American Journal of Potato Research最新文献

Four microplant planting densities (PD) for greenhouse production of minitubers of three varieties were used to assess the agronomic and economic efficiencies of increased PD compared to the baseline density (63 microplants m⁻²). The field performance of minitubers was also included in the agronomic (yield formation) efficiency assessment of minitubers production. The concept of a field value (FV) of greenhouse area and of microplant was introduced. Economic assessment of PD changes was based on partial budget analysis and the marginal rate of return between PDs in ascending order. Agronomic efficiency assessment, as an efficient utilization of greenhouse space, revealed that the number of minitubers per m² increased gradually with increasing PD and the magnitude of the increase was up to 2.6 times between PD 63 and 184 microplants m⁻² making this PD the most effective of the studied. The change in minituber number per microplant due to the increased PDs was closely related to the economic efficiency assessment. In the baseline scenario (microplant cost of 0.54 € and minituber cost of 0.41 €), only the shift from PD63 to PD95 was efficient without trade-offs for only one of three varieties.

Abstract

Biofumigation has been proposed as an alternative to soil fumigation to manage soil-borne diseases including potato early dying disease complex (PED). This study examined the potential of using brown mustard (Mustard juncea) biofumigation to manage PED under rain-fed potato production in New Brunswick, Canada in two trials between 2017 and 2020 in comparison with chloropicrin fumigation and a conventional barley rotation. Biofumigation increased yield in one trial, but not in a second trial where the potato crop experienced severe drought, whereas chloropicrin fumigation increased yield in both trials. Biofumigation was effective in suppressing root-lesion nematode (RLN, Pratylenchus spp.) counts in both trials, but was ineffective in suppressing V. dahliae population density. Chloropicrin fumigation was effective in suppressing RLN counts and V. dahliae population density only in the hill where injected, but the effect was short-lived as the population density of V. dahliae in the hill increased to the level of the control in one potato growing season. Biofumigation may be an alternative to chloropicrin fumigation in managing PED, particularly in fields with high RLN population but relatively low Verticillium population density. However, neither biofumigation nor fumigation used alone may be sustainable in the short-term potato rotations commonly used in New Brunswick, and additional beneficial practices are required to sustain productivity in the long-term.

This study was conducted to evaluate yield responses of four potato (Solanum tuberosum L.) cultivars (‘Russet Burbank’, ‘Shepody’, ‘Gold Rush’, and ‘Russet Prospect’) and soil N dynamic changes to two 3-year rotations in Prince Edward Island, Canada. The two rotations were the local industry standard potato–barley (Hordeum vulgare L.)–red clover (Trifolium pratense L.) rotation (PBC) and an alternative potato–soybean (Glycine max L.)–barley rotation (PSB). All potato cultivars received 170 kg N ha^− 1 input at planting without irrigation. Soil mineral N content before potato planting was significantly higher under the PBC rotation. However, the PBC rotation produced significantly lower yields, suggesting the possibility of excessive N supply from the plowed-down red clover. While cultivar and the interaction between cultivar and rotation did not show a significant difference in yield, yields of all cultivars were positively affected by the PSB rotation. The Gold Rush cultivar was affected the most (36%), followed by Russet Burbank (17%) and Prospect (14%) cultivars, with Shepody being the least affected (3%) by the alternative PSB rotation. Russet Burbank was the highest yielding cultivar under both rotations. With the three russet cultivars combined as a single russet cultivar, the PSB rotation significantly increased tuber yields, while the Shepody cultivar did not significantly benefit from the PSB rotation, suggesting that the russet cultivars responded more sensitively to the alternative rotation. Results demonstrate that adequately accounting for N supply from a preceding green manure crop is required for sustainable potato production in this humid temperate region.

In Uganda, potato is primarily grown as a cash crop and smallholder farmers sell majority of their produce immediately after harvest. Only a few farmers store ware potato for later sale using various traditional storage methods. Main reasons are farmers’ immediate need for cash, the low volumes of potato harvested, fear of loss during storage due to pests and diseases, and a lack of adequate storage facilities. In order to exploit the seasonal market price fluctuations and increase the economic return of potato farming, improved individual and collective ambient ware potato storage units were introduced. Unlike traditional storage facilities that maintain the marketability of stored potato up to five weeks only, improved ambient stores can maintain their marketability up to nine weeks. This article uses cost-benefit analysis methods to compare the economic performance of improved ambient stores with traditional storage facilities. Results indicate that few of the traditional and improved collective storage units generated profit, an aspect that was attributed to management challenges. The improved individual stores performed overall well, generating higher profit margins than improved collective stores. Improved individual stores had an average payback period of three to four years that could even be reduced to less than one year if used at full capacity. Due to their characteristics, improved individual ambient ware potato stores thus seem to be particularly suitable to substantially increase the income of potato farming households.

In New Zealand, potato crop yields of 90 t ha⁻¹ are achievable but at 55 t ha⁻¹, the average is becoming economically unsustainable. In 2012/13, a grower-initiated survey found that Rhizoctonia solani and Spongospora subterranea (soil-borne pathogens) and soil compaction were widespread in 11 Canterbury potato crops. Targeted areas in these crops had measured yield losses of 0 (healthy plants) – 42 (diseased, resource constrained plants) t ha⁻¹, limiting the farmer-measured field yield to a 56 t ha⁻¹ average. In 2014/15, growth, water use and health of three contrasting crops were measured. Near-potential yield was achieved in one crop when disease incidence and severity were low and resources adequate. The other two crops yielded less than potential; one had an inadequate water supply and the other widespread soil-borne disease. Any suspected links between soil-borne disease, soil compaction and yield were further investigated by using them as factors in replicated experiments reported elsewhere.

Postharvest storage of potatoes may result in compositional and textural changes, which may differ among different genotypes. These changes have been less documented in the literature. Ten potato cultivars (“Picasso”, “Red Scarlet”, “Sifra”, “Challenger”, “Sante”, “Banba”, “Arinda”, “Agria”, “Fontane’, and ‘Innovator”) were evaluated in pre- and post-harvest experiments. In the pre-harvest experiment, tuber number, diameter, and fresh weight of the plants were evaluated. Later, the traits were evaluated in three stages, including at harvest time and 90 and 180 days after harvest during storage. Fresh weight, dry weight, volume weight, firmness, TSS and carbohydrates, phenolic and vitamin C content, antioxidant activity, beta-carotene content, POX activity, and protein and starch content of the tubers were assessed. All the traits were significantly different among cultivars at both pre-harvest and post-harvest stages. “Red Scarlet”, “Challenger”, and “Innovator” are suitable cultivars for fresh consumption, and some including “Picasso”, “Sante” and “Banba” are appropriate for processing such as chips production. It was also found that some cultivars, e.g., “Challenger” and “Sante”, had longer shelf-life and acceptable marketability after six months of storage.