Search Results
Abstract
A procedure is given for measurement of carbon dioxide evolution from individual fruits during brief time intervals, by utilizing the change in optical density of a bromthymol blue-sodium bicarbonate solution exposed to varying CO2 atmospheres. The method permits the accurate estimation of CO2 evolution during a five-minute period from a single 100 g fruit respiring at the rate of less than 5 ml CO2/kg/hr. Although the system is “static,” build-up of CO2 concentrations surrounding the respiring fruit held to less than 1%.
Abstract
Four cultivars of sweet potatoes (Ipomoea batatas Lam.) were sampled bi-weekly during the period of storage root development Although the root weight increased nearly 8-fold during the sampling period there was only a 35% increase in the number of roots. Alcohol insoluble solids (AIS) and % dry matter generally showed a slight increase throughout the season and specific gravity a slight decrease. Total sugars and reducing sugars failed to show a trend. In contrast, the processed roots tended to become softer as the season progressed. Firmness was related to chronological age of roots rather than harvest date. The later the planting the higher were total and reducing sugars but planting date had no consistent effect on other raw product attributes.
Abstract
Inhibition on phenolase activity by blanching or restriction of exposure to oxygen greatly reduced the rate of internal corrosion of tinplated cans by sweet potatoes independent of variety effect or nitrate concentration of the raw product.
When phenolase activity was not inhibited, the severity of can corrosion varied widely among varieties of sweet potatoes. Varieties which caused more can corrosion had a high phenolase activity and a high nitrate concentration. ‘Nemagold’ and ‘California 20-51D’ sweet potatoes, which have a relatively low phenolase activity, did not accumulate high nitrate concentrations or severely corrode cans when ammonium nitrate fertilization of 1,000 lb./acre was applied. Ammonium nitrate fertilization greatly increased nitrate accumulation and can corrosion by ‘Goldrush’ sweet potatoes.
Abstract
Yields and size distribution of sweetpotato (Ipomoea batatas Lam) propagated from root pieces were similar to those grown from sprouts when comparable stands were obtained.
Abstract
The concentration and total content of P, K, Ca, Mg, N, Fe, Mn, and B in storage roots and in vines of sweet potatoes [Ipomoea batatas (L.) Lam.] was followed for a 14 week period beginning 2 months after planting. The concentration of N, P, K, Mn, and Mg in the vines and N, P, and K in the roots decreased slightly during the period. Other elements showed no definite seasonal trends. Total uptake by the vines showed little change after the second sampling period
Abstract
A procedure and device is described involving a small jet of water under pressure directed onto the surface of a sweetpotato (Ipomoea batatas L.) root. The time required for the stream to abrade the skin is taken as a measure of the “skin-toughness.” The time required for abrasion of 18 cultivars was correlated with their condition scores after mechanical harvesting. Skin was more resistant to abrasion 1 day after digging than when freshly dug and curing further increased skin-toughness. Relative skin-toughness of cultivars changes during curing and storage.
Abstract
A batch peeler using time-regulated, high-pressure steam is briefly described. Use of the equipment with sweet potatoes [Ipomoea batatas (L.) Lam.] avoided explosion of the roots encountered with conventional high-pressure steam peelers and resulted in effective peeling with minimal enzymatic discoloration of the product.
Abstract
The ratio-based Diagnosis and Recommendation Integrated System (DRIS) was used to evaluate the mineral status of ‘Royal Ann’ sweet cherry trees. Standard ratios were developed from experimental research plots and then applied to evaluate the nutritional status of a large number of trees in a commercial orchard. DRIS indices for each element were calculated from a formula, which included DRIS standard ratios, their standard deviations, and the observed ratios from the sample being calculated. Nutritional Imbalance Indices (NII) were compared as the sum of DRIS indices irrespective of sign. By selecting a sufficiency range that produced the best agreement with DRIS evaluations, independent sufficiency ranges were derived from the commercial orchard data. Trees with high NII were consistently low-yielding, and, in mulching treatments where unfavorable NIIs were improved, yields were increased. The NII was more strongly correlated with relative yield increases than any other mineral parameter. The data imply that it is possible to develop useful DRIS standards and DRIS-derived sufficiency ranges from survey data, even though conventional statistical approaches do not reveal strong relationships between mineral concentration and yield.