【正文】 該研究的初步數(shù)據(jù)表明，去除底部4片葉消除腳葉等級，去除底部8片葉消除腳葉和下部葉等級。Research was conducted from 2002 through 2004 to evaluate the effects of variety, nitrogen rate, topping height, and separation of the upperstalk tobacco at harvest on production of tip grades. The study included K 326, NC 71, and Speight 168 varieties and pared remended nitrogen rates to the remended rate plus 20 pounds of N and hightopping to normaltopping heights. 為了評估品種、氮用量、打頂高度和上部葉分次采收對生產(chǎn)頂葉等級的影響，從20022004年進行了研究。每一個部位的煙草對卷煙特征的貢獻是不同的，正確地混合不同類型煙草及其不同部位煙葉是生產(chǎn)優(yōu)質(zhì)卷煙和確保最終產(chǎn)品一致性的關(guān)鍵。然而，品種間在損失的量上差異顯著。 treatment 2, 10 days later than treatment 1 (ripe tobacco)。2002季節(jié)是歷史上最干旱的季節(jié)之一，2003和2004則是降雨量最大的兩個季節(jié)。早打頂還通過刺激根系的發(fā)育、生物堿的生成以及減少害蟲的危害而提高煙葉的化學和物理品質(zhì)。 ●天蛾幼蟲和蚜蟲的蟲口增加。隨著氮用量的增加，將會出現(xiàn)以下情況： ●產(chǎn)量增加到一定值，然后下降。Lesson 5 Agronomic Management Practices Affecting Tobacco QualityNew Words amp。 ●葉面積增大，但葉厚度減小。Many growers spend considerable time choosing among sidedressers such as calcium nitrate, sodium nitrate, 30 percent UAN liquid, and 24S UAN liquid. However, the data indicate that in the southeastern United States the rate and time of application are more important than the sidedresser. Unless leaching occurs, nitrogen should not be applied after layby. Late season application delays ripening and results in variegatedunripe grades. 許多種植者花費了相當多的時間選擇側(cè)施肥料，比如硝酸鈣、硝酸鈉、30％的UAN(尿素硝銨)液體肥料和24S的UAN液體肥料。Control of sucker growth is critical to maximizing yield because it allows the plant to concentrate resources on the production of leaves instead of suckers. Suckers can also interfere with mechanical harvesting and bee a significant source of foreign matter in cured leaves. The key to successful sucker control is proper timing of suckercide application and use of proper rates of contacts and systemics.抑制腋芽生長對最大限度地增產(chǎn)是很關(guān)鍵的，因為它使植株把資源集中到葉片而非腋芽的生產(chǎn)。In 2002, tobacco matured quickly in our tests and held for 10 to 20 days before quality declined due to excessive heat. In 2003 and 2004, tobacco ripened slowly, followed by a rapid decline in quality due to excessive rainfall. As a result, there was only a 10 day window to harvest tobacco at the optimum value per acre.2002年，在我們的試驗中，煙葉成熟很快，但由 于過多的熱量煙葉在質(zhì)量下降之前保持了10～20天。 treatment 3, 20 days later than treatment 1。From a quality perspective it is important to note that the price per pound almost always increased as harvest was delayed from 7 days early (unripe) to 10 or 20 days later. For the five varieties that were in the 2002 and 2003 tests, the range of increase was from $ to $ per pound in 2002。Therefore, separation of tobacco into distinct stalk