Effects of row and plant spacing, and minituber weight on potato yield

Background and objectives: Potato (Solanum tuberosum L.) plant is one of leading agricultural products in the world. It is the fourth most cultivated food crop after wheat, rice and maize. Planting density and weight of minituber are the factors influencing on the yield and yield components on seed tuber production in potato. Plant density strongly affected yield, both by number and by weight and more tubers and yield per square meter were expected in higher plant densities. Plants grown from lighter tubers spend more time for germination and their buds have thinner stems, smaller roots, and higher stem to root ratio; the number and weight of tubers produced was low in plants as well. The purpose of this study was to investigate the effects of row, plant spacing and minituber weight on Sante potato tuber yield in field conditions.
Materials and methods: This experiment was carried out in 2012 in research field of Razavi Khorasan Agricultural Research Station (Torogh) as a factorial experiment in randomized complete block design with three replications. The experimental factors were row spacing at two levels (37.5 and 75 cm), plant distances in row at two levels (15 and 20 cm) and minituber weight at three levels (<5, 5-10 and >10 gram). In this research, traits such as numbers and weight of tubers per m2, means of diameter, weight of tuber, tuber percent with diameter <35, 35-55 and >55 millimeter, dry matter percent and total yield were measured. Aanalysis of variance of the measured parameters were calculated using the software SAS 9.1. Mean comparisons were performed by LSD test at 5% probability level.
Results: Results of analysis of variance indicated that there are significant variation among spacing and minituber weight for all traits studied. In this experiment, in less spacing seed (15 centimeter within-row) more total yield obtained. In term of all traits related to yield, minituber weight >10 gram showed superiority. In this study, total yield was significantly increased with reduction of row spacing.
Comparison of correlation coefficients showed that there was significant positive correlation between tuber number per m2 and total yield. While, there was significant negative correlation between percentage of dry matter and total yield.
Conclusion: According to the results, the maximum number of tubers per m2 and the total yield were obtained from minituber planting (greater than 10 g) with 15 cm space between plants in the row. The maximum number of tuber per plant was obtained from minituber planting with average weight (5-10 gram) at the lowest density (75*20 cm).