Effect of seed piece population on the yield and processing quality of Russet Burbank potatoes

The effect of seed piece population on tuber yield, size distribution and processing quality of Russet Burbank potatoes grown under nonirrigated conditions in southern Manitoba from 1983 to 1987 was determined. Seed pieces were planted at 21.7, 26.3, 33.3 and 45.5 thousand seed pieces per hectare, and plant emergence generally exceeded 90% of the seed piece population. Marketable tuber (greater than 5 cm in diameter) yields were not affected by seed piece population. As population increased, however, the number of harvested tubers increased and average tuber size decreased, which resulted in a decreased yield of premium tubers (greater than 284 g) and an increased yield of small tubers (less than 5.0 cm in diameter). Specific gravity, the incidence of hollow heart in maingrade (5 cm in diameter to 284 g in weight) and premium tubers, and fry color were not significantly affected by seed piece population. In the one trial tested, sucrose content decreased as population increased, however, this was not reflected in improved fry color after storage.     

Effect of seed piece size on performance of three potato varieties in the Klamath Basin of Oregon

A survey of cut seed lots from Klamath Basin commercial potato operations showed poor uniformity of seed piece size and numerous undersize seed pieces in most of the 18 seed lots examined over two years. Experiments were conducted in 1995, 1996, and 1997 to evaluate effects of seed piece size on the performance of Russet Burbank, Russet Norkotah, and Century Russet cultivars. Weighed seed tubers were cut into four pieces to obtain seed piece sizes of 21, 35, 50, 64, and 78 g (+/-2 g). Seed pieces less than 50 g resulted in delayed emergence and reduced stem numbers in all varieties. Effects of seed piece size on yield and tuber size distribution were greatest for Century Russet and least for Russet Norkotah, but were significant for all varieties over the three-year study. Increasing seed piece size increased yield of U.S. No.1 and total yield, while reducing tuber size. An economic analysis, based on crop values for fresh market use and seed costs, found optimum seed piece sizes of 64 g for Russet Burbank and Century Russet and 50 g for Russet Norkotah.     

Influencing seed tuber yield of Ranger Russet and Shepody potatoes with gibberellic acid

Freshly-cut seed pieces of the potato cultivars Ranger Russet and Shepody were dipped in 0, 0.5, 1 or 2 mg/1 Gibberellic Acid (GA₃) prior to planting. GA₃ treatments increased stem and tuber numbers per hill of both cultivars and shifted tuber size profile toward the production of more seed-sized (up to 226 g) tubers and fewer large (greater than 340 g) tubers. The effect of GA₃ on reducing average tuber size was similar for the two cultivars. Total tuber yields were not affected. A 2 mg GA₃/1 seed piece dip decreased the yield of US#1 tubers in Ranger Russet primarily due to a significant increase in yield of tubers less than 226 g. Also, yields of culls were greater after a 1 mg GA₃/1 seed piece treatment, suggesting Ranger Russet is sensitive to this concentration of GA₃. One and 2 mg GA₃/1 seed piece dips to Shepody increased yields of tubers less than 113 g by 93% and reduced the yield of tubers greater than 340 g by 25% to 50%. GA₃ at 1 to 2 mg/1 may be useful in the production of seed potatoes with the cultivar Shepody which tends to produce many large tubers.     

Comparative performance of different-sized seed tubers derived from true potato seed

The growth and yield of plants from different-sized seed tubers derived from true potato seed were evaluated on a per stem, per plant, and per unit area basis using either single or multiple-sprout tubers. In single-sprout tubers, haulm dry weight per stem 47 days after planting was greater in the 40–60 g tubers when compared with that in the 5–10 g or the 10–20 g tubers. This resulted in greater tuber weight per stem in the 40–60 g tubers throughout the growing season. The number of tubers per stem was not affected by seed tuber size. In multiple-sprout seed tubers of increasing size, total tuber number and total tuber weight, as well as weight of those tubers larger than 45 mm, increased on a per plant basis but decreased on a per stem basis. At different rates of planting, 1–5 g seed tubers produced smaller tubers than 5–10 g or 10–20 g seed tubers. Increased rate of planting resulted in non-significant yield increases per unit area in plots planted with 1–5 g seed tubers. The yield increases were significant when 5–10 g and 10–20 g seed tubers were planted at higher rates. The number of main stems per unit of seed tuber weight was five times greater in 1–5 g tubers compared with that in 40–60 g tubers. This resulted in low seed weights per hectare when small tubers were planted and in a high ratio of harvested to planted tuber weight.     

Influence of seed placement on Russet Burbank potato yield and grade

Potato seed pieces were hand planted with different spacings in the row and percentages of doubles to determine the effects on total yield and tuber size distribution. The objective was to determine acceptable performance levels for commercial potato planters. Average tuber size increased as the percentage of double seed pieces decreased or as the in-row spacing between single seed pieces increased. Yield of tubers smaller than 113 g was the most sensitive parameter and they increased as in-row spacing decreased and as the percentage of double seed pieces increased. Yield of tubers larger than 283 g increased as in-row spacing increased but only for the first year. Total yield was not affected by the change of in-row spacing or the percentage of doubles.     

Soil water stress and the growth and yield of potato plants grown from microtubers and conventional seed tubers

Tuber yields of potato plants grown from microtubers in fields are more variable than yields from conventional seed tubers (CT). One reason could be their higher susceptibility to water stress. This study clarified the effect of soil water stress from 1 month after emergence on the growth and yield of plants grown from conventional seed tubers and microtubers in fields. Microtubers (0.5–3 g) and conventional seed tubers (50 g) were grown in Hokkaido, Japan, over three field seasons. One month after emergence, poly-shelters were placed over the plots to prevent rainfall, and either irrigated (wet plot) or non-irrigated (dry plot) treatments were formed. At mid-flowering (about 50 days after emergence) leaf area index (LAI) in microtuber plants was decreased relatively more due to soil water stress than LAI in conventional seed tuber plants. However, at maximum shoot growth (about 80 days after emergence) both microtuber and conventional seed tuber plants had a similar relative decrease in LAI due to soil water stress. At mid-flowering and maximum shoot growth microtuber and conventional seed tuber plants had reduced stomatal conductance due to soil water stress, but the reduction in stomatal conductance was greater in conventional seed tuber plants than in microtuber plants. Microtuber and conventional seed tuber plants had similar root development at maximum shoot growth. Tuber production from mid-flowering until plant maturity was similarly affected by soil water stress in microtuber and conventional seed tuber plants. At harvest, plants affected by soil water stress had about 87% of the tuber dry weight of irrigated plants. We conclude, that the greater variation on tuber yield of microtuber plants cannot be attributed to soil water stress from 1 month after emergence.     

Comparative performance of three small seed tuber sizes and standard size seed tubers planted at similar stem densities

Summary Small seed tubers of 1–5 g, 5–10 g and 10–20 g were planted at the same sprout densities as standard size seed tubers of 40–60 g in order to give similar stem densities. Early ground cover by foliage, total yield, and yield of tubers >45 mm were consistently greater in plots planted with larger seed tubers. The effect of seed tuber size on yield and tuber number per stem varied between years but 1–5 g seed tubers always gave lower yields per stem than larger seed tubers. Reducing the spacing between rows from 90 cm to 60 cm and maintaining the same sprout density was more effective in increasing yields from small seed tubers than increasing sprout density from 20 to 40 sprouts per m² by reducing plant spacing within the row.     

Effect of whole seed tuber size and pre-plant storage conditions on yield and tuber size distribution of Russet Burbank

Field experiments were conducted in 1995, 1996, and 1997 at Agriculture and Agri-Food Canada’s Harrington Research Farm to assess the effect of whole seed tuber size and pre-plant seed storage conditions on processing yield (> 51 mm dia.) of potato (Solanum tuberosum L. cv Russet Burbank). Following commercial storage, seed tubers were stored at 4.4 C then subjected to one of three pre-plant treatments: (1) planted directly from storage, (2) held at 10 C for 3 wk before planting, or (3) green-sprouted for 3 wk before planting. Five sizes of whole seed were used (28, 42, 56, 70, and 84 g) with a variable size cut seed treatment added for comparison. Plots were harvested 138,134, and 131 days after planting in 1995, 1996, and 1997, respectively. Cut seed produced a higher yield of tubers > 51 mm diameter in comparison to all whole tuber seed sizes, with the exception of the 28 and 56 g sizes. In terms of total yield, the 28and 42-g whole seed tubers yielded significantly less than all other seed sizes examined. Warming or greensprouting seed tubers prior to planting did not increase tuber yield. The larger whole seed tuber sizes tended to result in greater numbers of stems and tubers per plant. To maximize marketable yield of Russet Burbank planted from whole seed tubers, it is recommended that the seed be between 28 and 42 g in size. Accepted for publication 25 May 2004.     

The effect of density on tuber yield in plants grown from true potato seed in seed beds during two contrasting seasons

The production of potatoes from true seed was studied in direct-sown seed beds during both winter and summer seasons in Lima, Peru. After emergence, seedlings were thinned to give 6, 12, 24, 48 or 96 plants per m². In all five density treatments plants were arranged in a square configuration. In both seasons, increasing plant density significantly increased total tuber number as well as tuber weights in the grades 1–5 g, 5–20 g and 20–40 g. The yield of tubers larger than 40 g was similar in all densities. In the warm summer season, tuber number was significantly reduced and mean tuber weight was 56% greater compared with that in the winter season. The potential of producing consumer potatoes from true seed in seed beds in warm climates is discussed.     

Field production of potatoes from true seed and its use in a breeding programme

Summary Potato crops, grown from true potato seed (TPS) sown directly into fields, required a long growing season and the yield, tuber size and quality were inferior to tuber-propagated crops. Some plants produced excellent yields of high-quality tubers and some lines had earliness, high yield capacity, uniform tuber type and high solids. Field sowing of TPS has good potential, both as a breeding tool and for potato production in long-season, underdeveloped countries where healthy seed tubers are not readily available. Correlation analyses showed positive relationships between seedling vigour, mature plant size, and number and yield of tubers but these growth parameters were not significantly related to tuber size and they had a strong negative relationship to density (specific gravity). Mention of a trade name of a company is for specific information only and does not constitute a guarantee or warranty of a product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.     

Relationships between tuber size and time of harvest to hollow heart initiation in Dryland Norgold Russet potatoes

In four years of field trials approximately75% of hollow heart was initiated in tubers between 5.1 and 7.6 cm in diameter. Only rarely was hollow heart initiated in tubers less than 3.8 cm. The frequency of hollow heart was approximately nine times greater in medium sized tubers (6.4 to 7.6 cm) and 34 times greater in large tubers (over 7.6 cm) than in small tubers (5.1 to 6.4 cm). The number of tubers with hollow heart increased linearly through the last five weeks of the growing season. Hollow heart during the four years ranged from 4200 to 31900 tubers/ha or 2.9 to 13.0% of all tubers over 2.5 cm. There were consistent increases in tuber growth between harvests in each season, inferring an absence of severe plant stress and supporting the hypothesis that hollow heart was due to tissue tension associated with tuber enlargement.     

Rapid seed multiplication by planting into beds micro tubers and in vitro plants

Summary Micro tubers of 3 weight categories with means of 0.63 g, 1.25 g or 2.50 g and in vitro plants were planted in nursery beds at densities of 24 and 48 plants per m². The average tuber numbers and tuber weights were, respectively, 38% and 17% higher at 48 than at 24 plants per m². In vitro plants produced significantly more but smaller tubers than did plants grown from micro tubers. Plants grown from the larger micro tubers produced a similar number of tubers but larger ones than did plants grown from small micro tubers. Tuber yields and multiplication rates are discussed.     

Growth and yield of potato (Solanum tuberosum L.) cultivars Atlantic and Monona as influenced by seed type and size

Growth and yield of potato plants grown from several weight classes of whole “B” seed, unsorted “B” seed, and 56 g cut seed pieces were compared in Ohio in 1988 and 1989. Whole “B” seed classes were 8 g ranges with means of 35 g, 43 g, 51 g, and 58 g. Unsorted “B” seed was used as an experimental control. Treatment responses were inconsistent. Few significant differences were evident at bloom in leaf area, number of main stems, and total plant dry weight (without tubers) per hill. However, the number of tubers greater than 1 cm in diameter per hill at bloom was less for cut seed as compared with several whole seed treatments. Percent stand at four weeks was also less for cut seed compared with 51 g and 58 g whole tuber treatments. Significant differences in total and U.S. No. 1 yields were absent despite differences in several plant growth variables early in the 1988 and 1989 growing seasons.     

Comparative effects of cut and treated seed tubers vs untreated whole seed tubers on seed decay, Rhizoctonia stem canker, growth, and yield of Russet Burbank Potatoes

Whole seed tubers have been reported to have performance advantages over seed tubers that have been cut, even if the cut tuber pieces are treated with a fungicide dust. For this study, whole seed tubers were compared to cut seedpieces and to cut seedpieces treated with four different commercial fungicide dusts for five consecutive seasons. A new field generation 3 Russet Burbank seed lot was used for each of the five years of this study. Both whole tubers and cut seedpieces were inoculated withFusarium spp., and the seedpieces were then treated with a fungicide dust. Inoculated and uninoculated untreated controls were also included. Emergence,Fusarium seed decay,Rhizoctonia stem canker, stem numbers, and vigor, as well as yield and grade data were obtained.Rhizoctonia stem canker in stems grown from whole seed tubers was significantly higher than in stems from seedpieces receiving fungicide treatment in several of the study years. Predicting whole seed tuber performance is difficult because performance varies more from year to year than performance of cut and treated seedpieces. Yield performance of whole seed tubers was not significantly better than cut and fungicide-treated seedpieces in any experimental year, and yield of large (over 280 g) tubers was significantly less than that recorded for two of the treatments when data from all five years were combined. This study demonstrated that untreated whole seed did not outperform cut and treated seedpieces for vigor, stem numbers, disease ratings, or yield in small plot comparisons for five consecutive seasons.     

Inter-stem and inter-tuber competition in potatoes

Summary Seed pieces of varying size and bearing different numbers of uniform growing sprouts were planted in specific combinations. Sequential harvests were made and the growth of the plants followed. There appeared to be competition between emerging sprouts for nutrients and water from the soil. This competition influenced the number of stems produced per sprout and the size attained by these stems. There was no effect of size of the seed piece on the apparent time to tuber initiation. A constant number of tubers were formed per stem despite large variations in stem size, but the final weight of tubers per stem was lower the greater the number of stems per hill. The number of tubers larger than 2| inches (5.7 cm) remained constant over the whole range of stem numbers per hill and the mean weights of tubers in the two size categories larger than 1| inches (3.2 cm) remained constant after the second harvest. These results suggest that only a few of the tubers in each hill were growing rapidly at any one time. There was no effect of cutting the seed tubers on any aspect of the growth of potatoes that was measured which could not be attributed to an effect on either the size of the seed piece or on the number of sprouts per seed piece.     

The effect of stem population on tuber yield in a trial with single-stem seed pieces

Summary Excised eyes on 5 g of seed tuber tissue were used to grow plants with single stems. These were transplanted in the field at densities of 120 000, 180 000 and 240 000 plants/ha, with in-row spacings of 16 or 33 cm. Total tuber yield was not affected, although more tubers were produced at the high densities. Tuber numbers did not increase in proportion to the number of stems. This was due to the fact that the number of tubers per stem decreased from a mean of 4.8 to 2.9 with increasing stem populations.     

1,4-Dimethylnaphthalene treatment of seed potatoes affects tuber size distribution

1,4-DMN is a relatively new sprout inhibitor for use on maincrop and seed potatoes. Despite its registration as a “dormancy enhancer” for seed, relatively little is known about its effects on plant establishment and productivity. The main objective of this study was to evaluate the effects of 1,4-DMN on the productivity of seed potatoes. ‘Umatilla Russet’ (UR), ‘Ranger Russet’ (RR), and ‘Russet Burbank’ (RB) seed tubers were stored at 4, 7, and 9 C over three seasons to create 80-, 554- and 642-degree-day seed, and 1,4-DMN was applied to maintain dormancy several times during each season. 1,4-DMN residue levels at the end of storage were lower in seed aged at higher temperatures. Multiple applications of 1,4-DMN at higher-than-label rates were necessary to effectively inhibit sprouting of seed of all cultivars stored above 4 C. In field trials, depending on cultivar and year, 1,4-DMN either delayed plant emergence slightly or had no effect. 1,4-DMN increased stem numbers from RB and UR seed, but not from RR seed. 1,4-DMN reduced total tuber yields by 3.2 to 5.6 t ha^?1 (5% to 9%), and U.S. No. 1 tuber yields by 4.8 to 7.8 t ha^?1 (8% to 15%) in all cultivars, regardless of seed tuber age. 1,4-DMN also reduced the average tuber weight for all three cultivars and shifted the size distribution from larger (> 284 g) to smaller tubers. 1,4-DMN reduced the respective yields of > 397-g, 340-to 397-g, and 284-to 340-g tubers by 43%, 19%, and 18% for RR seed, 31%, 14%, and 11% for RB seed, and 40%, 47%, and 27% for UR seed. Conversely, depending on cultivar, yields of smaller tubers (≤170 g) were 11% to 38% higher from 1,4-DMN-treated seed. The shift in tuber size distribution for RR was accompanied by a 1,4-DMN-induced increase in tuber number per plant and per hectare. However, no such effects on tuber set occurred in RB and UR. Moreover, in most cases, the 1,4-DMN effects on yield and tuber size distribution were independent of seed age. Since the 1,4-DMN-induced shifts in tuber size distribution were greater than the reductions in total and U.S. No. 1 yields, 1,4-DMN may be a suitable treatment to reduce average tuber size and increase yield and uniformity of specific size classes of tubers to more closely match market requirements.     

整薯播种对马铃薯生育及产量的影响

1979～1984年,在黑龙江省北部黑土地区气象条件、生产水平和栽培条件下,通过田间试验,研究了整薯播种对马铃薯生育和产量的影响。结果表明:整薯播种与传统习惯的切块播种相比,6年期间平产出现频率为2次,一般年份整薯播种比切块播种增产9～12%,在春旱严重的1980年,整薯播种表现出非常突出的抗旱保苗效果。在群体叶面积发展进程上,整薯播种表现早发早衰,切块播种晚发晚表,一般年份光合势前者比后者高9.6%,春旱严重的1980年高82.8%。块茎商品率以112.5克为准时,6年平均整薯播种为74.1%,切块播种为80.0%,两者相差5.9%;以50克为准时,整薯播种为97.3%,切块播种为98.2%,两者相差0.9%。     

Effect of seed piece removal on yield and agronomic characteristics of Russet Burbank potatoes

There is inadequate information available to ascertain the length of time seed pieces contribute to the yield and agronomic characteristics of potatoes (Solanum tuberosum L.) under field conditions. Previous studies have not accounted for root system disturbance during seed piece removal. In 1994, 1995, and 1997 a field study was conducted using Russet Burbank to determine whether seed piece removal at each of three growth stages affects yield and agronomic characteristics. A trowel was used to tunnel into the side of potato hills to remove seed pieces by hand either at emergence, at 20- cm plant height, or at first bloom. Control plots consisted of plants with root systems disturbed on the same date as seed removal (disturbed control) or not treated (non-disturbed control). Seed pieces were analyzed for solids, sucrose, and reducing sugars before planting and after removal at each growth stage in 1997. Removing seed pieces or disturbing roots at all growth stages significantly decreased total and U.S. No. 1 yields compared with non- disturbed control. Total yield from plots disturbed at emergence was 37.8 Mg ha^-1 compared to 22.1 Mg ha^-1 when the seed pieces were removed. Disturbing seed pieces at emergence resulted in U.S. No. 1 yield of 21.2 Mg ha^-1 compared with 10.6 Mg ha^-1 when seed pieces were removed at the same growth stage. For U.S. No. 1 yield, a difference between removing the seed pieces and disturbing the root systems was still evident at the 20-cm plant height growth stage (15.4 Mg ha^-1 vs 20.3 Mg ha^-1, respectively). Disturbing plants at emergence or at 20-cm plant height growth stage reduced the number of tubers per plant to 8.8 for both treatments compared to 9.7 for the non-disturbed control. Removing seed pieces at these same growth stages further reduced tubers per plant to 6.9 and 7.6, respectively. Vines of plants with seed pieces removed at emergence were shorter and remained green later into the season compared with disturbed and non-disturbed control treatments. Percent solids in seed pieces decreased from 20.68 at planting to 5.03 at first bloom. Seed piece percent sucrose remained constant from planting through the 20-cm plant height growth stage and then fell to nearly zero at first bloom. Reducing sugar in the seed pieces atplanting and emergence was 0.67%, rose to 1.08% at the 20-cm plant height growth stage, and then decreased to 0.89% at first bloom.     

Growth-room and field studies with seed tubers treated with ethylene and 1-methylcyclopropene (1-MCP) during storage

Based on ethylene management in potato storage, we hypothesized that the applied treatments would modify number of sprouts per seed tuber. Thus, in combination with in-row spacing (closer for seed, wider for processing) in the field treatments will give either (1) a high number of small tubers destined for seed use, or (2) a relatively smaller number of large, uniform tubers suitable for processing. A three-year study (2001–2003), conducted with two french fry processing cultivars, Russet Burbank (RB) and Shepody (SH), aimed at the development of a novel modified atmosphere seed tuber storage treatment. Seed tubers were stored at 4 C from October to May of each year in a cold room under five modified atmospheric regimes: (1) air ventilation only (Control); (2) 4 µl L^?1 ethylene applied continuously beginning in November and (3) beginning in February; (4) 1 µ1 L^?1 MCP (1-methylcyclopropene) applied as a gas for 48 h only in early December followed by continuous 4 µl L^?1 ethylene and (5) MCP alone applied as above. Each year, once a month (mid-January until end of April), a number of seed tubers was taken from each storage treatment, planted to pots and grown for 4 wk in a growth-room. In these studies, shoot emergence from the ethylene-treated seeds of both cultivars occurred significantly earlier, giving higher number of stems per tuber and stolons per stem than Control and MCP treatments. Moreover, the time to emergence after planting decreased with the increased length of storage. Field studies that were conducted from the end of May (planting) until October each year, produced similar trends (although not significant atP≤0.05) and resulted in a higher number of tubers per stem. In RB at the closer in row spacing (30 cm) used for seed production, ethylene enhanced yield of smaller tubers in the 30- to 115-g and 115- to 300-g categories. The ethylene storage treatments also increased tuber number per plant, but not the total mass of harvested potatoes. The MCP treatment, in combination with the wider in-row spacing (40 cm) used for the production of processing tubers, significantly increased the percentage of large tubers (>300 g). In SH, contrary to RB, the ethylene treatments did not alter tuber size distribution and the application of MCP reduced tuber size rather than increasing it. Results from this study suggest that both ethylene and MCP can be used in seed potato storage to influence the tuber size distribution of the crop from that seed.