ALTERNATIVAS DE MANEJO DE LA MARCHITEZ (Fusarium oxysporum f.sp. gladioli) DEL GLADIOLO (Gladiolus spp.) EN ALMOLOYA DE JUÁREZ, ESTADO DE MÉXICO.

Abstract

The gladiolus is an important crop in the floriculture industry. It has one of the highest production demands among ornamentals at both the national and state levels. Over the past few years, large economic losses have been accrued due to ineffective production management from cultivation in the field through post-harvest storage of corms. This crop presents a variety of phytosanitary issues, key among which are gladiolus rust, thrips, and wilt. Fusarium oxysporum f.sp. gladioli attacks plants in the field as well as stored corms, causing the conditions known as wilt and dry rot, respectively. Its control has been ineffective due to a lack of healthy corms, which has led to constant application of fungicides, without combining other alternative control measures. This work evaluates the effect of two furrow heights (30 and 40 cm) in combination with four fungicides to determine their effectiveness for control of Fusarium oxysporum f.sp. gladioli. The study was carried out in a plot with a history of wilt in Cieneguillas de Guadalupe Almoloya de Juarez, in Mexico State. Corms of the Roja Borrega variety from San Nicolas, Tenancingo, Mexico State were used. The study used a divided plot design. The large plot was furrow height and the small plot was the different fungicide treatments: Captan 50 (Captan), Sportak (Prochloraz), Cercobin (Thiophanate-methyl), Tecto 60 (Thiabendazole) and a control with no fungicide applied, whose locations were randomly assigned. The variables evaluated were: percent germination, stalk thickness, plant height, flowering days, size of the floral spike, number of flowers, and incidence of wilt, as well as the curve of the progression of the disease over time. The results showed that the presence of Fusarium oxysporum f.sp. gladioli began 70 days after planting with the expression of characteristic signs such as yellowing of the lower leaves and subsequent wilting, leading to the death of the plant. An analysis of variance showed a significant difference among treatments for the variable of wilt incidence. The control treatment had the largest number of sick plants, (17.86%), followed by Captan (13.94%), while the treatment with the lowest incidence was Cercobin (7.83%). There was no significant interaction with furrow height. There was also a significant difference among treatments for the area under the curve of the progression of the disease, though there was no significant interaction between furrow height and treatment. The largest area was in the control treatment, followed by Captan, while Cercobin had the smallest area, indicating that the behavior of the disease over time was different. On the other hand, while there was no significant difference among treatments or in interaction with furrow height, Cercobin combined with a 40 cm furrow height yielded better flower quality (increased floral spike length and number of flowers) and decreased disease incidence, compared to the 30 cm furrow height, which presented a larger number of sick plants.