Riboflavin Nullification of Inhibitory Actions of 3-Amino-1,2,4-Triazole on Seedling Growth.
The physiological mechanislmis involved in the toxic actions of 3-amino-1,2,4-triazole (amitrole) have been actively investigated since the chemical was first introduced as a potential herbicide in 1954 (2). Much of the research has been guided by hypotheses involving one of three major metabolic processes: A, porphyrin synthesis, B, cation functions, and more recently C, the metabolism of purines and their derivatives. The extensive literature associated with the first two categories will not be considered herein. Amitrole interferences in some of the biochemiiical processes of the third category now appear to be the actions of nmajor physiological importance in the response of plants to the herbicide. Much of the pertinent research deals with attempts to find physiological compounds capable of reducing the toxicity of amitrole to various organisms. The most effective conmpounds are purines (23, 24) or histidine (13, 23) for unicellular plants anid riboflavin or riboflavin derivatives (22, 24) for higher plants. The investigations reported herein Nwere initiated as a result of my observations that the riboflavin effect could not be denmonstrated with barley seedlings by tecliiques that had been used successfully with other herbicidemetabolite combinations (9, 14, 18). The objectives of this study were: A, to develop techniques by whiclh the riboflavin nullification of amitrole toxicity could be observed with higher plants, and to compare adenine and histidine with riboflavin by these techniques; BR, to consider the possibilitv that the riboflavin effect was the result of non-physiological processes: C, to compare the effectiveness of riboflavin in species of higher plants that differ in their response to amitrole, and D, to determine if certain other metabolites of theoretical interest might give additional reductionis in amitrole toxicity.
Effect of 3‐Amino‐1,2,4‐Triazole on the Alcohol Soluble Nitrogen Compounds in Cirsium arvense
Changes in the soluble nitrogen compounds after application of 3-amino-1,2,4-triazole (amitrole) to amitrole susceptible and amitrole resistant ecotypes of Cirsium arvense were investigated. One day after treatment with amitrole the concentration of all nitrogen compounds tested in the leaves of the susceptible ecotype was reduced, but none was eliminated. Five days after treatment the concentration of the same compounds increased in the leaves above the control (0 amitrole) concentration. The resistant ecotype had less change in nitrogen compounds than did the susceptible ecotype. Changes in the soluble nitrogen compounds in the stem and root fraction were less than in the leaf fraction. The authors suggest a two phase reaction of the soluble nitrogen compounds due to amitrole treatment. It is concluded that the primary biochemical lesion of amirole in mature Cirsium arvense is not the elimination of glycine, serine, or any other soluble nitrogen compound.
Drivers of Live Cattle Price in the Livestock Trading System of Central Cameroon
Livestock production and trade are critical for the food security and welfare of rural households in sub-Saharan Africa. In Cameroon, animal trade consists mainly of live cattle commercialized through livestock markets. Identifying the factors contributing to cattle price formation is critical for designing effective policies for sustainable production and for increasing food availability. In this study, we evaluated the influence of a range of individual- and market-level factors on the price of cattle that were sold in all transactions (n = 118,017) recorded over a 12-month period from 31 livestock markets in the main cattle production area of the country. An information-theoretic approach using a generalized additive mixed-effect model was implemented to select the best explanatory model as well as evaluate the robustness of the identified drivers and the predictive ability of the model. The age and gender of the cattle traded were consistently found to be important drivers of the price (p < 0.01). Also, strong, but complex, relationships were found between cattle prices and both local human and bovine population densities. Finally, the model highlighted a positive association between the number of incoming trading connections of a livestock market and the price of the traded live cattle (p < 0.01). Although our analysis did not account for factors informing on specific phenotypic traits nor breed characteristics of cattle traded, nearly 50% of the observed variation in live cattle prices was explained by the final model. Ultimately, our model gives a large scale overview of drivers of cattle price formation in Cameroon and to our knowledge is the first study of this scale in Central Africa. Our findings represent an important milestone in designing efficient and sustainable animal health management programme in Cameroon and ensure livelihood sustainability for rural households.