Walter C. Sparks

Changes in chlorpropham residues in stored potatoes

Chlorpropham (CIPC)3 concentrations were measured in peel samples of tubers taken from large commercial potato storages and from test bins after aerosol application. Tuber samples were taken at different levels within the pile and at numerous sites near the surface. The minimum concentration of CIPC in the peel layer for complete inhibition of sprouting was estimated to be 20 ppm. Immediately after commercial application of CIPC, 99% of the sample sites had concentrations high enough to completely inhibit sprouting, and residues in the peel were generally highest in samples obtained from the surface and from the bottom of the pile. CIPC concentrations decreased during the storage season in nearly all sites tested. Storages differed in the rate at which CIPC was lost. Mean peel residues fell below the level necessary for sprout inhibition in some storages but not in others. The rate of CIPC loss increased at the same time that air movement to maintain the desired temperature increased. With the 20 ppm threshold level as a guide, it is possible to monitor commercial storages for sprout-inhibition status. Retreatment before peel residues drop below 20 ppm can extend sprout inhibition in storage.ResumenConcentraciones de Clorprofan (CIPC) fueron medidas en muestras de tubérculos pelados tomadas de grandes almacenes comerciales de papa y de cajas de muestreo después de una aplicación aerosol.Las muestras de tubérculos fueron tomadas de diferentes niveles dentro de la pila y en numerosos lugares cercanos a la superficie. La concentración minima de CIPC en la capa pelada para la inhibición completa del brotamiento fue estimada en 20 ppm. Inmediatamente después de la aplicación comercial de CIPC, 99% de los lugares muestreados presentaron concentraciones suficientemente altas para inhibir el brotamiento por completo, y los residuos en el pelado fueron generalmente más altos en las muestras obtenidas de la superficie y del fondo de la pila.Las concentraciones de CIPC disminuyeron durante la temporada de almacenamiento en casi todos los lugares muestreados. Los almacenamientos difirieron en la tasa en que el CIPC disminuyó.Las medias de los residuos pelados, cayeron debajo del nivel necesario para inhibir el brotamiento en algunos almacenamiento pero no en otros.La tasa périda de CIPC aumentó al mismo tiempo que el movimiento del aire para mantener el aumento de temperatura deseada.Con el nivel inicial de 20 ppm como guía, es posible medir almacenamientos comerciales para estados de inhibición del brotamiento.Nuevos tratamientos antes que los residuos pelados disminuyeron bajo los 20 ppm pueden extender la inhibición del brotamiento en almacenaje.

Butte: A long Russet potato variety with excellent dehydrating quality

Abstract‘BUTTE’, a new long russet potato variety, was released by the Agricultural Research Service, U. S. Department of Agriculture and the Idaho, Oregon, and Washington Agricultural Experiment Stations in April, 1977. Its tubers are similar to those of ‘Russet Burbank’ but BUTTE offers several advantages to growers and processors. BUTTE has averaged 7% more total yield and 25% more U.S. No. 1’s than Russet Burbank over 51 location-years of testing across southern Idaho, eastern Oregon, and in the Columbia Basin. Its specific gravity in these trials averaged .004 higher than that of Russet Burbank. Dehydrating quality of BUTTE is superior to that of Russet Burbank and the product has longer shelf life. BUTTE french fries well although it accumulates slightly more sugars in storage than does Russet Burbank. Its vitamin C content has averaged 58% higher and protein content 20% higher than that of Russet Burbank. BUTTE is hypersensitive to virus X and resistant to net necrosis. Other disease reactions are similar to those of Russet Burbank.ResumenEl Servicio de Investigación Agrícola del Departamento de Agricultura de los Estados Unidos y las Estaciones Experimentales Agrícola de Idaho, Oregón y Washington, lanzaron en Abril de 1977 una nueva variedad de papa alargada y casposa denominada BUTTE. Sus tubérculos son similares a aquellos de “Russet Burbank” aunque BUTTE ofrece varias ventajas para los agricultores y procesadores. BUTTE tuvo un 7% de mayor rendimiento y 25% más en el grado U.S. N° 1 que “Russet Burbank” en una combinación de pruebas conducidas en 51 localidades/año en el sur de Idaho, al este de Oregón y en la hoya del rió Columbia. En estos experimentes su gravedad especffica promedio fué de .004 más alta que la de “Russet Burbank”. Su calidad para el deshidratado es también superior y el producto tiene una vida más larga. La calidad de BUTTE para papas fritas es buena a pesar de que acumula, en almacenamiento, ligeramente más azúcar que la “Russet Burbank”. Su contenido de vitamina C y proteinas en promedio ha sido 58% y 20% respectivamente, mayor que aquellos de “Russet Burbank”. BUTTE es hipersensible al virus X y resistente a la necrosis en red. Su reacción a otras enfermedades es similar a aquella de “Russet Burbank”.

Effect of storage temperature on storage losses of Russet Burbank potatoes

SummaryThree storage trials involving Idaho-grown Russet Burbank potatoes showed that storage at 45 F resulted in less weight loss than storage at 38 or 52 F. Unwashed potatoes stored at 45 F had less storage loss throughout a 345-day storage period than tubers from the same source stored at 38 or 52 F. Washed tubers destined for the fresh market and treated with various inhibitors in April had less loss after 90 days of storage at 45 F than at 38, 52, or 59 F, but after 130 days of storage, 38 F showed the least loss. Washed and unwashed potatoes stored at 45 F in CIPC treated bags for 92 days showed less loss than those stored at 38, 52, 59, or 68 F.

Sugar content and color of Russet Burbank potatoes as related to storage temperature and sprout inhibitors

SummaryReducing and total sugar assays and cooked flesh color measurements were made on Idaho-grown Russet Burbank potatoes at monthly intervals during 12 months of storage. The six storage treatments included untreated tubers stored at 38 F, 45 F, and 52 F; untreated tubers stored at 38 F followed by one week of conditioning at room temperature; tubers treated with MH-30 stored at 45 F; and tubers treated with CIPC stored at 45 F.The tubers stored at 45 F contained significantly less reducing and total sugars and were significantly lighter in color than those stored at 38 F. Tubers stored at 45 F were comparable to those stored at 52 F in sugar content and color and had a longer storage life. Treatment with MH-30 or CIPC had no effect on sugar accumulation and no important effect on color.Conditioning potatoes from storage at 38 F for one week at room temperature significantly decreased the contents of total and reducing sugars, although they remained significantly higher than those of tubers stored at 45 F. Conditioning did not reverse the yellow color which had developed during 38 F storage.ResumenSe efectuaron determinaciones de azucares totales y reductores así como estimaciones de color de pulpa cocida a intervalos mensuales, durante un período de 12 meses de almacenaje, en tubérculos de papa de la variedad Russet Burbank, cosechados en Idaho.Los six tratamientos de almacenaje incluian tubérculos sin tratar almacenados a 38, 45 y 52 F; tubérculos sin tratar almacenados a 38 F seguido por una semana de acondicionamiento a temperatura ambiente; tubérculos tratados con MH-30 almacenados a 45 F; y tubérculos tratados con CIPC almacenados a 45 F.Los tubérculos almacenados a 45 F contuvieron menos azucares totales y reductores y eran de un color mas ligero que aquellos almacenados a 38 F. Las diferencias fueron significativas en ambos casos.Los tubérculos almacenados a 45 F tuvieron un contenido de azucares y color comparable a aquellos almacenados a 55 F, además exibieron una capacidad de almacenaje mas larga.Los tratamientos con MH-30 o CIPC no tuvieron efecto sobre la acumulación de azucares o en la coloración de los tubérculos.Acondicionando los tubérculos por una semana a temperatura ambiente después de estar almacenados a 38 F, disminuyó significativamente el contenido de azucares totales y reductores. El contenido de estos azucares, sin embargo, se mantuvo significativamente mas alto que en aquellos tubérculos almacenados a 45 F.Tubérculos almacenados a 38 F exibieron un color amarillo el cual no fue trastrocado por medio del acondicionamiento a temperatura ambiente.

Potato storage factors of economic importance

There has been a marked increase in the length of time potatoes are stored. The cost of storing potatoes for longer periods of time has been controversial because of the lack of acceptable figures relating to the various factors involved. This paper summarizes the costs involved due to various storage environments and various storage periods. In addition to representative investment and operational costs, the costs of weight losses, quality changes, and peel and trim losses are presented.ResumenSe ha dado un incremento considerable al período de tiempo del almacena miento de la papa. El costo de almacenar las papas por más tiempo ha sido muy controvertido debido a la falta de datos aceptables relacionados con los distintos factores involucrados. Este trabajo resume los costos involucrados debido a los diferentes ambientes y períodos de almacenamiento. Además de los costos de inversión inicial y del mantenimiento, se presentan aquellos referentes a pérdidas de peso, cambios de calidad y mermas por daños.

Storage temperature for maintenance of internal quality in Idaho Russet Burbank potatoes

Idaho-grown Russet Burbank potatoes treated with a sprout inhibitor were stored at 42 F, 45 F, and 48 F for 11 months. Monthly quality evaluations showed that tubers stored at 42 F were less mealy, contained more reducing sugars, and were yellower in color than those stored at 45 F or 48 F. The latter two treatments were not significantly different in mealiness and were generally similar in yellowness of color. Tubers stored at 48 F had less reducing sugars than those stored at 45 F. Although all treatments resulted in a gradual darkening of the potatoes during storage, differences in grayness among the three storage treatments were minor from a practical standpoint. It is suggested that a storage temperature no lower than 45 F be used to maintain the internal quality of Russet Burbank potatoes.

Potato storage quality as influenced by rate of ventilation

Insulated bins containing approximately 1800 kg (2 ton) were ventilated at airflow rates of 0, 2.3, 4.7, 9.4, 18.7, 37.5, and 74.9 m3/h/T(0, 1.25, 2.5, 10, 20, and 40 cfm/t). Replicated trials over a three year period showed that ventilating with an airflow rate of 18.7 m3/h/T (10 cfm/t) resulted in the lowest combined storage loss due to weight, sprouts, and rot. The time required to grade the tubers from the bins ventilated with airflow rates greater than 9.4 m3/h/T (5 cfm/t) was significantly less than that from those receiving lower airflow rates. There was no significant difference in tuber temperature at the top of the bins having an airflow rate of 9.4 m3/h/T (5 cfm/t) or more.ResumenSe ventilaron almacenes aislados, de una capacidad de aproximadamente 1,800 kgs. (2 tons.), con corrientes de aire a ritmos de 0, 2.3, 4.7, 9.4, 18.7, 37.5 y 74.9 m3/h/T (0, 1.25, 2.5, 10, 20 y 40 cfm/t). Pruebas replicadas realizadas durante un período de tres años mostraron que el hecho de ventilar con corriente de aire a un ritmo de 18.7 m3/h/T (10 p c /tm) dio como resultado la pérdida combinada por almacenamiento más baja en cuanto a peso, brotamiento y pudrición. El tiempo requerido para clasificar los tubérculos de los depósitos ventilados con corriente de aire a ritmos mayores de 9.4 m3/h/T (5 pmc/t) fue significativamente menor que en los casos de los que recibieron corrientes de aire a ritmos más bajos. No se registró diferencia significativa en la temperatura de tubérculo en la parte alta de los depósitos con ritmos de corriente de aire de 9: 4m3/h/T (5 pcm/t) o más.

Abstracts of papers presented at the Fifty-Second Annual Meeting of The Potato Association of America

F I F T Y S E C O N D A N N U A L M E E T I N G

Internal quality of Russet Burbank potatoes following chilling

Russet Burbank potatoes were chilled at 25 F (−3.8 C), 27.5 F (−2.5 C), or 30 F (−1.1 C) for various periods of time and were then held at 45 F (7.2 C) for one or four weeks before testing. Susceptibility to injury was quite variable between the two crops and among tubers of the same lot exposed to the same treatment. The greatest amount of low temperature breakdown occurred in tubers chilled at 27.5 F (−2.5 C) for 10 hours. Flesh color, reducing sugar content, mealiness, and amount of sloughing in tubers that survived chilling were not markedly different from those in control samples although certain trends were observed indicating that the quality of chilled tubers was beginning to deteriorate. Chilling increased yellowness of flesh color in most treatments and darkness in several. Chilled tubers had a reducing sugar content slightly to moderately higher than the controls. They sloughed less than the controls and tended to be less mealyResumenPlantas de papa de la variedad Russet Burbank fueron congelados a temperaturas de 25°F (−3.8°C), 27.5°F (−2.5°C) o 30°F (−1.1°C) por varios períodos y luego mantenidos a 45°F (7.2°C) por una a cuatro semanas antes de analizarlas. La suseptibilidad del daño fue bastante variable entre los dos cultivos y entre tubérculos del mismo lote expuestos al mismo tratamiento. La mayor descomposición debida a bajas temperaturas ocurrió en tubérculos sometidos a congelamiento de 27.5°F (−2.5°C) por 10 horas. El color del tubérculo, el contenido de azúcares reductores, harinosidad y la abertura de la capa superficial de tejido en tubérculos que sobrevivieron al congelamiento no fueron marcadamente diferentes de aquellos: de las muestras de control si bien ciertas tendencias fueron observadas indicando que la calidad de los tubérculos congelados estaba empezando a deteriorarse. El congelamiento incrementó el color amarillento del tubérculo en la mayoría de los tratamientos y la oscuridad en varios de ellos. Los tubérculos congelados tuvieron un contenido de azúcares reductores ligera a moderadamente más alto que los controles, la capa superficial se abrió menos y tendieron a ser menos harinosas

Shoshoni: a new russet-skinned potato with resistance to common scab and Verticillium wilt

SummaryField trials have shown that Shoshoni is adapted to southeastern Idaho; it has consistently produced high yields, with dehydrating quality comparable to that of Russet Burbank. Shoshoni is late-maturing and the tubers are round to oblong, slightly flattened, and moderately netted. Shoshoni possesses moderate resistance to common scab and Verticillium wilt.