Investigation on the responses of cumin plants to certain horticultural agro-chemicals. III: influences of phosphon-D on foliage growth, fruit yield, essential oil and chemical compositions

摘要

The effects of phosphon-D (CBBP), as growth retardant, with different concentrations vis., zero, 250, 500 and 1000 ppm and three methods of application, namely: 1- initial pre-sawing soaking alone, 2-initial pre-sawing soaking, supplemented with post-emergence one time spray, and 3- initial pre-sawing soaking, supplemented with post-emergence two time sprays, on the performance of Cuminurn cyminunm, L. were studied, in a split-plot experiment. Phosphon-D at low concentration (250 ppm)improved cuminvegetative growth, fruit yield and weight and essential oil yield per plant. Increasing phosphon-D concentrations up to 1000 ppm increased the volatile oil content in cumin fruits. Phosphon-D application, generally, underscored cumin essential oil quality, by reducing myrcene and cuminaldehyde. Initial pre-sawing soaking alone, of cumin fruits, in the different phosphon-D concentrations was, generally, as effective as supplemental post-emergence spray(s), in addition to the pre-sawing soaking. Increasing supplemental post-emergence spraying frequencies increased the C//N ratio in cumin fruits. The mutual interactive effect of phosphon-D concentrations and the three methods of applications, revealed that phosphon-D at 250 ppm applied as pre-sawing soaking alone produced the highest cumin plants, in comparison to 1000 ppm applied as supplemental two times post-emergence sprays, in addition to the initial pre-sawing soaking.