Investigate the effect of resource limitations on the physiological traits, yield and yield components of canola in wet weather conditions

Considering the importance of modify the source and reservoir, a factorial experiment in a randomized complete blocks statistical design was carried out in four replications in order to investigate the effect of source limitation (leaf cut) on yield and growth characteristics of canola Hyola 401 cultivar in Golestan province. The first factor defoliation time on two-leaf, four-leaf, six-leaf, eight-leaf and ten-leaf stages (retaining the remaining leaves after this time) and the second factor no defoliation (as control treatment), removing 50 percent of the plant leaves and cut off 100 percent plant leaves. The effect of defoliation stage on days to flowering and flowering period was significant at one percentage level and on days to maturity was non-significant. Defoliation had a significant effect on plant height, number of pods per plant, number of seeds per pod, one-thousand grain weight and grain yield. The highest grain yield in the treatment of no defoliation (control) and the lowest yield in treatment in the six-leaf stage were produced. The treatment no defoliation with the average of 2349 kilogram per hectare allocated the highest grain yield. The average grain yield in defoliation treatment at two-leaf stage was 2066 kilogram per hectare and defoliation in the six-leaf stage was 1885 kilogram per hectare. The results of the present research showed that the leaf area reduction caused by environmental and live tension especially at the beginning of the growing season and in periods of growth. In the absence of resource limitation, canola yield is increased due to increased levels of photosynthesis and increased production of assimilation.