Development of soil testing program for tobacco production [Philippines].
1983
Briones A.M.
Nutrient content of tobacco leaves gave the following range of values: 2 to 6.4% N, 0.27 to 0.81% P, 1.5 to 5.2% K, 0.57 to 2.17% Ca, 0.24 to 0.58% Mg, and 0.67 to 1.86% Cl. Consistent with the crop's response to N application, there was increasing trend in N content and N uptake with increasing rates of N applied. As percent N in the leaves increased, quality index generally decreased for each site; however, there was no definite level of percent N consistently associated with high or low quality indices for all sites. The other nutrients (P, K, Ca, Mg and Cl) did not individually show any defined relationship between nutrient concentration in the leaves and yield or leaf quality index. In terms of nutrient ratios, leaf quality index generally decreased with increase in N/K ratio for Batac, Marcos and San Juan sites. Quality indices lower than 4 were not observed when N/K ratios were less than 1.2 for San Juan and Marcos and less than 0.8 for Batac.
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