The influence of plant density and covering on yield of bell peppers (Capsicum annuum L.)

Abstract

The effects of plant density and polypropylene cover on the marketable yield of bell peppers were studied at the Experimental Field of the Biotehnical Faculty in Ljubljana. Plants of cv. 'Soroksari' were transplanted in four population densities of 21.8, 13.2, 10.9 and 6.6 plant m-2. All plants were grown on soil covered with black PE film. The treatments consisted of covered plants in comparison to no cover control. Mean daily air temperatures under the covers were between 2.3 oC to 5.8 oC higher than outside temperatures. Cover was removed after 8 weeks when mean daily maximum temperatures exceeded 32 oC. Yield component analysis indicated that the fruit size was larger under covered treatments in comparison to uncovered treatments at all population densities. Total marketable yield per m2 were significantly higher under cover. In addition, increasing population density enhanced total marketable yield. The interactions of cover and population density were not significant for total marketable yield. The strongest influence in terms of an earlier yield has the covered crop at the second harvest on August 25. At this harvesting, the covered treatments had 109 % higher yield than uncovered treatments. The total accumulated marketable yield under cover was 71.8 % greater than with no cover control.