|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|4927433||1363207||2018||7 صفحه PDF||ندارد||دانلود کنید|
â¢Time period between harvest and tillage determines soil seed bank size of oilseed rape.â¢Soil seed bank and volunteer density decrease with delayed timings of stubble tillage.â¢Very shallow stubble tillage can lead to soil seed banks and volunteers.â¢Seed set of volunteer oilseed rape depends on timing and depth of post-harvest tillage.
Appropriate timing of post-harvest tillage to oilseed rape (OSR, Brassica napus L.) is crucial for the creation of a soil seed bank and unwanted OSR volunteers. Existing recommendations, however, can contrast with needs for early post-harvest tillage e.g. for pest control. To specify and to systematically further improve preventive volunteer management through post-harvest tillage of imidazolinone-tolerant oilseed rape (ClearfieldÂ®; CL OSR), field experiments were set up at two locations in two separate trial periods at each location (2013â2014 and 2014â2015) in south-west Germany. After OSR harvest, and average harvest losses of 1500âmâ2 seeds, or artificially broadcasting of 20Â 000 OSR seeds mâ2, stubble tillage was performed at weekly intervals (immediate (0), 1, 2, 3, and 4 weeks) at each of three depths (1â2, 6â8, and 15â17Â cm). To depict a worst case scenario in which herbicides were ineffective, no herbicides were applied. There were significantly smaller soil seed banks found in spring the longer the period lasted between seed rain and stubble tillage; 265 vs 145 seeds mâ2 referred to 0 week vs. 4 weeks on average. Depth of stubble tillage had no significant effects on the seed number in the soil. In the first spring after seed loss, 0â2.6 CL OSR volunteers mâ2 were found in the winter wheat, and the number decreased with delayed timing depth of stubble tillage. These volunteers mainly emerged in the treatment of shallow stubble tillage (1â2Â cm), with 0.7-0.9 flowering volunteer mâ2, while volunteers averaged less than 0.04 plants mâ2 in the treatment â15â17Â cmâ. OSR volunteers in winter wheat got ripened only in one out of the four fields, and produced 1.0 seed mâ2 on average. The delay between harvest and stubble tillage can be limited to approximately three weeks if stubble tillage is performed at a depth of about 6â8Â cm; further delay did not bring additional advantage. We recommend to retain the stubble for three weeks as further delay does not bring additional advantage, and then to apply stubble tillage deeper than 6Â cm. Very superficial or shallow stubble tillage should be avoided. This procedure seems appropriate for avoiding oilseed rape volunteers without use of herbicides.
Journal: Soil and Tillage Research - Volume 175, January 2018, Pages 187-193