YIELD AND NUTRIMENTAL QUALITY OF SNAP BEAN (Phaseolus vulgaris L.) THROUGH PLANTING DATES

Abstract

In México the per capita consumption of snap bean (Phaseolus vulgaris L.) has increased from 0.9 to 1.1 kg during the last years, thus making necessary to increase its productivity and quality; this can be achieved through agronomic practices. An optimal sowing time is important since it allows for taking advantaje of environmental conditions so that a cultivar may express its yield potential and nutritional quality. This study was carried out at Montecillo, State of México during 2005, under rainfed conditions. The snap bean cv. ‘Hav-14’ of indeterminate climbing growth habit and sunflower (Helianthus annuus L.) cultivar ‘Victoria’ as living trellis, were used. The fresh pod yield and its nutritional quality in five sowing dates (May 2, May 17, June 1, June16 and July 1) were evaluated. The registered climate variables were: maximum and minimum temperatures, photosynthetic active radiation, rain, evaporation and photoperiod. The highest yield (1170 g m^-2) was obtained on May 2 and the lowest (540 g m^-2) on July 1. The fresh pods showed the highest values of: ashes (9 %), phosphorus (0.13 %), acid detergent fiber (22 %), lignin (8.3 %), protein (28.9 %) and fat (0.88 %) on the first planting date. On July 1 date the highest values were reached for calcium (1.8 %), soluble carbohydrates (47 %), neutral detergent fiber (27.7 %), hemicellulose (12.3 %) and organic matter (93.8 %). The freezing conservation of fresh pods during six months did not diminish its protein content.