RAINFALL IMPACT ON THE GRAIN CORN YIELD IN AZUERO REGION, PANAMA, 1995-2003. II. YIELD ANALYSIS AND ITS RELATIONSHIP WITH THE PLANTING DATE.
The objective of this study was evaluating the rainfall impact over corn grain yield in the 1995-2003 periods, according planting dates. Another objective was assessing the thecnological change impact over the cultivars trails yield during the years 1995 to 2003. The average throughout 1995-1998 was 4.54 t/ha. The yield increased to 5.99 t/ha during 1999-2002 period. Due to researches carried out during the last three years, in 2003 the Nitrogen rates was increased to 200 kg N/ha and the yield average improved to 7.35 t/ha in the trials planted across 10 localities. Consistent with the objective of this paper, it was analyzed the grain yield of the 73 trials planted since 1995 to 2003 and it was correlated with the planting dates and rainfall accumulated during the critical grain filling phases. The crop period was divided in three phases (30-50 dap, 51-80 dap and 81-100 dap). lt was observed in majority of the localities a significant statistical decrease yield when the planting dates were reached later. In the years 2000 and 2002 it was appeared a severe stress in 51-100 dap period in the later planting dates, it caused a yield decreasing by 19.6 and 35.4% regarding sooner planting dates. The stress in 1996 and 2003 later planting dates showed in the 81-100 dap period, causing 15.2 and 14.6% depletes. The 1995, 1998 and 2001 yields was reduced in the later planting dates in 8.4, 9.7 and 7.5%, regarding to sooner planting dates. The outcomes of this study suggest that the technological changes have impacted positively the grain yield, however, the planting date is very important to minimize the water stress impact in the critical fenological period what affected negatively the grain yield.
| Main Authors: | , , , |
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| Format: | Digital revista |
| Language: | spa |
| Published: |
Instituto de Innovación Agropecuaria de Panamá
2004
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| Online Access: | http://www.revistacienciaagropecuaria.ac.pa/index.php/ciencia-agropecuaria/article/view/218 |
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