Field experiments were conducted to study cotton nitrogen diagnosis and topdressing recommendation by measuring cotton tissue NO3- concentration with Reflectoquant. Results showed that the order of NO3- concentration ...Field experiments were conducted to study cotton nitrogen diagnosis and topdressing recommendation by measuring cotton tissue NO3- concentration with Reflectoquant. Results showed that the order of NO3- concentration in different cotton plant tissues is petiole > stem > leaf, and upper parts> lower parts. There was significant change in each growth period, which was, NO3- concentration in budding-blooming period was the highest whereas it was the lowest in full blooming period. NO3- concentration in the 4th expanding petiole is relatively stable and can sensitively indicate cotton nitrogen state so it was chosen as diagnosis tissue. NO3- content in budding-blooming period was significantly correlated with seed-cotton yield so it was chosen as diagnosis period. Primary cotton's nitrogen diagnosis index and amount of topdressing was formulated by regression of NO3- concentration against seed-cotton yield. It was not only rapid and accurate but also time-saving and flexible by using Reflectoquant to diagnose cotton nitrogen states and make side-dressing recommendation , so it is an agricultural technique with promising prospect.展开更多
文摘Field experiments were conducted to study cotton nitrogen diagnosis and topdressing recommendation by measuring cotton tissue NO3- concentration with Reflectoquant. Results showed that the order of NO3- concentration in different cotton plant tissues is petiole > stem > leaf, and upper parts> lower parts. There was significant change in each growth period, which was, NO3- concentration in budding-blooming period was the highest whereas it was the lowest in full blooming period. NO3- concentration in the 4th expanding petiole is relatively stable and can sensitively indicate cotton nitrogen state so it was chosen as diagnosis tissue. NO3- content in budding-blooming period was significantly correlated with seed-cotton yield so it was chosen as diagnosis period. Primary cotton's nitrogen diagnosis index and amount of topdressing was formulated by regression of NO3- concentration against seed-cotton yield. It was not only rapid and accurate but also time-saving and flexible by using Reflectoquant to diagnose cotton nitrogen states and make side-dressing recommendation , so it is an agricultural technique with promising prospect.
