For the proper development of the potato (Solanum tuberosum L.), it is essential to provide the plant with micronutrients, including selenium. The availability of the potato for starch industry after harvest is determined by proper storage conditions. Research was undertaken to determine tuber yield, starch yield and quality characteristics of potato starch in relation to cultivar and foliar feeding of plants with selenium during cultivation. Two-factor field experiment was conducted in 2018–2019: I factor – cultivar (Albatros, Jumbo, Maxilla Terrana, Transit), II factor – selenium fertilization (0, 10, 20 g Se/ha). The tests were carried out directly after harvest and after 6 months of tubers storage under constant conditions: temperature 4°C, 95% RH. The highest total tuber and starch yields were obtained by potatoes after application of 20 g Se/ha: 39.42 and 7.94 Mg/ha, respectively. Proportion of large starch grains (>20 μm) was significantly higher for cv. Maxilla – 24.5%. The highest sticking temperature was demonstrated by starch from cv. Maxilla, 69.9°C, while the lowest for the starch of cv. Terrana, 63.3°C. The largest natural losses resulting from transpiration and respiration after long-term storage of tubers received the cv. Transit – 5.0%, and the smallest losses were characterized by the cv. Albatros – 3.9%. Selenium applied during cultivation at dose of 20 g/ha reduced natural losses (−4.3%) and yield starch (−6.2%) and starch content (−1.7%) in tubers. The quality parameters of starch were changed after storage from 0.8 to −3.0%.

User-oriented research is important in breeding improved genotypes, for developing and validating product concepts (mostly involving trait prioritisation), as well as evaluating breeding products in use situations (mostly involving participatory variety evaluation). This paper examines key aspects that enable cumulative learning in user-oriented research for root, tuber and banana (RTB) crop breeding. We reviewed empirical user-oriented studies on RTB crops published between 1996 and 2020. We examined the ability of user-oriented research to foster cumulative learning by examining four key aspects: spatial and temporal coverage; gender aspects; the range of traits considered and publishing practices as evident in reports and datasets. We conclude that user-oriented studies have received attention in RTB breeding but fall short of enabling cumulative learning. Substantial investments in methodology development and capacity are needed to bring greater coherence to this field and enable cumulative learning about user perspectives to iteratively increase the fit between improved genotypes and user preferences.

Complementary archaeological and paleoenvironmental datasets from North Creek Shelter (Colorado Plateau, Utah, USA) are analyzed using the diet breadth model, revealing human dietary patterns during the early and middle Holocene. Abundance indices are derived from botanical and faunal datasets and, along with stone tools, are used to test the prediction that increasing aridity caused the decline of high-return resources. This prediction appears valid with respect to botanical resources, given that high-ranked plants drop out of the diet after 9800 cal BP and are replaced with low-ranked, small seeds. The prediction is not met, however, with respect to faunal resources: high-ranked artiodactyls are consistently abundant in the diet. The effects of climate change on dietary choices are also examined. Findings show that increased aridity coincides with greater use of small seeds and ground stone tools but not with increases in low-ranked fauna, such as leporids. The patterns observed from the North Creek Shelter botanical and faunal datasets may reflect different foraging strategies between men and women. This would explain why low-ranked plant resources became increasingly abundant in the diet without a corresponding decrease in abundance of high-ranked artiodactyls. If so, then archaeological records with similar datasets should be reexamined with this perspective.

Lusala (Dioscorea hirtiflora Benth. subsp. pedicellata Milne-Redh) is an important wild edible tuber foraged widely from natural forests in Southern Zambia, but at risk from overharvesting and deforestation. Its propagation was investigated in glasshouse studies to explore potential domestication and future in situ and ex situ genetic resources conservation. Almost all tubers planted with visible shoot buds produced vines, with no effect of tuber size on vine emergence or tuber yield. Few tubers without visible shoot buds at planting produced vines, but those that did not re-tuberized. The progeny provided good vine emergence and similar tuber yield, with vines from tubers produced by re-tuberization being more vigorous. Re-tuberization in the absence of vine emergence also occurred in other experiments. Minisetts cut from the proximal end of tubers provided better vine emergence (with more from 20-mm than 10-mm-long sections) and greater tuber yield than mid- or distal minisetts. Nodal stem cuttings rooted well, vined, and provided small tubers. This study shows that lusala can be propagated successfully from tubers, minisetts, nodal vine cuttings, or mini-tubers from nodal vine cuttings, for genetic resources conservation and/or domestication. Domestication is likely to be hampered by the long period required for vines to emerge and establish. More sustainable foraging, including re-planting in natural forests, is recommended to balance consumption of lusala in the region and promote its long-term conservation.

Nondestructive means for estimating air potato (also known as air yam; Dioscorea bulbifera L.) biomass will help gauge its management efficacy over time. We developed allometric equations to estimate total and fractional biomass components and densities of aerial bulbils and underground tubers of field-grown D. bulbifera in Florida. We selected four naturally infested sites representing its southern, central, and northern distribution in Florida and measured three independent variables (vine densities, stem diameters, and top heights) of 84 (21 site−1) discrete D. bulbifera patches during late October to early December of 2012. We destructively harvested D. bulbifera biomass, sorted by tubers, stems, leaves, and bulbils; counted units of bulbils and underground tubers (dependent variables); and dried to a constant weight. Mean percentages of tuber, stem, leaf, and bulbil fractions in total biomass were 42.0, 15.6, 26.0, and 16.4, respectively. We developed a parameterized multiplicative prediction model and regression equation for each dependent variable. Slopes of relationships among independent and dependent variables varied by biomass and density (bulbil and tuber) of plant components. Multiplied values of independent variables: all three for total, tuber, stem, and leaf biomass; two (vine base diameter*patch height) for bulbil biomass; two (vine density*patch height) for bulbil density; and only one (stem density) for tuber density provided best (R2-based) prediction values. These models will provide nondestructive methods for estimating biomass components and density of vegetative propagules of naturally growing D. bulbifera. Models are critical for understanding the performance of D. bulbifera in its exotic range, estimating biomass to project control costs, and comparing biomass components and bulbil/tuber densities during pre- and postmanagement periods to gauge control efficacy.

This article provides results from a full morphological, use-wear and microfossil residue analysis of a notched bone tool made from a camelid scapula, which was recovered from the late pre-Hispanic site of Boyo Paso 2 (1500–750 years BP, Sierras of Córdoba, Argentina). The use-wear pattern showed striations similar to those recorded in experimental bone tools used for scraping activities. The starch grains found on the active or working edge are similar to the Andean tuber crop Oxalis tuberosa, and suggest that the tool was used for peeling wild or domesticated Oxalis sp. tubers, thereby questioning the disproportionate attention directed towards maize in late pre-Hispanic economies.

The upper 30 cm of soil in a field infested with purple nutsedge (Cyperus rotundus L. #3 CYPRO) contained 4900 to 5100 corms and tubers/m2 6 weeks after soil rotovation and irrigation. The upper 4, 8, 12 and 16 cm of soil had 45, 79, 95 and 99%, respectively, of the corms and tubers. Lower depths of soil contained larger tubers with higher percent dry matter than the shallow depths. Of the total number of corms and tubers, 51% were from the parent population. At 6 weeks, only 15% of the total tuber and corm population were not connected to aerial parts. Tubers from the parent population had a higher fresh weight than those from the new population. Parent tubers occurred singly or in chains of up to eight tubers.

Four cropping systems were evaluated from 1975 to 1977 for the control of yellow nutsedge (Cyperus esculentus L.). Crops grown in 1975 and 1976 included alfalfa (Medicago sativa L. ‘Elcamino WL-600′), barley (Hordeum vulgare L. ‘CM-67′), corn (Zea mays L. ‘Dekalb T214′), and cotton (Gossypium hirsutum L. ‘Acala SJ-2′). Herbicides used included butylate (S-ethyl diisobutylthiocarbamate) in corn, EPTC (S-ethyl dipropylthiocarbamate) in alfalfa, glyphosate [N-(phosphonomethyl)glycine] in fallow plots, and MSMA (monosodium methanearsonate) in cotton. Cotton, which was grown continuously as one of the four cropping systems, was the only crop grown in 1977. Based on weed counts, crop yields, and the consistent decline in the number of tubers, all cropping systems provided substantial control of yellow nutsedge each year. Two years of either alfalfa treated with EPTC or double cropping barley with corn treated with butylate preceeding cotton reduced the number of viable yellow nutsedge tubers by 96%. Two years of chemically fallowing plots with glyphosate following barley and preceeding cotton was 98% effective in reducing viable tubers. Treating continuous cotton with MSMA, although somewhat inferior to the above systems, reduced the number of viable nutsedge tubers by 91% in 3 yr.

Survival of hydrilla (Hydrilla verticillata Royle) plants and propagules after removal from water and desiccation under controlled conditions were studied. Both apical and sub-apical sections of hydrilla plants were physiologically alive after drying for 16 h at 30 C and 40% relative humidity. Tubers survived drying conditions longer than turions. There was 16.7% sprouting in tubers that had been dried for 64 h, while percent sprouting of turions decreased sharply as the drying period increased from 0 to 8 h.

Selected biological and physiological parameters of hydrilla [Hydrilla verticillata (L.f.) Royle # HYLLI] biotypes were compared in growth chambers, glasshouse, or outside aquaria. Salinity tolerance was similar for both biotypes with an injury threshold of approximately 13 parts per thousand (ppt). The registered aquatic herbicides diquat (6,7-dihydrodipyrido [1,2-α:2′,1′-c] pyrazinediium ion) and dipotassium and monoamine salts of endothall (7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic acid)4 produced similar injury to both biotypes. Biomass of the monoecious plants, growing in controlled environments, declined under short days. Tuber production in monoecious plants was greatest under short days and was significantly higher than in dioecious plants under the same conditions. Growth response to temperature was similar among all plants and was retarded at 15 C. Tuber germination occurred at lower temperatures in the monoecious plants, which was indicative of a lower temperature tolerance. Vegetative propagules were the only perennating structures observed in the monoecious biotype, and regrowth was entirely from tubers and turions. The annual growth habit, in conjunction with rapid and abundant propagule production, adapts the monoecious biotype to northern areas with short growing seasons.

A simple technique is described for rapid determination of weed seed, rhizome, corm, or bulb populations in soil. Soil samples were placed in nylon mesh bags. The soil was washed from the bags by machine leaving only a small residue including the desired propagules. These were hand separated and the soil population of a given plant species calculated. The total manipulation time per sample was approximately 10 min.

A root washer was constructed which rapidly separated Canada thistle [Cirsium arvense (L.) Scop. # CIRAR] roots larger than 1.3-mm diam with 96% or greater efficiency from cohesive clay soil. The washer removed 93 ± 15% of 43 200 cm clay soil from Canada thistle roots in 2 h. Small residual soil clods and organic debris were removed by hand after washing. The washing action did not damage the root system. From 4 to 6 h were required to wash the large Canada thistle roots from an equivalent volume of clay soil by hand, without using the washer. Rhizomes, seeds, and tubers also may be separated from soil with the washer. The tank and frame of this washer are durable, and moving parts such as bearings can be replaced easily.

Studies in outdoor, circular pools have shown that one shoot tip of hydrilla (Hydrilla verticillata Royle) produced as much plant dry weight during a 16-week period as 16 tips planted under the same conditions. Dry weight of plants 16 weeks after planting was as high as 1,561 times that of the shoot tips planted. Tubers were present within 8 weeks after planting the tips; higher numbers of these vegetative propagules were associated with the higher number of tips planted. Plants under a photoperiod of 11.5 h or less produced more tubers than those exposed to 12 h or more of light.

The response of 22 potato (Solanum tuberosum L.) cultivars to soil-incorporated and foliar applications of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)one] at rates of 0.5 and 1.0 kg ai/ha, was evaluated in field experiments from 1979 to 1982. Metribuzin significantly reduced the yield of marketable tubers in several potato cultivars. Foliar applications generally resulted in more injury than soil applications. Yields were reduced primarily through stand reduction and a decreased number of tubers per plant. Neither tuber size nor specific gravity of tubers was significantly reduced in the cultivars studied. The most susceptible cultivar was ‘Alaska Red’, followed by ‘Rhine Red’, F72117, ‘Caribe’, and ‘Shepody’. Other cultivars evaluated were highly tolerant to metribuzin, irrespective of rate or method of application. There was an increase in hollow heart in cultivars ‘Atlantic’ and ‘Lemhi Russet’ following treatment with metribuzin.

Greenhouse and field research evaluated yellow nutsedge growth, vegetative control, and tuber production after application of glyphosate, various acetolactase synthase (ALS)–inhibiting herbicides, and tank mixtures thereof. Yellow nutsedge was controlled by the herbicides halosulfuron at 35 g ai/ha, chlorimuron at 12 g ai/ha, and imazethapyr–imazapyr at 62 g ai/ha (> 70% control); imazethapyr at 70 g ai/ha, glyphosate at 840 g ae/ha, cloransulam at 17.5 g ai/ha, and rimsulfuron at 17.5 g ai/ha (40 to 70% control); and imazamox at 45 g ai/ha (< 40% control). Compared with the untreated control, tuber fresh weight in the field was reduced 45 to 91%, and tuber density was reduced 33 to 90% by all herbicide treatments 42 wk after treatment (WAT) except imazamox and rimsulfuron. Tuber sprouting was reduced to 19% in plots treated with halosulfuron and pyrithiobac compared with untreated yellow nutsedge 42 WAT. Chlorimuron and imazethapyr–imazapyr controlled yellow nutsedge at least 90%, prevented panicle formation, and reduced tuber density and fresh weight by 90% or more 14 WAT in the greenhouse. The addition of glyphosate to cloransulam or imazethapyr increased yellow nutsedge control and reduced tuber density and fresh weight when compared with either ALS-inhibiting herbicide or glyphosate applied alone. Tuber density data indicated that there were 8 tubers for every gram of tubers harvested. Yellow nutsedge height was 15 to 20 cm 4 to 5 wk after tillage, using growth analysis data. Long-term yellow nutsedge management may be aided with treatments that reduce tuber production.