Variabilidade da produção de frutos de pimentão em estufa plástica, relacionada com técnicas experimentais

Abstract

Plastic greenhouses are considered an homogeneous environment, however, this affirmation has not been proven, because there are many variations among plants influenced by factors such as soil, climate, position of the plant inside the experimental area, handling the plants and the environment. There is a lack of information in techniques of experimental planning for reduction of experimental error in protected crop, where the variations in between harvests are not considered, allowing the researcher to conclude and make recommendations with low experimental precision. Then, were installed experiments with the culture of sweet pepper in plastic greenhouse in two different seasons in the Crop Science Department/UFSM, in order to determine the variability of the production for each harvest and for the whole prodution around the average, for different plot size; to establish correlations between the position of the plant in the plastic greenhouse, morphologic and productions variables; verify the direct and indirect effect of such variables on the standard desviation of fruits production, obtained between the times when the plants were harvested. With the variances homogeneity test, for each harvest and total production, the dispersion on the production of the average. It was verified that there is a high heterogeneity in the distribution of the production between the experimental plots in protected chili culture, regardless the cultivation station, and that parcels of 14 plants in line had reduce the variations of soil, as well as the failure effects by dead plants or not harvested plants. Pearson s coefficients of correlation indicates that the standart desviation was correlated, in greater magnitude, with the total produced, the total number and the average weight of fruits and the number of times that the plants were harvested. After eliminating the highly correlated variable, estimating their direct and indirect effect on the desviation the number of times that each plant was harvested. It was verified that the location of the culture line and the plant position in line had not interfered significantly with the desviation of the production of fruits between harvests, having to be rejected on the moment the planning the experiments; the increasing of the total production induced the addition of the variance between harvests; the plants harvested less times, besides the economy of resources and time of permanence in the experiment at the field, induce the reduction of the variance between harvests.