Sunrise: An early maturing,golden nematode resistant,round, white potato variety

The Sunrise potato variety is an early maturing variety with round to oblong, moderately smooth, white skinned tubers with medium-shallow eyes. Its characteristics are closely parallel to those of Superior, except Sunrise is resistant to race A of the golden nematode (Globodera rostochiensis). Sunrise is primarily a table potato; however, in southern areas it can be used for chips when processed without prolonged storage at low temperatures. Sunrise is resistant to virus X and does not show the net necrosis symptoms caused by leafroll virus. Its parents are Wauseon and B 6563-2, a selection from the USDA breeding program.     

Leaching of solutes and sloughing of potato tuber tissue

Thin slices of tissue from low (1.075–1.078 and high (1.092–1.094) specific gravity tubers were soaked in distilled water (100g/250ml) for 0, 1, 2, 3, 4, and 6 hours. Following the soak periods, the soak water and remaining tissues were separated and analyzed. Analyses of the soak water included pH, electrical conductivity, total solids, K, P and citric acid. The tissue analyses included total ash, alkalinity of ash, Ca, Mg, total N and phytate P. Other tissue samples were soaked the same periods of time and used to evaluate the amount of sloughing that occurred during cooking. All constituents studied diffused into the water during the soak periods. The greatest loss from the slices occurred in the first 2 to 3 hours and were similar for both specific gravity groups. After 6 hours the average amounts of material in the soak water were: total solids — 23%, P — 68%, phytate P —55%, K — 71%, total ash — 62%, total nitrogen — 56%, Ca — 35% and Mg —50%. Citric acid diffused into the soak water during the first 3 hours and the amount in the water then decreased. This apparent change may be due to metabolism of the acid. The sloughing of tissue decreased with the length of the soak period. The decrease in sloughing was highly correlated (P<1 %) with the length of the soak period, increases in electrical conductivity of the soak water, and with the leaching of all constituents measured.     

Measurement of color in potatoes

Reproducible, objective methods which conformed closely to visual appraisal were developed for measuring color differences in either cooked or raw potatoes. Experimental samples, selected from lots stored at various temperatures for different periods of time, differed in extent of graying and yellowing. Ricing was found to be preferable to mashing as a method of cooked sample preparation. A comparison of methods of sample presentation using the Gardner Color Difference Meter showed thin-layer measurement was most successful in separating cooked samples differing in amount of yellow pigment; deep-layer measurement was most successful in separating grayed samples. A simple method for measurement of color differences in raw tubers successfully separated the samples. All three methods of sample presentation were significantly correlated with visual ranking.     

草莓新品种引种试验

对引进的74个国内外草莓新优品种进行栽培试验比较研究,筛选出鬼怒甘、公四莓、法兰地和麦特来4个优于主栽种丰香、适宜在我省推广栽培的品种。     

Efficacy and residues of phloxine B and uranine for the suppression of Mediterranean fruit fly in coffee fields

The field efficacy of a bait containing phloxine B, uranine and Provesta 621 protein was tested against Mediterranean fruit fly (Ceratitis capitata; Medfly) by aerial and ground spraying in about 84 ha of coffee fields in Kauai, Hawaii, USA. Concurrently, soil and crop samples were collected from the aerially sprayed field and its unsprayed control field for residue studies. Efficacy of the sprays was assessed through trapping with both protein-baited and trimedlure-baited traps and through the infestation level of coffee cherries collected at least three-quarters ripe. The C capitata population was low at the start of the aerial and ground spray studies, but dramatically increased in the control fields. This increase coincided with initial ripening of coffee cherries. During times of peak population levels, C capitata populations were reduced by more than 91% in the ground-sprayed field and 99% in the aerial-sprayed field, relative to the populations in their respective control fields and based on protein-baited trap catches. Results of residue analyses indicated that uranine dissipated quickly compared with phloxine B on coffee and soil. Coffee samples collected at pre-spray periods had phloxine B residues of 7.2-25.5 ng g-1 on berries. Phloxine B concentrations were much higher on coffee leaves (163-1120 ng g-1). Lower concentrations of the dye were found from coffee samples collected during rainy days. Average phloxine B concentrations immediately after spraying were 56 and 2840 ng g-1 in coffee berries and leaves, respectively. Dissipation of phloxine B on berries was fast, with a half-life (t1/2) of 3 days. Dissipation of phloxine B on leaves was fitted to two linear phases: the initial (0-4 days) with a shorter t1/2 of 3 days and the later phase (4-28 days) with a longer t1/2 of 15 days. Average concentrations of phloxine B in the top soil ranged from 50 to 590 ng g-1 at pre-spray. Phloxine B initial concentration (770 ng g-1) reached a plateau immediately after the last spraying, but showed a steady decline over time with t1/2 of 16 days. Fast dissipation of the dyes in the field indicates that these chemicals may be environmentally compatible and therefore a promising alternative for fruit fly control.     

Antibacterial and antifungal activity of Indonesian ethnomedical plants

Methylene chloride and methanol extracts of 20 Indonesian plants with ethnomedical uses have been assessed for in vitro antibacterial and antifungal properties by disk diffusion method. Extracts of the six plants: Terminalia catappa, Swietenia mahagoni Jacq., Phyllanthus acuminatus, Ipomoea spp., Tylophora asthmatica and Hyptis brevipes demonstrated high activity in this bioassay system. These findings should stimulate the search for novel, natural product such as new antibacterial and antifungal agents.