In coffee conilon seedlings (Coffea canephora) with shading levels of 30%, 50%, 75% and full light, in the region of Alegre-ES/Brazil, it was found that the stem diameter was not influenced by the environment, but the height, the fresh and dry weight, volume and leaf area were greater where shading was 70% (Braun et al., 2007). But in coffee seedlings (Coffea arabica L.), Paiva et al. (2003) reported that of the with shading levels of 30%, 50% and 90%, 50% was most favorable, resulting in greater height, number of leaves and leaf area, consequently, greater vegetative growth.

Mezalira et al. (2009) when evaluating the effect of substrate, harvest period and environment of fig (Ficus carica L.) rooting in plots without cover, plots under low tunnel cover with plastic film (150 p) and plots under a low tunnel with monofilament screen (50% shading) in Dois Vizinhos-PR/Brazil, observed the greatest root production in plots with the use of low tunnel with monofilament screen and the lowest in full sun.

		Fresh mass	of the aerial portion (g)
		Greenhouse Monofilament Aluminized	coconut
			screen	screen	palm
Soil + organic compost vermiculite	+	0.52 Ac *	0.75 Ab	0.86 Aa	0.52 Ac
Soil + organic compost sawdust	+	0.17 Bc	0.27 Cb	0.38 Ca	0.09 Bc
Soil + organic compost vermiculite + sawdust	+	0.56 Ab	0.62 Bb	0.73 Ba	0.55 Ab
		Fresh mass	of the root portion (g)
Soil + organic compost vermiculite	+	1.88 Ac	3.00 Ab	4.01 Aa	1.35 Ac
Soil + organic compost sawdust	+	0.57 Bb	0.75 Bb	0.91 Ca	0.25 Bb
Soil + organic compost vermiculite + sawdust	+	2.37 Aa	2.61 Aa	2.74 Ba	1.40 Ab
		Dry mass of root portion (g)
Soil + organic compost vermiculite	+	0.18 Ab	0.27 Aa	0.26 Aa	0.11 Ac
Soil + organic compost sawdust	+	0.05 Bb	0.07 Ca	0.07 Ca	0.02 Bb
Soil + organic compost vermiculite + sawdust	+	0.21 Aa	0.20 Ba	0.19 Ba	0.11 Ab

* Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%; Adapted from Costa et al. (2009a). Table 4. Interactions between environments and substrates for production of fresh mass of the aerial portion (FMAP), fresh mass of the root portion (FMRP) and dry mass of root portion (DMRP) for papaya seedlings, "Sunrise solo".

In Alegre-ES/Brazil, studies of germination and seedling production of guava (Psidium guajava L.) in full sun, environments covered with one, two and three screens showed that full sun and one screen promoted higher germination, rate of emergence, number of leafs, plant height and stem diameters, revealing that seedlings tend to develop less with increased levels of shading (Lopes & Freitas, 2009).

Araujo et al. (2006) evaluated the effects of three pots and three environmental conditions (greenhouse tunnel, nursery with a monofilament screen with 50% shading and natural environment) on the development of papaya (Carica papaya L.) cv. Sunrise Solo and concluded that the natural environment was most adequate for development of the seedlings at 45 days after sowing.

Fresh mass of the aerial portion (g)

Greenhouse Monofilament Aluminized coconut palm screen screen

polyethylene bag 5.50 Ac * 7.88 Ab 10.77 Aa 5.63 Ac

polystyrene trays______ 0.39 Ba___________ 0.46__________ Ba 0.48______ Ba 0.65 Ba

Dry mass of the aerial portion (g)

polyethylene bag 0.77 Ac 1.01 Ab 1.23 Aa 0.68 Ac

polystyrene trays______ 0.07 Ba___________ 0.08__________ Ba 0.09______ Ba 0.10 Ba

Fresh mass of the root portion (g)

polyethylene bag 2.67 Ac 3.71 Ab 4.57 Aa 1.57 Ad

polystyrene trays______ 0.55 Ba___________ 0.54__________ Ba 0.53______ Ba 0.43_ Ba

Dry mass of root portion (g)

polyethylene bag 0.25 Ab 0.32 Aa 0.30 Aa 0.12 Ac

polystyrene trays______ 0.05 Ba___________ 0.05__________ Ba 0.05______ Ba 0.04 Ba

* Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%;

Adapted from Costa et al. (2009a).

Table 5. Interactions between environments and pots for production of fresh mass of the aerial portion (FMAP), dry mass of the aerial portion (DMAP), fresh mass of the root portion (FMRP) and dry mass of root portion (DMRP) for papaya seedlings, "Sunrise solo". Greenhouse Monofilament Aluminized coconut screen screen palm AFM polyethylene bag 4.499 Ab * 7.703 Aa 7.159 Aa 3.937 Ab polystyrene trays 0.449 Ba 0.775 Ba 0.699 Ba 0.644 Ba ADM polyethylene bag 0.697 Ab 1.248 Aa 1.149 Aa 0.618 Ab polystyrene trays 0.087 Ba 0.161 Ba 0.140 Ba 0.186 Ba RFM polyethylene bag polystyrene trays 1.063 Ab 0.288 Ba 1.539 Aa 0.493 Ba 1.435 Aa 0.385 Ba 0.589 Ac 0.439 Aa RDM polyethylene bag polystyrene trays 0.163 Ab 0.054 Ba 0.212 Aa 0.064 Ba 0.221 Aa 0.057 Ba 0.099 Ac 0.067 Ba * Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%; Adapted from Costa et al. (2009b).

Table 6. Review of the analyses of mean aerial fresh mass (AFM), aerial dry mass (ADM), fresh root (RFM) and dry mass of root (RDM) in grams for the container (R) within environments (A); environments (A) inside the container (R) for the yellow passion fruit.

Costa et al. (2009a) when evaluating the production of papaya seedlings (Carica papaya L., cv ‘Sunrise Solo’) in a greenhouse with low density polyethylene film, nursery with black monofilament screen, nursery with aluminized screen and nursery with native coconut palm, using different substrates and containers in Aquidauana-MS/Brazil, observed that the best growth environment was the nursery with aluminized screen for leaf fresh weight, dry weight and fresh weight of the root system (Tables 4 and 5). The same treatments in the same region were applied on the development of passion fruit seedlings (Passiflora edulis Sims. f. flavicarpa Deg.) by Costa et al. (2009b), who found that the black monofilament screen environment provided good conditions for seedlings development. The environment with the aluminized screen also favored seedling growth (Tables 6 and 7).

		Greenhouse	Monofilament screen	Aluminized screen	coconut palm
	Soil + organic compost + vermiculite	0.534 Ac *	0.955 Aa	0.788 Ab	0.545 Ac
	Soil + organic compost + sawdust	0.205 Bb	0.378 Ca	0.379 Ba	0.135 Bb
ADM
	Soil + organic compost + vermiculite + sawdust	0.437 Ab	0.781 Ba	0.767 Aa	0.526 Ab
	Soil + organic compost + vermiculite	1.063 Aa	1.284 Aa	1.187 Aa	0.785 Ab
	Soil + organic compost + sawdust	0.292 Cab	0.411 Bab	0.435 Ba	0.176 Cb
RFM
	Soil + organic compost + vermiculite + sawdust	0.673 Bb	1.353 Aa	1.107 Aa	0.582 Bb

* Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%; Adapted from Costa et al. (2009b). Table 7. Review of the analyses of mean aerial dry mass (ADM) and the fresh root (RFM) in grams of substrate (S) within environments (A); environments (A) within the substrate (S) for passion fruit.

Initial growth of licuri seedling (Syagrus coronata (Mart.) Becc.), at luminosity levels of 30% (monofilament screen) and 100% (full sun) in the municipality of Feira de Santana — BA/Brazil showed greatest plant growth when subjected to 30% light intensity (Chapman et al., 2006).

Martelleto et al. (2008) studied the effect of the plastic covered greenhouse, shaded greenhouse with an additional monofilament screen (30%, over the plastic), shading with only the monofilament screen (30%) and the natural environment in development of papaya cv. Baixinho de Santa Amalia (‘Solo’), and concluded that growth is favored, both in terms of plant height and trunk diameter, foliage (number of leafs/plant) and leaf area inside the greenhouse without the additional monofilament screen (Tables 8 and 9).

Plant height Environment of cultivation, . (cm)	Diameter of the trunk (cm)	Leaves Leaf area number per plant (cm2)

Greenhouse	183.8 A *	13.0 A	35.3 A	2077.7	A
Shaded greenhouse	174.8 B	10.0 B	35.4 A	1702.6	B
Screen	156.4 C	8.5 C	29.5 B	1376.3	D
Natural environment	144.2 D	10.0 B	29.4 B	1529.5	C
Coefficient of variation (%)	5.8	6.7	4.6	12.2

* Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%; Table 8. Vegetative growth of the ‘Baixinho de Santa Amalia’ papaya subjected to organic management in different cultivation environments, where the values of height and trunk diameter are relative to 12 months after transplanting the seedlings and the values of the leafs number per plant and leaf area correspond to monthly averages during one year of cultivation (Seropedica-RJ, 2004/2005).

Environment of cultivation	Number of fruits per plant	Fruit weight (kg per plant)	Average fruit weight (g)
Greenhouse	9.7 A *	3.53 A	364.7 A
Shaded greenhouse	7.3 B	2.01 B	276.1 D
Screen	4.6 C	1.39 C	302.8 C
Natural environment	6.5 B	2.12 B	326.1 B
Coefficient of variation (%)	20.9	22.2	9.8

* Means followed by same uppercase letters in the columns and same lowercase letters in the rows do not differ by the Tukey test at 5%; Table 9. Commercial production of ‘Baixinho de Santa Amalia’ papaya subjected to organic management in different cultivation environments where the values represent monthly averages during the first 12 months of harvest (Seropedica-RJ, 2004/2005).

Seedlings of tamarind (Tamarindus indica), in Lavras-MG/Brazil, were more vigorous when cultivated in the natural environment when compared to those produced in the greenhouse and nursery with black monofilament screen providing 50% shading (Mendonga et al.,

2008) .

In Flores da Cunha-RS/Brazil, grape yields (cv. Moscato Giallo), with and without plastic cover over the crop rows, was higher in the covered environment, with greater stability of production, but did not affect the relationship between shell and pulp mass of the berries. The film increased the daily temperature at the plant canopy, not affecting relative humidity, but decreasing the photosynthetic active radiation and wind speed (Chavarria et al., 2009).

Medina et al. (2002) found a better photosynthetic performance of citrus seedlings of the orange ‘Pera’ (Citrus sinensis Osbeck) and Rangpur lime (Citrus limonia Osbeck) in the greenhouse with the use of the termorrefletora screen applying 50% of shading (aluminized screen) below the polyethylene film, in comparison with the greenhouse without the screen. According to these authors, as well as increasing photosynthesis, the screen reduced the photosynthetically active radiation and leaf temperature. These effects were not only beneficial for the maintenance of proper stomatal aperture for gas exchange, but also for better functioning of the photochemical system under adverse conditions.

With the objective of evaluating biomass of passion fruit seedlings in function of environmental conditions and substrates with percentages of organic compound in Aquidauana-MS/Brazil, Sassaqui et al. (2008) conducted an experiment in six environmental conditions: greenhouse with a height of 2.5 m; nursery with black monofilament screen with 50% shading and height of 2.5 m; nursery with aluminized screen with 50% shading and height of 2.5 m; nursery covered with native coconut palm with height of 1.8 m; plastic greenhouse with height of 4.0, zenithal opening and mobile aluminized screen beneath the film at a height of 3.5 m. The authors concluded that the polyethylene film and aluminized screen together promoted better environmental conditions for the accumulation of biomass.