Fall Potato Research Articles

Response of Potato Tuber Number and Spatial Distribution to Plant Density in Different Growing Seasons in Southwest China.

The aim of this study was to explore the effects of different density treatments on potato spatial distribution and yield in spring and fall. Plant density influenced yield and composition, horizontal, and vertical distribution distances between potato tubers, and spatial distribution position of tuber weights. The results indicated that: (1) Spring potato yield had a convex quadratic curve relationship with density, and the highest value was observed at 15.75 × 104 tubers per hectare. However, the yield of fall potatoes showed a linear relationship with plant density, and the highest value was observed at 18 × 104 tubers per hectare; (2) Density had a greater influence on the tuber weight of spring potatoes and fruit number of single fall potatoes; (3) The number of potato tubers in the longitudinal concentration exhibited a negative linear relationship with density, whereas the average vertical distribution distance of tubers exhibited a positive incremental hyperbolic relationship. For spring and fall potato tubers, the maximum distances were 8.4152 and 6.3316 cm, and the minimum distances 8.7666 and 6.9366 cm, respectively; and (4) Based on the artificial neural network model of the spatial distribution of tuber weight, density mainly affected the number and spatial distribution of tubers over 80 g. Tubers over 80 g were mainly distributed longitudinally (6–10 cm) and transversely (12–20 cm) within the high density treatment, and the transverse distribution scope and number of tubers over 80 g were reduced significantly. Spring potato tubers over 80 g grown at the lowest density were mainly distributed between 12 and 20 cm, whereas those at the highest density were primarily distributed between 10 and 15 cm.

Efficiency of Nitrogen Fertilizer for Potato under Fertigation Utilizing a Nitrogen Tracer Technique

Efficient crop use of nitrogen (N) fertilizer is critical from economic and environmental viewpoints, especially under irrigated conditions. Nitrogen fertilizer (15N‐labeled urea) and irrigation methods (drip and furrow) were evaluated on spring and fall potato cultivars under Syrian Mediterranean climatic conditions. Field experiments were conducted in the El‐Ghab Valley near Hama in fall 2000 and spring 2001 on a heavy clay soil. Four N‐fertilizer applications (70, 140, 210, and 280 kg N/ha) were applied in five equally split treatments for both irrigation methods. Potato was irrigated when soil moisture in the specified active root depth reached 80% of the field capacity as indicated by the neutron probe. Higher marketable tuber yield of spring potato was obtained by fertigation compared to furrow irrigation; the magnitude of tuber yield increases was 4, 2, 31, and 13%, whereas for fall potato the tuber yield increases were 13, 27, 20, and 35% for N fertilizer rates of 70, 140, 210, and 280 kg N/ha, respectively. Shoot dry matter and tuber yields at the bulking stage were not good parameters to estimate marketable tuber yield. The effect of N treatments on potato yield with furrow irrigation and fertigation was limited and not significant. Drip fertigation improved tuber yield of fall potato relative to national average yield. Nitrogen uptake increased with increasing N input under both irrigation methods. Reducing N input under both irrigation methods improved N recoveries. Increasing N input significantly increased total N content in plant tissues at the bulking stage. Spring potato yields were almost double those of fall potato under both irrigation methods and all N treatments. Nitrate (NO3) movement in the soil solution for fall potato was monitored using soil solution extractors. Furrow irrigation resulted in greater movements of NO3‐N below the rooting zone than drip fertigation. Harvest index did not follow a clear trend but tended to decrease upon increasing N fertilization rates beyond 140 kg N/ha under both irrigation methods. Drip fertigation improved field water‐use efficiencies at the bulking and harvest stages. Fertigation increased specific gravity of potato tubers relative to furrow irrigation. Higher N input decreased specific gravity of potato tubers under both irrigation methods.

2기작 감자 품종의 재배 시기별 PVY 감염 정도 조사

최근 감자 바이러스의 발생 양상은 과거에는 PLRV의 이병율이 높았으나 현재에는 PVY의 발생이 많아지고 있는 추세인데 이는 '대서'와 '추백' 같은 감수성 품종의 재배 면적의 증가와 바이러스 이병율이 높은 재배 환경에서의 채종 때문일 것이다. 특히 2기작 감자 포장에서의 당대 감염율을 보더라도 '대서'와 '추백'의 이병율이 높아 감수성 품종으로 '수미'와 '대지'는 이병율이 비교적 낮아 저항성으로 나타났다. 또한 2기작 감자 재배지대에서 PVY에 감수성인 '추백' 품종의 안전한 씨감자 생산을 위해서 주위에 일반감자 재배가 없는 격리가 양호한 환경에서의 채종과 그렇지 못한 환경에서의 채종을 비교하여 재감염 정도를 조사하였는데 조직 배양후 2세대 걸친 노지 재배에서 바이러스 이병율이 약 3배의 차이를 보여 씨감자 생산에서 채종 환경의 중요성을 입증한 결과로 판명되었다. One of major potato viruses is Potato virus Y (PVY) in Korea. In the southern part of Korea, potatoes have been grown as double crops in a year by using cv. 'Dejima' and 'Chubak' due to very short dormancy. However, they have caused a serious problem such as a rapid degeneration. It has been thought that the degeneration is affected by the high incidence of PVY in neighboring potato fields. Therefore, the investigation of factors causing the degeneration is very important in the production of healthy seed potato. In this study, the PVY reinfection rates of several potato varieties and the different seed sources of cv. 'Chubak' have been investigated. Results show that the lowest infection rate of PVY among four potato cultivars derived from minitubers is cv. 'Superior'. The others are in order of 'Dejima', 'Atlantic' and 'Chubak'. Also, the incidences of PVY differ significantly when several seed sources are examined. When the seed potatoes (G2, the progeny of microtuber) as spring potato crops are planted in area without potato field nearby, the infection rate of PVY is as low as that of microtubers. However, PVY incidence in the progenies of minitubers as fall potato crops largely increases. Therefore, the best way of potato production under double cropping system is to use the healthy seed potato produced in area without potato field and plant relatively resistant cultivar such as Dejima.

Spatial distribution and sampling plans for Thrips palmi (Thysanoptera: Thripidae) infesting fall potato in Korea.

The spatial distribution of adult and immature Thrips palmi Karny on fall potato, Solanum tuberosum L., on Cheju Island, Korea, was studied over a 2-yr period by visually inspecting potato leaves. The majority of thrips collected from the leaves were observed in the top one-third of the plant. The within-field spatial patterns of adults and immature thrips were aggregated. The slopes and intercepts of Taylor's power law did not differ among adults and immature thrips. A fixed-precision-level sampling plan was developed using the parameters from Taylor's power law and was tested with resampling simulations using eight independent data sets. Over a wide range of densities, the simulation demonstrated that actual sampling precision (d = SEM/mean) values at d = 0.25 averaged < 0.24 in all cases. A binomial sampling plan for estimating mean density was developed using an empirical model evaluated at tally thresholds (the minimum number of insects present before a leaf is considered infested) of one, three, five, and eight thrips per leaf. Increasing sampling size had little effect on the precision of the estimated mean regardless of tally threshold (T). However, increasing T had a dramatic effect on precision. The best tally threshold for estimating thrips density based on the applicable density ranges and the precision of the model was T = 5. A binomial sampling plan with a tally threshold of five and a fixed sample size of 30 leaves should be an effective replacement for enumerative counts when thrips average < 10 per leaf.

Respirable Dust and Crystalline Silica (Quartz) Exposure Resulting from Potato Harvesting Operations

Occupational exposure to silica dust has historically been known to cause chronicrespiratory conditions. Workers and workplaces within agricultural industries remainremoved from the attention of occupational health and safety. The identification anddegree of exposure to respirable dust, crystalline silica, and endotoxins throughout thepotato harvesting process has been uncharacterized. A description of the potentialoccupational risks in this setting was therefore warranted. The purpose of this researchwas to identify the components of dust during the fall potato harvest in the San LuisValley of southern Colorado. The agricultural practices specific to potato harvest, thegeographic region, and the soil of San Luis Valley are believed to contribute tooccupational risk. Testing sites included seven farms in this region, chosen based ontheir location, variable soil types, and owner interest. The following parameters:respirable dust, respirable silica, bacterial endotoxins, and particle identification byscanning electron microscopy were measured. All exposures were based on 8-h time-weightedaverages. Exposure impact included: location of the farm, soil type (sand,rock, loam), job description, weather conditions; wind, rain, wet or dry soil duringharvest, humidity, and temperature. Results of air monitoring include 122 samplescollected, 93 revealed the presence of respirable dust, 18 detected respirable silica(quartz). The maximum respirable dust exposure was 5.05 mg/m 3 , respirable silica0.105 mg/m 3 , and percent silica of 12.85%. This information will allow employers torecognize where respirable dust and silica are generated and allow for planning andcontrol implementation to adequately protect workers.

Potential impacts of climate change on citrus and potato production in the US

Potential impacts of global climate change on fruit and vegetable yield in the US were investigated through simulations of citrus and potato. Simulated treatments included combinations of three increased temperature regimes (+ 1·5, + 2·5 and + 5·0°C), and estimates of the impact of three levels of atmospheric carbon dioxide (440, 530, and 600 ppm) in addition to control runs representing current climatic conditions. Adaptive planting dates of −28, −14, + 14 and + 28 days were included in the potato simulations for current and increased temperature regimes. Twenty-two sites were simulated for citrus yields and 12 sites for potato, using climate records from 1951 to 1980. Response surfaces were developed for all combinations of increased temperature and CO 2. Results of citrus simulations without CO 2-induced yield improvement indicate that production may shift slightly northward in the southern states, but yields may decline in southern Florida and Texas due to excessive heat during the winter. CO 2 effects tended to counteract the decline in simulated citrus yields. Fall potato production under current management practices appears vulnerable to an increase in temperature in the northern states; increased CO 2 and changes in planting date were estimated to have minimal compensating impacts on simulated potato yields.

Intraseasonal Demand for Fall Potatoes under Rational Expectations

AbstractAn iterative numerical strategy combining maximum likelihood methods and stochastic‐dynamic programming is used to estimate a dynamic nonlinear rational expectations model of the U.S. fall potato market. The model captures the essential processes governing the intraseasonal dynamics of potato consumption and storage, including the impact of price expectations on stockholding decisions. The model is used to analyze the temporal pattern of demand for fall potatoes.

Soil Insecticide Treatments to Control European Corn Borer and Potato Tuberworm in Fall Potatoes, 1981

Abstract ‘Red Lasoda’ Irish potatoes were planted in open furrows in State sandy loam soil (typic Hapludult) on Jul 28. Each plot consisted of 3 rows (36 inch rows), 25 ft long. Treatments were replicated 4 times in a randomized block design. Furrow applications were made at planting time by spreading the granular insecticide over the potato seed using a hand held shaker and then covering the seed. The sidedress application was made on Oct 5 by sprinkling the granules in a 2 inch band on each side of the row ca 4 inches from the center of the row and lightly incorporting the granules in the top 2-3 inches of soil with a garden hand rake. Evaluations were made by counting the number tuberworm mines/10 stems taken from 10 separate plants/plot and counting the number of vines with obvious European corn borer injury/10 hills.

The Storage of Potatoes and the Maine Potatoes Futures Market

The relationship between the storage of potatoes and the carrying charges reflected on the futures market for Maine potatoes gives rise to a situation in which the observed facts do not seem to agree with the accepted theory. The theory regarding intertemporal price relationships based on the work of Brennan, Telser, and Working establishes that the difference between the current price and the expected price of a storable commodity must be equal to the marginal cost of storage minus the convenience yield. The relationship between the amount of a commodity held in storage and the equality of the marginal cost of storage with the temporal price spread gives rise to a supply of storage curve. As estimated by Brennan, Telser, and Working, this supply of storage curve slopes upward to the right. More storage will be supplied at a high return per unit and less storage at a low return per unit stored. The carrying charges reflected on the Maine potatoes futures market seemingly contradict the theory of the price of storage in two respects. First, the spreads between futures, which establish a return to storage, sometimes appear to greatly exceed any typically plausible cost of storage. On 1 March 1976, the March future for Maine potatoes sold for $8.35 per hundredweight, whereas the May future was selling for $12.63 per hundredweight. The return to storing potatoes for two months was $4.28 per hundredweight. Second, the relationship between the level of potato stocks and the carrying charge appears to be the opposite of that previously estimated for commodities with continuous inventories. For potatoes, the seasonal pattern associates large stocks with a narrow carrying charge and small stocks with a wide carrying charge. The level of potato inventories and the spread on the futures market produce a relationship that slopes downward to the right. The fall potato crop accounts for over 75% of annual U.S. production and in recent years has been about 84% of the total. Fall crop potatoes are stored for consumption over a sevenor eight-month period. However, potatoes cannot be effectively stored for a whole year, since they are semiperishable. Potatoes, therefore, give rise to a discontinuous inventory situation. The task of intertemporal allocation is more difficult for a discontinuous inventory commodity. Potato prices must be established during the storage season with the objective of exhausting the supply of potatoes in storage coincidently with the availability of spring and early summer potatoes (Gray). Potato storage is conducted not by merchandising or storage specialists but primarily by growers. The primary requirements of a potato storage facility are adequate insulation, ventilation, and heating and the means to enter and remove the tubers efficiently.

Control of Wireworms on Summer Potatoes in Eastern Washington123

When granular carbofuran, Dyfonate® ( O -ethyl S -phenyl cthylphosphonodithioate), and parathion were applied in mid-March for control of the Great Basin wireworm, Ctenicera pruinina (Horn), and the Pacific Coast Wireworm, Limonius canus LeConte, on summer potatoes, band treatments at a rate of about 2.3 lb of toxicant per acre gave better average control with less variation than broadcast treatments with 4–8 lb of the same toxicant per acre. The reverse has been observed when similar treatments were applied in mid-April or later for control of these wireworms on fall potatoes.

USDA recommends acreage guides for summer and fall potatoes

USDA recommends acreage guides for summer and fall potatoes

USDA studies marketing margins for fall potatoes

USDA studies marketing margins for fall potatoes