ABSTRACT Variation in rainfall affects crops; therefore, agricultural practices become essential for forage production in semi-arid regions. This study aimed to evaluate the influence of different agricultural practices on phyllochron, structural characteristics of forage cactus and millet, and their relations with crop yield using the principal component analysis (PCA). The design was in randomized blocks, with six treatments: sole cropped cactus without straw mulching, sole cropped cactus with straw mulching, sole cropped millet without straw mulching, sole cropped millet with straw mulching, and cactus intercropping with millet, with and without straw mulching, each with four replicates. There were three cactus cycles and nine millet cycles (three cycles of cultivars BRS1501 and six of IPA Bulk-1-BF). Biometric parameters were evaluated monthly, while yield was determined after the crop harvest. Phyllochron was determined with the regression analysis. The PCA was applied to structural characteristics and yield. The systems adopted did not influence the structural characteristics of cactus and millet ( p > 0.05), except for cladode thickness, which increased with straw mulching. Phyllochron of the millet reduced when the crop was intercropped. The structural characteristics of cladode length, width, and thickness influenced crop yield, mainly in systems with straw mulching. Straw mulching and intercropping alter phyllochron of cactus and millet. The adoption of straw mulching has a more significant relationship with cactus yield, whereas biometric variables influence crop yield for millet, not the cropping system.

ABSTRACT The objective was to verify how differences in the accelerated aging test, traditional method (water) or saturated NaCl solution influence the differentiation of the physiological potential of Encholirium spectabile seeds from two geographic regions of Brazil (Graça-CE and Serra Talhada-PE). The experimental design was completely randomized in a 2 × 2 × 5 factorial scheme, in which two methods (water and saturated NaCl solution), seeds from two geographic regions and five aging periods (0 h, 24 h, 48 h, 72 h and 96 h) were evaluated. Results indicated that seeds from Graça-CE were less vigorous than those from Serra Talhada-PE. However, both aging methods (water and saturated NaCl solution) increased the physiological potential of seeds harvested from Graça-CE. E. spectabile seeds presented different levels of physiological potential by the accelerated aging test.

Objetivou-se avaliar características morfológicas de clones de Panicum maximum durante o período de rebrota após a interrupção da irrigação. Os clones de Panicum foram coletados em Sergipe e em três locais de Pernambuco ("São Bento do Una", "Itambé" e "São João da Coroa Grande"), além das cultivares 'Mombaça', 'Tanzânia' e 'Massai'. Os tratamentos consistiram de sete clones submetidos a 7, 14, 21 ou 28 dias de suspensão da irrigação. O delineamento utilizado foi o inteiramente casualizado em arranjo fatorial 7 × 4 com quatro repetições. Foram avaliados o número de perfilhos, altura da planta, comprimento da lâmina foliar, número de folhas verdes por perfilho e número de folhas mortas por perfilho. O fator clone afetou significativamente o número de perfilhos por vaso e o número de folhas mortas por perfilho (P≤0,05). O clone de Sergipe produziu mais perfilhos (8.39) que os demais após 28 dias de interrupção da irrigação, enquanto a cultivar 'Mombaça' apresentou mais folhas mortas (5.39) após 7 dias sem irrigação. Em geral, a interrupção da irrigação por 28 dias resultou em plantas mais altas com lâminas foliares maiores e com número superior de folhas verdes por perfilho.

This study aimed to evaluate the morphological characteristics of Panicum maximum clones during the regrowth period following cessation of irrigation. Panicum clones were collected in Sergipe and in three Pernambuco locations (‘São Bento do Una’, ‘Itambé’ and ‘São João da Coroa Grande’), in addition to ‘Mombaça’, ‘Tanzânia’ and ‘Massai’ cultivars. The treatments consisted of seven clones, which were subjected to either 7, 14, 21 or 28 days of water suspension. The experimental design was completely randomized in a factorial 7 × 4 design, with four replicates. The morphological characteristics evaluated included the number of tillers, plant height, leaf blade length, number of green leaves per tiller and number of dead leaves per tiller. The clone factor significantly affected the number of tillers per pot and the number of dead leaves per tiller (P ≤ 0.05). The clone from Sergipe produced a greater number of tillers (8.39) than the other clones following 28 days of water suspension, while the ‘Mombaça’ cultivar had a greater number of dead leaves (5.39) after 7 days of water suspension. In general, the 28-day cessation of irrigation period resulted in taller plants with larger leaf blades and a greater number of green leaves per tiller.