Dataset for: On-farm potato tuber yields along an altitude gradient in Northern Rwanda

Field experiments were conducted during 2016 and 2017 growing seasons at 24 different farmers’ fields representing three different altitudes classes 1800, 2000 and 2400 masl of potato production in Ruhengeri, Rwanda. Since almost no irrigation is practiced by farmers in the study area, all on-farm potato trials were planted under dry-land conditions. Twelve potato fields were set up in a completely randomized block design with four replications at three altitude ranges: 1800 (Ntaruka) 2000 (Nyange) and 2400 (Gataraga) masl in the project action sites of Rwanda. Season 1 trials were planted in April and harvested in August 2016 while season 2 trials were planted in Sep/Oct 2017 and harvested in Dec 2017/Jan 2018. The four treatments consisted of: 1. Fungicide + insecticide + clean seed; 2. Fungicide + insecticide + farmer seed; 3. fungicide only + clean seed; 4. insecticide only + clean seed; 5. the control (no fungicide + no insecticide + clean seed). Two commonly grown varieties were used Kinigi (tolerant to pests and diseases) and Kirundo (highly susceptible to pests and diseases but high yielding). Clean seed was sourced from the Rwanda Agricultural Board research stations while farmers seed was bought from local weekly markets in Musanze district. Net plot size was 8.4 (1.4 X 6 m2) with 80 (40 plants per variety, 20 plants per row) in two rows. Spacing was 0.7 m between rows and 0.3 m between plants. Fertilization and weed control as well as any other agricultural activities was uniform for all plots of the trial and conformed to local agriculture practices. This included application of NPK 17:17:17 fertilizers at rates of 300 kg/ha (at planting and at first weeding). Weeds were removed whenever it necessary (2-3 times) and this was done by the farmer. Insecticides (Cypermethrin and Abamectin) and fungicides (Metalaxyl and Mancozeb) were sprayed on a bi-weekly basis or whenever signs of pest or disease damage were seen. Metalxyl was sprayed only twice in the first month. Data were subjected to analysis of variance (ANOVA) using SAS software computer program (SAS 9.3). Mean values of tuber yields across altitudinal classes and treatments were tested for significant differences using the F-test at 5% and were separated using Fisher’s least significance difference (LSD) test at P ≤ 0.05. Potato tuber yield data for the two seasons was combined and analyzed together because some plots were lost due to theft.