A interação entre variedades de sorgo com diferentes graus de resistência à mosca (Contarinia sorghicola) (Coquillet) e ao pulgão (Rhopalosiphum maidis) (Fitch), com épocas de plantio, foi estudada em Campinas, em 1967-1968. Essa interação foi significativa. Algumas variedades como sumac e b. leoti, quando plantadas mais cedo, praticamente não sofreram dano de mosca, mas em plantio tardio foram completamente danificadas. Ambas são precoces e moderadamente resistentes à mosca. A variedade AF 117 teve comportamento uniforme, não sofrendo o efeito de épocas: é tardia e resistente à mosca. Em média, a infestação de mosca aumentou nos plantios tardios e a do pulgão, ao contrário, caiu. As variedades de panícula aberta foram mais resistentes ao pulgão que as de panícula compacta. A variedade AF-28 foi mais resistente ao pulgão e à mosca; a M 35-1 foi mais suscetível ao pulgão e à mosca; e a AF-37 mostrou-se bem resistente ao pulgão e suscetível à mosca. As variedades sumac e b. leoti, de resistência moderada à mosca, são suscetíveis ao pulgão. Os resultados demonstram uma independência entre a resistência à mosca e ao pulgão.

The sorghum midge Contarinia sorghicola (Coquillet) (Diptera Cecidomyiidae) is a severe sorghum pest in the State of São Paulo, Brazil, and the aphid Rhopa-losiphum maidis (Fitch) (Hemiptera Aphididae) is commonly found in the crop. The interaction among varieties of different cycles and resistance, planted in successive dates in relation to the damage done by sorghum midge and the size of the aphid population were studied in 1967-1968. The planting season for sorghum in the State of São Paulo goes from October to January. The plantings were made on XI-3-1967, XI-23-1967, XII-13-1967, and I-2-1968. The different responses of the varieties in relation to the sorghum midge damage were evident. Varieties AF-28 and AF-117 were resistant and Sumac and B. Leoti were moderately resistant. These last two varieties are early flowering and had low damage in the first plantings but had as much damage as the susceptible varieties in the last plantings. The interaction between varieties and planting season was significant. In general the sorghum midge infestation was low in the first flowering plots and increased thereafter whereas the aphid infestation was high in the first flow-erings and decreased thereafter. The response of the varieties to the aphid was studied protecting the heads of five plants per replication of each variety of each planting date, with a non treated paper bag and grading the aphid population afterwards. The varieties AF-28, AF-37, and AF-117 all with open type panicles were resistant to the aphid whereas the other varieties with compact type of head were susceptible or moderately resistant. There was independence between the resistance against the aphid and the sorghum midge. Varieties AF-28 and AF-117 were resistant to both insects. Variety AF-37 was susceptible to the midge and resistant to the aphid. Variety Sumac was moderately resistant to the midge and susceptible to the aphid and varieties Double Dwarf Feterita and M 35-1 were susceptible to both insects.

Foram estudados três dos principais cultivares de arroz plantados em várzeas irrigadas no Estado de São Paulo, quais sejam: cv IAC-435, cv IAC-120 e cv IAC-68. Os resultados obtidos referem-se às observações realizadas nos anos agrícolas de 1969/70 e 1970/71, no Centro Experimental de Campinas e estações experimentais de Mococa e Pindamonhangaba, e permitem não apenas a exata identificação e caracterização dos cultivares, como também estabelecem normas para o estudo de novos cultivares, dando-se ênfase especial às características morfológicas diretamente ligadas à produção.

This paper reports a study of three cultivars of rice (Oryza sativa,L.), namely cv IAC-435, cv IAC-120, and cv IAC-68 cultivated as main crops in the lowland conditions of the State of São Paulo, Brazil. Observations on these cultivars were made in 1969/70 and 1970/71 fiscal years at the Campinas, Mococa and Pindamonhangaba Experiment Stations of the Instituto Agronômico of the State of São Paulo. The results obtained in this study permit a correct identification of the cultivars, and also establish proper procedures to study other cultivars of rice, with special emphasis to their morphological characteristics related with seed production.

No Estado de São Paulo cultiva-se quase que exclusivamente o cultivar de mamoeira 'IAC-38', que possui porte pequeno, grande vigor, chegando a dar 2000 kg de sementes por hectare e 41% de óleo. Tem, porém, o inconveniente de apresentar frutos deiscentes, resultando na necessidade de várias colheitas por ano, o que encarece o produto. Em 1957 realizaram-se hibridações visando transferir o caráter indeiscência do cultivar 'Cimarron' para o 'IAC-38'. Das numerosas progênies estudadas até F5, duas se destacaram e deram origem a promissoras linhagens de frutos indeiscentes. Após a análise destas duas seleções em ensaios comparativos de produção, aproveitou-se a melhor delas para multiplicação. Essa linhagem constituiu o cultivar 'Campinas'. Além de ter produção comparável à do 'IAC-38' e de apresentar frutos in-deiscentes, tem ainda a vantagem do porte médio e de possuir o teor de 46% de óleo nas sementes.

The castor bean crop in São Paulo has been expanding in recent years and reached about 30,000 tona of seed annually. The IAC-38 cultivar is the most planted It has a dwarf size, a cycle of 180 to 200 days, and yields about 2,000 tons of seed per hectare. Its seed oil content is 41%. It is an outstanding cultivar, but has the disadvantage of having dehiscent fruit. This requires a great number of harvests and consequently increases the labor costs. Hybrids between IAC-38 and the non-shattering cultivar Cimarron were made in 1957. After five generations of successive selfings and individual selection testings, a progeny was found that associates good vegetative characters with high yield and indehiscent capsules. Plants representative of this new selected cultivar have medium height, erect branches, and a cycle of 140 to 150 days. They show a partial defoliation at hervest time. The yield is comparable to that of the IAC-38 and its seed oil content is better (46%). The new cultivar that has been named Campinas will probably be released to farmers in the next two years.