Influence of planting date, intercropping and plant growth promoting rhizobacteria on cumin (Cuminum cyminum L.) with particular respect to disease infestation in Iran

Abstract

This study was performed to evaluate the effect of different planting dates, planting pattern and plant growth promoting rhizobacteria (PGPR) on yield, growth and also disease development in cumin (Cuminum cyminum L.) when intercropped with fenugreek (Trigonella foenum-graecum L.). For this purpose, a field experiment was conducted in a split-plot factorial arrangement based on randomized complete block design with three replications in Ferdowsi University of Mashhad, Iran in 2012 and repeated in 2013. The experimental treatments were planting dates (5 November, 5 December and 5 March) assigned to main plots, planting patterns (sole cropping and intercropping of cumin and fenugreek) and PGPR (control, Pseudomonas putida and Azotobacter chroococcum) that were randomized in subplot. Results showed that fall planting dates and intercropping system had positive effects on cumin disease control, whereas application of PGPR had no significant effect in both years. Fall planting dates produced more seed yield in both crops than spring planting. The benefit of Pseudomonas was demonstrated on seed yield of cumin and fenugreek. The values of land equivalent ratio (LER) for all treatments of planting dates and PGPR were more than one. This issue indicated that the intercropping system had positive effect on diseases control because of the physical barrier established by the fenugreek and subsequently on seed yield for 2012 and 2013 growing seasons. In essence, modifying planting date and using intercropping systems contribute to the reduction of disease infestation of cumin without using chemicals.