Phenology and agronomic components of first and second-cycle strawberry

Several strawberry growers have cultivated the same plants for two consecutive cycles aiming a greater economic return after seedling transplant. However, the phenological development and the agronomic potential of second-cycle strawberry have to be estimated. This research was installed to estimate the thermal need, leaf appearance rate, phyllochron and yield of strawberry cultivars in two consecutive crop cycles in the region of the Third Planalto Paranaense. Cultivars Camarosa, Camino Real, Albion, Aromas, Monterrey and San Andreas were evaluated in the first and second growing cycles using completely randomized blocks and four replications. Leaf appearance rate was estimated by linear regression coefficient between the number of leaves and the accumulated thermal sum. Phyllochron was estimated by the inverse of regression coefficient. Aromas was the only cultivar with an increased fruit production in the second cycle. On the contrary, there was a considerable reduction of production for ‘Camino Real’, ‘Albion’, ‘Monterrey’ and ‘San Andreas’ in that same cycle. The highest number and mass of marketable fruits of the second and first cycles were observed for ‘Camarosa’ and ‘Camino Real’, respectively. In the second crop cycle, strawberry cultivars required a lower thermal sum to begin flowering and fruit harvest. The plants presented a higher leaf appearance rate and low phyllochron values.Em busca de maior retorno econômico após o transplantio das mudas, muitos produtores de morango têm feito o cultivo por dois ciclos consecutivos. No entanto, há necessidade de estimar o desenvolvimento fenológico e avaliar o potencial agronômico do morangueiro nesse sistema. O objetivo deste trabalho foi comparar a necessidade térmica, a taxa de aparecimento foliar, o filocrono e a produtividade de cultivares de morangueiro no segundo ciclo de cultivo, em comparação ao primeiro, na região do Terceiro Planalto Paranaense. Avaliaram-se as cultivares Camarosa, Camino Real, Albion, Aromas, Monterrey e San Andreas, utilizando o delineamento experimental de blocos ao acaso e com quatro repetições. A taxa de aparecimento foliar foi estimada a partir do coeficiente angular da regressão linear entre o número de folhas e a soma térmica acumulada, enquanto o filocrono foi estimado pelo inverso do coeficiente angular da regressão. Observou-se que Aromas foi a única cultivar que aumentou a produção de frutos no segundo ciclo. Ao contrário, nesse mesmo ciclo houve considerável redução da produção para ‘Camino Real’, ‘Albion’, ‘Monterrey’ e ‘San Andreas’. Destacaram-se com maior número e massa de frutos comerciais do segundo e primeiro ciclo, ‘Camarosa’ e ‘Camino Real’, respectivamente. No segundo ciclo de cultivo, as cultivares de morangueiro necessitaram menor soma térmica acumulada para iniciar o florescimento e colheita dos frutos e, apresentaram maior taxa de aparecimento foliar e menores valores de filocrono

Selection of processing tomato genotypes resistant to two spotted spider mite

<div><p>ABSTRACT One of the major problems in cultivation of tomato is the occurrence of pests and diseases. The objective of the research was to select genotypes from the second generation of the first backcross (F2BC1) between the tomato cultivar for processing S. lycopersicum (cv. Redenção) and the wild access S. habrochaites var. hirsutum (PI-127826), with high levels of zingiberene (ZGB), resistant to the twospotted spider mite Tetranychus urticae (Acari: Tetranychidae). From the F2BC1 population. The ZGB content was quantified and five plants with high zingiberene selected (RVTZ 2011-079-117, RVTZ 2011-079-185, RVTZ 2011-079-335, RVTZ 2011-079-345 and RVTZ 2011-079-503) and four with low zingiberene content (RVTZ 2011-079-417, RVTZ 2011-331-460, RVTZ 2011-079-538 and RVTZ 2011-079-548) were selected. Genotypes selected for high and low ZGB content and the parentals S. habrochaites var. hirsutum access PI-127826 and ‘Redenção’ were evaluated for repellency to the twospotted spider mite. There was a significant and inverse correlation between ZGB content and average distances travelled by mites on tomato leaflets. The genotypes of the F2BC1 generation with high zingiberene levels RVTZ 2011-079-117, RVTZ 2011-079-185, RVTZ 2011-079-335, RVTZ 2011-079-345 and RVTZ 2011-079-503 are promising for progress in achieving resistant lines to arthropod pests. Among them RVTZ 2011-079-117 stands out for resistance to twospotted spider mite.</p></div