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.     

Relationships between weather,plant spacing and the incidence of hollow heart in Norgold Russet potatoes

Partial regression analysis of ten years’ data showed the percent of hollow heart (HH) tubers by weight in Norgold Russet potatoes increased with an increase in number of days and rainfall between tuber initiation and plant killing, and decreased with an increase in plant population and degree day accumulation during the same period. Highly significant third order partial correlation coefficients for these variables with percent HH were: days between tuber initiation and plant killing 0.699, rainfall between tuber initiation and plant killing 0.320, plant population -0.530 and degree day accumulation between tuber initiation and plant killing -0.753. When these variables were used in a multiple linear regression model with% HH as the dependent variable the coefficient of determination (R²) was 0.72. The model was not significantly improved by including solar radiation, yield of tubers, number of tubers, or soil moisture at tuber initiation as other independent variables.     

Tuber initiation and development in irrigated and non-irrigated potatoes

Tuber initiation and development are processes basic to potato production and are particularly critical in areas with short growing seasons. It is important to know how and to what extent management decisions affect these processes in order to maximize the yield of marketable tubers. A two-year field study, conducted in southcentral Alaska, examined top growth, tuber initiation, and tuber development in eight potato cultivars grown with and without irrigation. Plants of the cultivars Allagash Russet, Bake-King, Green Mountain, Kennebec, Lemhi Russet, Russet Burbank, Shepody, and Superior were harvested weekly throughout the growing season, and top dry weight, numbers of tubers, and individual tuber fresh weights were recorded. Top dry weight was reduced by moisture stress shortly after emergence in 1993, and about one month following emergence in 1994, when early-season soil moisture was greater. The weight of tubers was similarly affected within approximately 5 wk of emergence in 1993 and 6 weeks in 1994. Tuber weight at harvest was increased two-to three-fold by irrigation in all cultivars. The number of tubers each plant set was affected by irrigation in most, but not all, cultivars. Some varieties (Lemhi Russet in 1994, Allagash Russet both years) set more tubers than were maintained through the growing season. Tuber remnants found during sample collection indicated that tuber reabsorption had occurred. Irrigated Green Mountain had more than one tuber initiation period during the season, whereas other varieties such as Shepody maintained a relatively constant number of tubers following initial tuber set. Tuber size distribution at the end of the growing season showed that larger tubers were favored by irrigation.     

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.     

Growth attributes of potato and their inter-relationship with yield

Summary In the mild and short winter of the Ganges plains, the yield contributing characters such as number of shoots/plant, plant height, leaflet size, tuber yield/plant and tuber number/plant were studied for fifty varieties of potato. From the simple, partial and genotypic and phenotypic correlation studies it was observed that leaflet size, number of tubers/plant and plant height were closely connected with the yield of potato tubers. A multiple regression equation was also prepared and it was found that the leaflet size had the maximum influence on yield followed by number of tubers/plant and plant height.     

Chip color of the developing potato tuber

Chip color was unacceptable from tubers of Kennebec in an immature condition soon after the tubers were set. Dark colored chips were also obtained from tubers harvested late in the season when soil temperatures were 50 F or less. Two high quality experimental varieties, F5889 in particular, gave excellent chip color regardless of tuber maturity all season and until soil temperatures in fall declined to 40 F. The data indicate that acceptable chip color may be obtained at most stages of tuber development in varieties of high chipping quality. Therefore when selecting seedlings from hybrid plant populations, chip color determined from selections made soon after tuber initiation could be useful. In a supplementary study no marked variations in chip color were obtained from tubers located different distances from the mother plant.     

Assessment of Opportunities for Burundian Small-Scale Potato Farmers to Increase Productivity and Income

From 2014 through 2016, on-farm experiments were carried out in three provinces surrounding Bujumbura town in Burundi to improve the low potato (Solanum tuberosum) yields, which currently stand at about 6 t ha^?1. It was hypothesised that in rain-fed conditions, improved varieties, healthier seed tubers, pre-sprouting in light, proper fertilisation and protection from late blight attack would improve yield and quality, such as tuber weight, tuber size and lower brown rot incidence. The treatments in the on-farm trials at five farms in each of three sites (15 replicates) were applied in two seasons, giving 30 replicates in 580 plots. The following treatments were compared with growers’ current practices: introduction of two new varieties, use of early generation seed from a rapid multiplication scheme, earlier harvesting of a seed crop, seed storage in a diffused light store, and research-based timing and dose rate of fertilisers and fungicides. Marginal rates of return on investments were calculated at farm level and current and tested alternative technologies were compared. Costs and benefits of applying such techniques were calculated. An improved variety contributed up to 20% yield increase and healthier seed 80%. Early harvesting reduced yield by 30% and reduced incidence of brown rot in the current season, but increased it (from 21 to 39%) in the following season when tubers were replanted. Diffused light storage, alternating contact and systemic fungicide application, and application of chemical fertilisers resulted in 30, 50 and 60% yield increases, respectively. It was shown that it is possible to double yields and economic returns (marginal rates of return) under the growing conditions in Burundi when growers plant healthy pre-sprouted seed of a new variety and apply chemical fertilisers and fungicides.     

Yield-enhancing and tuber-downsizing effects of transplantation cultivation method of case-held tuber seedlings in the sweet potato cultivar Beniharuka

We developed transplantation cultivation method of case-held tuber seedlings (CTS), which was derived from direct planting method of seed tubers, and applied this method to the sweet potato cultivar Beniharuka. A plastic case made of polypropylene was designed for cultivation of CTS. Seed tubers of cultivar Beniharuka in the range of 30–80 g were cut in half. The half-cut tubers were placed inside the plastic cases, and the cases were filled with a commercial soil mix. The case-held tubers were incubated under natural sunlight in a glass house. After 3–4 wk, the CTS were transplanted into a field. Mother tuber (seed tuber) enlargement was suppressed by the plastic confinement of the cases, and daughter tubers were formed above the case as vine-root-originated tubers. In the field experiments in 2012 and 2013, daughter tuber yields were increased 19% and 21% by case-held tuber seedling transplanting (CTST) over conventional vine-planting (VP), the number of daughter tubers per plant in CTST were 36 and 68% higher than in VP, and the mother tuber yields were limited to 2.1 and 4.3% of the total fresh yield of mother and daughter tubers, respectively in 2012 and 2013. Application of CTST method to cultivar Beniharuka enhanced tuber yield, increased the number of daughter tubers per plant, downsized daughter tubers compared to VP, and mother tuber enlargement was suppressed by case-holding. The CTST method is expected to produce more and smaller good in shape tubers of cultivar Beniharuka compared to VP.     

Russette: A Russet-skin potato variety,combining high quality,high yields,and adaptation to the Northeastern states and Florida

Russette is a new, late maturing, russet potato variety adapted primarily for the northeastern United States and northern Florida. Tubers are oval to oblong, smooth with a medium-russet skin, and shallow eyes. Its specific gravity is similar to those of BelRus and Russet Burbank in areas of adaptation. Glycoalkaloid content is about 11 mg/100 g fresh weight. Baking quality is excellent, flesh is white, and best color of french fries is obtained from tubers stored at or above 13°C (55°F). Its long rest period makes it amenable to storage at a relatively high temperature before a chemical sprout inhibitor is needed. Russette is immune to virus A and leaf roll-induced tuber net necrosis; highly resistant to Verticillium wilt, tuber pinkeye, and tuber heat necrosis; and has good tolerance to scab, early blight, and Rhizoctonia infection of sprouts, stolon, and roots. Losses to rots and shrinkage in storage have been minimal. Russette is not resistant to viruses X, S, Y, and leaf roll and bacterial ring rot. Russette emerges to a stand about 10 days later than most varieties, however, subsequent vine growth is rapid until tuberization begins. Large-sized tubers may develop hollow heart under a late-season regime of high nitrogen and high moisture. A 22–30 cm (9″- to -12″) seed-piece spacing and 220 kg/ha (180 pounds/a) of nitrogen are recommended for production on mineral soils.     

IdaRose: A potato variety with bright red skin, excellent culinary quality, and long tuber dormancy

IdaRose is a late-maturing, potato variety with round, dark red tubers. It has high yield potential and exceptionally long tuber dormancy. IdaRose was released in 2000 by the USDA/ARS and the experiment stations of Idaho, Oregon, and Washington. It resulted from a 1982 cross of Sangre and TXA218-7. IdaRose is suited for use in both the early summer and storage fresh markets. Tuber yield of IdaRose is higher than that of Dark Red Norland and Sangre. It has yield potential similar to or slightly lower than Red LaSoda. Tubers of IdaRose have good internal and external quality. Culinary quality of boiled, baked, and micro-waved IdaRose tubers is excellent. It has moderate resistance to growth cracks, hollow heart, and other defect problems. IdaRose is susceptible or moderately susceptible to most common field diseases of potato. Tubers of IdaRose have dry matter content (19.2%) similar to other standard red varieties, and have a relatively high concentration of sugars and low concentration of glycoalkaloids (2.4 mg/100 g).     

Growth and preharvest stress and processing quality of potatoes

The quality factors influenced by stress conditions are: total dry matter or starch content and distribution of starch, sugar content, types of sugars and distribution, texture, mealiness, flesh color, tuber size and shape, and tuber defects such as growth cracks, and hollow heart. Early stress during growth can cause tubers to become pointed on the stem-end with low starch content and high reducing sugars. Uneven growth due to stress results in growth cracks, or hollow heart and malformed tubers. Varieties differ considerably as to susceptibility. Stress generally causes lower starch content in tubers which results in greater sugar accumulation in storage. Relative maturity is also influenced by stress during growth. Immature and over-mature tubers (from prematurely dead plants) accumulate greater amounts of sugar in storage than tubers properly matured. Stress can also cause poor texture of processed products, such as tough texture of French fries as well as lack of mealiness. Flavor and color of processed products can also be detrimentally influenced by stress.     

The relationship between tuber size and hollow heart in Norgold Russet potatoes

Hollow heart (HH) when found in potatoes is predominately in the largest tubers. Various tuber lots of cv Norgold Russets ranged from 3.4 to 55.9% HH by weight. In the lot with the least HH approximately 43% of the tubers over 8.89 cm in diameter were hollow compared to 0.2% of those between 3.81 and 5.07 cm. By first removing the very largest, followed by successively smaller tubers there was a continuous reduction in HH in all tuber lots. There were only small differences among the five years in the effect of sizing on HH, and these appeared to be associated with yield differences among years. Figures illustrate the specific effect of removing progressively smaller tubers on the amount of HH remaining.     

Ivory Crisp: A potato variety with high tuber solids and cold chipping ability

Ivory Crisp was released in 2002 by the experiment stations of Idaho, Oregon, Washington, and North Dakota, and by the USDA/ARS. It resulted from a 1980 cross of ND292-1 and A77268-4. Ivory Crisp is suited for use in both the direct delivery and storage chipping markets. Ivory Crisp is a medium-maturing potato variety with round, white tubers and excellent chipping quality. It has medium to high yield potential, high tuber solids, resistance to most internal and external tuber defects, and the ability to chip from cold storage. In trials in Idaho, Oregon, and Washington, total and U.S. No. 1 tuber yield of Ivory Crisp was similar to Atlantic but lower than Chipeta. Yield of tubers in the size range 113–336 g for Ivory Crisp is higher than for either Atlantic or Chipeta. Ivory Crisp is resistant to growth cracks, secondary growth, hollow heart, and stem-end necrosis, but susceptible to shatter bruise. Tuber sugar content has consistently remained low following cold storage and near-acceptable chip color retained at 4.4 C. Ivory Crisp is susceptible or moderately susceptible to most common field diseases of potato. It is highly susceptible to common scab, powdery scab, and pink rot. Tubers of Ivory Crisp have dry matter content (22.4%) lower than those of Atlantic, but higher than those of Chipeta. Glycoalkaloid content of Ivory Crisp tubers is very low (4.3 mg 100 g^-1). An application for Plant Variety Protection has been filed for Ivory Crisp. Seed is available from potato seed growers in Idaho, North Dakota, and Canada. Small amounts of seed, for research purposes, can be obtained by contacting the corresponding author.     

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.     

种植密度与马铃薯块茎大小的分布 Ⅰ.密度与块茎生长的关系

种植密度是影响马铃薯块茎生长发育的主要因素之一。主栽品种 Mira 和783-1各3种密度的试验结果表明,随着单位面积播种密度的增加,单位面积上的主茎数及块茎数目均增加,而块茎的平均重量及大中薯率则减少。单位面积上的光能截获量与植株干重、块茎干重和块茎的平均重量均呈极显著的直线相关。Mira 和783-1的光能转化系数分别为1.444克干重/兆焦和1.106克干重/兆焦。分配到块茎的干物质比率随着块茎的生长而增加,最终两品种的干物质转化率均为85%左右。而密度对各品种的光能转化率及块茎干重分配率均无显著影响。因此,种植密度主要是通过对单位面积上块茎数量的控制来影响块茎所获得的屯合产物的数量及块茎的生长发育。     

Glyphosate Carryover in Seed Potato: Effects on Mother Crop and Daughter Tubers

Field studies were conducted in 2008 and 2009 in Aberdeen, ID, Ontario, OR, and Paterson, WA to determine the effect of simulated glyphosate drift on ‘Ranger Russet’ potato during the application year and the crop growing the next year from the daughter tubers. Glyphosate was applied at 8.5, 54, 107, 215, and 423 g ae ha^?1 which corresponds to 1/00, 1/16, 1/8, ¼, and 1/2 of the lowest recommended single-application rate for glyphosate-resistant corn and sugar beet of 846 g ha^–1. Glyphosate was applied when potato plants were at 10 to 15 cm tall (Early), or at stolon hooking (H), tuber initiation (TI), or during mid-bulking (MB). In general, the MB applications caused less visual foliar injury to the mother crop than earlier applications at ID or OR, and H applications at WA. Mother crop injury increased as glyphosate rate increased regardless of location, application timing, and rating date. U.S. No.1 and total tuber yields were usually related to the injury level resulting from glyphosate application timings and rates. Although injury to the mother crop from glyphosate applied at MB usually was the lowest compared to injury from other application timings, when daughter tubers from that timing were planted the following year, emergence, plant vigor, and yield was most detrimentally impacted compared with that of daughter tubers from other timing treatments. MB daughter tuber emergence was less than 30 % of the nontreated control tuber emergence while emergence of daughter tubers from the other treatments was 60 to 95 %. As rate of glyphosate applied to the mother crop increased, daughter tuber emergence decreased. When MB daughter tubers did emerge, plants were chlorotic and stunted as if the plants had been directly sprayed with glyphosate. Regardless of whether the daughter tubers had defects or not, results the following year were the same. Implications are that if a mother seed crop encounters glyphosate during bulking, injury may not even be noticeable on the foliage or the tubers, however, emergence, vigor, and yield of the crop growing the following year from the daughter tubers could be greatly impacted.     

马铃薯块茎的生长模型及块茎生长率与细胞分裂的关系

块茎的生长率各不相同,其生长的时间变化状态呈S型曲线。现发现逻辑斯蒂克(Logistic)方程适宜于用来模拟块茎的生长。块茎的大小与块茎的生长率及生长的时间密切相关,但生长率是影响块茎大小的主要因素。块茎绝对生长率的加权平均与块茎细胞数量的直线相关证明了块茎的生长在很大程度上受细胞分裂控制。块茎生长率与细胞膨大无显著相关。     

Effect of two plant growth regulators on the yield and quality of russet burbank potatoes

Summary Foliar applications of ethephon (ETH) 300 g a.i. ha⁻¹; chlormequat chloride (CCC) 920 g a.i. ha⁻¹, with a second application of 230 g a.i. ha⁻¹ approximately 2 weeks later; and a mixture of the two (ETH/CCC) 156 g a.i. ethephon and 299 g a.i. chlormequat chloride ha⁻¹ were made to field-grown Russet Burbank potatoes in 1986, 1987 and 1989. All the treatments increased the number of tubers set and reduced the average tuber weight compared to the control resulting in a reduction in premium and marketable tubers, and an increase in small tubers. Differences were greatest for ETH and least for CCC. ETH and ETH/CCC decreased the specific gravity, increased the incidence of deformities, and decreased the incidence of tubers with hollow heart. The growth regulators did not affect fry colour.     

Expression of hollow heart in segregating tetraploid potato families

Expression of hollow heart, a physiological disorder in potato, is controlled by both genotype and environment. Development of high levels of resistance in cultivars would reduce economic yield losses that occur under conditions that promote hollow heart. This experiment was conducted to study hollow heart in segregating populations from parents in a breeding program. Nine families were planted in a replicated trial under dryland conditions and five of those families were also grown at an irrigated location under conditions favoring the expression of hollow heart. As expected, positive correlations between hollow heart and both mean yield and tuber weight were detected; correlations between hollow heart and tuber number were negative. Hierarchical regression analysis was performed on these yield traits to determine the independent contribution of each to the overall results. The highest levels of hollow heart were found in families with susceptible parents, but susceptible clones were obtained in families with two resistant parents. Regardless of the type of cross, selection of clones with large tubers increased the probability of selecting for susceptibility to hollow heart.     

Sprouting of seed tubers during cold storage and its influence on tuber formation, flowering and the duration of the life cycle in a diploid population of potato

Summary The influence of a short tuber dormancy and the subsequent sprout growth of the seed tubers during storage at 4 °C on the processes related to plant development and tuber formation was investigated in a diploid population with 238 genotypes, its crossing parents and seven tetraploid varieties. Sprout growth during storage at 4 °C was positively correlated to the duration of the dormancy period at 18–22 °C, the low temperature prolonging the dormancy period. Results show that the duration of the dormancy period and the sprouting of seed tubers during storage at low temperature did not have a determinant influence on plant development, tuber formation or the duration of the plant cycle in this large and highly diverse population of potato.