Screening and Evaluation of Initial Clonal Generations of Potato Hybrids for Yield and Yield Attributing Characters

A field experiment was conducted during Rabi 2015-16 and 2016-17 at ICAR-Central Potato Research Station, Patna Bihar. In this experiment F1 with initial clonal generations viz F1C1, F1C2 and F1C3 were evaluated. The screening and selection of these generations were done in randomized block design for the character like early bulking, tuber size, tuber shape, depth of eye, tuber colour and resistance to late blight of potato etc. A total of 12,360 True Potato Seeds of 17 successful crosses and 7,322 True Potato Seeds of 23 successful crosses were sown and seedlings were transplanted, out of these 610 and 187 clones were selected during 2015-16 and 2016-17 respectively. Large number of potato cultures were planted for further evaluation in next generations. In F1C3 the cultures were planted along with more than six check varieties of potato. Cultures were evaluated and selected considering total tuber yield, shape, colour and disease reactions for further evaluation in PYT.

Quantifying Control Efficacy of Fungicides Commonly Applied for Potato Early Blight Management

Early blight is an economically important foliar disease of potato in the United States. Because of the lack of resistant potato cultivars, fungicides are applied extensively to obtain adequate control. To manage early blight, standard protectant fungicides and single-site mode-of-action “specialty” fungicides are applied either alone or incorporated into a fungicide rotation program. Control efficacy at two crop growth stages (tuber initiation/early bulking and late bulking/tuber maturation) and the overall tuber yield response to standard and specialty fungicides were assessed using network metaanalytic models. Control efficacy of fungicides ranged from moderate to very high (>30 to 75%) compared with the nontreated control. For both potato growth stages, specialty fungicides performed better than standard protectant fungicides. Furthermore, control efficacy of both fungicides was higher (3 to 9%) at late bulking and tuber maturation when compared with early bulking crop growth stage. Specialty fungicide programs increased overall tuber yields by 4 and 9% over standard fungicides and nontreated control, respectively. Based on the results, more precise fungicide use recommendations and fungicide programs can be developed for early blight management.