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71.
Huckleberry Gold is a purple-skin, yellow-flesh fresh market cultivar with similar culinary qualities to the market standard Yukon Gold. It has lower specific gravity, sucrose and vitamin C content, but a significantly higher level of tuber antioxidants than Yukon Gold. Notable disease resistant characteristics are Potato virus X resistance based on the presence of molecular markers for the PVX resistance genes, Nb and Rx1. In addition it also has the H1 gene present which confers resistance to the potato cyst nematode, Globodera rostochiensis, which has been confirmed by bioassay to pathotype Ro1. The size profile of Huckleberry Gold is smaller than Yukon Gold, allowing a better fit into specialty markets that are geared to smaller size for fresh use. Huckleberry Gold represents the first purple-skin, yellow-flesh cultivar to come from the Northwest (Tri-State) Potato Variety Development program.  相似文献   
72.
During the 1988, 1989 and 1990 growing seasons, canopy and air temperatures, solar and net radiation, relative humidity and wind speed were measured at 10 minute intervals during daytime hours in a field of wellwatered Russet Burbank potatoes in southeast Idaho. A linear relationship between canopy temperature minus air temperature and vapor pressure deficit (TC-TA = 0.2 -2.0 VPD) was developed for use in the Crop Water Stress Index (CWSI). Values of CWSI for well-watered potatoes were generally in the -0.4 to 0.4 range, and exhibited a diurnal trend of decreasing values towards midday and increasing values during the afternoon. Wind speed appeared to increase the CWSI and may account for some of the observed variability.  相似文献   
73.
Management practices for the suppression of Verticillium wilt of Russet Burbank potato include sanitation, use of optimum sprinkler-irrigation practices, soil solarization, and an adequate soil fertility program. Among all cultural factors considered, nitrogen (N) deficiency in potato tissue was most commonly associated with the severity of Verticiilium wilt in Russet Burbank potato. Field studies have shown that increased N availability suppresses Verticiilium incidence on cv Russet Burbank while having no effect on cv Norgold Russet. Studies from both greenhouse and field show that the colonization ofV dahliae in potato stem tissue is suppressed in cv Russet Burbank when the availability of Phosphorous (P) is increased to the optimum. Following one season of cropping with Russet Burbank potato, the treatment providing the optimal N availability also suppressed the increases ofV dahliae populations in the soil during the following year of consecutive cropping. Similarly, after two seasons of continuous potato cropping, treatments with optimal P had lower soil populations ofV. dahliae in soil. Results show the suppression of Verticiilium wilt with optimal fertility. Verticiilium wilt [caused by eitherVerticiilium dahliae Kleb, (microsclerotial form) orVerticiilium albo- atrum Reinke and Berthold (dark mycelial form)] is one of the most severe diseases of potato in the United States. Potato yields, tuber size, and specific gravity may be substantially reduced by this disease, depending on severity, time of occurrence, and growing season. In Idaho and other arid growing regions of the United States, Verticiilium wilt is caused byVerticillium dahliae Kleb. Idaho field studies involving cropping practices, soil fumigation treatments, solarization, and Verticillium-resistant potato clones all support the importance ofV dahliae upon potato yield. Data from these studies show that yield losses due toV. dahliae commonly approximate 5 to 12 metric T/ha (5, 6). Table 1 illustrates the effect of several cropping practices upon relativeV dahliae populations in soil with the effects upon both disease severity and potato yield. With continuous cropping of Russet Burbank,V dahliae populations in soil increased, and yields were reduced by 18 to 19 metric Tlha when compared to locations that had been allowed to remain either weed-free and fallow or where corn had been previously cropped. It was estimated thatV dahliae was influencing yield by about 10 to 12 metric Tlha based on a regression analysis of yield as a function ofV dahliae populations in soil. Similarly, whenV dahliae was suppressed by fumigation treatments involving mixtures of dichloropropene and picfume, yields more significantly increased by 6.5 to 12 metric T/ha (5). Although many factors may influence yields, clones with higher Verticillium resistance than Russet Burbank generally out-yield Russet Burbank. Figure 1 demonstrates the effect of solarization (a technique involving the laying of clear plastic on soil for the purpose of elevating soil temperatures to killV dahliae). When Verticillium was controlled in this manner (lo), there was no significant yield difference between the Russet Burbank potato and the highly resistant A68113-4 clone. The A68113-4 clone grown in non-solarized soil out-yielded the Russet Burbank in non-solarized soil by 31 percent while the solarization treatment significantly increased yield for the Russet Burbank and A68113-4 clones by 46 and 18 percent, respectively. These yield responses were observed in a field where inoculum levels ofV dahliae were relatively low (2.10 cfulgrn of soil). With these losses, the need to develop control procedures is great and to achieve this control the need also exists to accurately evaluate the effect of treatments uponV dahliae. Our Idaho studies have routinely utilized such a procedure (9) in combination with comparisons of both disease severity and yield.  相似文献   
74.
The effects of natural antioxidants on nitric oxide (NO) modulation and oxidative status were determined in rat epithelial lung cells (L-2). Cells were stimulated with cytokines and treated with one of the following: resveratrol, soybean saponin group B (SSB), quercetin, genistein, olive leaf polyphenol concentrate (OLPC), or N-acetyl-L-cystein (NAC). NAC had no effect on NO levels, whereas resveratrol and OLPC were found to be effective in reducing nitrite levels, modifying iNOS mRNA, and decreasing free radical production. OLPC affected the levels of MnSOD while resveratrol did not, indicating that they act via different pathways. Quercetin and genistein reduced nitrite levels without affecting iNOS levels, presumably by scavenging NO. SSB did not affect nitrite levels, but exposure did reduce iNOS mRNA expression and protein levels, possibly due to antioxidant activity. Naturally occurring antioxidants, in particular resveratrol and OLPC, may have therapeutic potential in the treatment of inflammatory diseases.  相似文献   
75.
Data from the telephone interview portion of the New York State Farm Family Health and Hazard Surveillance Project were used to study the prevalence and predictors of joint pain in a cohort of farmers and farm residents. The participants were owner/operators, workers, and residents from a representative sample of farms from 12 New York counties. A total of 1706 participants completed a telephone interview on musculoskeletal conditions. Joint trouble was defined as self-reported aches, pain, or discomfort in the past year in each of five different joint areas. The 12-month prevalence of joint trouble was: lower back 41%, neck/shoulders 35%, knees 29%, hands/wrists 28%, and hips 15%. Using logistic regression modeling, significant risk factors for joint trouble were identified (p < 0.05). Older age and being female increased the risk of aches, pain, or discomfort in most joints. Being the owner/operator increased the risk of neck/shoulder and lower back trouble, and being a worker increased the risk of neck/shoulder trouble. Doing tractor work was associated with trouble in all five joint areas, and milking was associated with knee trouble. These findings indicate that personal risk factors and the intensity and nature of the farm work contribute to joint trouble. Ergonomic improvements to tractors and milking facilities should be a high priority.  相似文献   
76.
Hairy roots can be used for metabolic studies and also as a substrate for arbuscular mycorrhizal fungi (AMF). However, little is known about the behavior of these roots when infected with AMF. The metabolism of hairy roots grown with or without AMF, on two culture media, was investigated. An increase in protease activity was observed when the roots were cultured on medium with high nitrogen (N)-content. Glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) activities increased along the development in both carrot and clover hairy roots. With the advancement of root senescence (at 132 d) a greater degradation of root tissue occurred, which was characterized by an increase in catabolic enzymes activity (proteases and GDH deamination). The results indicate that the glutamine synthetase/GOGAT pathway, characteristic of plant tissues, ceases to act in synchronism and is replaced by the GDH/GOGAT system under conditions of stress or senescence when excess ammonium is present.  相似文献   
77.
AIM: To investigate the anthelmintic properties of New Zealand native flax (Phormium tenax) for cattle, using a faecal egg count reduction test (FECRT).

METHODS: Twenty-six heifer calves with high (>300 epg) faecal nematode egg counts (FEC) were paired into two groups and fed either chopped flax leaves ad libitum, or barley straw at an equivalent dry matter (DM) rate, from Day 0–7; all were supplemented with 1.5 kg/head/day cereal feed supplement. On Days 8–10, all heifers were fed a common diet of 3.5 kg DM/ head/day barley straw and 1.5 kg/head/day cereal feed supplement. Heifers were weighed and faecal samples were collected on Days —6, 0, 7, and 10; samples were analysed in triplicate for FEC. The nutritive value of the flax and straw was analysed.

RESULTS: Both the flax and straw had low dry matter digestibility (DMD) and protein content. Although the flax-fed claves grew more than the controls, this may have been related to gut fill. Total daily faecal egg output was similar for flax and straw groups on Day 7 (14.7 vs 15.0 x 106 eggs/day, respectively) and Day 10 (14.9 vs 15.1 x 106 eggs/day, respectively). There was no difference in the change in FEC with time between the calves fed flax or straw diets.

CONCLUSION: Consumption of flax leaves did not reduce FEC in calves with a mixed nematode infection.  相似文献   
78.
AIM: To determine the effects of liveweight (LW) and use of teaser rams prior to mating on both the mating performance and pregnancy rate of ewe hoggets.

METHODS: Romney hoggets (n=841) were weighed and randomly assigned to one of two treatment groups; either exposed to seven harnessed, vasectomised (teaser) rams for 17 days prior to the breeding period (n=283); or not exposed to teaser rams (unteased, n=558). Harnessed Perendale rams were then introduced for two oestrous cycles. Using crayon marks, hoggets were identified as having been mated during the first 17 days only, during the second 17 days only, during both periods, or not mated. All mated hoggets were then scanned for pregnancy using ultrasound, 48 days after the end of the breeding period, and identified as being either non-pregnant, or as single-, twinor triplet-bearing.

RESULTS: Hoggets mated in either the first 17 days only or in both the first and second 17-day periods were heavier than those mated in the second period only (p<0.001). Those mated in the first or second 17-day period only, and those mated in both periods were all heavier prior to mating than those not mated at all (p<0.001). Twin-bearing hoggets were heavier than both their single-bearing and non-pregnant counterparts (p<0.001). A greater proportion of the teased hoggets were mated in the first 17 days only compared with unteased hoggets (62.6 vs 32.1%; p<0.001). In contrast, more of the unteased hoggets were marked in the second 17-day period only (p<0.001). A greater proportion of mated, unteased hoggets were found to be non-pregnant in comparison to their teased counterparts (17.8 vs 11.2%; p=0.02).

CONCLUSIONS: Heavier hoggets at breeding were more likely to be mated in the first 17 days of the breeding period and more likely to be twin-bearing. Use of teaser rams for 17 days prior to the breeding period increased the proportion of hoggets mated in the first 17 days, increased conception rates, and thus increased the proportion of pregnant hoggets. These results indicate that farmers should utilise teasers for 17 days prior to commencement of the breeding period and avoid mating hoggets that weigh below 36 kg.  相似文献   
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