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.     

Potassium fertilizer trials with potatoes on coarse-textured soils in southeastern Idaho

American Journal of Potato Research - Potassium fertilizer needs of potatoes were evaluated with a set of research plots established on coarse textured soils in southeastern Idaho. Over the...     

Some properties of soils affecting russet scab and silver scurf of potatoes

The relationship of soil ammonia, nitrates, pH, total bacteria,Streptomyces sp., temperature and moisture on the incidence of russet scab and silver scurf of potatoes was studied. The soil properties were changed by the addition of various levels of alfalfa, wheat straw and green rye residues. Within the limits of the changes caused by these residues, the most consistent relationship was found between the nitrate level in the soil and russet scab, and to a lesser extent, silver scurf. In both instances there was a general decrease in russet scab and silver scurf with increasing levels of nitrates. Also, in the only comparison made, an increasing total bacterial count in the soil resulted in a decreasing level of infection from silver scurf. In some instances the alfalfa, rye and straw residue applications caused small changes in soil pH, soil temperature, and soil moisture. These changes were not great enough to show any consistent significant relationship to russet scab or silver scurf, except for a significant negative correlation between soil moisture at the 6-inch level and silver scurf in both years.     

Fertility and management practices to control verticillium wilt of the russet burbank potato

Management practices for the suppression of Verticillium wilt of Russet Burbank potato include sanitation, use of optimum sprinkler-irrigation practices, soil solarization, and an adequate soil fertility program. Among all cultural factors considered, nitrogen (N) deficiency in potato tissue was most commonly associated with the severity of Verticiilium wilt in Russet Burbank potato. Field studies have shown that increased N availability suppresses Verticiilium incidence on cv Russet Burbank while having no effect on cv Norgold Russet. Studies from both greenhouse and field show that the colonization ofV dahliae in potato stem tissue is suppressed in cv Russet Burbank when the availability of Phosphorous (P) is increased to the optimum. Following one season of cropping with Russet Burbank potato, the treatment providing the optimal N availability also suppressed the increases ofV dahliae populations in the soil during the following year of consecutive cropping. Similarly, after two seasons of continuous potato cropping, treatments with optimal P had lower soil populations ofV. dahliae in soil. Results show the suppression of Verticiilium wilt with optimal fertility. Verticiilium wilt [caused by eitherVerticiilium dahliae Kleb, (microsclerotial form) orVerticiilium albo- atrum Reinke and Berthold (dark mycelial form)] is one of the most severe diseases of potato in the United States. Potato yields, tuber size, and specific gravity may be substantially reduced by this disease, depending on severity, time of occurrence, and growing season. In Idaho and other arid growing regions of the United States, Verticiilium wilt is caused byVerticillium dahliae Kleb. Idaho field studies involving cropping practices, soil fumigation treatments, solarization, and Verticillium-resistant potato clones all support the importance ofV dahliae upon potato yield. Data from these studies show that yield losses due toV. dahliae commonly approximate 5 to 12 metric T/ha (5, 6). Table 1 illustrates the effect of several cropping practices upon relativeV dahliae populations in soil with the effects upon both disease severity and potato yield. With continuous cropping of Russet Burbank,V dahliae populations in soil increased, and yields were reduced by 18 to 19 metric Tlha when compared to locations that had been allowed to remain either weed-free and fallow or where corn had been previously cropped. It was estimated thatV dahliae was influencing yield by about 10 to 12 metric Tlha based on a regression analysis of yield as a function ofV dahliae populations in soil. Similarly, whenV dahliae was suppressed by fumigation treatments involving mixtures of dichloropropene and picfume, yields more significantly increased by 6.5 to 12 metric T/ha (5). Although many factors may influence yields, clones with higher Verticillium resistance than Russet Burbank generally out-yield Russet Burbank. Figure 1 demonstrates the effect of solarization (a technique involving the laying of clear plastic on soil for the purpose of elevating soil temperatures to killV dahliae). When Verticillium was controlled in this manner (lo), there was no significant yield difference between the Russet Burbank potato and the highly resistant A68113-4 clone. The A68113-4 clone grown in non-solarized soil out-yielded the Russet Burbank in non-solarized soil by 31 percent while the solarization treatment significantly increased yield for the Russet Burbank and A68113-4 clones by 46 and 18 percent, respectively. These yield responses were observed in a field where inoculum levels ofV dahliae were relatively low (2.10 cfulgrn of soil). With these losses, the need to develop control procedures is great and to achieve this control the need also exists to accurately evaluate the effect of treatments uponV dahliae. Our Idaho studies have routinely utilized such a procedure (9) in combination with comparisons of both disease severity and yield.     

Response of potatoes (cv russet burbank) to supplemental calcium applications under field conditions: Tuber calcium, yield, and incidence of internal brown spot

Potato tuber tissue is low in calcium as compared to leaves and stems. Several recent studies have provided evidence linking tuber quality with tuber tissue Ca concentration. The purpose of the present study was to determine the influence of supplemental Ca and N fertilization on tuber Ca concentration and internal brown spot of potato. Three soluble products (calcium nitrate, calcium chloride, and N-Plus; 9N:0K:0P:11Ca) were used as Ca sources with and without gypsum. In addition, a combination of calcium chloride, urea, and calcium nitrate (CUC) was also used without gypsum. Each treatment consisted of five replications, which received the same total amount of N (252 kg ha^?1) supplied either alone or in various combinations of ammonium nitrate, urea, calcium nitrate, calcium chloride, and N-Plus. The soluble sources of Ca were added at 68.8 to 168.0 kg ha^?1 while gypsum supplied Ca at 49 kg ha^?1. The application of all N by hilling (non-split) was compared to split application of N and Ca at hilling and 2, 4, and 6 wk after hilling. Tubers were mechanically harvested and graded according to industry standards. About 100 U.S. No. 1 tubers from each replication were cut in half along the longitudinal axis and visually inspected for internal defects. From each replication, non-periderm tissue from 15 tubers was combined for Ca analysis. There was no treatment effect on tuber yield in both years. Application of gypsum, either alone or in combination with the soluble sources, was not effective in reducing incidence of internal brown spot (IBS). Furthermore, with one exception, application of gypsum either alone or in combination with soluble sources of Ca was not effective at increasing tuber tissue Ca concentration. Combined analyses of data from 2 years showed that the application of soluble sources of Ca without gypsum increased tuber Ca concentration and decreased the incidence of IBS. Furthermore, split application of N had similar beneficial effects as compared to non-split N. Data from 1997 (a year with high IBS) gave a significant inverse relationship between tuber Ca and IBS, suggesting that an increase in tuber Ca can reduce IBS incidence.     

Estimation of critical nutrient range of petiole nitrate for sprinkler-irrigated potatoes

The relationship of yield to concentration of NO₃ in petioles of potatoes (Solanum tuberosum L.) was studied as part of a comprehensive project on N use efficiency. The objective of this study was to estimate the critical nutrient range (CNR) of petiole NO₃ for Russet Burbank potatoes treated with N supplements during the season. Treatments totaled 224, 336, and 560 kg N ha^-1 for the season as NH₄NO₃ on this low N soil with one-third to one-half of the N applied at planting and the rest as periodical supplements during the season. Average yield of potatoes (74 Mt ha^-1) was highest with 336 kg N ha^-1. From this it was assumed that 224 N was optimum. Petiole NO₃ decreased through the season with linear regressions of petiole NO₃ versus time for each of three N rates accounting for variation in petiole NO₃. It was concluded that at the start of the season, the estimated CNR for petiole NO₃-N of potatoes was within the range from 9 to 13 g kg^-1. Numerically, CNR values decrease with time as the season progresses. It is concluded that until more precise calibrations are made available, the CNR approach with petiole NO₃ will be more helpful in cross checking the nutritional status of potatoes fertilized periodically with N supplements than in serving as a primary fertilizer guide.     

Effect of planting and harvest dates,location in the hill and tuber size on sugar content of Kennebec potatoes

A study was made with the Kennebec cultivar on the effect of planting and harvest times, location of tubers in the hill and tuber size on fructose, glucose and sucrose in tubers at harvest. The location of tubers in the hill did not affect fructose or glucose and had only a small effect on sucrose found in the tubers. Small tubers were higher in all three sugars than large tubers, and tubers from plants seeded later were higher in glucose and sucrose than tubers from plants seeded early. The early plantings at all harvests outyielded the late plantings. This together with the higher quality (lower sugars) support the recommendation that Kennebec potatoes to be used for processing should be planted early.     

Uptake of PCBs by potatoes grown on sludge-amended soils

Katahdin potatoes were grown on soil treated with anaerobically digested sewage sludge to determine the level of PGBs absorbed. The sewage sludge treated soil contained 1.52±0.71µg/g PCB. Potato plant leaves and tuber pulp contained less than the detectable level (<0.007µg/g) of PCB. Potato peels contained 0.04µg/g PCB which is less than the FDA tolerance limit. From these data it appears unlikely that potatoes grown in PCB-contaminated soil will absorb sufficient quantities of PCBs to pose a significant health risk, especially if the potatoes are peeled prior to eating.     

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 cutting and gibberellin treatment on autumn-grown seed potatoes for spring planting

Summary Length of dormancy limits the use of autumn-grown seed potatoes for planting the spring crop. Trials of different treatments for breaking dormancy were carried out for four successive seasons (1958–1961). Cutting the seed and dipping in gibberellic acid (GA) was effective in breaking dormancy. Cutting two weeks before planting and dipping the seed pieces in a 1 ppm GA solution gave the best results. Instead of cutting, smaller sized seed can be pierced, thus enabling the entire yield of tubers to be used for seed. Higher concentrations of GA induced growth abnormalities in both plants and tubers without producing any improvement in the breaking of dormancy over the lowest concentration used (1 ppm). Physiological aspects of seed potatoes are discussed.

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Zusammenfassung In Israel wird der Gebrauch von Saatkartoffeln aus Herbsternte für die Frühjahrspflanzung durch die L?nge der Keimruhe beschr?nkt. W?hrend vier aufeinanderfolgenden Anbauperioden (1959–1961) wurden Versuche mit verschiedenen Behandlungen zur Brechung der Keimruhe durchgeführt. Durch Schneiden und Eintauchen der Saatknollen in Gibberellins?ure (GA) wurde die Keimruhe wirksam gebrochen. Die besten Ergebnisse wurden erzielt, wenn das Saatgut zwei Wochen vor der Pflanzung geschnitten und die Knollenstücke in eine GA-L?sung von 1 ppm eingetaucht wurden (Tabellen 1 und 2). Kleinere Saatknollen k?nnen statt geschnitten nur durchstochen werden, so dass der ganze Knollenertrag für Saatzwecke gebraucht werden kann (Tabelle 2). H?here GA-Konzentrationen führten zu Missbildungen sowohl der Pflanzen wie der Knollen, ohne eine Verbesserung im Brechen der Keimruhe gegenüber der niedrigsten angewendeten Konzentration (1 ppm) zu bewirken. Physiologische Aspekte der Pflanzkartoffeln werden besprochen.

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Résumé En Isra?l, la longueur de la dormance limite l’utilisation de plants de pomme de terre poussés en automne pour la plantation de printemps. Différents traitements pour rompre la dormance ont été effectués pendant quatre saisons successives (1959–1961). Le sectionnement des plants et le trempage dans l’acide giberellique (GA) sont efficaces pour rompre la dormance. Le sectionnement deux semaines avant la plantation et le trempage des fragments dans une solution à 1 ppm¹ de GA donnent les meilleurs résultats (Tableaux 1 et 2). Les petits plants peuvent être perforés plut?t que sectionnés, ce qui permet alors d’utiliser la récolte entière de tubercules comme plants (Tableau 2). Une plus haute concentration de GA provoquait le développement d’anomalies à la fois dans les plantes et les tubercules sans apporter d’avantage dans la rupture de la dormance, par rapport à la plus basse concentration utilisée (1 ppm¹). Le point de vue physiologique est discuté. ¹ppm.=partie par million.

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Publication of the National and University Institute of Agriculture, Rehovot, Israel. 1963 series. No. 571-E.     

Shortening the dormant period of spring-grown seed potatoes for midsummer planting

Summary Experiments on breaking the dormancy of spring-grown seed potatoes for midsummer planting of an autumn crop were carried out during 1961–1965. Seventeen varieties were tested with rindite vapour, applied to whole tubers, and with gibberellic acid (GA) and the auxin 2,4-dichlorophenoxyacetic acid (2,4D), applied by dipping whole or cut tubers in solutions. Treatments were given at different intervals between harvest and planting of the seed. Rindite was the most effective; GA less so. Rindite curtailed the dormant period of all the varieties tested, while GA hastened the sprouting of the majority of tubers after the dormant period was terminated. GA was much more effective if applied shortly before planting cut rather than whole tubers. With most varieties suberisation of cut surfaces before planting was needed to avoid rotting of the seed pieces.

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Zusammenfassung In den Jahren 1961 bis 1965 wurden Versuche zur Brechung der Keimruhe bei Saatkartoffeln aus Frühjahrsanbau, die zur Auspflanzung im Hochsommer zwecks Erzielung einer Herbsternte bestimmt waren, durchgeführt. Siebzehn Sorten wurden geprüft, indem sie mit Rindite-Dampf (ganze Knollen) sowie mit Gibberellins?ure (GA) und mit dem Auxin 2,4-dichlorophenoxyessigs?ure (2,4D) (ganze oder geschnittene Knollen in L?sungen getaucht) behandelt wurden. Die Behandlungen erfolgten in verschiedenen Abst?nden zwischen Ernte und Auspflanzung des Saatgutes. Wenn die Knollen lange vor dem Auspflanzen geschnitten wurden, sorgte man für die Wundkorkbildung der geschnittenen Oberfl?chen. Die Behandlung mit Rindite war am wirksamsten, GA blieb etwas weniger wirksam. Rindite verkürzte die Ruhezeit von vielen der geprüften Sorten, w?hrend GA gew?hnlich nur eine geringe Wirkung erzielte (Tabelle 1). Die gebrauchten Substanzen hatten entweder keine Wirkung oder übten einen toxischen Einfluss auf Sorten mit sehr kurzer Ruheperiode, z.B.Ari oderFina, aus; Saatknollenstücke dieser Sorten sollten deshalb ohne Behandlung ausgepflanzt werden (Tabelle 2). Eintauchen ganzer Knollen in GA zwei Wochen vor dem Auspflanzen beschleunigte das Auflaufen nicht, doch war GA bei geschnittenen Knollen, die einen Tag vor dem Auspflanzen in eine L?sung getaucht wurden, wirksamer (Tabelle 1). Dies k?nnte auf biochemische Vorg?nge in den geschnittenen Knollen, die den Ruhezustand beeinflussen, und/oder auf gr?ssere Wasserabsorption der frisch geschnittenen Oberfl?chen zurückgeführt werden. Das Schneiden der Knollen lange (22 Tage) vor dem Auspflanzen, jedoch ohne weitere Behandlung, verz?gerte in der Regel das Auskeimen. Anwendung von GA hob manchmal, aber nicht immer, diese Verz?gerung auf. 2,4D war entweder antagonistisch oder neutral gegenüber GA, und manchmal wirkte es keimhemmend (Tabellen 1 und 2). Bei der Mehrzahl der Sorten was es die Regel, dass nicht verkorkte Saatknollenstücke nach dem Auspflanzen verfaulten: diese Tendenz wurde manchmal durch die Behandlung mit keimruhebrechenden Mitteln verst?rkt.Isola, zum Beispiel, war nach Rinditebehandlung,Sebago undAvenir nach GA-Behandlung, undAri undSieglinde nach beiden Behandlungen für F?ulnis anf?llig. Ganz allgemein müssen die Schnittfl?chen von Saatkartoffeln vor dem Auspflanzen verkorkt sein, damit das Verlaufen der Knollenstücke vermieden wird. Um die keimhemmende Wirkung einer l?ngeren Zeitspanne zwischen Schneiden und Auspflazen auf ein Minimum herabzusetzen, muss die Zeit für die Wundkorkbildung auf h?chstens zwei Wochen beschr?nkt werden.

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Résumé Des expériences de rupture de la dormance chez des plants de pomme de terre poussés au printemps en vue de la plantation au milieu de l'été ont été effectuées au cours des années 1961–1965. Dix-sept variétés furent testées à la vapeur de rindite appliquée avec tubercules entiers, de même l'acide gibberellique (GA) et à l'auxine 2,4-acide dichlorophénoxacétique (2,4D) appliqués en solutions à des tubercules entiers ou coupés. Les traitements furent appliqués à différents intervalles entre la récolte et la plantation. Lorsque les tubercules étaient sectionnés longtemps avant la plantation, on prenait soin d'assurer la subérisation des surfaces coupées. Le traitement à la rindite est le plus efficace; le traitement au GA l'est moins. La rindite écourtait la période de dormance de beaucoup de variétés testées, tandis que, habituellement, GA avait seulement un faible effet (Tableau 1). Les substances utilisées n'avaient pas d'effet ou avaient d'effet toxique sur les variétes qui présentent une très courte période de dormance, tellesAri etFina; des fragments de plants de ces variétés devraient, par conséquent, être plantés sans traitement (Tableau 2). Le trempage de tubercules entiers dans GA une quinzaine avant la plantation n'avait aucun effet sur l'accélération de la levée; mais était plus efficace lorsque les tubercules étaient sectionnés et trempés un jour avant la plantation (Tableau 1). Ce phénomène pourrait être attribué à des modifications biochimiques chez les tubercules sectionnés, modifications qui affectent l'état de dormance et — ou — à une plus grande absorption d'eau par les surfaces fra?ches exposées. Le sectionnement longtemps (22 jours) avant la plantation, sans aucun traitement, retarde généralement la germination. L'application de GA élimine parfois, mais non toujours, ce retard. 2,4D est, soit antagoniste, soit neutre, vis-à-vis du GA et, parfois inhibe la germination (Tableau 1 et 2). Dans la majorité des variétés, le dépérissement après plantation des fragments de tubercules non cicatrisés est fréquent; cette tendance est parfois accentuée par le traitement avec les substances rompant la dormance. Par exempleIsola est susceptible au dépérissement lors de l'application de rindite,Sebago etAvenir lors de traitement GA, etAri etSieglinde lors de l'application de l'une et l'autre traitement. Généralement les surfaces de sectionnement des plants doivent être subérisées avant la plantation pour éviter la pourriture. En vue de réduire l'effet inhibiteur d'une longue période entre sectionnement et plantation, le temps admis pour la subérisation doit être limité à deux semaines maximum.

     

赣北丘陵杂交棉适宜种植密度展示小结

江西省湖口县地处长江南岸,鄱阳湖与长江交汇口处,是江西植棉大县之一.21世纪初,该地区以常规棉种植为主,抗虫棉、杂交棉种植少,全县棉花平均密度达到52 500株/hm2;之后随着抗虫棉、杂交棉的普及种植时,其密度在27000株/hm2左右;2007～2008年湖口县平均栽植密度只有16 500株/hm2,甚至个别地块出现密度不到10 000株/hm2的现象.2009年湖口县实施棉花高产创建项目,在其影响下,全县平均密度有所提高,示范区密度达到22 500株/hm2,全县平均密度也达到18 000株/hm2.为了展示棉花合理密植的增产效果,湖口县农业局于2010年在"万亩"棉花高产创建示范片(武山镇)进行了棉花合理密植展示示范,现将结果汇报如下.