MORPHOMETRIC INDICATORS IN NEW MEGATERMAL VARIETIES OF Cenchrus purpureus TOLERANT TO WATER STRESS

Abstract

The objective of the present study was to characterize growth rates of new megatérmicas varieties of Cenchrus purpureus with tolerance to water stress in Valle del Cauto conditions. To this end, new varieties of C. purpureus were used (CT-601, CT-603, CT-605, CT-608, CT-609 and CT-115 as control), at different regrowth ages (60, 90, 120 and 150 days), which were arranged in a random block design with factorial arrangement with four replicas. Within the low rainfall season, CT-601 stood out in the absolute growth rate (106.6 g day-1), but did not present significant differences (p≥0.05) with the rest of the varieties in this age group. . While the CT-115 variety presented the highest values for the relative growth rate at 60 days (114.4 g day-1), foliar area at the ages of 90 and 120 (285, 8 and 211.6 cm2, respectively ) and leaf area index (41.4) between 90 and 150 days the leaf area at 120 days of age (48.5 cm2 days-1) (p≤0.001). For the rainy season only TCA was affected by the interaction variety and age, and was represented by CT-608 at 60 days (p≤0.01) with 347.7 g day-1 of dry matter accumulation. It is concluded that the low rainfall regime, characteristic of Valle del Cauto, conditioned the morphological response in a marked way when combined the use of the new varieties in different ages of regrowth, while, in the rains, only the absolute growth rate is affected by this effect.