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The reaction of nineteen different cultivars of Cucurbita spp. including Cucurbita pepo, Cucurbita maxima and Lagenaria siceraria to Phytophthora capsici, Phytophthora melonis and Phytophthora drechsleri was studied under greenhouse conditions. Plants were grown in steam sterilized soil. One-month-old plants were inoculated with vermiculate hempseed extract inocula of Phytophthora and were flooded for 24 hours. The activity of the pathogens was monitored during the experiment by using citrus leaf discs. Seedling mortality was monitored two months after inoculation. None of the species were infected with P. drechsleri or P. melonis. Cucurbita maxima cultivars Hamedan and ACE South Korea, C. pepo cultivar Shabestar and Lagenaria siceraria were not infected with P. capcisi. The possibility of using these cultivars as root stocks for grafting against Phytophthora species is discussed.

Differences in performance of grafting seedling were estimated from effect of using the root-stock and scion clones. This research aimed to study the differences of performance of some root-stock and scion clones on grafting seedling. The study used split plot design. First factor was root-stock consisted of ICS 60, Sca 6, Sca 12 and KW 165 and the second factor were 12 scions clones consisted of ICCRI 01, ICCRI 04, ICCRI 05, DR 2, Sulawesi 1, Sulawesi 2, KW 516, KW 514, KW 617, KW 570, KEE 2, and KW 604. There were three replication in each treatment and each replication consisted of 15 samples. Viability, lingkage diameter, ratio of root-stock and scion, hight of shoot, number of leaves and shoot were observed. The study showed that differences of root-stock just affected viability, lingkage diameter, and high of shoot. Scion clones factor affected to all of the characters. Their interaction caused the differences of all characters except of the number of shoot. Root-stock Sca 6 showed the lowest viability and number of the shoot, however root-stock KW 165 and ICS 60 showed the best performance to all parameters. The cluster analysis was done based on growth parameters and viability on lingkage distance of 15. There were three clusters; cluster 1 (KW 570), cluster 2 (ICCRI 04, ICCRI 05, Sulawesi 1, Sulawesi 2, KW 514, KW 165) and cluster 3 (ICCRI 01, DR 2, KW 516, KW 617, KW 604). Correlation analysis showed that main factor which affected the high viability root-stock diameter and diameter ratio of root-stock and scion were used.

Com o objetivo de obter informações, que visem solucionar o grave problema de desuniformidade na brotação da gema do enxerto e do crescimento atrofiado desta após a decepagem da parte aérea do porta-enxerto, foram aplicados N e K na presença e ausência de P, em adubações regulares e variáveis, em diferentes datas antes e após a decepagem da parte aérea do porta-enxerto (mudas formadas diretamente em sacos de plástico). A adubação no período de pós-enxertia, mostrou-se extremamente necessária para o crescimento e vigor das mudas. Em relação à época, a adubação feita na data da decepagem do porta-enxerto, não apresentou resultados satisfatórios. A antecipação na emissão, uniformidade e vigor do 1° lançamento foliar, foram obtidos quando as plantas foram adubadas aos 15 dias antes da decepagem e eliminação da parte aérea do porta-enxerto. As maiores taxas de crescimento e uniformidade das plantas e vigor do 2° lançamento, ocorreram nas plantas adubadas com NPK, aos 30 dias após a decepagem do porta-enxerto.Nitrogen and potassium were applied with and withoult phosphorus to rubber seedlings at various rates and intervals prior to and after root stock pruning in an attempt to observe budding uniformity and stunting. The use of fertilizers pos-grafting was effective in promoting seedling growth and vigor. Uniformity, vigor and precocity of first whorl was related to fertilizing stocks 15 days prior to pruning, but the better at the 2nd whorld stage was obtained in stocks receiving NPK 30 days after pruning.