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151.
152.
Twenty-five domestic rice (Oryza sativa L.) cultivars were evaluated in a simulated rice/crawfish double cropping system in southwest Louisiana during 1983 and 1984. Wide variation was observed among cultivars in parameters believed to be important for maximizing productivity in such a system. Mean maturity ranged from 99 (Labelle) to 118 days (Starbonnet), while height ranged from 76 (Bellemont) to 130 cm (Della, Nato). Significant differences in grain yield response were observed, with yields ranging from 4,101 (Bluebelle) to 6,665 kg/hectare (Newbonnet). Straw dry matter production varied greatly, from 3,831 (Bellemont) to 9,170 kg/hectare (Della), and was positively correlated with plant height (r = 0.64; P = 0.0001). Ratoon biomass production was negatively correlated with both grain yield (r = -0.39; P = 0.0001) and maturity group (r = -0.69; P = 0.0001). Plant senescence at grain maturity also varied greatly and appears to be a factor in post-harvest ratoon capability. Early or very early maturing cultivars with both proven grain production and good ratooning capability appear best suited. Cultivar selection should be based upon individual farm situations and currently employed agronomic practices.  相似文献   
153.
Meat regulations also involve game inspection. This publication deals with the regulations concerning furred game intended for slaughter and furred game hunted for food.  相似文献   
154.
Abstract –  The interaction between brown trout ( Salmo trutta ; fork length (FL) range 255–390 mm) and inanga ( Galaxias maculatus ; FL range 55–115 mm) was tested during summer through autumn in an artificial stream consisting of a single run-riffle-pool sequence with a natural food supply. Each experimental trial lasted for 15 days, and consisted of two brown trout and 50 inanga collected fresh from a nearby stream, with each species given prior residence in four replicate tests, totalling eight trials in all. In addition, two control trials (each 10 days), with 50 inanga in each, were run. Brown trout almost exclusively occupied the pool, whereas inanga occupied all habitat types, although in different proportions, when tested with and without brown trout. The proportion of inanga in the pool was appreciably lower in the experimental trials with brown trout than in the control trials with no brown trout; prior residence had no significant effect on inanga habitat use. Mortality of inanga attributable to predation by brown trout ranged from 0 to 40% with a mean of 14.5 ± 4.7%. The results suggest that habitat use and survival of inanga populations in small streams can be adversely affected by brown trout.  相似文献   
155.
Abstract. Experiments were conducted for one year on two different soil types. On a clay soil straw was either (a) burnt, (b) baled leaving the stubble, or (c) chopped and spread. The soil was tine cultivated to depths of 5, 10 or 15 cm or ploughed to 20 or 30 cm before winter wheat was sown conventionally. In addition, a direct-drilled crop was sown after each straw treatment. On a silt loam soil the direct-drilled, tine cultivated to 15 cm and ploughed to 30 cm treatments following burning or chopping and spreading straw were repeated.
Tine cultivation incorporated less straw than ploughing, decreased plant establishment and early growth but did not decrease yield. Direct-drilling through chopped straw decreased yield on the silt loam but not on the clay soil. Short straw (< 5 cm) was easier to incorporate than longer straw. Ploughing was the most efficient method of straw incorporation because it inverts soil. Early effects on crop growth and nutrient uptake following straw incorporation were transient and associated with large amounts of straw in the seeded layer of soil.  相似文献   
156.
Duration of maternal immunity to peste des petits ruminants   总被引:1,自引:0,他引:1  
  相似文献   
157.
Efficacy of ivermectin treatment (0.2 mg/kg) against 28-day experimental infections of Parascaris equorum was determined in 18 pony foals6–17.5 weeks old. There were 6 foals in each group: nontreated control, ivermectin injectable or oral paste. In comparison with larvae found in the nontreated controls, ivermectin injectable or paste was 96.0% and 99.9% efficacious. There was a distinct difference in drug effect against the larger (ca 26mm.) vs the smaller (13–19mm) larvae by the 2 formulations of ivermectin. There were no adverse signs related to treatment of the young foals.  相似文献   
158.
本文详细报道了西瓜蔓枯病的症状和病原菌的形态特点,并鉴定其有性阶段为Mycosphaerellamelonis(Pass)Chiu et Walker,无性阶段为Ascochyta-cucumis Fautr et Roum.此外,还在其他瓜类作物上作了病原菌的致病性试验.  相似文献   
159.
160.
We studied the ability of lambs to select safe foods in the presence of harmful foods. In a series of feeding experiments, 3- to 6-mo-old lambs were offered a choice between 1) a familiar, safe and a novel, harmful food, 2) a novel, safe and a novel, harmful food and 3) a familiar, harmful and a novel, safe food. All harmful foods were palatable feeds that had been treated with lithium chloride (LiCl), a non-lethal gastrointestinal poison. When lambs ingested a meal composed of a novel food containing LiCl and a familiar, safe food, lambs subsequently avoided the novel food. Lambs avoided the novel food even when the familiar food contained LiCl. The response of lambs varied when lambs were given a choice between a novel, safe food and a novel food containing LiCl. Lambs either avoided the novel food containing LiCl and ingested the safe food or they limited their intake of both novel foods. Their response was dependent on the novelty of the food containing LiCl. When a novel, palatable food contained 2% LiCl, lambs always ate some of the food, even after experiencing illness from ingesting it. Lambs experienced with foods containing LiCl displayed greater food neophobia than lambs naive to LiCl-treated foods. Thus, novelty was the major criterion that lambs used to associate foods with gastrointestinal illness.  相似文献   
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