The effect of nitrogen and late blight on crop growth, solar radiation interception and yield of two potato cultivars

• Published in: Field crops research 2014-01, Vol.155, p.56-66
• Main Authors: Bangemann, Lars-Wilhelm, Sieling, Klaus, Kage, Henning
• Format: Article
• Language: English
• Subjects: Crop growth; Nitrogen; Phytophthora infestans; Radiation interception; Radiation use efficiency; Solanum tuberosum; Solanum tuberosum L
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/j.fcr.2013.09.022

•N supply (4 levels) and late blight infestation effects on yield formation of two potato cultivars (early/late maturing) were studied.•Nitrogen, late blight control and cultivar strongly affected green leaf area duration.•Potato total DM was closely correlated with amounts of intercepted radiation when corrected for disease effects.•Radiation use efficiency of potato cultivars was hardly affected by N supply and late blight infestation.•Indications for options of an optimised crop management could be derived. Late blight (Phytophthora infestans (Mont.) de Bary) and nitrogen (N) significantly affect crop growth of potato (Solanum tuberosum L.), but little is known about their interactive effects on radiation interception (RI) and radiation use efficiency (RUE). Two field experiments were conducted in 2006 and 2007 at Braunschweig, Germany, to assess the effects of N supply and late blight infestation on crop growth dynamics of potato in terms of RI, RUE, and dry matter (DM) accumulation. Four nitrogen supply levels (unfertilised up to 160kgN ha−1N supply (soil mineral+fertilisation) in 2006, unfertilised – 240kgN ha−1 in 2007) were tested in combination with two fungicide regimes (sprayed, unsprayed) in two cultivars differing in maturity. N fertilisation increased leaf area index (LAI), leaf area duration (LAD), and RI, and in consequence, tuber yield, but had no significant effect on RUE within a single cultivar. Late blight infection caused premature senescence and defoliation resulting in smaller LAI, shorter LAD, less RI and lower tuber yields. Late blight had no effect on RUE if leaf area was corrected for disease severity. Significant interactions between N level, fungicide treatment and cultivar on late blight disease spread were found affecting LAI and RI. This study shows that total DM accumulation of potatoes can be predicted by RI and RUE, even if N supply is limited and late blight control incomplete as long as the late blight effect on RI can be properly estimated.