Dry matter production and rate of change of harvest index at high temperature in peanut

• Published in: Crop science 2002, Vol.42 (1), p.146-151
• Main Authors: CRAUFURD, P. Q, VARA PRASAD, P. V, SUMMERFIELD, R. J
• Format: Article
• Language: English
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agricultural production; Agronomy. Soil science and plant productions; Biological and medical sciences; Botanical research; Climatic models of plant production; Development; Dry matter; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Techniques. Climatology. Meteorology. Climatic models of plant production; Harvesting; High temperature; Peanuts; Plants; Temperature
• ISSN: 0011-183X; 1435-0653; 1435-0653
• DOI: 10.2135/cropsci2002.0146

The concept of a linear increase in harvest index, dHI/dt, has proven very useful for crop simulation modeling. The effect of high temperature on the response of dHI/dt of pods and seeds of peanut (Arachis hypogaea L.) has not been described. The objectives of this work were to determine (i) whether dHI/dt was linear at high temperature, (ii) whether high temperature affected dHI/dt and/or the timing of the linear phase of increase in HI, and (iii) whether there was genotypic variation in the response of dHI/dt to high temperature. Four peanut genotypes varying in heat tolerance were grown in pots at either 28/22 or 38/22 degrees C from 21 to 90 d after planting (DAP). Plants were harvested on 10 occasions starting 27 DAP and total dry matter accumulation and partitioning measured. High temperature reduced total dry weight by 20 to 35%, seed HI by 0 to 65%, and seed dry weight by 23 to 78%. At 28/22 degrees C, dHI/dt for pods and seeds was linear and varied from 0.0058 to 0.0109 d(-1). At 38/22 degrees C, dHI/dt of pods and seeds was also linear and varied from 0.0028 to 0.0089 d(-1). There were genotypic differences in response to temperature. High temperature had no effect on dHI/dt in moderately tolerant genotypes 796 and 47-16. In susceptible genotypes ICGV 86016 and ICGV 87282, however, the start of pod and seed filling was delayed by 5 to 9 d and dHI/dt reduced by 20 to 65% at 38/22 degrees C. Reductions in pod and seed dry weight at 38/22 degrees C were therefore due to reductions in total dry matter and dHI/dt, depending on the heat tolerance of the genotype. Crop models need to account for genotypic differences in the response of timing and rate of dHI/dt to high temperature to successfully simulate yields in warmer environments.