Relationships of seed size,spacing, stem numbers to yield of Russet Burbank potatoes

Studies were conducted in 1970 and 1971 to determine the relationships among seed size, spacing, stem numbers and yield of Russet Burbank potatoes. Cut seed sizes of 0.5, 1.0, 1.5, 2.0, 2 oz whole and a treatment consisting of 14% 0.5 oz seed, 62% 1 oz and 24% 1.5 oz seed were used in combination with seed spacings of 6, 9 and 12 inches. As seed became larger the average number of stems per seed piece increased. Percent stand and plant size rating also increased with larger seed. Total yields increased with an increase of seed size. The highest U.S. No. 1 yield was obtained with 2 oz whole seed spaced 6 inches apart with cut seed of the same size yielding slightly less. Within each spacing, the greater stem numbers per plot resulted in higher yields. However, when combinations of seed size and spacings were used to obtain a given stem number per plot, the higher stem numbers did not result in higher yields. A positive correlation coefficient of +0.982 was obtained between weight of seed piece/stem and total yield.     

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.     

Interrelationships of the number of initial sprouts,stems, stolons and tubers per potato plant

Summary The relationships between the number of initial sprouts, the number of main stems, stolons and tubers per plant are depicted in 4-quadrant figures. The number of sprouts per seed tuber varied because of different pre-sprouting conditions and/or because of the use of different cultivars. Good linear relationships are shown between the numbers of sprouts and stems, stolons and tubers, and sprouts and tubers, but especially between stolons and tubers within each trial with the one cultivar. When comparing different experiments with the one cultivar the linear relationship between the numbers of stems and stolons disappeared. When comparing different cultivars, no relation was found between the numbers of sprouts and stems. These two cases also led to a statistically less significant relation between the number of sprouts planted and the number of tubers harvested.     

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.     

Beziehungen zwischen Stengel- und Knollenzahl bei der Kartoffel in Abhängigkeit von wichtigen Einflußfaktoren. I. Der Einfluß der Pflanzgutvorbehandlung und der Sorte

Zusammenfassung Die Pflanzgutvorbehandlung beeinflu?te die Stengelzahl signifikant. Abgekeimtes Pflanzgut der Sorten ‘Adretta’ und ‘Mariella’ entwickelte weniger Stengel und Knollen pro Pflanze jedoch mehr Knollen pro Stengel als vorgekeimtes und keimgestimmtes Pflanzgut. Die st?rker negativen Korrelationen zwischen Stengelzahl pro Pflanze und Knollenzahl pro Stengel sowie die h?here Reduktionsrate der angelegten Knollen bei der Sorte ‘Adretta’ weisen auf Sortenunterschiede in der Sch?rfe der Konkurrenz zwischen den Stengeln und innerhalb der Knollenanlagen eines Stengels hin. Die Ernteknollenzahl wurde bei ‘Mariella’ wesentlich durch die Zahl der Knollenanlagen, bei ‘Adretta’ hingegen st?rker durch die Reduktionsrate bestimmt.

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Summary Three different seed treatments and two cultivars were studied over seven years of field experiments (Table 1). Differences were detected between the cultivars in all characteristics studied: numbers of stems, maximum number of tubers (tuber initials), the number of harvestable tubers (>3 cm) at maturity per plant and per stem, and tuber reduction (percentage of initiated tubers that did not develop). Apart from the number of harvestable tubers, there were also differences between seed treatments (Tables 2, 3 and 4). Chitted seed of ‘Mariella’ and sprouted seed of ‘Adretta’ gave the greatest number of tubers per plant (Tables 3 and 4). In both cases desprouting reduced the numbers of stems and tubers per plant but increased the number of harvestable tubers per stem. Chitted seed set the most tubers per plant and per stem but had the highest levels of tuber reduction (Table 4). Due to intra- and inter-stem competition in both cultivars the percentage tuber reduction is significantly correlated with the number of tuber initials (maximum tuber number, Table 5). Smaller numbers of tubers per stem (Table 3) and significantly negative correlations between the number of stems and the maximum and harvestable number of tubers per stem (Table 5) highlight the effect of strong inter-stem competition in ‘Adretta’. Moreover, in this cultivar intra-stem competition seems to play an important role too. The rate of tuber reduction was significantly higher than in ‘Mariella’ (Table 3), and the final number of tubers significantly depended on the percentage of tuber reduction during the period of tuber growth (r=0,57^*, Table 5). In contrast, the number of harvestable tubers per plant in ‘Mariella’ was significantly correlated with the maximum tuber number during the period of tuber set (r=0,61^*, Table 5).

     

Hill to hill variations in tuber yield of potatoes in Alberta

The hill to hill variation in tuber yield and mainstem number was studied on 18 potato farms. There were up to 14-fold differences in the tuber yield per hill among plants of Norland, Russet Burbank, Norchip, Carlton and Alaska Red. The mainstem number was more variable than tuber weight per hill in Norland, Russet Burbank and Alaska Red. However, the opposite was true in Norchip and Carlton. In nearly all comparisons, the number of tubers per hill was less variable than tuber weight and mainstem number per hill. The total variation in tuber weight found in about 50% of the samples could be explained by the variance of hills within rows. Even in samples where an added variance component due to differences among rows was present, relatively more variation occurred within than among rows. The correlation coefficients between the number of mainstems and tuber weight per hill were positive but significant (P&< 0.05) only in Norland and Norchip. The correlation coefficients between the number of mainstems and number of tubers per hill were also positive but slightly higher and significant (P<0.01) in all 5 cultivars. The coefficient of determination values indicated that variation in cut seed piece weight explained only about 10% of the total variation in tuber weight harvested per hill. At a spacing of 30 cm within the row, a major proportion of hill to hill variation in tuber yield had to be explained by factors other than the seed piece weight.     

Effect of seed tuber and seed piece size on growth and incidence of hollow heart in Norgold Russet potatoes

Small seed pieces decreased yield and number of tubers. Both seed tuber and seed piece size affected the percentage of tubers with hollow heart. Hollow heart increased from 14 to 22% as the seed tuber size increased from 57 to 228 g and decreased from 27 to 19% as the seed piece size increased from 28 to 57 g. The least hollow heart (11%) occurred in tubers of plants grown from 57 g whole seed pieces and the most (26%) in tubers of plants grown from 228 g seed tubers cut into 28 g seed pieces. Hollow heart was positively correlated with the mean tuber size and negatively correlated with the number of mainstems per hill, total yield, and total number of tubers.     

Relationships between stem number,tuber set and yield of Russet Burbank potatoes

Five storage temperatures and three planting dates were used to obtain differences in seed performance. As seed storage temperature increased, average stem number per seed piece significantly increased. Stem number also increased with later planting dates. Germination tests, conducted under controlled temperatures, resulted in a curvilinear response with the least stems per seed piece at 10°C. a maximum stem number at 16°C and a slight decline in number at 21°C. The major effect of planting date was manifested through differences in germinating temperatures which resulted in increased stem number with later plantings. Yield of U.S. No. 1 tubers (5cm or 112 gm minimum) declined significantly as stem number increased. In the first planting, the correlation coefficient between stem number per seed piece and yield was r = ?0.95. Increased stem number and declining yield were attributed to advanced physiological age resulting from exposure to higher temperatures in storage and in the field. As stem number increased with planting date, tuber number also increased. The correlation coefficient between stem and tuber number for the first planting date was r = 0.92. The relationship declined significantly on the third planting date to r = 0.46. From these results it was concluded that economic yields are influenced by stem and tuber number which in turn can be manipulated by control of seed storage temperatures and planting dates.     

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.     

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.     

Improving the field performance of micro-and minitubers

Summary In many seed potato producing areas, micro- and minitubers are too small for direct planting as seed tubers in the field. Such use of these propagules can, however, be feasible if the crop's growth and development can be advanced. Increasing light interception, harvest index and yield of useable progeny tubers has been proved possible with plastic mulch and pre-planting of small tubers in a greenhouse. High amounts of nitrogen (up to 180 kg ha⁻¹) or deep planting (up to 9 cm) were less effective. Using older or pre-sprouted micro- or minitubers may be beneficial, because this might increase the number of sprouts per mother tuber (and thus stems per plant) or advance the growth of sprouts or stems. However, this would require even more careful management, due to the weakness of these sprouts and stems. Micro- and minitubers should be as large as feasible when used for direct planting in the field.     

Beziehungen zwischen Stengel- und Knollenzahl bei Kartoffeln in Abhängigkeit von Wachstumsregulatoren

Zusammenfassung In dreij?hrigen Feldversuchen führte eine Behandlung der Pflanzknollen mit vier Wachstumsregulatoren zu einer signifikanten Erh?hung der Stengel- und Knollenzahl pro Pflanze sowie einer Verminderung der Knollenzahl pro Stengel. Die durch die Behandlung erzielte signifikante Erh?hung des Pflanzgutertrages war jahres- und sortenabh?ngig. Eine hohe Effektivit?t der Behandlung ist nur zu erwarten, wenn die Erh?hung der Stengelzahl nicht zu einer sorten- oder jahresbedingten starken Verminderung der Knollenzahl pro Stengel führt.

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Summary Growth regulators (K350, GA₃, Azoluron and thiourea) were applied in a three-year field experiment to tubers of four large-tubered cultivars of different maturities (‘Arkula’, ‘Auralia’, ‘Dorisa’ and ‘Libana’). They produced significant increases in the numbers of stems and tubers per plant and a decrease in the number of tubers per stem. Only the most effective preparations increased the yield of seed and decreased overall yield, averaged over cultivar and year. Positive correlations between numbers of stems and tubers per plant contrasted with the negative correlation between the number of stems and number of tubers per stem (Fig. 1). The preparations ranked in effectiveness as follows: K350>GA₃>thiourea>Azoluron, and this was reflected in the number of stems and tubers per plant (Table 2). Increases in number of stems resulting from treatment with the regulators effectively increased the yield of seed, but only if the increases were not accompanied by strong year or cultivar related reductions in the number of tubers per stem caused by inter-stem competition (Tables 3 and 4).

     

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.     

Effect of weight of potato minitubers on sprout growth,emergence and plant characteristics at emergence

Summary The behaviour of minitubers in five weight classes, having mid-point values between 0.19 and 3.00 g, was studied during sprouting and emergence under controlled conditions. Lighter tubers took longer to produce sprouts of 2 mm, and their sprouts grew more slowly between 2 and 4 mm and 4 and 6 mm. As sprouts lengthened their rate of growth increased. The influence of tuber weight was less for heavier tubers and also decreased as the sprouts grew longer. When tubers with sprouts of the same length were planted in pots, sprouts from lighter tubers took longer to emerge. Emergence was later and differences between weight classes were larger when tubers were planted deeper (6 or 9 cm) or when they had shorter sprouts at planting (2 or 4 mm). At emergence, plants from lighter tubers had thinner stems and lower stem and root weights, but higher stem weights proportional to tuber weights and higher shoot:root ratios.     

Beziehungen zwischen Stengel- und Knollenzahl bei der Kartoffel in Abhängigkeit von wichtigen Einflußfaktoren. II. Der Einfluß des Jahres

Zusammenfassung In sieben Versuchsjahren beeinflusste die jahrestypische Stengelzahl die Zahl der Knollenanlagen pro Pflanze positiv (r=+0,77^*) und der Knollenanlagen pro Stengel in der Tendenz negativ (r= −0,39). Die signifikanten Jahresunterschiede in der Zahl erntef?higer Knollen (>3 cm) pro Pflanze und pro Stengel wurden in gewissem Grade durch die Zahl der angelegten Knollen (r= −0,53 bzw. +0,63), in st?rkerem Ausma? jedoch durch die jahrestypische Reduktionsrate der Knollen bestimmt (r= −0,72 bzw. −0,91^*). Diese war hoch, wenn ein Wechsel von guter Wasserversorgung w?hrend der Knollenbildung zu Wassermangelsituationen w?hrend der Knollenwachstumsphase erfolgte.

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Summary In seven years of field experiments, there were significant differences in the numbers of stems per plant and the number of harvestable tubers (>3 cm) at maturity, per plant and per stem, averaged for two cultivars and three seed treatments (Table 1). There was only a weakly positive correlation between the typical stem number for each year and the number of harvestable tubers per plant (r= +0.2, Table 2), whilst the correlation with the number of tubers initiated was much closer (r= +0.77^*, Table 2). The negative influence of number of stems on number of tubers per stem is shown byr= −0.39 and −0.47 (Table 2). Identical stem populations in the wet, cold spring of 1987, and the warm, dry season of 1983 initiated fewer tubers per stem than in 1989 with its average temperatures and modest precipitation (Table 1). Tuber set per plant and per stem correlated positively with the number of harvested tubers per plant and per stem (r= +0.53 and +0.63) and accounted for some of the yearly variation. A much stronger effect on the number of harvestable tubers came from the annual reduction of tubers (r= −0.72 and −0.91^*, Table 2). This was high if the availability of water deteriorated in the period of growth succeeding tuber formation (Table 1, Fig. 1). The same applied to the seed treatments planted at different stages of development. Tuber development occurred earlier with chitted seed, often at times when there was an adequate water supply. A large number of tubers were initiated and these were in large part reduced in the short dry spells which followed (Figs 2 and 4). Irrigation programmes must take account of this relationship.

     

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.     

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.     

赤霉素打破种薯休眠对马铃薯生长及产量的影响

实验结果表明:用50mg/L赤霉素浸泡小整薯1h不但可以有效的打破休眠,同时还可以增加有效茎数,提高单株叶面积,从而使单株结薯数和产量增加。     

Growth and yield of potatoes as affected by severity of stem canker (Rhizoctonia solani)

Summary Different amounts ofRhizoctonia solani inoculum were applied to sprouted and non-sprouted seed tubers cultivar Désirée during planting in field experiments at Rothamsted in 1984 and 1985. Severity of stem canker and stolon infection increased with increasing amounts of inoculum; with small or medium amounts these infections were most severe on plants from sprouted seed. In 1985 plants grown from non-sprouted, seed had most stem canker when large amounts of inoculum were applied. Severe infection following high inoculum levels delayed shoot emergence, increased the variability in stem height and decreased the mean height of stems and weight of foliage but did not affect the number of stems per plant or final plant populations. Tuber initiation was delayed and tuber numbers slightly decreased by severe infection and at harvest the size distribution of tubers was altered. Tuber yields from severely infected plants were decreased by 15% (sprouted seed) and 19% (non-sprouted seed) in 1984 and by 17 and 28% respectively in 1985.     

Hill Shape Effect on Yield,Quality, Stolon Length and Tuber Orientation of Two Potato Cultivars

Potato (Solanum tuberosum L.) cultivars are mostly planted using similar seed piece planting depths and hill shapes even though cultivars have unique tuber and stolon characteristics. A hill-shape study was conducted at Aberdeen, Idaho to determine the effects of hill shape on yield and field-green tuber yields and quality along with stolon length and tuber spatial orientation for two potato cultivars, 'Defender' and 'Summit Russet.' Plots were planted in late April to early May. Prior to emergence four hill shapes were formed: 1) plant-and-drag, 2) broad, 3) normal, and 4) peaked. Defender had higher total yield with the broad hill, but there were no differences among the remaining three hill shapes. For Defender, U.S. No. 1 yield was lower with the plant-and-drag hill shape, and the normal and peaked hills produced lower field-green tuber yield. Hill shape had no effect on total, U.S. No. 1, or field-green tuber yields of Summit Russet. The peaked hill resulted in a deeper uppermost tuber for Defender, while the uppermost tuber was deeper in the normal and peaked hills for Summit Russet. The broad hill resulted in a larger average tuber size for Defender, but hill shape had no effect on tuber size for Summit Russet. Total number of tubers per plant, stolon length and tuber spatial orientation were not affected by hill shape for either cultivar. Hill shape and height are important considerations in maximizing yield of saleable tubers, so needs to be customized according to cultivar-dependent stolon length and tuber orientation characteristics.