PHYTOSANITARY AND ENVIRONMENTAL CHARACTERIZATION OF MAIZE CROPS IN THE PROVINCE OF SAN LUIS, ARGENTINA

BONIVARDO, S; ANDRADA, N; RAUBER, R.B; ARROYO, D; MARTÍNEZ, AN; MICCA, RAMÍREZ, M; FUNES, MB; SUAREZ, A

Congreso; XXXVI REUNIÓN CIENTIFICA ANUAL DE LA SOCIEDAD DE BIOLOGÍA DE CUYO; 2018

According to global tendencies related to food demand, research efforts must be oriented towards a coexistence of production and conservation in order to achieve sustainable production systems. In the semi-arid central region of Argentina, the cultivation of maize is the second most important in relation to the cultivated area. Agricultural production systems are complex and may be affected by several factors simultaneously, including biotic factors. For this reason, it is appropriate to apply a multidisciplinary approach to characterize and understand how each of these factors affects productivity. The objective of this work was to make a description of different aspects of the phytosanitary status of maize cultivation and environmental variables in the region. For this, censuses were carried out in 25 lots distributed along a climatic gradient between the isohiets of 600 and 700 mm and average annual temperature between 14 and 16 ºC. In each site (1) the severity of corn common rust, (2) weed cover, (3) damage severity caused by the corn earworm, (4) grain production, was recorded. The severity was evaluated in the functional sheets expressing as the percentage of damaged tissue / plant, according to Peterson´s scale, the average of 10 plants in three replications per sampling site (Peterson R. F., A. B. Campbell, A. E. Hannah. 1948). The coverage of weeds was registered with the modified Braun-Blanquet method (Mueller-Dumbois and Ellenberg 1974) in an area of 10 x 10 m and the percentage of lost grains was calculated as the number of missing grains / total grains in the spike. Additionally, soil samples were taken for analysis and characterization. Descriptive statistics was performed to all data set. At the regional level, the average severity of damage caused by phytopathogenic agents was almost 5%, the average cover of weeds was 13.8% and the average percentage of grains affected by insects was 2.1%, on an average production of grains of 204 grams / plant. With regard to soil characteristics, the average percentage was 0.4% C, 0.83 mg / g N, 21.26 mg / kg P, with 0.75% MO, a pH (1 / 2.5) of 6.32 and conductivity (1 / 2.5) of 0.04. The weed cover was lower than in other more arid west region in the same province. This sanitary and environmental characterization will allow, based on the parameters obtained, to propose trials to determine the effect of each of these factors and their interaction on maize yield and then be able to design integrated management strategies for sustainable agriculture.