proper timing of nitrogen fertilizer appliction can increase tuber yield ...
PROPER TIMING OF NITROGEN FERTILIZER APPLICTION CAN INCREASE TUBER YIELD AND QUALITY PERFORMANCE OF IRRIGATED POTATO Samuel YC Essah Colorado State University, Dept. of Horticulture & Landscape Architecture, San Luis Valley Research Center, Center, Colorado E-Mail: [email protected] FORTRESS RUSSET (medium to late cultivar) Leaf Area Index (LAI) @ Late Tuber Bulking:
BACKGROUND INFORMATION Nitrogen (N) fertilizer application timing is one of the most important management techniques that potato growers can use to increase N Use Efficiency, and to improve tuber yield and quality. For efficient nitrogen utilization, nitrogen fertilizer application has to be synchronized with times of higher N demand by the potato crop.
4.5
Irrigated potato
In earlier studies conducted by Roberts et al. (1982), they concluded that low levels of early season nitrogen fertilizer application may result in low yields due to poor tuber set, than when adequate N is applied early in the season. However, Kleinkopf et al. (1981) showed that the application of high levels of N at planting delayed tuber initiation and growth. In studies with Kennebec potatoes, MacLean (1984) observed that applying all N at planting increased tuber yield. Results of these earlier studies indicate that potato cultivars vary in their response to N fertilizer application timing.
The objective of this study was to evaluate the yield and quality response of early and medium maturity Russet potato cultivars to nitrogen application timing.
EXPERIMENTAL PROCEDURE
MERCURY RUSSET (early cultivar) Leaf Area Index (LAI) @ Late Tuber Bulking:
Experimental Design and Treatments
a
490 480
b
470
b
460 450 440
b
33% 50% 66% ALL
430 420
Fig 4a
400
360 350
b 340
33% 50% 66% ALL
bc 330 320
c
310 300
Fig 4b
Leaf Area Index
1
SUMMARY
33% 50%
0.6
The purpose of this study was to evaluate the effect of nitrogen application timing on the performance of early and medium maturity Russet potato cultivars.
66% ALL
0.4 0.2
Mercury Russet and Fortress Russet were used as candidate potato cultivars to represent early and medium maturity Russets, respectively.
Fig 1
0
Tuber Yield: Higher rates of required N (50-66%) applied pre-plant maximized total tuber yield of Mercury Russet (early maturity cultivar) - fig 2a. Total yield was significantly reduced when all required N was applied Pre-plant. Application of 50% required N pre-plant, and the remaining N applied in-season maximized marketable tuber yield (fig 2b). 395 390
ab
385 380
33% 50% 66% ALL
b
375 370 365
c
360 355 350
Fig 2a
Marketable (> 4 oz.) Tuber Yield (cwt/acre)
a
Total Tuber Yield (cwt/acre)
Plant samples were taken during tuber bulking to evaluate green leaf area (Leaf Area Index) and rate of tuber bulking. At maturity, tubers from two center rows were harvested for total yield. Harvested tubers were mechanically sized into marketable (> 4 oz.), large marketable (> 6 oz.), and premium size (> 10 oz.) tubers. Tubers from each plot were evaluated for external (growth cracks, knobs, and misshapes) and internal (hollow heart) defects. Tuber specific gravity was measured using the weight-in-air/weight-in-water method.
Tuber Yield:
ALL
410
0.8
Data Collection and Measurements
3
a
Green leaves were more persistent and senescence was delayed when higher rates of N were applied pre-plant and lower rates of N applied in-season (fig 1)
The field study was conducted at the San Luis Valley Research Center, Colorado State University, on a gravely sandy loam soil.
The experimental plots were part of a two year barley-potato crop rotation. Cut seed pieces (2.5-3.0 oz.) from potato cultivars Mercury Russet (early maturity) and Fortress Russet (medium maturity) were machine planted. Each plot consisted of four rows 25 feet long and 34 inches between rows. All other cultural management practices followed recommendations for Russet potato management in Colorado.
66%
RESULTS AND DISCUSSION
1.2
Cultural Management
50%
Total and marketable tuber yield of Fortress Russet was maximized 2 Fig 3 when lower levels of seasonal required N (33% of required N) was applied pre-plant, and the remaining N applied in split application after tuber formation (Fig 4a and b).
Experimental Site
The experiment was laid out as a randomized complete block design, with each treatment replicated four times. A total of 140 lb. N/Acre was applied to all treatments. The difference in treatments was N rate applied pre-plant and how much N was applied in-season. Treatments included the following: 1. All required N fertilizer applied pre-plant (All) 2. 33% of required N applied pre-plant and the remainder applied in split application after tuber formation (33%) 3. . 50% of required N applied pre-plant and the remainder applied in split application after tuber formation (50%) 4. 66% of required N applied pre-plant and the remainder applied in split application after tuber formation (66%)
3.5
Marketable (> 4 oz.) Tuber Yield (cwt/acre)
STUDY OBJECTIVE
33%
2.5
Total Tuber Yield (cwt/acre)
With the development of new potato cultivars, there is the need to evaluate the appropriate N application timing for new potato cultivars to increase their N Use Efficiency for increased tuber yield and quality.
Leaf Area Index
4
Green leaves were more persistent and senescence was delayed when 50% or all of the required N was applied pre-plant (fig 3).
a
230 220
Data from these studies indicate that for early maturity Russets such as Mercury Russet, pre-plant application of higher levels (50 to 66%) of seasonal required nitrogen could maximize total and marketable tuber yield. For medium to late maturity cultivars such as Fortress Russet, application of very low levels (33%) of required nitrogen pre-plant, could maximize tuber yield.
b 210
LITERATURE CITED b
200 190
33% 50% 66% ALL
Kleinkopf, G.E., D.T. Westermann, and R.B. Dwelle. 1981. Dry matter production and nitrogen utilization by six potato cultivars. Agron. J. 73:799-802.
180
c
MacLean, A.A. 1984. Time of application of fertilizer for potatoes in Atlantic Canada. Am. Potato J. 61:23-29.
170 160 150
Fig 2b
Roberts, S., W.H. Weaver, and J.P. Phelps. 1982. Effect of rate and time of fertilization of nitrogen and yield of Russet Burbank potatoes under Center pivot irrigation. Am Potato J. 59:77-96.
BACKGROUND INFORMATION Nitrogen (N) fertilizer application timing is one of the most important management techniques that potato growers can use to increase N Use Efficiency, and to improve tuber yield and quality. For efficient nitrogen utilization, nitrogen fertilizer application has to be synchronized with times of higher N demand by the potato crop.
4.5
Irrigated potato
In earlier studies conducted by Roberts et al. (1982), they concluded that low levels of early season nitrogen fertilizer application may result in low yields due to poor tuber set, than when adequate N is applied early in the season. However, Kleinkopf et al. (1981) showed that the application of high levels of N at planting delayed tuber initiation and growth. In studies with Kennebec potatoes, MacLean (1984) observed that applying all N at planting increased tuber yield. Results of these earlier studies indicate that potato cultivars vary in their response to N fertilizer application timing.
The objective of this study was to evaluate the yield and quality response of early and medium maturity Russet potato cultivars to nitrogen application timing.
EXPERIMENTAL PROCEDURE
MERCURY RUSSET (early cultivar) Leaf Area Index (LAI) @ Late Tuber Bulking:
Experimental Design and Treatments
a
490 480
b
470
b
460 450 440
b
33% 50% 66% ALL
430 420
Fig 4a
400
360 350
b 340
33% 50% 66% ALL
bc 330 320
c
310 300
Fig 4b
Leaf Area Index
1
SUMMARY
33% 50%
0.6
The purpose of this study was to evaluate the effect of nitrogen application timing on the performance of early and medium maturity Russet potato cultivars.
66% ALL
0.4 0.2
Mercury Russet and Fortress Russet were used as candidate potato cultivars to represent early and medium maturity Russets, respectively.
Fig 1
0
Tuber Yield: Higher rates of required N (50-66%) applied pre-plant maximized total tuber yield of Mercury Russet (early maturity cultivar) - fig 2a. Total yield was significantly reduced when all required N was applied Pre-plant. Application of 50% required N pre-plant, and the remaining N applied in-season maximized marketable tuber yield (fig 2b). 395 390
ab
385 380
33% 50% 66% ALL
b
375 370 365
c
360 355 350
Fig 2a
Marketable (> 4 oz.) Tuber Yield (cwt/acre)
a
Total Tuber Yield (cwt/acre)
Plant samples were taken during tuber bulking to evaluate green leaf area (Leaf Area Index) and rate of tuber bulking. At maturity, tubers from two center rows were harvested for total yield. Harvested tubers were mechanically sized into marketable (> 4 oz.), large marketable (> 6 oz.), and premium size (> 10 oz.) tubers. Tubers from each plot were evaluated for external (growth cracks, knobs, and misshapes) and internal (hollow heart) defects. Tuber specific gravity was measured using the weight-in-air/weight-in-water method.
Tuber Yield:
ALL
410
0.8
Data Collection and Measurements
3
a
Green leaves were more persistent and senescence was delayed when higher rates of N were applied pre-plant and lower rates of N applied in-season (fig 1)
The field study was conducted at the San Luis Valley Research Center, Colorado State University, on a gravely sandy loam soil.
The experimental plots were part of a two year barley-potato crop rotation. Cut seed pieces (2.5-3.0 oz.) from potato cultivars Mercury Russet (early maturity) and Fortress Russet (medium maturity) were machine planted. Each plot consisted of four rows 25 feet long and 34 inches between rows. All other cultural management practices followed recommendations for Russet potato management in Colorado.
66%
RESULTS AND DISCUSSION
1.2
Cultural Management
50%
Total and marketable tuber yield of Fortress Russet was maximized 2 Fig 3 when lower levels of seasonal required N (33% of required N) was applied pre-plant, and the remaining N applied in split application after tuber formation (Fig 4a and b).
Experimental Site
The experiment was laid out as a randomized complete block design, with each treatment replicated four times. A total of 140 lb. N/Acre was applied to all treatments. The difference in treatments was N rate applied pre-plant and how much N was applied in-season. Treatments included the following: 1. All required N fertilizer applied pre-plant (All) 2. 33% of required N applied pre-plant and the remainder applied in split application after tuber formation (33%) 3. . 50% of required N applied pre-plant and the remainder applied in split application after tuber formation (50%) 4. 66% of required N applied pre-plant and the remainder applied in split application after tuber formation (66%)
3.5
Marketable (> 4 oz.) Tuber Yield (cwt/acre)
STUDY OBJECTIVE
33%
2.5
Total Tuber Yield (cwt/acre)
With the development of new potato cultivars, there is the need to evaluate the appropriate N application timing for new potato cultivars to increase their N Use Efficiency for increased tuber yield and quality.
Leaf Area Index
4
Green leaves were more persistent and senescence was delayed when 50% or all of the required N was applied pre-plant (fig 3).
a
230 220
Data from these studies indicate that for early maturity Russets such as Mercury Russet, pre-plant application of higher levels (50 to 66%) of seasonal required nitrogen could maximize total and marketable tuber yield. For medium to late maturity cultivars such as Fortress Russet, application of very low levels (33%) of required nitrogen pre-plant, could maximize tuber yield.
b 210
LITERATURE CITED b
200 190
33% 50% 66% ALL
Kleinkopf, G.E., D.T. Westermann, and R.B. Dwelle. 1981. Dry matter production and nitrogen utilization by six potato cultivars. Agron. J. 73:799-802.
180
c
MacLean, A.A. 1984. Time of application of fertilizer for potatoes in Atlantic Canada. Am. Potato J. 61:23-29.
170 160 150
Fig 2b
Roberts, S., W.H. Weaver, and J.P. Phelps. 1982. Effect of rate and time of fertilization of nitrogen and yield of Russet Burbank potatoes under Center pivot irrigation. Am Potato J. 59:77-96.
