tailieunhanh - Doctoral thesis summary of agriculture: Application of chlorophyll and ratio vegetation indexes to calculate nitrogen rates at 10 days before tassel emergence period for two hybrid maize varieties LVN99 and LVN14

Doctoral thesis summary of agriculture: Application of chlorophyll and ratio vegetation indexes to calculate nitrogen rates at 10 days before tassel emergence period for two hybrid maize varieties LVN99 and LVN14. | MINISTRY ÒF EDUCATION AND TRAINING THAI NGUYEN UNIVERSITY BUI VAN QUANG APPLICATION OF CHLOROPHYLL AND RATIO VEGETATION INDEXES TO CALCULATE NITROGEN RATES AT 10 DAYS BEFORE TASSEL EMERGENCE PERIOD FOR TWO HYBRID MAIZE VARIETIES LVN99 AND LVN14 MAJOR CROP SCIENCE CODE DOCTORAL THESIS SUMMARY OF AGRICULTURE THAI NGUYEN - 2016 The thesis was completed at the Department of Vegetables -Flowers - Fruits Faculty of Agronomy Thai Nguyen University of Agriculture and Forestry Supervisors 1. Ass. Prof. Dr. Nguyen The Hung 2. Dr. Phan Xuan Hao Reviewer 1 . Reviewer 2 . The thesis will be protected at the Council level thesis University dots meeting in Thai Nguyen University of Agriculture and Forestry .2016 Thesis can be found at - Learning Resource Center Thai Nguyen University - Library University of Thai Nguyen - National Library 1 PREAMBLE 1. Research Rationale Maize Zeamays L. is an important plant to the livestock feed and an food for many people in the world. Fertilization timing has been significant in enhancing the effect of nitrogen N and increasing productivity. At present N is usually applied to 3 stages 4-5 leaves 8-9 leaves and especially 10 days before tassel emergence in which N content in stem and leaves has correlated with the performance of productivity. Currently fertilizer application in Vietnam still remains in a predefined rate and timing for each specific region or productivity goals according to topography climate soil crops etc. that less based on the nutritional status of the plant. Therefore we conducted a study Application of chlorophyll and ratio vegetation indexes to calculate nitrogen rates at 10 days before tassel emergence period for two hybrid maize varieties LVN99 and LVN14 . 2. Objectives of the study . Overall objectives Determination of N rates applied to 2 maize varieties LVN14 and LVN99 based on using the method of rapid assessment of N status at 10 days before tassel emergence period in order to achieve target yield .