Early Tuber Research Articles

Andover: An early to midseason golden nematode resistant variety for use as chipstock or tablestock

Andover may be used as an early to midseason tablestock and chipstock variety. It has a very rapid emergence and early tuber set. The vine maturity is similar to Superior in the absence of severe stress. In New York trials harvested 90 days after planting, the yields of Andover and Superior are nearly equal, 274 cwt/A. At 120 days, over eight seasons at two Ithaca locations, Andover yielded 87% Atlantic. Andover appears to be susceptible to drought and heat stress which can cause early senescence and reduce late season yields. It has few external and internal defectS. Specific gravity is high for an early variety, being .009 less than Atlantic. Andover has excellent chip color from the field from a range of environments and from 7 C storage. It has good boiling and baking properties. The mealiness of the baked potatoes is especially good. Tuber dormancy is two weeks longer than Atlantic. The reaction to common scab is like that of Monona, which is considered to be resistant. It is also resistant to powdery scab and the golden nematode.

Portable rhizotron and color scanner system for monitoring root development

Rhizotrons allow the examination of spatial and temporal in situ root development. Permanent rhizotron installations provide 2-D images of whole root profiles, but their immobility limits the number of soil-plant systems that can be studied. Our objectives were to develop a portable rhizotron and color scanning system for studying the development of whole root systems. Potato root development was monitored in an irrigated experiment at Othello, WA. Covered, rectangular hollow boxes with a transparent glass face were installed perpendicular to planted potato rows, and a seed piece was planted in the soil adjacent to the glass. Rooting in the hill furrow topography was measured 2 to 4 week intervals. Images of roots growing along the glass face were captured with five scans with a portable, color scanner and a portable computer. Image thresholding discriminated roots from soil using primary color values, color intensity differences, color proportions, or overall intensity. Seasonal patterns of computed root lengths by image analysis were comparable to manual tracing. Primary roots extended to 15 cm from the seed piece prior to shoot emergence, 21 days after planting. Lateral roots began to develop shortly thereafter. Potato roots extended to depths of 60 cm by 4 to 6 weeks after planting, and maximum root density in the hill and furrow was observed by tuber initiation to early tuber bulking. Temporal and spatial trends were similar to previous results using destructive sampling. The method has promise for studying the root growth and development of field-grown plants.

Isolation, Characterization, and in Situ Hybridization Studies of the Abundantly Transcribed Potato (Solanum tuberosum `Superior') Homeobox cDNA POTH1

Homeobox genes contain sequences coding for DNA-binding motifs. These sequences are highly conserved across both the animal and plant kingdoms. Members of this gene family code for transcription factors that are key regulators of developmental organization. In an attempt to further elucidate the developmental process of tuberization in the potato plant, a full-length homeobox cDNA has been isolated via sequence homology from an early tuberization stage cDNA library constructed from 4-day axillary bud tubers. This cDNA, POTH1, has been sequenced and characterized by Southern blotting, northern analysis, sequence comparison, and in situ hybridization. POTH1 is shown to be a class I homeobox gene with 45% overall similarity to Kn-1 of maize and 73% match in the homeobox region. Messenger RNA accumulation studies indicate that POTH1 mRNA, unlike most homeobox transcripts, is not limited to a particular organ or developmental stage. Instead, POTH1 mRNA accumulates in rapidly growing cells of the potato plant: the apical meristems, the vascular cambium, the edges of young leaves, axillary buds, and root tips. In situ studies indicate accumulation of POTH1 mRNA in the tunica and corpus layers of the apical dome of the shoot apex and the stolon apex. In the stolon, growth and proliferation of the parenchymal cells associated with the vascular cambium contribute to swelling during early stages of tuberization, and this tissue accumulates POTH1 mRNA. It is possible that POTH1 may be posttranscriptionally regulated in a particular organ or stage of growth, or that it is involved in a wider range of growth processes than most plant homeobox genes.

Effects of transitory water stress on potato tuber stem-end reducing sugar and fry color

Potatoes grown for processing in irrigated regions of the Pacific North-west sometimes develop undesirably high concentrations of reducing sugars in tuber stem ends due to hot weather and water stress during tuber development. Such tubers usually produce french fries with dark stem ends or sugar ends. In order to better quantify the relationship between water stress and stem-end sugar levels for Russet Burbank, single episodes of transitory water stress were established by delaying irrigations until soil water potentials ranging from -32 to -107 kPa were reached during early tuber bulking. To determine when the increase in reducing sugars occurred, tubers were sampled before transitory stress, at maximum stress, after stress was relieved with sprinkler irrigation, and post harvest. Reducing sugar concentrations did not increase in tuber stem ends until two weeks or longer after the plant water stress was relieved. Increased reducing sugar concentrations were positively associated with decreased soil water potential (drier soil). Tubers were sliced and fried at harvest and six weeks post-harvest. Decreasing soil water potential (drier soil) was associated with progressively darker fry colors at harvest and post harvest. Significant darkening in the average stem-end fry color light reflectance of tubers at harvest as observed at -80 kPa in 1988 and -69 kPa in 1989. The effect of imposed water stress on tuber stem-end reducing sugar concentrations was most pronounced post harvest.

A novel MADS-box gene of potato (Solanum tuberosum L.) expressed during the early stages of tuberization.

A potato MADS-box gene cDNA (POTM1-1) from an early tuber cDNA library has been isolated and characterized. The deduced amino acid sequence of POTM1-1 cDNA encodes 250 amino acids of a putative transcription factor containing a MADS-box domain and a K-box domain. These conserved domains share high homologies to those of flower-specific homeotic proteins, TM4 of tomato and AP1 of Arabidopsis, indicating that POTM1-1 gene is a homologue of the AP1 gene family. The levels of POTM1-1 transcripts were high in axillary buds, underground stolen tips, and newly formed tubers, but relatively low in mature tubers. During axillary bud development in a model petiole-leaf cutting system, the levels of POTM1-1 transcripts were abundant in actively growing shoots and during the early stages of microtuber development. It is possible that POTM1-1 functions as a transcription factor that regulates plant developmental processes in a number of tissue types.

Effects of temperature and photoperiod on early growth and final number of tubers in potato (Solanum tuberosum L.)

A phytotron experiment with all combinations of two photoperiod (12 or 18 h) and four temperature (18/12, 22/16, 26/20 or 30/24 °C; 12h/12h) treatments was carried out to analyse quantitative effects on early tuber growth, dry-matter partitioning and number of tubers of two cultivars. Higher temperatures and longer photoperiod delayed the onset of expolinear tuber growth and the onset of linear tuber bulking. Higher temperatures also gave lower absolute tuber growth rates. Photoperiod did not affect absolute tuber growth rate at lower temperatures. Higher temperature and longer photoperiod gave lower relative rates of partitioning of dry matter to the tubers. Differences between treatments in numbers of tubers initiated were inconsistent. This quantitative analysis of the effects of temperature and photoperiod on characteristics of tuber growth should prove useful in potato modelling.

The dependence of internal brown spot development upon calcium fertility in potato tubers

To determine calcium fertility and high temperature effects on internal brown spot development in potato, cv. Russet Burbank plants were fertilised with Hoagland's nutrient solution with or without calcium. Prevalence and severity of internal brown spot were greatest in tubers receiving no calcium fertilisation during growth. Internal brown spot was evident as early as tuber initiation. A high growth medium temperature (32°C) at tuber maturity with a lack of calcium increased internal brown spot incidence and severity. No tubers subjected to the high temperature and fertilised with calcium developed internal brown spot. Peel calcium concentration of tubers receiving no calcium fertilisation was lower (0.5–0.8 g/kg) than tubers receiving calcium (1.2–1.9 g/kg). Medullary tissue calcium concentration was similar under both calcium regimes. Calcium availability during early tuber growth was an influential factor in internal brown spot development, however high temperature effects may not be discounted in exacerbating the disorder.

Dry gibberellic acid combined with talc or fir bark enhances early stem and tuber growth of Shepody potato

Gibberellic acid (GA3) powder was applied to seed pieces of Shepody potato in combination with water, fir bark and talc carriers. In a greenhouse study, emergence, stem growth and tuber number from seed pieces treated with dry GA3 and carriers were compared with that of an untreated control. All carriers alone reduced stem emergence. GA3 (0.5,1 and 2 mg/ kg) combined with talc, and 0.5 and 2 mg GA3/kg with fir bark+talc enhanced emergence. Only 2 mg GA3/kg enhanced emergence when applied in solution. Emergence of stems from pieces treated with GA3 and fir bark was no different or slower than the control. In the absence of GA3, water and talc increased stem number and fir bark-containing treatments reduced tuber number. All concentrations of GA3 applied with talc or fir bark+talc, and 2 mg GA3/kg with fir bark increased stem and tuber number. With water, 0.5, 1 and 2 mg GA3/kg increased stem number but only 2 mg GA3/ kg resulted in more tubers. One and 2 mg GA3/kg combined with talc resulted in the most stems and tubers 58 days after planting. GA3 was as effective or more effective in speeding emergence and increasing stem and tuber number when applied in the dry form with talc or fir bark+talc as when applied in solution.

Effects of plastic film covers on dry‐matter production and early tuber yield in potato crops

SummaryThree experiments, conducted in 1988, 1989 and 1990, examined the effects of date of removal of a clear, perforated (200 X 10 mm holes m‐2), plastic film cover on the growth and early yield of potato crops. Results confirmed that the highest early yields were achieved when the cover was removed 2 wk after 50% crop emergence and the resulting yield increase over a non‐covered control varied from 6–14 t ha‐1. Later removal reduced the benefit from covering and in some cases eliminated any advantage. Covering increased mean soil and air temperatures 2.9°C and 3.2°C respectively (mean of three experiments), thereadvancing crop emergence between 3 and 5 days. The number of day‐degrem accumulated between planting and emergence was very similar in covered and non‐covered treatments within a season but varied between seasons from 190°C to 293°C day (> 0°C). Delaying removal resulted in an increased physical restriction to canopy expansion and reduced the capacity of the crop to intercept solar radiation. Total dry‐matter yield was determined largely the amount of radiation intercepted crops (R2= 0.98). Plastic covering had relatively little effect on partitioning of dry matter to tubers but reduced tuber dry‐matter percentage at early harvests when removal occurred later than 3 wk after crop emergence.

Plant Growth Regulators and Yields of Seed Potatoes

Seed potato growers seek to maximize yields of desirable sized tubers. This study examined how foliar applications of plant growth regulators influence yields of drop or single-cut seed tubers under field conditions. In 1993, paclobutrazol (PTZ; 300, 450, and 600 mg·liter–1), kinetin (KIN; 10 and 20 mg·liter–1), and methyl jasmonate (MJ; 10–7, 10–6, 10–5, and 10–4 M) were applied to `Norland' (NOR) and `Russet Burbank' (RB) potatoes. In 1994, PTZ (300 mg·liter–1), KIN (both rates), and MJ (10–7 and 10–6 M) treatments were eliminated, and GA3 at 250 mg·liter–1 or KIN at 20 mg·liter–1 was applied to some of PTZ treatments. In 1994, the cultivar Shepody (SH) also was included. Plants were treated at two growth stages; NOR (1993), RB (1993 and 1994), and SH (1994) were treated when tubers were <10 mm or <20 mm in diameter. NOR (1994) was treated at stolon initiation (no tubers) or early tuber initiation (<8 mm in diameter). PTZ had no effect on seed tuber (25–50 mm in diameter) yield in NOR in either season. PTZ increased seed tuber number (STN) in RB by 29% to 40% and in SH by 57% to 70% over the controls. KIN had no effect on STN in any cultivar. MJ had no effect on STN in NOR (1993) or in RB in either season or in SH in 1994. In 1994, the highest rate of MJ (10–4 M) increased STN in NOR by 40% over the controls. GA3 had no beneficial effect on STN when applied after PTZ. This study suggests that, under field conditions, PTZ can increase seed tuber production in RB and SH while MJ was effective in NOR potatoes.

Developmental changes in carbohydrate content and sucrose degrading enzymes in tuberising stolons of potato (Solanum tuberosum)

Tuberising stolon tips of potato (Solanum tuberosum L. cv. Record) accumulate starch and sucrose but the hexose content, particularly fructose, declines rapidly. Similar changes occur in the region 2 cm behind the swelling apex but the decline in glucose is far more pronounced than in the developing tuber. Tuberisation is characterised by an apparent switch from an invertase‐dominated sucrolytic system (both acid and alkaline invertases [EC 3.2.1.26] are present) to one dominated by sucrose synthase (EC 2.4.1.13). Sucrose synthase and fructokinase (EC 2.7.1.4) activities were, at a maximum, ca 10‐ and 5‐fold higher, respectively in the swelling stolon tip compared with the non‐tuberising region. At the highest starch contents attained, the starch level in the young developing tuber was approximately double that in the adjacent non‐tuberising stolon region. Immunoblots revealed that developmental changes in sucrose synthase. fructokinase and alkaline invertase polypeptides corresponded with enzyme activities. Antibodies raised against the N‐terminal amino acid sequence of a soluble invertase purified from mature tubers did not detect significant quantities of a polypeptide in stolons and young, developing tubers. Antibodies raised against an in vitro expression product of an apoplastic invertase cloned from a leaf cDNA library detected a polypeptide in developing tubers but not in mature ones. However, expression of the protein did not correlate well with acid invertase activity during early tuber formation.

Seed tuber production from true potato seed (TPS) in Egypt and the influence of environmental conditions in different growing periods

The effect of environmental conditions on seed tuber production from true potato seed (TPS) in nurseries was evaluated in different growing periods during two seasons in Egypt. In the autumn season, high soil and air temperatures reduced emergence and initial foliage development of early-sown seedlings, and decreased tuber yields. In late-sown seedlings low night temperatures and short daylengths caused early tuberization, poor foliage development and low tuber yields. In the spring season, low temperatures and short daylengths resulted in a slow initial foliage development and early haulm-tuber competition for assimilates in early-sown seedlings. However, tuber yields were higher than for late-sown seedlings, presumably because net assimilation and assimilate partitioning to the tubers were impaired by above optimum air and soil temperatures in May and June. Slow development of true seed-sown plants caused a high sensitivity towards adverse environmental conditions and would limit yielding ability in Egypt.

Development of DRIS norms for potato in the calcareous soils of iran1

Abstract The Diagnosis and Recommendation Integrated System (DRIS) has been proposed to determine nutrient balance in plants at different stages of growth. The DRIS index for each nutrient allows ranking of nutrients in order of their deficiency. Preliminary DRIS norms for potato (Solanwn tuberosum L.) were developed during the 1991 growing season in Damavand area located 70 km. northeast of Tehran. The soil and leaf samples at flowering stage (early tuber development stage) were collected from 50 different farms. Average concentrations of nutrients in both high‐ and low‐yielding populations were calculated. The following average foliar nutrient concentration were obtained from the high‐yielding populations: N = 5.22, P = 0.38, K = 4.20, Ca = 1.50, and Mg = 0.65 percent; and Fe = 150, Mn = 50, Zn = 40, Cu = 11, and B = 38 ppm. The average nutrient concentrations for the low‐yielding population were close to those in high‐yielding ones except for K which was 3.23 in contrast to 4.20‐percent. There was no s...

POTATO PRODUCTION IN NASA'S BIOMASS PRODUCTION CHAMBER WITH REFERENCE TO ATMOSPHERIC VOLATILES

Potatoes (Solanum tuberosum cv. Norland) were grown for 105 days in a large (20 m2), closed chamber to assess their potential for life support in space. Cultural conditions included a recirculating NFT culture, 12/12 photoperiod, 16°C, 1000 μmol mol-1 CO2, and approximately 900 μmol m-2 s-1 PPF from HPS lamps. The chamber was separated into two halves with one atmosphere continuously passed through charcoal filters, while the other was not filtered. Plants grown in the filtered air showed a more “induced” appearance early in growth in comparison to plants in the unfiltered air (i.e. reduced shoot growth and early tuber bulking). Ethylene levels in the atmospheres ranged from 10 to 60 ppb in the unfiltered treatment and 10 to 40 ppb in the filtered. Mass spectral analyses indicate that the filters efficiently reduced heavier organic volatiles, but were not effective for lighter volatiles (e.g. ethylene). Biogenic emissions from the plants were identified, as well as components from glues and caulking compounds. Final tuber yields were similar but shoot biomass was higher and harvest index lower in the unfiltered treatment: charcoal filtered--10.1 kg m-2 tuber FW, 1.9 kg m-2 tuber DW, 2.5 kg m-2 total plant DW, 76% harvest index; unfiltered--10.9 kg m-2 tuber FW, 1.9 kg m-2 tuber DW, 3.1 kg m-2 total plant DW, and 61% harvest index.

Temperature accumulation and physiological ageing of seed potato tubers

SummaryTubers of cv. Maris Bard were allowed to accumulate different numbers of day‐degrees early, late or continuously throughout the seed storage period. Sprout growth, time of emergence, development of early canopy cover and early tuber yield were increased more by late temperature accumulation than by increasing the number of day‐degrees experienced from 250 up to a maximum of 700°C days. The relative physiological age of seed, as indicated by the subsequent rate of early crop growth, was poorly related to the number of day‐degrees accumulated. The implications for the quantification of seed physiological age are discussed.

Effects of kinetin, paclobutrazol and their interactions on the microtuberization of potato stem segments cultured in vitro in the light

Single-nodal cuttings of Solanum tuberosum (four cultivars) and Solanum chacoense were induced to produce in vitro microtubers on Murashige & Skoog (MS) medium supplemented with 8 g l−1 sucrose and various concentrations of kinetin and paclobutrazol. The cultures were kept 10 days in darkness and then transferred to a 14 h daylength with 100 µE m−2 sec−1 light intensity at 21 °C. Kinetin (2.5 mg l−1) had no significant influence on tuber formation. However, its addition together with paclobutrazol (0.001 mg l−1) significantly enhanced tuberization. Paclobutrazol alone stimulated early tuber initiation and inhibited stem growth. Despite some genotype × treatment interactions, all genotypes (from very early to late and wild type) formed the maximum proportion of explants bearing microtubers on the media containing both plant growth regulators.

Plot Sprinklers for Irrigation Research

AbstractPortable plot sprinklers were developed that allowed individual plots to be irrigated independently of other plots. Each plot sprinkler consisted of three rotary‐pendulum, square‐pattern sprinkler heads mounted on a PVC pipe frame. Plot sprinkler water output was 0.9 m3 h−l, on an area 4.6 m wide by 13.7 m long, with Cu = 80%, when operated at 86 kPa. Plot sprinklers were used to apply irrigation treatments In a randomized block design to evaluate potato (Solanum tuberosum L. ‘Russet Burbank’) tuber quality response to six levels of transitory drought stress during early tuber bulking. Yield of U.S. Number One tubers decreased and yield of U.S. Number Two tubers increased with increasing severity of transitory drought stress. Plot sprinklers allow irrigation of plots in an experiment at different frequencies or durations.

Effects of soil moisture deficits on yield and quality of ‘Russet Burbank’ potatoes

Abstract A ‘Russet Burbank’ potato crop was subjected to 14 irrigation treatments in a rainshelter experiment at Lincoln, New Zealand in the 1987–88 growing season. In 12 treatments, plots were trickle irrigated and covered automatically by the shelter whenever rain fell, so that precise responses of yield and quality to water deficit timing and severity could be obtained. These treatments ranged from overwatering to withholding water to develop maximum potential deficits of up to 138 mm. The water stress treatments were applied either ac tuber initiation, early tuber bulking, or late tuber bulking (assessed by sampling spare plants). Except when fit was raining, these plots were exposed to prevailing climatic conditions. The two remaining treatments, which were outside the rainshelter, checked for direct effects of the shelter on the crop. One treatment was irrigated to achieve the same deficits as one of the treatments inside the rainshelter, and the other was not irrigated. Highest yields of process grade tubers (63 t/ha} were obtained from the overwatered plots. Among the drought-stressed treatments, the highest yields were 58 t/ha of process grade tubers, obtained from plots subjected to drought during tuber initiation; these had fewer bit larger tubers. Drought during late tuber bulking reduced process grade yields by 20%, with both tuber size and tuber number being reduced by up to 20%. Non-irrigated rainfed plots outside the shelter had low yields and small tubers because the season had half the average rainfall. The levels of water deficit imposed had no effect on tuber processing quality.

Potassium nutrition of Kennebec and Russet Burbank potatoes in Tasmania: effect of soil and fertiliser potassium on yield, petiole and tuber potassium concentrations, and tuber quality

The response of potato (Solanum tuberosum L.) cultivars Russet Burbank and Kennebec to soil and fertiliser potassium (K) was studied on basaltic krasnozems of north-west Tasmania. Yield increases in response to fertiliser K were recorded at sites with up to 300-400 mg/kg of bicarbonate extractable soil K. The close correlation between relative yield and soil K indicated that soil K can reliably predict fertiliser requirements. Petiole K concentrations at early tuber set increased with fertiliser K at responsive sites; maximum yields were achieved with 12-14% petiole K for Kennebec and 11-13% for Russet Burbank. Petiole K concentrations provide an excellent indication of the K status of a growing crop. Tuber K concentrations increased with both soil and fertiliser K, and yields of 50-80 t/ha removed 180-380 kg K/ha in the tubers. At severely deficient sites specific gravity and crisp colour increased with low rates of fertiliser K, but the general trend was for fertiliser K to reduce specific gravity and crisp colour. Bruising susceptibility decreased with fertiliser K at some sites but the physiological disorder, 'hollow heart', was not influenced by fertiliser K. There were consistent differences between the 2 cultivars. Russet Burbank required higher soil K, had lower petiole and tuber K concentrations and removed less K in the marketable tubers.

Growth and Yield Performance of Several Potato Clones Grown at Three Elevations in Hawaii. I. Plant Morphology.

There are few data on the growth and yield of potato (Solanum tuberosum L.) genotypes in the field in tropical and subtropical environments despite interest in such work. Among other things, the data were needed to validate a potato growth model being developed for use in agriculture technology transfer in the tropics. A genotype by environment experiment was conducted on Mr. Haleakala, Maui, HI in 1985 and 1986 at elevations of 91, 282, 640, and 1097 m. The 91 and 1097 m elevations were common in both years. Mean maximum air temperatures during the experimental period for 1985 and 1986 were 29.2 and 30.3 °C at 91 m and 23.1 and 24.0 °C at 1097 m. Mean minimum air temperatures for the same period in 1985 and 1986 were 20.9 and 20.5 °C at 91 m and 14.3 and 15.0 °C at 1097 m. Differences in irradiance across the sites was small. The growth and yield of the standard temperate cultivars Desiree, Katahdin, Kennebec, and Norchip and three heat tolerant clones LT‐1, C14‐343, and C1‐884 were contrasted across the sites. Stem numbers per plant did not differ across elevations but plants were taller, internodes were longer, there were more branches per stem, and the leaf area index was greater for plants grown as the low‐elevation sites. Days to tuber initiation decreased significantly as the elevation increased. Numbers of nonmarketable tubers (diam. < 5 cm) were greater at the lowest elevation, whereas a higher percentage of marketable tubers (diam. > 5 cm) was produced at the highest elevation. Katahdin outperformed all cultivars producing relatively high yields of marketable tubers at all elevations. The heat‐tolerant clones began tuber initiation earlier than the cultivars, but early tuber formation did not result in higher yields. There was little evidence that the heat‐tolerant clones were superior to the temperate cultivars, even at the lowest elevation where temperatures were warmest.