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1.
Maize (Zea mays L.) is the most important cereal crop produced in Ghana. However, yield of the crop is generally low, producing just about 1.7 t/ha. The low yield is attributed to continuous use of local/unimproved varieties. Generally, hybrid varieties have proven to out-yield the local/unimproved varieties due to improved vigour. Development of hybrid varieties depend on good understanding of combining ability and inheritance of important quantitative traits such as grain yield (GY). 45 half-diallel crosses generated from 10 extra-early maturing yellow inbred lines were evaluated in 2015 under rain-fed conditions. The objectives were to determine the genetic control, breeding value and estimate heritability for GY and agronomic traits of the inbred lines under contrasting growing environments in Ghana. General combining ability (GCA) and specific combining ability (SCA) were important in the inheritance of GY and agronomic traits of the inbred lines. However, GCA was more important than SCA across environments to suggest that additive gene action was more important than non-additive gene action in the inheritance of GY and agronomic traits in the inbred lines. High broad-sense heritability, for GY and other agronomic traits indicated preponderance of additive gene action in trait expression, thus, selection based on phenotypic expression could be feasible. Inbred lines P1, P4 and P8 were good combiners for high GY. The genotype, P4 × P8, was identified as the ideal and most yielding single-cross hybrid across research environments and should be further tested on-farm before commercialization.  相似文献   
2.
Mature oil palms at the Oil Palm Research Institute at Kusi, Ghana were underplanted with cocoa to study the feasibility of mixed cropping of the two crops under West African conditions. The oil palm trees used in this trial were planted in 1970 and had achieved maximum canopy formation. Three triangular spacings of the oil palms used were 8.7, 9.9 and 10.5 m. The cocoa was underplanted in June 1988 at a spacing of 2.4 m triangular using mixed hybrids. There were no significant differences in oil palm yield between plots with cocoa and the controls. There was no appreciable damage to the cocoa trees from falling palm fronds and fruits during harvesting or pruning. Cocoa seedling growth and yield were significantly better under the oil palm spaced at 9.9 or 10.5 m triangular than under oil palm space at 8.7 m triangular.  相似文献   
3.
Factors thought to influence monthly body weight and average daily gain of 122 first and second generation Canadian Holstein calves aged six to 24 months were studied. All factors (generation, sex, parity, season, age and year) studied accounted for 55.9 to 71.2% and 35.6 to 69.1% of the variation in body weight and average daily gain respectively. Parity, year and generation were the most important factors influencing all traits and accounted for 34.4 to 64.3% and 22.9 to 66.8% of the variation in body weight and average daily gain. Least squares means were, for body weight 144.2, 222.6, 330.5 and 377.9 kg at six, 12, 18 and 24 months and for average daily gain 0.42, 0.37, 0.50 and 0.39 kg at six to nine, nine to 12, 12 to 18 and 18 to 24 month intervals. It was concluded that offspring of Canadian Holsteins in this environment under adequate management and nutrition will be of adequate size for heifers to calve under 30 months of age and steers to reach 400 kg slaughter weight in 24 months.  相似文献   
4.
Three different dietary additives were evaluated based on growth performance, innate immune responses and disease resistance in juvenile Amur catfish Silurus asotus. Four diets were prepared by supplementing 0.4% Song-gang® stone (SG), 0.05% Yucca meal (YM), 0.05% β-glucan (BG) in combination with 0.04% SG and 0.05% BG (SG + BG) to a basal commercial diet (control; CONT). Triplicate groups of fish averaging 4.95 ± 0.05 g were fed one of the test diets between 3 and 5% body weight for 8 weeks. At the end of the feeding trial, weight gain, specific growth rate, feed efficiency and protein efficiency ratio of fish fed SG and SG + BG were significantly higher than those of fish fed the BG and CONT diets (P < 0.05). Lysozyme activity in fish fed the SG, YM, and SG + BG diets was significantly higher than those of fish fed the CONT diet. Super oxide dismutase (SOD) activity was significantly higher among fish fed the SG, YM, BG and SG + BG diets than fish fed the CONT diet. After 14 days challenge test with Edwardsiella tarda, cumulative survival rates of fish fed the SG and SG + BG diets were significantly higher than those of fish fed the BG and CONT diets. Results revealed that dietary SG or SG + BG diets had positive responses over other additives in juvenile Amur catfish. However, Song-gang® stone is proposed to be a cheaper dietary additive contributing 0.04 cents/kg of feed based on economic point of view.  相似文献   
5.
This study aimed to elucidate the effects of dietary Bacillus licheniformis ATCC 11946 (BL) on the growth, immune and antioxidant activities, intestinal morphology and microbiota, and susceptibility to Vibrio parahaemolyticus (VPAHPND) in juvenile pacific white shrimp, Litopenaeus vannamei (LV). Juvenile LV (initial weight = 0.63 ± 0.001) were fed diets containing varying BL concentrations (0 (BL0), 106 (BL1), 107 (BL2) and 108 (BL3) CFU/g feed) for 8 weeks. Growth performance, immune and antioxidant enzyme activities, and intestinal morphology significantly improved in the probiotic‐treated groups than the untreated. Regardless of the treatment group, the two dominant phyla were Proteobacteria and Bacteroidetes, whereas the two dominant genera were Ruegeria and Vibrio. Increasing inclusion of probiotics in diets led to significant increase in beneficial bacterial genera (Ruegeria, and Pseudoalteromonas) and a significant decrease in some known opportunistic pathogens (Vibrio, Tenacibaculum, Photobacterium, Kangiella and Spongiimonas) with the BL3 group witnessing the best. A 7‐day challenge study with VPAHPND showed significantly high protection in the probiotic‐treated groups, with the BL3, BL2 and BL1 obtaining 51%, 34% and 22% relative percentage survival, respectively. In conclusion, BL at 108 CFU/g feed should be used to help in shrimp production since it attained the most significant improvement.  相似文献   
6.
7.
Cookies were produced from different sorghum flours to determine their potential as vectors of antioxidants. Different sorghum cultivars and their flour extraction rates were evaluated for their effects on phenolic content and antioxidant activity of the cookies. Consumer acceptance of the sorghum cookies was compared with that of wheat flour cookies. For each sorghum cultivar, cookies of 100% extraction rate flours had two to three times more total phenolics compared with those of 70% extraction rate flours, while antioxidant activity was 22–90% higher. Cookies of the condensed tannin sorghum had two to five times more phenolics compared with those of condensed tannin‐free sorghum. Antioxidant activity was 145–227 μMol Trolox equivalents (TE)/g in cookies of condensed tannin sorghum compared with 10–102 μMol TE/g in those of condensed tannin‐free sorghum. The sorghum flours had slightly higher phenolic content and antioxidant activity values than their corresponding cookies. Cookies of the red tannin‐free sorghum flours (PAN 8564/8446) were equally liked as wheat flour cookies, except for texture. However, cookies of condensed tannin sorghum were least accepted compared with wheat flour cookies despite their high antioxidant activity.  相似文献   
8.
Summary One hundred and three calving records of 35 Canadian Holstein-Friesian cattle introduced in 1974 into Ashanti constituted the data for this study. Age, year, lactation number, season and age × season effects on 305-day yield, lactation length and components of the lactation curve were estimated from 84 complete lactation records.Analysis of variance by General Linear Models Procedure showed significant effect of age and year on all traits studied. Age, year, lactation number, season, concentrate fed and season × age accounted for 61.1, 64.6, 66.9, 68.5 and 38.1% of the variation in 305-day yield, 300-day yield, monthly peak yield, persistency index and lactation length respectively. Age and year significantly affected all traits except lactation length. Lactation number only significantly affected 305-day yield of the traits studied. Season was not an important factor affecting any of the traits. The productive life span of the animals was up to five calvings (eight years). The mean life time milk production was 16,186 kg. Unadjusted means of the 103 records were: 305-day yield 3,878 ± 93.7 kg; actual 305-yield 4,451 ± 102.7 kg; total yield 4,225 ± 160.6 kg; lactation length 332 ± 14.5 days; days dry 96 ± 5.9 and total yield per day of calving interval 10.6 ± 0.33 kg. Performance of Holsteins in Ashanti was better than in most tropical areas.
Productividad Del Ganado Holstein-Friesian Canadiense En La Zona Boscosa Humeda De Gana. I. Produccion De Leche
Resumen Los datos para este estudio, salieron de 103 registros de pariciones pertenecientes a 35 Holstein-Friesian Canadienses, introducidas a Ashanti en 1974. Se estimaron la edad, año, número de lactancias, estación y edad × effectos estacionales 305 días de producción, duración de la lactancia y componentes de la curva de lactancia, con base en 84 registros completos de lactancia.El análisis de varianza, efectuado por el procedimiento de Modelos Generales Lineares, mostró efectos significativos de edad y años sobre todos los rasgos estudiados. La edad, año, número de lactancias, estación, alimento concentrado y estación × edad, influyeron en 61.1, 64.6, 66.9, 68.5 y 38.1% de la variación en 305 días de producción, 300 días de producción, pico mensual de producción, índice persistente y duración de la lactancia, respectivamente. La edad y el año afectaron significativamente todos los rasgos, excepto la duración de la lactancia. El número de lactancias solo afectó significativamente la producción de 305 días, de todos los rasgos estudiados. La estación tampoco fué factor importante para los rasgos. La vida productiva de los animales estuvo por encima de las 5 pariciones (8 años). La media de producción de leche durante la vida productiva, fué de 16.186 kg. Las medias sin ajustar de los 103 registros fueron; producción de 305 días 3.878±93.7 kg; producción actual de 305 dias 4.451±102.7 kg; producción total 4.225±160.6 kg; duración de la lactancia 332±14.5 días; días secas 96±5.9 y producción total por día de intervalo de parto 10.6±0.33 kg. La productividad de las Holstein en Ashanti, fué superior a la de la mayoría de áreas tropicales.

Performances De Bovins Canadiens Holstein-Frisons En Zone Forestiere Humide Au Ghana. I. Production Laitiere
Résumé 103 relevés de vêlage de 35 bovins canadiens Holstein-Frisons importés en 1974 à Ashanti ont fourni les données de cete étude. L'âge, l'année, le nombre de lactations, la saison, les effets conjugués de l'âge et de la saison sur une production de 305 jours, la durée de la lactation et les composantes de la courbe de lactation ont été évalués à partir de 84 relevés de lactation complète.L'analyse de variance par le modèle linéaire général a montré que l'âge et l'année avaient un effet significatif sur tous les paramètres étudiés. L'âge, l'année, le nombre de lactations, la saison, le concentré donné et l'effet saison/âge étaient responsables de 61,1; 66,9; 68,5 et 38,1 p.100 de la variation pour respectivement une production de 305 jours, une production de 300 jours, les pointes de production mensuelle, l'index de persistance et la durée de lactation. L'âge et l'année avaient un effet significatif sur toutes les performances sauf la durée de lactation. Le nombre de lactations n'avait un effet significatif que sur la production de 305 jours des traits zootechniques étudiés. La durée de vie productive des animaux allait jusqu'au cinquième vêlage (8 ans). La production laitière moyenne sur un temps de vie a été évaluée à 16 186 kg. Les moyennes non-ajustées des 103 relevés ont été les suivantes: production de 305 jours: 3878±93,7 kg; production de fait de 305 jours: 4451±102,7 kg; production totale: 4255±160,6 kg; durée de lactation: 332±14,5 jours; jours de tarrissement: 96±5,9 et production totale journalière pendant l'interval entre vêlages: 10,6±0,33 kg. Les performances des Holstein à Ashanti ont été meilleures que dans la plupart des régions tropicales.
  相似文献   
9.
10.
Cacao-coconut intercropping in Ghana: agronomic and economic perspectives   总被引:1,自引:0,他引:1  
In Ghana, shade for cacao (Theobroma cacao L.) is becoming a critical issue because of extensive deforestation. Unlike in some other cacao-growing countries, cacao is not grown under the shade of coconut (Cocos nucifera) in Ghana. An experiment to compare the merits of four cacao-coconut intercropping systems with the traditional cultivation of cacao under Gliricidia sepium shade was undertaken at the Cocoa Research Institute of Ghana. Cacao seedling girth was not affected when intercropped with coconut but was significantly (P = 0.01) reduced when intercropped with G. sepium. High density cacao facilitated better early canopy formation. Yield of cacao spaced at 2.5 m triangular (1739 plants ha–1) with coconut at 9.8 m triangular (105 plants ha–1) was significantly higher (P = 0.05) than from the other treatments during 1993/94 to 1995/96. There were no major disease problems associated with intercropping cacao with coconuts. Widely spaced coconuts intercropped with cacao spaced at 3 m × 3 m showed better flowering and gave higher coconut yields, but cacao spaced at 2.5 m triangular under coconuts spaced at 9.8 m triangular was more profitable than the other treatments. Moisture stress was the greatest in cacao system with G. sepium shade and this could be responsible for the low yield of cacao in that treatment. It is suggested that properly arranged high density cacao under widely spaced coconuts can be a profitable intercrop system for adoption by cacao farmers in Ghana.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   
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