ارزیابی جذب و کارایی مصرف نور در کشت مخلوط ذرت (Zea mays L.) وسیب زمینی Solanum tuberosum L.))

Abstract

Plant dry matter accumulation has a linear relation with accumulative photosynthetically active radiation (PAR). Intercropping could be a strategy for increasing light absorption in agronomic systems and it may improve radiation use efficiency (RUE). Thus this study was conducted in order to evaluate radiation absorption and use efficiency in potato (Solanum tuberosum L.) –corn (Zea mays L.) intercropping. The experimental treatments were consisted of monocropping corn (MC), monocropping potato (MP), strip intercropping (S), intercropping with three different patterns (I25, I50 and I75 are 25%, 50% and 75% overlaps of corn and potato rows in strip treatment, respectively) and row intercropping (R). Results showed that corn RUE increased in all intercropping treatments compared with mono-cropping plots while potato RUE reduced in the intercropping plots. Mean of corn RUE in growing season was from 2.65 g.MJ-1 in the MC up to 3.27 g.mJ-1 in the R. Mean of potato RUE was from 1.27 g.MJ-1 in the R to 1.47 g.MJ-1 in MP treatment. With shifting row intercropping, where row spacing was doubled compared with mono-crop corn plots, towards strip intercropping, where distance of rows was similar to mono-crop corn plots, RUE decreased. This could be due to decreasing the number of rows that their distances were double of mono-crop plots. Moreover, with shifting from strip intercropping towards row intercropping (i.e. I25, I50, I75 and R treatment, respectively), the number of potato rows that were under the corn direct shading increased and this resulted to decreasing potato RUE. Further studies on the effects of various densities of potato and corn plants and delayed intercropping systems for these crops are required.