Effect of production environments on radiation interception and radiation use efficiency of potato (Solanum tuberosum) grown in Canterbury, New Zealand

Abstract

Four experiments were conducted over two growing seasons during 1995/96 and 1996/97 at Lincoln University and New Zealand Institute for Crop & Food Research, Lincoln, Canterbury, to assess whether radiation interception (RI) alone is a good predictor of potato (Solanum tuberosum) total dry matter (TDM) grown under different environments. In the two field experiments production environments were altered by different rates of nitrogen application and in bag experiments, the different production environments were created with the presence of different amounts of potato cyst nematode (Globodera rostochiensis) per ml of soil. The different production environments significantly affected leaf area index (LAI), RI, radiation use efficiency (RUE), and TDM. Increased soil fertility significantly increased RI, RUE, and TDM where as the presence of potato cyst nematode significantly decreased RI, RUE, and TDM. There was a strong (P < 0.001) positive linear relationship between RUE and applied nitrogen, whereas there was a linear, negative relationship between RUE and the numbers of potato cyst nematode per ml of soil. On the basis of this study it was concluded that under different production environments both RI and RUE must be known to accurately predict the TDM of potatoes.