts on yield to restricted rooting volume. Therefore, the impacts plug cell volume had on sweet corn transplant root architecture and biomass accumulation were investigated. These changes were quantified in the greenhouse and then tested in the field. Zea mays L. 'Temptation' was sown in cell volumes of 14, 15, 19, and 29 mL with three media substrate environments; compost-based blend, soilless commercial greenhouse mix (Fafard), and soilless commercial mix fertilized with 200 ppm N 3N-3P-3K organic fertilizer (F+F). Transplants were raised for 2 weeks before transplanted into 8 inch (20.3 cm) pots and were grown for an additional 2 weeks to simulate field planting effects. After an initial 2-week growth period, for each experimental treatment center cells were harvested from each replicate for analysis using the WinRHIZO Pro root scanning system.
Based on mean separation tests (SNK), increasing cell volume before transplanting significantly increased root surface area and total root length. Mean root surface area was 30% greater and total root length 67% greater when raised in a 29 mL cell versus a 15 mL cell pre-transplanting. After transplanting into 8 inch pots, the trend in root surface area remained the same with a 26% increase in surface area in the 29 mL cells compared to the 15 mt cells. Substrate environment also significantly impacted root and shoot biomass production. Root biomass pre-transplanting was 11% greater in the Fafard substrate compared to the compost substrate. Post-transplanting, significant effects on root biomass accumulation resulting from substrate, environment were nullified. The compost substrate produced shoots 17% greater in biomass than the F+F treatment pre- and posttransplanting. Under ideal growth conditions, the 29 mL cells had the most positive influence on root architecture. However, no significant differences were detected in the 14, 15, and 19 mL cells in regard to root architecture and biomass accumulation pre- and posttransplanting.
Although transplanting sweet corn in the Northeast has proved to be successful, early spring storms and labor constraints can delay transplanting when establishment is most desirable. 'Temptation' se sweet corn transplants 14, 16, 18,20, and 22 d old at the time of field planting were compared against a direct seeded (DS) treatment to explore the effects delayed planting combined with plug cell volume differences would have on transp1ant ear quality and early yield. All transplanted and DS treatments were field planted on 24 May 2004 at two contrasting field sites. Field 1 classified as a Deerfield soil; loamy fine sand, moderately drained and Field 2 classified as a Windsor soil; loamy sand, excessively drained. Cell volume had no significant effect on transplant ear quality and yield. Ear length was significantly affected by field site (p Đ0.0001) where ear diameter was significantly affected by planting delay (p=0.0145). Field site (p Đ0.0001) and planting delay (p=0.0090) both significantly affected early marketable ears/acre. The results indicate that transplants can remain in the plug cells up to 6 d before significant differences negatively impact ear diameter, tip fill, and early marketable yields. The DS treatment provided similar results in ear length, diameter, and early marketable yield indicating that transplanting sweet corn is a viable practice and can be achieved without negative effects with a delay of up to 6 d.
Based on mean separation tests (SNK), increasing cell volume before transplanting significantly increased root surface area and total root length. Mean root surface area was 30% greater and total root length 67% greater when raised in a 29 mL cell versus a 15 mL cell pre-transplanting. After transplanting into 8 inch pots, the trend in root surface area remained the same with a 26% increase in surface area in the 29 mL cells compared to the 15 mt cells. Substrate environment also significantly impacted root and shoot biomass production. Root biomass pre-transplanting was 11% greater in the Fafard substrate compared to the compost substrate. Post-transplanting, significant effects on root biomass accumulation resulting from substrate, environment were nullified. The compost substrate produced shoots 17% greater in biomass than the F+F treatment pre- and posttransplanting. Under ideal growth conditions, the 29 mL cells had the most positive influence on root architecture. However, no significant differences were detected in the 14, 15, and 19 mL cells in regard to root architecture and biomass accumulation pre- and posttransplanting.
Although transplanting sweet corn in the Northeast has proved to be successful, early spring storms and labor constraints can delay transplanting when establishment is most desirable. 'Temptation' se sweet corn transplants 14, 16, 18,20, and 22 d old at the time of field planting were compared against a direct seeded (DS) treatment to explore the effects delayed planting combined with plug cell volume differences would have on transp1ant ear quality and early yield. All transplanted and DS treatments were field planted on 24 May 2004 at two contrasting field sites. Field 1 classified as a Deerfield soil; loamy fine sand, moderately drained and Field 2 classified as a Windsor soil; loamy sand, excessively drained. Cell volume had no significant effect on transplant ear quality and yield. Ear length was significantly affected by field site (p Đ0.0001) where ear diameter was significantly affected by planting delay (p=0.0145). Field site (p Đ0.0001) and planting delay (p=0.0090) both significantly affected early marketable ears/acre. The results indicate that transplants can remain in the plug cells up to 6 d before significant differences negatively impact ear diameter, tip fill, and early marketable yields. The DS treatment provided similar results in ear length, diameter, and early marketable yield indicating that transplanting sweet corn is a viable practice and can be achieved without negative effects with a delay of up to 6 d.