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An experiment was carried out at the Olericulture field of Horticulture Research Centre of BARJ, Joydebpur, Gazipur during September 2006 to April 2007 to investigate yield and yield attributes of sweet pepper as influenced by plant spacing and sowing time. There were altogether 21 treatments comprising seven sowing dates viz. 1 September, 15 September, 1 October, 15 October, 30 October, 15 November, 30 November and three spacings viz. 50 × 50 cm, 50x40 cm, and 50 × 30 cm. The experiment was laid out in a Randomized Complete Block Design (factorial) with three replications. The results of the experiment showed that majority of the yield and yield components significantly varied with variation of spacing and sowing time. Only number of fruits per plant and fruit yield per plant resulted significantly higher which reflected higher yield for 1 October sowing. The number of branches per plant, number of fruits per plant, fruit length, individual fruit weight, yield per plant were found significantly increased with the increasing plant spacings but other parameters were found to be significantly increased with the decreasing plant spacing. The combined effect of sowing date and plant spacing also had significant effect on different growth and yield parameters and yield. The highest yield (19.36 t/ha) of fruit was recorded from the earlier sowing (1 October) with the closest spacing (50 × 30 cm). But reasonable yield could be obtained up to 30 October with same spacing. Keywords: Sowing time and plant spacing; yield and yield attributes; sweet pepper. DOI: http://dx.doi.org/10.3329/bjar.v36i2.9254 BJAR 2011; 36(2): 271-278

The correlation of fruit size with seed no. was high (r = 0.96 to 0.99) in fruit growing at high or low night temperatures. The proportionate wt of fruit per seed decreased with increasing seed no., and was higher in fruit growing under low temp than under high temp. The night temp prevailing before anthesis was not significant for parthenocarpic fruit development, but low temp after anthesis did enable such fruit to develop. High (18-20°C) temp during flower development is a prerequisite for the formation of good-shaped, elongated fruit. The highest length/diam ratio in both fertilized and non-fertilized fruit was obtained with high night temp up to anthesis and low (8-10°C) thereafter.

The paper describes in detail the course of meiosis in the cytoplasmic pollen sterile plants C. annuum L. The occurrence of meiotic irregularities which are one of the causes of the pollen abortion was studied in the pollen sterile mother and in three hybrid combinations with non restors of the sterility. The course of the irregular meiosis is determined by the nuclear factors ms susceptible to the hereditary constitution of plasmon.

The effects of polyethylene (PE) and polyvinyl chloride (PVC) plastic film tunnels (perforated, whole and double layer) on fruit set and yield of winter peppers were tested alone and in combination with soil mulches of black bitumen and black PE film. Whereas double4ayer cover induced more vigorous plant development, good fruit set on lower nodes, resulting in higher early yields of large fruit, was obtained only from plants covered throughout flowering by perforated plastic film. The addition of bitumen mulch resulted in higher total and early yield, while black PE mulch reduced the early yield, Factors inducing flower abscission when double-layer plastic is in use during flowering, as well as the differences between black bitumen and black PE mulch, are discussed.

A highly prevalent type of mosaic that induces heavey losses to sweet pepper (Capsicum annuum L.) plantings in Sao Paulo and other neighboring states is caused by two groups of the potato virus Y complex, designated as n and w. Group n is represented by strain Yn; group w by strains Yw and Yf. Screening tests with 45 sweet pepper varieties and 46 others of the pungent type, belonging to several species of Capsicum, were carried out in the greenhouse and in the field to detect resistance to mosaic. A hypersensitive type of resistance to Yn was found in the sweet pepper varieties Mogi-das-Cruzes and Casca-Dura. Porto Rico Wonder was tolerant to Yw, but not so to a related strain, Yf. A sweet pepper variety called Moura was highly tolerant to Yf. A variety known as P 11 (P.I. 264281) (Capsicum annuum) was found to be immune to all Y virus strains tested. The pungent types SA 112 (C. pubescens), 1-30771 and 1-30772 (C. pendulum) also behaved immune to Y virus strains, but were not used as sources of resistance because they are not compatible with C. annuum. Inheritance studies disclosed the existence of 3 new pairs of genes responsible for the various types of resistant reactions to strains of the potato Y virus in Capsicum annuum. They can be described as follows: Gene "H" is a dominant allele found in Mogi-das-Cruzes and Casca-Dura, that conditions hypersensitivity to Yn. Gene "w" is a recessive factor that controls tolerance of Porto Rico Wonder to strains of Yw. Gene "f" is a recessive factor that conditions tolerance to Yf in the sweet pepper variety Moura. Gene "f" behaves as an allele of "w", affording a higher level of tolerance to strains of the Y virus complex. The immunity to various strains of the Y virus complex found in Florida in P 11 (P.I. 264281) by COOK & ANDERSON (7), and attributed by these investigators to a pair of recessive genes "yaya", was also verified for strains of the Y virus complex present in Sao Paulo. The sweet pepper varieties Yolo Wonder and All Big were introduced in the breeding program because they carry the partially dominant genes "LiLi" (17) that controls resistance to tobacco mosaic virus in pepper. Early in the development of the present breeding program, the genes "HH", "ww" and "LiLi" were combined in several improved lines, but appearence of a new strain Yf showed the need of a higher resistance level than that present in these tri-hybrid lines. The incorporation of the Moura type of tolerance due to genes "ff" permitted the development of commercial lines highly tolerant to strains of the Y virus complex. The immunity to strains of the Y virus complex from P 11, due to genes "yaya", was incorporated to sweet pepper genotypes already possessing the other types of resistance to Y mosaic and to TMV. This resulted in two new groups of sweet pepper varieties that are immune to all strains of the Y complex so far tested, resistant to TMV, high yielding, and with good commercial characteristics: Agronomico 7 has fruits of the blocky type (California Wonder type) and Agronomico 8 has tapering, elongated fruits (Casca-Dura type).

Okra (Hibiscus esculentus L. cv. Clem son Spineless) and sweet pepper(Capsicum annuum L. cv. Yolo Wonder L)were grown at 2 fertility levels with treatments of full bed mulch, strip mulch, and bare soil. A black paper coated on both sides with a thin layer of clear polyethylene was used as mulch. Germination of okra and the early growth and seasonal marketable yield of both vegetables were greatest with the full bed mulch treatment. The strip mulch treatments increased yield of pepper over that of the unmulched but had little effect on okra yield. Yields were always higher with the higher fertility level, but differences were usually not significant. Pepper fruit size and no. and okra pods per plant were increased by mulch treatment. As amount of bed covered by mulch increased so did the soil NO3 and K. Higher fertilizer rates generally increased soil NO3 and K but differences were significant only in 1972.

Tendo em vista as perdas consideráveis causadas pela moléstia conhecida como "mosaico do pimentão", induzida por estirpes do vírus Y da batatinha, nas culturas de pimentão (Capsicum annuum L.), formulou-se um projeto visando criar variedades resistentes. Como fontes de resistência, cêrca de 45 introduções de pimentão e 46 de pimenteiras, compreendendo oito espécies do gênero Capsicum, foram submetidas aos testes de inoculação. Três novos fatores genéticos responsáveis pela resistência aos grupos n e w do vírus Y foram encontrados em certas variedades de C. annuum: Gene "H": dominante, encontrado nas variedades Casca Dura e Mogi cias Cruzes, que condiciona reação de hipersensibilidade ao vírus Yn. Gene "w": recessivo, que controla a tolerância da var. Pôrto Rico Wonder ao vírus Yw. Gene "f": recessivo, que condiciona a tolerância ao vírus Yf na var. Moura. Há indicação de alelismo entre os genes "w" e "f", sendo que o nível de tolerância dêste é mais elevado que o daquele. A imunidade ao vírus Y constatada em P 11 (P. I. 264281), cujo comportamento foi atribuído à ação de um par de genes recessivos "yª", foi confirmada também com relação às estirpes do virus Y que aqui ocorrem. As combinações de tôdas as fontes de resistência acima citadas possibilitaram a criação de novas variedades de pimentão pràticamente imunes ao vírus Y, bastante produtivas e com características comerciais satisfatórias. Agronômico 7 produz frutos quadrados (tipo California Wonder) e Agronômico 8 apresenta frutos cônico-alongados (tipo Casca Dura). A highly prevalent type of mosaic that induces heavey losses to sweet pepper (Capsicum annuum L.) plantings in São Paulo and other neighboring states is caused by two groups of the potato virus Y complex, designated as n and w. Group n is represented by strain Yn; group w by strains Yw and Yf. Screening tests with 45 sweet pepper varieties and 46 others of the pungent type, belonging to several species of Capsicum, were carried out in the greenhouse and in the field to detect resistance to mosaic. A hypersensitive type of resistance to Yn was found in the sweet pepper varieties Mogi-das-Cruzes and Casca-Dura. Porto Rico Wonder was tolerant to Yw, but not so to a related strain, Yf. A sweet pepper variety called Moura was highly tolerant to Yf. A variety known as P 11 (P.I. 264281) (Capsicum annuum) was found to be immune to all Y virus strains tested. The pungent types SA 112 (C. pubescens), 1-30771 and 1-30772 (C. pendulum) also behaved immune to Y virus strains, but were not used as sources of resistance because they are not compatible with C. annuum. Inheritance studies disclosed the existence of 3 new pairs of genes responsible for the various types of resistant reactions to strains of the potato Y virus in Capsicum annuum. They can be described as follows: Gene "H" is a dominant allele found in Mogi-das-Cruzes and Casca-Dura, that conditions hypersensitivity to Yn. Gene "w" is a recessive factor that controls tolerance of Porto Rico Wonder to strains of Yw. Gene "f" is a recessive factor that conditions tolerance to Yf in the sweet pepper variety Moura. Gene "f" behaves as an allele of "w", affording a higher level of tolerance to strains of the Y virus complex. The immunity to various strains of the Y virus complex found in Florida in P 11 (P.I. 264281) by COOK & ANDERSON (7), and attributed by these investigators to a pair of recessive genes "yªyª", was also verified for strains of the Y virus complex present in São Paulo. The sweet pepper varieties Yolo Wonder and All Big were introduced in the breeding program because they carry the partially dominant genes "LiLi" (17) that controls resistance to tobacco mosaic virus in pepper. Early in the development of the present breeding program, the genes "HH", "ww" and "LiLi" were combined in several improved lines, but appearence of a new strain Yf showed the need of a higher resistance level than that present in these tri-hybrid lines. The incorporation of the Moura type of tolerance due to genes "ff" permitted the development of commercial lines highly tolerant to strains of the Y virus complex. The immunity to strains of the Y virus complex from P 11, due to genes "yªyª", was incorporated to sweet pepper genotypes already possessing the other types of resistance to Y mosaic and to TMV. This resulted in two new groups of sweet pepper varieties that are immune to all strains of the Y complex so far tested, resistant to TMV, high yielding, and with good commercial characteristics: Agronomico 7 has fruits of the blocky type (California Wonder type) and Agronomico 8 has tapering, elongated fruits (Casca-Dura type).