Experiências foram conduzidas, em diferentes localidades do Estado de São Paulo, para estudar o efeito da adubação verde com Crotalaria juncea L., em cultura do feijoeiro "da sêca", incorporando-se ao solo tôda a vegetação desta ou retirando-se do campo experimental as hastes despojadas de suas fôlhas. O aumento médio de produção proporcionado pela adubação verde correspondeu a 41%, no primeiro caso, mas baixou para 28%, no segundo.

Sunn-hemp (Crotalaria juncea L.) was tested as a green manure for beans (Phaseolus vulgaris L.) in several localities of the State of São Paulo. The green manure was planted in the same area that was subsequently sown with beans. Incorporation of the whole plants or only their leaves were compared. The mean yield increase resulting from the treatments when compared with the checks was 41 % in the first case and 28 % in the second.

São discutidos neste trabalho os resultados de 32 ensaios de variedades x espaçamento x adubação realizados no ano agrícola 1959-60, em São Paolo, instalados com o propósito de estudar o comportamento do H. 6999, Asteca e Catêto, plantados nos espaçamentos de 20, 30 e 40 cm entre plantas, nos níveis 0, 1 e 2 de adubação. A dose 1 correspondeu a 25-68-22,5 kg/ha de N, P2O5 e K2O. Feita a análise estatística de cada ensaio, foram reunidos de acôrdo com os grandes tipos de solos do Estado de São Paulo, efetuando-se a seguir a análise por grupos e de todo o conjunto. A produção média dos 12 ensaios localizados em solos do arenito Bauru foi de 3557 kg/ha. O H. 6999 deu 452 kg/ha mais do que o Asteca e êstes, em média, 1091 kg/ha mais do que Catêto, a mais alta diferença assinalada nos quatro grupos estabelecidos. Entre espaçamentos, a diferença foi de 746 kg/ha, linear e altamente significativa. Houve efeito linear significativo da adubação correspondente a 1271 kg/ha. A produção média nos 8 ensaios realizados em solos massapê e salmourão foi de 3154 kg/ha. O H. 6999 superou o Asteca de 683 kg/ha; a média dêstes ultrapassou a do Catêto em 676 kg/ha. O efeito linear para espaçamento foi de 400 kg/ha. A diferença entre dose 0 e 2 de adubos foi de 1 240 kg/ha. A média de produção dos 8 ensaios efetuados em terra-roxa e roxa-misturada foi de 4 275 kg/ha, superando a de todos os outros grupos. O H. 6999 produziu 600 kg/ha mais que Asteca, e êstes em média, 824 kg/ha mais do que Catêto. O efeito linear para espaçamento foi de 726 kg/ha, significativo no nível de 0,1% de probabilidade. O efeito linear da adubação foi de 1448 kg/ha, também altamente significativo. A média de produção para os 4 ensaios conduzidos em solos do Terciário e do Glacial foi de 3 086 kg/ha. O H. 6999 superou o Asteca em 534 kg/ha e, a média dêstes, a do Catêto em 468 kg/ha. O efeito do espaçamento foi de 370 kg/ha, linear e altamente significativo. Os tratamentos com a dose 2 de adubos superaram significativamente os sem adubo em 1 214 kg/ha. A produção média geral dos 32 ensaios foi de 3577 kg/ha. No total, o H. 6999, com uma dose de adubos, produziu quase o dôbro da variedade Catêto não adubada.

This paper reports the results of 32 yield trials carried out in different localities, covering - Massapê, Terra Roxa, Arenito Bauru, Glacial and Terciário - great types of soils in the State of São Panlo. The experimental design was a 3³ with the following treatments: three varieties - Cateto, Asteca and H. 6999; three populations 50, 33 and 25 thousand plants per hectare; and three fertilizer levels - 0, 1 and 2. Dosis 1 corresponds to 25-68-22.5 kg/ha of NPK. Each plot was 30 m². Statistical analyses of each trial and also of the groups of experiments were made to test main effectB and interactions. According to the adopted model, Y = m + v + a + e + va + ve + ae + l+ lv-f-la + le + lev + lva + lea + b (1) + E. m was the general average, v, a, e, and l, i, e, variety, fertilization, spacing, location and their interactions; b(1), replication effect within localities and E the residual error including some high order interactions. Linear and quadratic components for a and e were orthogonally decomposed; V1 being Cateto against H. 6999 + Asteca and v2 being H. 6999 against Asteca. The average variation coefficient was 15 per cent; only in 4 of the 32 trials was the variation coefficient larger than 20 per cent. On the average the double cross hybrid H. 6999 outyielded significantly the variety Asteea by 572 kg/ha. Asteca + H. 6999 were 834 kg/ha better than Cateto. An increase of 843 kg/ha was obtained with a population of 50,000 plants over the treatment which corresponds to 25,000 plants per hectare. The average response to fertilisation did not differ for the great types of soils. A significant linear effect of 1,300 kg/ha measured from level 0 to level 2 was recorded; also a quadratic significant response was verified, indicating that the maximum whould be obtained with 50-150-50 kg/ha of NPK. The data obtained in this group of trials indicated that the highest average yield 5,395 kg/ha was attained with the hybrid H. 6999 that received the high level of fertilizers rated to a 50,000 plant population. For this treatment 1.07 ears per plant were recorded. The average weight per ear was 151 g.

A project for isolation of local inbred lines of corn and production of hybrid corn is being carried on since 1932 at the Instituto Agronômico de Campinas. The organization of the Hybrid Corn Service stablished in 1946 for hybrid corn seed production under supervision of the State Government of São Paulo is presented here. Basic investigation on inbred lines isolation and testing of hybrids are carried out at several Experiment Stations of the Instituto Agronômico by the Genetics and Cereals and Leguminous Plants Departments. Seed production of the required inbred lines and single crosses is made in cooperation with Federal Government at the Ipanema Exp. Sta. at São Paulo. Double cross seeds are produced in selected private farms under a contract with the Hybrid Corn Service. These seeds are stored at seven different places, where they are cleaned, classified by size, treated with DDT and conditioned in bags of 50 kg each. The hybrid seeds are sold to the farmers through the county agents of the State Extension Service. An average of 2,420 kg per hectar (about 1,500 kg of clean seeds) of hybrid seeds has been produced in the cooperative fields in the last three years. It has been estimated that about 3,000,000 kg of hybrid seeds have been produced in these cooperative fields during 1951. These amounts of seeds are used for only 1/5 of the total corn acreage in the State of São Paulo. Total corn production in this State is estimated in 1,200,000 metric tons produced in an area of about 900,000 hectars. The average cost of production of hybrid seeds in the cooperative fields in 1951 was calculated as Cr$ 1,45 per kg. The detasseling operation has been calculated in Cr$0,118 per kg of seeds (only 9% of the total cost). The most expensive operation resulted from use of chemical fertilizers, the harvesting and soil cultivation including soil erosion control. The advantages of the present organization for hybrid corn seed production in São Paulo are stressed. A similar organization for cottcn seed production is already operating in São Paulo for several years, with reasonable success.