The effect of nonwowen polypropylene protection condition and plant density on the yield of two cultivars of snap beans was evaluated. The current work was carried out at an experimental area of the Universidade Estadual de Ponta Grossa, Paraná State, Brazil. The experimental design was a completely randomized in split plots 2x2x2 (cultivars x protection x plant density), with four replications. The cultivars Turmalina and Coralina were sown in March (autumn), 2000, in two plant densities (6.6 and 3.3 pl m-1) under nonwowen protection (PP) and natural environment (AN). Early yield, total yield, number and weight of pods were evaluated. The air (Tar) and soil temperature amplitudes (Ts) under PP and AN were also evaluated. Nonwoven protection and plant density did not influence the early yield. However, the use of nonwoven protection increased yield of 'Turmalina' as a result of higher number of pods per plant, compared with AN. There was no difference between PP and AN on yield of 'Coralina'. The plant density did not influence yield response of 'Turmalina'. On the other hand, 'Coralina' was more productive when cultivated under plant density of 3,3 pl m-1, when compared to 6,6 pl m-1. 'Coralina' was more productive than 'Turmalina' when cultivated under 3,3 pl m-1, however without differences between cultivars under 6,6 pl m-1. Air and soil temperature were higher under PP compared to AN, during the whole cycle of the culture, with medium differences between PP and AN of 2,63 and 1,97ºC, respectively for Tar and Ts. The difference between PP and AN, for Tar and Ts, was higher at the beginning of plant growing and decreased with the development of snap bean.
Phaseolus vulgaris L.; protected cultivation; nonwoven polypropylene
