Efeito da temperatura na biologia de tres racas de Meloidogyne incognita (Tylenchida - Meloidogynidae) em cafeeiro (Coffea arabica L.) e estimativa do número de geracoes para o estado de Sao Paulo
The biology of the races 1, 2 and 4 of Meloidogyne incognita 376/4 coffee seedlings was studied. The experiment was set up in completely randomized design with 5 treatments, being 4 at constant temperatures (20, 24, 28 and 32 grade C) in growing chambers, and one at field temperature (mean of 21.9 grade C; standard deviation 1.9 grade C; minimum of 18.9 grade C and maximum of 26.5 grade C). The results were as follows: The total hatching of larvae of race 1 showed an efficiency higher than 80 percent at all temperatures in the growing chambers, although differing among themselves as to the number of days to hatch. For races 2 and 4 the highest efficiency ranged from 70 to 80 percent at temperature intervals between 20 and 28 grade C, and also differing among themselves as to the hatching period. At field temperature the efficiency of hatching was lower and the period even longer. The porcentage of total hatching was 67.7 percent for race 1, 46.6 percent for race 2, and 53.3 percent for race 4. The lower temperatures (20, 24 grade C and field temperature) favoured the percentage of penetration of the larvae into the roots, while the higher ones (28 and 32 grade C) stimulated the speed of penetration. Compared to race 1, races 2 and 4 presented, respectively, 67 percent and 52 percent of efficiency of the number of penetrating larvae. Concerning the nematode development in the roots, the temperatures of 28 and 32 grade C were equally favourable for races 1 and 2, and, although with lower speed, for race 4 as well. At these temperatures (28 and 32 grade C) the growing period was sensibly reduce. This reduction was also observed in the life cycles of the three races at 28 and 32 grade C. The beginning of the egg laying periods were 28 days for race 1, 32 days for race 2, and 36 days for race 4
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| Format: | biblioteca |
| Published: |
Piracicaba (Brasil)
1989
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| Subjects: | COFFEA ARABICA, PLANTULAS, MUNDO NOVO, MELOIDOGYNE INCOGNITA, NEMATODOS DE LAS PLANTAS, CICLO VITAL, EFECTOS DEL MEDIO AMBIENTE, ECLOSION, SAO PAULO, BRASIL, |
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